This PDF file contains the front matter associated with SPIE Proceedings Volume 8902, including the Title Page, Copyright Information, Table of Contents, and the Conference Committee listing.

The paper presents a digest of chosen research and technical work results shown by researchers from technical universities, governmental institutes and research firms during the XIth Scientific Conference on Electron Technology ELTE 2013. ELTE Conference has been held every three years since more than three decades. The ELTE 2013 conference was held in Ryn Castle (Poland) on 16-20 April 2013 and gathered around 270 scientists, theoreticians, technologists and engineers from such areas as material engineering, chemistry, sensors, integrated circuits, electronics engineering, laser industry, photonics, etc. The conference featured the following major four topical sessions – Micro and Nano, Photonics, Materials and Technologies, and Microsystems; two dedicated sessions – a keynote plenary session on hot topics in electron technology, as well as a session on large research projects and grants realized by the relevant community. Oral topical sessions were accompanied by poster sessions. The paper is a succinct topical introduction to the volume of ELTE 2013 proceedings. Over 100 papers, gathered in the volume, present a very relevant cross section and state-of-the-art of this branch of science and technology in Poland with involved international co-operation.

Today, power semiconductor devices enable sustaining several kilovolts and kiloamperes. New structures are constantly being developed for almost every particular device type. However, below the advanced technological concepts, proper design still relies on a few simple rules that result from physical operating principles and limits of semiconductor structures.

Hybrid pixel detectors working in a single photon counting mode are very attractive solutions for material science and medical X-ray imaging applications. Readout electronics of these detectors has to match the geometry of pixel detectors with an area of readout channel of 100 μm × 100 μm (or even less) and very small power consumption (a few tens of μW). New solutions of readout ASICs are going into directions of better spatial resolutions, higher data throughput and more advanced functionality. We report on the design and measurement results of two pixel prototype ASICs in nanometer technology and 3D technology which offer fast signal processing, low noise performance and advanced functionality per single readout pixel cell.

Recent investigations in the area of photovoltaics and microelectronics generated interest in thin-film technologies with nanostructural modifications. In this paper we concentrate on technological experiments, structure and composition control of the components of a thin silicon solar cell and opto-electonic devices. The results of high resolution electron microscopy and optical transmission and reflection analysis are presented. Additionally, the authors carried out theoretical calculations of scattering, absorption and reflection of the Ag nanoparticles located at the surface and also within the films on the absorber border.

The behavioral and circuit equivalent models applied to silicon carbide semiconductor power devices have been presented. The MOSFET and Merged PiN Schottky diode (MPS) including dynamic electro-thermal modeling have been described in details. The authors also show the problems of the active power estimation for dynamic SiC MPS diode and unrealistic results for manufacturer-provided models.

This paper presents a new architecture of a charge pump voltage converter. The charge pump implements novel parasitic capacitances precharge control loop. Output voltage ripples are significantly reduced.

The dielectric barrier discharge (DBD) used to generate low-temperature plasmas at atmospheric pressure are suitable for the atomization of volatile species and can also be served as an ionization source for ambient mass spectrometry and ion mobility spectrometry. The paper presents a source based on a plasma jet established at the end of a capillary dielectric barrier discharge at atmospheric pressure and its application to mass spectrometry. Early results of spectroscopic analysis are given.

The results of analysis of filling pulse parameters influence on the ICTS spectra recorded for Au/Pd/Ti-SiO₂ – (n) GaAs MIS structures have been presented. It was demonstrated that the amplitude and the width of filling pulse strongly affects: the shape, the amplitude and the position of ICTS peaks. Furthermore it was found that the pulse amplitude of 1 V, in the case of investigated structures, corresponds to a small pulse and the width of filling pulse is not connected in simple way with the pulse amplitude as follows from literature. It was shown that both the measurements at short and long time of filling pulse reveal a complex structure of ICTS spectrum. It was also demonstrated that different time constants of interface states are obtained when the measurements are not performed with a small pulse and when the filling pulse time is not long enough to achieve a complete states filling.

Thin film chemical compounds can be obtained as a result of sputtering of dielectric target (High-Frequency sputtering) or sputtering of conductive target in reactive atmosphere (Direct Current or pulsed sputtering). Achievement of high efficiency of thin films deposition is possible when conductive target is sputtered, as its surface is not covered (or is covered only partially) with dielectric compound. Aim of this work was obtaining aluminum oxide thin films with highest efficiency, using reactive pulsed magnetron sputtering of aluminum target in Ar+O₂ atmosphere.

Modern electronic devices are more and more complex and multifunctional. It could be done by producing faster and more reliable active components and increasing number of passives and interconnections’ density. To form such complex devices one can embed components in substrate of printed circuit board (PCB) or build multilayer boards. The other way is to form multi-terminal passive components to spare free surface and decrease number of interconnections. Authors created three-terminal thin-film (TF) resistors embedded in PCBs and investigated their selected properties such as resistance repeatability, long term stability, pulse durability and thermal characteristics.

Impedance Spectroscopy (IS) is a widely used measurement technique for determining the characteristics of a variety of materials and systems. Analysis of object’s AC-response can allow determine of different electrical properties due to its structure. IS can also be used to study electronic components such as gas and humidity sensors, thermistors, varistors, capacitors or resistors. The resulting impedance spectrum can be approximated by electrical equivalent circuit. However, It is difficult to find papers dedicated to the electronic systems investigated by IS method. For this reason authors analyzed properties of RC low-pass filters embedded in printed circuit boards using IS technique. These four-contact structures were made of special Ohmega/FaradFlex^® composite material. It consists of a resistive/capacitive core containing OhmegaPly RCM layer (resistive NiP alloy) laminated to FaradFlex dielectric of Oak-Mitsui company. Analysis of the measurements results using impedance spectroscopy allowed a more precise determination of the filter parameters than an analysis using standard method based on ideal components. Additionally selected filters were subjected to one of the aging process (thermal aging or thermal-humidity exposure), and found that this results in a frequency shift of the filter.

A variety of currently operational GNSS frequencies and rapid development of new navigation satellite systems resulted in the need for interoperability and compatibility. Recent state-of-the-art integrated GNSS front-ends are capable of simultaneous support of multiple navigation systems [1, 2]. A unification of the signal processing part is also possible and, what is more, desirable. This paper introduces a proposal for universal instruction set extension (ISE), which is used for accelerating signal processing in SDR (Software Defined Radio) based GNSS applications. The results of this work were implemented and tested on the chip multithreading general purpose processor – AGATE [3], running on the Xilinx Virtex-6 ML605 FPGA evaluation board.

This study described a novel and original method of ultra-shallow fluorine and nitrogen implantation from radio frequency (RF = 13,56MHz) CF4 and NH3 plasmas, performed in classical RIE / PECVD reactors. The performed experiments indicate that ultra-shallow implantation of high concentration of fluorine and nitrogen ions by using r.f. plasma reactors (PECVD ad RIE) is feasible. It is also possible to control the implantation process parameters, ie implantation depth and maximum concentration, by controlling the parameters of the plasma processes. Electrical characterization of MOS structures with HfO2 layer as a gate dielectric, shows that samples implanted with nitrogen, have the best insulating properties, better even the reference sample. Samples prepared by fluorine implantation, exhibit much worse I-V behavior for low, medium and high electric fields, than all samples studied in this article. This samples exhibit the highest leakage currents, too.

We have investigated deep-level defects in InGaAsN/GaAs 3xQW structures by means of conventional as well as high-resolution deep level transient spectroscopy (DLTS). The three samples were grown by atmospheric pressure metalorganic vapour phase epitaxy (AP-MOVPE) in different growth temperatures (566°C, 575°C and 585°C). The DLTS measurements revealed four electron traps E1 (0.17-0.24 eV), E2 (0.36-0.38 eV), E3 (0.46-0.49 eV) and E4 (0.81-0.84 eV) and one hole trap H1(0.8 eV) in our structures. The electron trap E1 was associated with N-related complexes while the other electron traps with native defects, usually observed in GaAs-based structures EL6, EL3 and EL2, respectively. Finally, the trap E2 and H1, observed in the structure grown at lowest temperature, were associated with the same trap, which can act as both an electron and hole trap. It was thus concluded that E2/H1 may be a generation-recombination center.

In this work we present the grid of microstructures which is used for the graphene mechanical and electrical properties investigations. The design of the mask used for the grid production was presented. Afterwards the technological process steps for the grid production were described. In result the support structures – trenches – in shape of lines, squares and circles are obtained with the detail dimensions varied from 1 micrometer up to 30 micrometers. Examples of graphite and graphene deposited on the support structures are also presented.

In the paper we report the results of investigation focused on conditions of the ohmic contacts formation on p-type non-implanted 4H-SiC substrates. Aluminum layers were deposited, photolithographically etched and annealed at temperatures from 700 to 1000°C to obtain electrical contacts to SiC. On substrates annealed at temperatures 900 and 1000C the I-V characteristics confirmed ohmic type contacts formation. Lowest resistivity of fabricated contacts calculated using Circular Transfer Line Model (CTLM) was 2.64·10^-4 Ωcm2. TOF SIMS profiling and RDX analysis were used to verify the microstructure of the Al/SiC interface. Ohmic contacts are characterized by an increased intensity of Si2- ion emission, which are characteristic for silicon nanocrystals, with respect to the emission from the pure SiC. This observation indicates that the ohmic nature of the received contacts can be affected by the presence of nanocrystalline silicon contact area. Presence of the nanocrystalline silicon has been also confirmed by XRD analysis.

In this paper application of Si3N4, AlN and polyimide to passivate GaAsN/GaAs MSM photodetectors is presented. The MSM structures were made on the undoped GaAsN epitaxial layers in which concentration of nitrogen was varied from 1.0 to 2.6 %. The dark and illuminated I-V characteristics of the devices are presented. Comparison of the dark current value and photoresponse obtained, for selected wavelengths in visible and IR range, from the MSM devices with different passivation layers is provided. Measurements of the dark current and photoresponse in the unpassivated and passivated MSM structures allowed to estimate relation between the bulk and surface components of the dark current. Therefore crystal quality of the epitaxial layers grown in different process conditions could be compared.

GaAsN and InGaAsN semiconductor alloys with a small amount of nitrogen, so called dilute nitrides, are especially attractive for telecom lasers and very efficient multijunction solar cells applications. The epitaxial growth of these materials using MBE and MOVPE is a big challenge for technologists due to the large miscibility gap between GaAs and GaN. Additionally, elaboration of the growth process of quaternary alloys InGaAsN is more complicated than GaAsN epitaxy because a precise determination of their composition requires applying different examination methods and comparison of the obtained results. This work presents the influence of the growth parameters on the properties and alloy composition of the triple quantum wells 3×InGaAsN/GaAs grown by atmospheric pressure metal organic vapour phase epitaxy AP MOVPE. Dependence of the structural and optical parameters of the investigated heterostructures on the growth temperature and the nitrogen source concentration in the reactor atmosphere was analyzed. Material quality of the obtained InGaAsN quantum wells was studied using high resolution X-Ray diffraction HRXRD, contactless electro-reflectance spectroscopy CER, photoluminescence PL, secondary ion mass spectrometry SIMS, photocurrent PC and Raman RS spectroscopies, deep level transient spectroscopy DLTS and transmission electron microscopy TEM.

In this study, measurements of resistance of polysilicon resistors with different widths have been done over the whole surface of the SOI wafers. The obtained results have been used to determine changes in their width, which is equivalent with shortening of the channel length in the photoli-thography process. By studying the elements distributed across the wafers it was possible to assess the homogeneity of the MOS transistor gate manufacturing process. the abstract two lines below author names and addresses.

Drain current and transconductance of a symmetrical, undoped double-gate MOSFET is modeled for the first time with mobility depending on both the applied voltage and position in the channel leading to analytical formulae. The obtained models are compared with simplified formulae assuming position-independent effective mobility. Good agreement is obtained in the case of one of the selected mobility models.

VESTIC technology was proposed as an alternative for traditional CMOS technology. It offers a new FET-type twin gate junctionless device called VeSFET. In addition, in the basic VESTIC device structure many different active devices can be made, including bipolar transistors. This allows easy integration of bipolar transistors (called here VeSBJT) with VeSFET transistors. The purpose of this paper is to investigate the expected properties of VeSBJT in order to answer the following questions: are the expected parameters of VeSBJT promising enough to justify further research and fabrication experiments, and will VeSBJTs be technologically compatible with VeSFETs? Our theoretical predictions are based on the concept of effective base width for bipolar transistors with non-plane-parallel emitter and collector junctions. The conclusion is that VeSBJT can be a device with useful characteristics. As a result, VESTIC may have the potential to become a new BiCMOS-type technology.

We report on the fabrication and performance of amorphous oxide thin-film transistors with In-Ga-Zn-O deposited by RF magnetron reactive sputtering for semiconductor channel layer. The influence of the electrical transport properties of the channel on the electrical parameters of thin-film transistors has been determined. By optimizing process parameters depletion-mode n-channel devices with maximum field-effect mobility (μ_FE) 10.1 cm²/Vs, threshold voltage V_th=-4.85V and on to off current ratio (I_on/I_off)=2.1x10² have been demonstrated.

The influence of the method of series resistance determination on the extracted channel mobility is investigated in MOS transistors with relaxed and strained Ge channel. The dependence of the extracted mobility on the channel length and the frequency of the signal used to measure capacitance-voltage characteristics are examined.

A description of the tunnel current in the metal-insulator-metal structure including Coulomb blockade is considered, which reduces to a commonly known “orthodox model” for sufficiently low temperatures. The current-voltage characteristics are calculated for various variants of the description and various parameters of the MIM structure.

This paper presents how an array of sensors with various sensitivities can be used for reliable detection and recognition of gases. An array of six different thin film metal oxide gas sensors has been constructed and tested. The selected sensors are based on indium, zinc, tin and titanium thin film oxides deposited by reactive magnetron sputtering. Sensors operate inside a measuring chamber at elevated temperatures of 250 – 300°C. The sensors responses upon hydrogen and ammonia exposure (0 – 3000 ppm) at relative humidity (0 – 75%Rh) are studied. The results show that exploiting the cross sensitivity and different sensing performance of the sensors allows to increase the reliability of gas sensing at relatively low operating temperatures.

Analysis of the temperature effect on electrical characteristics of double barrier metal-oxide-semiconductor structure is presented in the work. Results of the simulation of electrical characteristics obtained with the original theoretical model are compared with the measurements of the fabricated DB MOS structure.

An influence of the potential in the quantum well in the DB MOS structure on its current-voltage characteristics is considered under the assumption of a sequential tunneling through the double barrier system due to the effective recombination in the well.

The aim of our paper is to consider the possibility of applying pure Ag technology for assembly of SiC Schottky diode into a ceramic package able to work at temperatures up to 350°C. Ag micropowder was used for assembly SiC structure to DBC interposer of the ceramic package. Ag wire bonds as well as flip-chip technology using Ag balls were used as material for interconnection systems. The parameters of I-V characteristics were used as a quality factor to determine the Schottky diode after hermetization into ceramic package as well as after ageing in air at 350°C in comparison with characteristics of bare SiC diode.

The channel mobility and reliability of NMOSFETs with GaN channel are investigated by means of split CV and constant-voltage-stress techniques. The influence of stress polarity and duration on current in the off-state, threshold voltage and subthreshold slope is studied.

The development of the technology of fabricating hydrogenated amorphous silicon (a-Si:H) or silicon oxide (SiO_x) matrix with nanocrystalline inclusions (nc-Si:H) is the next step in improving the properties of electronic devices, such as solar cells, thin film transistors (TFT), floating gate transistors and others. Those films exhibit increased stability, absorption and carrier mobility. This paper is focused on the technology of manufacturing such films by means of Radio Frequency Plasma Enhanced Chemical Vapor Deposition (RF PECVD), which is use to fabricate electronic devices. The technology was developed in the Semiconductor Thin Films and Solar Cells Laboratory at the Department of Electronics at the AGH University of Science and Technology. The author describes the manufacturing process based on periodical variation of the process parameters, such as hydrogen to silane ratio (R_h), gas flows, RF power and pressure in the process chamber, during the deposition process. The author also presents the results of the measurements of typical samples with High Resolution Transmission Electron Microscopy (HRTEM), which confirms the existence of the nanocrystallites in the a-Si:H/SiO_x matrix.

This paper presents an extended method of CMOS standard cells characterization for defect based voltage testing. Resistance of a short defect is taken into account while considering faulty behavior caused by this defect and finding the test vectors that detect this fault. Finally, all of found vectors are validated to check their effectiveness in fault covering and the optimal test sequence for all detectable faults is constructed. Experimental results for cells from industrial standard cell library are presented.

In this work split-gate charge trap FLASH memory with a storage layer containing 3D nano-crystals is proposed and compared with existing sub-90 nm solutions. We estimate electrical properties, cell operations and reliability issues. Analytical predictions show that for nano-crystals with the diameter < 3 nm metals could be the preferred material. The presented 3D layers were fabricated in a CMOS compatible process. We also show what kinds of nano-crystal geometries and distributions could be achieved. The study shows that the proposed memory cells have very good program/erase/read characteristics approaching those of SONOS cells but better retention time than standard discrete charge storage cells. Also dense nano-crystal structure should allow 2-bits of information to be stored.

This work presents examination of a novel current source circuit. The implementation of a linear combination of two reference voltages and a voltage drop across a load resistor to control a power supply voltage in a typical bipolar current source allows limitation of the correlation between the output stage collector-emitter voltage and the load current, resistance. The first reference voltage, V_ref1, controls the load current, while the second reference voltage, V_ref2, controls the output stage emitter-collector voltage. Consequently, this voltage is independent of the load current and resistance, which is particularly important for reducing the influence of Early effect. The presented circuit is characterized by a simple design and relatively low cost.

In this papers, a fully differential operational transconductance amplifier (OTA) implemented in 65 nm CMOS technology is analyzed to determine which component of the calibration circuitry is most susceptible to manufacturing process disturbances and thus impairs robustness of the calibration methodology. The average offset voltage of the OTA can be significantly reduced. It has been shown that effectiveness of the calibration methodology is limited by the offset voltage of the comparator that calculates sign of the OTA offset voltage.

Paper presents research on the sub-micron gate, AlGaN /GaN HEMT type transistors, fabrication by e-beam lithography and lift-off technique. The impact of the electron beam on the resists layer and the substrate was analyzed by MC method in Casino v3.2 software. The influence of technological process parameters on the metal structures resolution and quality for paths 100 nm, 300 nm and 500 nm wide and 20 μm long was studied. Qualitative simulation correspondences to the conducted experiments were obtained.

The quality of the die bonding is critical to the operation and reliability of the laser diodes since it can affect the electrical, thermal, and optical properties of the device. We investigated the effect of mounting induced strain and defects on the performance of high power laser. In this paper measurements of the temperature distribution, the spontaneous emission spectrum and the electroluminescence along the cavity of quantum well lasers are presented. The electro-optical parameters of the high output power laser diodes, such as emission wavelength, output power, threshold current, slope efficiency, and operating lifetime are presented too. In the experiment, high power diode lasers emitting in 808 nm and 880 nm- range are investigated. We have observed that defect lines tend to create in areas where temperature gradients were observed in thermovision measurements.

The paper discusses the design of charged-particle detectors commissioned and developed at the Institute of Electron Technology (ITE) in collaboration with foreign partners, used in international research on transactinide elements and to build personal radiation protection devices in Germany. Properties of these detectors and the results obtained using the devices are also presented. The design of the following epiplanar detector structures is discussed: ♦ 64-element chromatographic arrays for the COMPACT (Cryo On-line Multidetector for Physics And Chemistry of Transactinides) detection system used at the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt (GSI) for research on Hassium, Copernicium and Flerovium, as well as elements 119 and 120, ♦ 2-element flow detectors for the COLD (Cryo On-Line Detector) system used for research on Copernicium and Flerovium at the Joint Institute for Nuclear Research, Dubna, ♦ detectors for a radon exposimeter and sensors for a neutron dosimeter developed at the Institut für Strahlenschutz, Helmholtz Zentrum München. The design of planar detectors – single-sided and double-sided strip detectors for the Focal Plane Detector Box used at GSI for research on Flerovium and elements 119 and 120 is also discussed.

Mastitis is the inflammation of the mammary gland in animals under the influence of micro-organisms causing functional disorder of udder. Mastitis causes a variety of qualitative changes in the milk, which classified as mastitis milk, has a reduced value. A number of chemical procedures and lab instruments were developed to test for mastitis, of which the widest used are the California mastitis test and the somatic cell counter. This work presents the progress in development of new photonic sensors of mastitis using a conductometer, a spectrometer and a capillary head with local heating with improved measuring procedures. We showed that the significant increase in mastitis detection sensitivity is achieved by measuring the whey acidic instead of milk. The whey can be obtained from milk in a relatively simple and inexpensive chemical process. We correlated the conductivity measurement and the measurement of the number of somatic cells in the milk. The application of the measurement of optical transmission absorption in whey instead of the classic milk measurement increases the resolution of resistance measuring more than 3 times. However, the application of the method of capillary phase-transition to whey examination increases the resolution of measurement 15 times. The changes in resistance and time of the phase transitions are linearly correlated with the number of somatic cells.

In this paper, we demonstrate the feasibility of using the nanostructured micro-optics technology to create a large diameter quantized elliptical microlens. Nanostructured gradient index elements have discrete internal structure with feature sizes much smaller than the wavelength of the incident light. The nanostructured lens is composed of two silicate glasses with various refractive indexes. Large diameter elliptical microlens is developed. Optical performance of microlens is verified numerically. Effective focal lengths of 220 and 116 for are predicted for wavelength of 1300 nm.

Supercontinuum generation spanning an octave from 900 nm to 2400 nm was obtained in all-solid glass, photonic crystal fiber, designed with flattened, all-normal dispersion and optimized for pumping in the 1500-1560 nm range. The report includes designing of microstructure of all-solid glass photonic crystal fiber and relation of dispersion profile to fiber filling factor d/Λ, numerical and experimental characteristic of fabricated fiber dispersion profile, supercontinuum generation experiment under 1530 nm pumping with 70 fs pulses, concluded with numerical analysis based on solution to nonlinear Schrödinger equation. Interplay among self-phase modulation, optical wave breaking and four-wave mixing is discussed in context of observed pump pulse broadening.

The paper presents two methods of determining the planar waveguide birefringence and the measuring stands, which are used to determine the birefringence of planar waveguide structures. The light is introduced into the waveguide through a prism coupler. First method uses the measurement of scattered light. The second method uses an immersion coupler. The most fundamental property of an immersion coupler is the possibility to change fluently the propagation length while immersing the waveguide with an invariable efficiency of output coupling.

The quality of the beam emitted by high-power laser diodes is still the main disadvantage of these devices. One of the ways to improve it is to design diode as a matrix of narrow active stripes – so called: phase-locked arrays. The optical coupling which is occurs in such devices causes the emission in the form of a few almost diffraction limited beams (lobes). Unfortunately, because of temperature dependence of refractive indices this coupling often disappears at high drive currents. In this paper the CW operation (up to 4I_th) of the phase-locked semiconductor laser arrays is reported. The devices are based on asymmetric heterostructure which is designed for improving thermal and electrical resistances. The single supermode operation is obtained and the lasers are emitted up to 1 W of the optical power in CW.

We report on free-running operation in a side-pumped Yb:YAG slab laser. For maximum available pump pulse energy of 850 mJ at 967.7 nm delivered by a 2D laser diode stack with fast-axis-collimation, the output pulses with energy of 150 mJ at 1.03 μm were obtained. The laser system operated in room temperature providing a slope efficiency of 26.9%. The performance of the laser is described.

A compact and efficient, passively cooled, diode pumped Tm:YLF laser is presented. The power of over 15 W for 10% duty cycle and 55-W of pump power was achieved. When applying the pump power of 25 W and using elongated 120-mm long optical cavity, the output power as high as 5 W with a slope efficiency of 50% was also presented. The maximum pulse peak power and pulse duration achieved, recorded for 20 Hz of repetition rate and 10% pump duty factor was near 0.5 MW and 11 ns, respectively. The output laser beam was characterized by very good quality with divergence angle of 3.5 mrad and M² < 1.15.

We demonstrate broadband supercontinuum (SC) generation in a single-mode fluoride (ZBLAN) fiber pumped by 1.55 μm nanosecond pulses amplified in a cascade of fiber amplifiers. The recorded spectrum spread from ~ 900 nm to 3600 nm. The total output power was measured to be 0.66 W in entire spectral band. Over 65% of this power corresponded to wavelengths longer than 1.65 μm. The SC spectrum was generated in two steps: first the ~1 ns pulses were broken in a single-mode silica fiber (SMF) into a train of shorter sub-pulses leading to initial spectrum extension (from ~1.4 to 2.2 μm) and then the spectrum was further broadened into a ZBLAN fiber. The performance of the SC source is described.

The issue of temporal pulse distortion occurring during amplification process in a 2-stage, fiber amplifier, operating in the eye-safe spectral region, is discussed. The amplifier was built in a Master Oscillator Power Amplifier (MOPA) configuration and seeded by a distributed feedback (DFB) laser providing nanosecond pulses at a repetition rate of 20 kHz. It operated at a wavelength of 1549.13 nm and generated over 200 mW of output power with a slope efficiency of up to 28%. The comparison between the calculated and measured results on saturation-induced pulse shape deformation, for ~300-ns pulses, is presented. The analyzed pulse shapes embraced rectangle, Gaussian, triangle and "M" letter.

This article describes a study on the influence construction and technology on the time stability of neutron sensors developed at the Institute of Electron Technology, and was prepared the need to eliminate the dark current growth in long-term use, not associated with radiative exposures. After analyzing the construction of detectors makes some changes to technological processes. To improve the assembly technology changed the type of converter (hard wax is replaced with a soft petroleum jelly) and introduced the foam insert to the casing of the sensor in order to avoid mechanical stresses in the structure. These stresses occur as a result of thermal shrinkage of wax (almost abrupt change of state from liquid to crystalline phase), which caused the piezoelectric effect. After conducting structural and technological changes detectors were long-term electric load.

In the paper is described the concept and architecture of the multi-channel control system for set of high-power LEDs. The broadband source of radiation for prototype illuminator is dedicated to the investigation of Low Level Laser Therapy procedures. The general scheme of the system, detailed schemes, control algorithm and its implementation description in FPGA structure is presented. The temperature conditions and the opportunity to work with a microcomputer are characterized.

This paper describes an approximate analysis of Raman generation in silicon-on-insulator (SOI) rib waveguide with DBR/F-P resonator and an integrated p-i-n (PIN) junction, taking into account spatial field distribution and nonlinear effects involved in silicon. These effects comprise especially, stimulated Raman scattering (SRS), free-carrier absorption (FCA), degenerate two-photon absorption (i.e. the pump-pump TPA) and non-degenerate two-photon absorption (i.e. the pump-Stokes TPA and the Stokes-pump TPA). Applying the reverse biased PIN junction allows to reduce the nonlinear optical losses due to TPA-induced FCA. The model is based on the semiclassical approach and an energy theorem. In threshold analysis of steady-state Raman laser operation, an analytical formula relating input pump power to the system parameters is obtained. It allows analyzing the influence of all physical and geometrical parameters on the threshold pump power. The analysis of the above threshold operation is based on the exact energy conservation relation, in which the approximated pump and Stokes field distributions are used. The Stokes field distributions are approximated by that existing at the threshold, whereas the approximate pump field distributions are obtained by integrating the equations for the pump signal using the linear (threshold) pump field distributions and the threshold Stokes field distributions. We obtain an approximate, semi-analytical expression related the Raman output power to the pump power and system parameters.

For the growth of many high-quality photonic devices, especially surface emission lasers with a vertical resonance cavity (Vertical External Cavity Surface Emitting Laser, VECSEL) very important is to know the actual concentration of the carriers in each layer laser structure resulting from the presence of unintentional impurities. Studies of doping profile of this type multilayer structure can be carried out only by comparing the measured capacitance - voltage characteristics with the calculated theoretically. The paper presents results of research VECSEL structures with different numbers of quantum wells 4, 8, 12, 16, produced by molecular beam epitaxy. Measurements of the capacitance - voltage characteristics has been performed using mercury probe in the system for automatic measurement of C-V, I-V, G–V. The results of C-V measurements and numerical simulations have confirmed the possibility to control the level of unintentional impurities in the different layers of the laser VECSEL structure. The lowest concentrations of unintentional impurities were obtained for structures with highest power output.

In this paper the specifics of FTTH (Fiber To The Home) networks in terms of requirements for optical fibers has been presented. Optical fiber samples used in FTTH applications acquired from the worldwide leading manufacturers were subjected to small diameter mandrel wraps tests. The detailed procedures of performed tests and the measurement results has been presented.

In this paper, a method of designing a Raman laser structures with Bragg mirrors used to coupling pump signal, forming a resonator and lead-out laser signal outside is presented. The Raman laser is SOI waveguide structure (such as "rib," i.e. ridge waveguide) with built-in reverse biased p-i-n diode, wherein the optical gain is generated by stimulated Raman effect in the waveguide. Our way of designing is based on the effective refractive index method. Design of Raman laser with Bragg mirrors consists of two main stages: the first step is the choice of the optimum size and shape of the rib waveguide; the second step is the selection of Bragg gratings parameters. Our method of designing such Raman laser structures is a design tool, which uses analytical dependences and allows specifying optimal geometric parameters of one mode laser.

The paper discusses the technology of silicon charged-particle detectors developed at the Institute of Electron Technology (ITE). The developed technology enables the fabrication of both planar and epiplanar p⁺-ν-n⁺ detector structures with an active area of up to 50 cm². The starting material for epiplanar structures are silicon wafers with a high-resistivity n-type epitaxial layer ( ν layer - ρ < 3 kΩcm) deposited on a highly doped n⁺-type substrate (ρ< 0,02Ωcm) developed and fabricated at the Institute of Electronic Materials Technology. Active layer thickness of the epiplanar detectors (νlayer) may range from 10 μm to 150 μm. Imported silicon with min. 5 kΩcm resistivity is used to fabricate planar detectors. Active layer thickness of the planar detectors (ν) layer) may range from 200 μm to 1 mm. This technology enables the fabrication of both discrete and multi-junction detectors (monolithic detector arrays), such as single-sided strip detectors (epiplanar and planar) and double-sided strip detectors (planar). Examples of process diagrams for fabrication of the epiplanar and planar detectors are presented in the paper, and selected technological processes are discussed.

The article describes an application one of the most sensitive optoelectronic method – Cavity Enhanced Absorption Spectroscopy in investigation of nitric oxide in exhaled breath. Measurement of nitric oxide concentration in exhaled breath is a quantitative, non-invasive, simple, and safe method of respiratory inflammation and asthma diagnosis. For detection of nitric oxide by developed optoelectronic sensor the vibronic molecular transitions were used. The wavelength ranges of these transitions are situated in the infrared spectral region. A setup consists of the optoelectronic nitric oxide sensor integrated with sampling and sample conditioning unit. The constructed detection system provides to measure nitric oxide in a sample of 0-97% relative humidity.

In the paper we discuss crucial aspects of selective deep wet etching technology of fused silica optical fibers. The technology includes preparation of the fiber, photolithography aiming to create a mask for etching, wet etching process and photoresist removal. We also discuss the influence of removing polyimide layer from the fiber, photoresist type, thickness of the photoresist and etching time. The developed technology allows for obtaining periodic variations in the fiber diameter resulting in formation of corrugated long-period grating (LPG). Introduction of strain induces appearing of attenuation peak in the transmission spectrum of the fiber. The developed technology can be also applied for fabrication of other optical fiber devices.

The main aim of this paper is to describe the process of assembling the GSF3S detectors of thoron particles. Its purpose is also to present the ways of adaptation of the assembly technology of the above mentioned detector to the conditions which allow for the detection of particles in the area of optical radiation. The main issues illustrated in the report regard the method of protecting detector parts which are outside the active surface from light which generates photo-electric current constituting background that alters the signal.

In this paper, we present opportunities to use photonic techniques in tuning process of opto-electronic oscillators. These opportunities involve wavelength controlled delay lines and fiber Bragg gratings.

This paper presents the sensor characteristics of highly birefringent polymer side-hole optical fiber. The fiber core with greater refractive index was made of copolymer PMMA-PS, while the cladding of pure PMMA. The fabricated fiber showed relatively low losses of the order of 6 dB/m in the visible range. We measured several sensing characteristics in the fabricated fiber, including birefringence and polarimetric sensitivity to pressure and temperature. The fiber showed high polarimetric sensitivity to pressure, which is directly related to the presence of two large holes transferring symmetrical load applied to the cladding into nonsymmetric stress distribution in the core region. This in turn changes modal birefringence of the investigated fiber and increases the sensitivity to pressure.

This work discusses methods of applying biological films on the surface of high-sensitive long-period grating (LPG) in the process of developing optical fiber sensors, which allow for label-free detection. Referred techniques prepare the surface of LPG structure for further coating with layers providing specificity of the sensor system. Presented are two methods of fiber coating, based on self-organizing layers, which were applied on two different LPGs. Short and thermally undemanding method was used on UV-written LPG fiber whilst heat requiring method was applied on LPG written by arc method, with silicon nitride (SiNx) nano-coated surface. Sensitivity of fibers was testes through immersing in liquids of various refractive indexes (RIs) and found to be 925.5 nm/RIU for UV-written and nano-coated arc-written LPGs to be -1115.8 nm/RIU, respectively. Shifts of resonance wavelengths occurring during the processes of coating are presented and discussed. Experiments were performed using simple instruments and in short-term proceedings and can therefore be easily repeated as well as applied to industrial production processes. We confirmed effectiveness of both methods and proved that selected fibers were suitable for use in each of those approaches respectively.

This paper discusses the influence of coating long-period gratings with a silicon nitride thin overlay on the grating’s spectral response. The overlays have been obtained with a radio frequency plasma enhanced chemical vapor deposition method. During the experiment, the structures were positioned on various heights over the electrode using specially developed sample holder. The results of the experiment show that the investigated long period grating structures have increased their sensitivity to variations of external medium refractive index in the range of n_D=1.33 to 1.43 RIU. The relation between the height at which the long period grating was placed over the electrode and the deposited overlay symmetry is discussed. The highest sensitivity of 2080 nm/RIU has been observed for the grating placed at the highest positions of the holder out of the examined range of 3 to 8 mm over the electrode. This overlay also shows the highest symmetry around the fiber.

Measuring system designed and manufactured by the authors and based on mobile computers (smartphones and tablets) working as data recorders has been invented to support diagnosis of orthopedic, especially feet, diseases. The basic idea is to examine a patient in his natural environment, during the usual activities (such as walking or running). The paper describes the proposed system with sensors manufactured from piezoelectric film (PVDF film) and placed in the shoe insole. The mechanical reliability of PVDF film is excellent, though elimination of the pyroelectric effect is required. A possible solution of the problem and the test results are presented in the paper. Data recording is based on wireless transmission to a mobile device used as a data logger.

This paper presents the relation between the temperature value and the time constant value for the voltammetry electrode. The problem in voltammetry measurements is the accuracy of the time constant value. Based on mathematical analysis and laboratory verification, it was shown that it is possible to calculate the time constant of the electrode by measuring the current. The current must equal to the diffusion limited current value. It was also shown how important in the voltammetry measurements is the accuracy of the time constant value, because this value determines the dynamic error of electrode.

In this article, the concept of a prototype femtosecond laser micromachining system and a femtosecond solid-state Yb:KYW laser is presented. Ultrashort laser pulses have many advantages over the long pulses in laser micromachining, due to their unique ability to interact with different materials without transferring heat to them. This allows very precise and pure laser-processing, clean cuts and sharp edges. A femtosecond laser micromachining device presented in this article is equipped with high-precision galvo scanner, quality optical elements and automatic process supporting tools, resulting in the maximum use of the femtosecond laser potential for precise micromachining and MEMS fabrication.

In this paper we present studies of hydrogen sensors based on nanostructural C-Pd films deposited on alundum substrate with silver or titanium electrodes. These C-Pd films were prepared by PVD method. Films were characterized by SEM and EDS. Sensitivity of films toward hydrogen were measured in specially prepare experimental set-up with small chamber (50ml). Response time was also registered for different percentage of hydrogen / nitrogen mixture (up to 1% of hydrogen).

A study of pH sensitivity of miniature ISFET-type sensors with silicon nitride sensitive layer has been presented. 4 μm wide SOI FET microsensor process and 100 nm FinFET nanosensor process have been completed with oxygen plasma treatment. I_D(V_DS) and g_ds characteristics of the devices as well as source follower circuit output signal measurements have been reported. An influence of 1% HF etching of the gate dielectric on pH sensitivity of the sensors has been described and an explanation of phenomenon of the sensitivity adjustment has been proposed.

In this paper the application of the ink-jet printing technology to microstrip line fabrication on tunable ferroelectric ceramic-polymer composites for devices operating at sub-terahertz range have been presented. Measurement results shown that the designed material is usable for creating structures able to tune some their electromagnetic characteristics. Relatively low temperature technology process (ink-jet printing technology) is able to deposit conductive lines on the ceramic polymer. The ink-jet printed silver microstrip lines can operate at sub-terahertz range.

Microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS) are the promising platforms for mass change observations. These systems in optimal solutions allow to observe the deposition of single molecules. This is achieved by the structure miniaturization which entails increase of resolution. In this paper, we present fabrication process of silicon nitride double-clamped beam structures. Moreover, it is presented the basic description of the beam mechanics which is based on the Euler-Bernoulli beam theory. Additionally results of the measurements of the fabricated devices are shown. Thanks to the possibility of recording force curves at nanometer deflections using atomic force microscopy (AFM) system there is a possibility to determine the properties of the MEMS and/or NEMS devices. The obtained experimental results show that the parameters of the fabricated structures differ basing on the theoretical ones, which were calculated from the elasticity theory. This results from the stress in the silicon nitride film, which forms the elastic beam structure and from the stress in the metallization deposited on the bridge. The influence of the described factors on the bridge structure properties is also described. Bridge structures with thickness of 120 nm, width and length ranging from 3 to 10 μm and from 20 μm to 80 μm respectively were investigated.

Increased interest in micro-and nano-electromechanical systems (MEMS and NEMS) entail the development of reliable measurement techniques for the basic parameters of the designed and manufactured devices. The proposed methodology should provide high resolution, wide frequency range and the possibility to investigate both mechanical and electrical parameters during inspection process. In this article authors present methods for manufacturing of electrostatic MEMS devices. Measurement techniques will be presented for specifying parameters such as resonant frequency, quality factor and sensitivity of the previously manufactured structures. Manufacturing techniques will be presented on the example of the micropusher structure, whereas measurement techniques will be presented on the example of the microgripper structure.

Anisotropic etching process of Si (100) and (110) planes in low concentrated potassium hydroxide (KOH) solutions containing Triton X-100 surfactant is studied in this paper. Addition of a little amount of the surfactant to the etchant considerably reduces etch rates of both the planes, though the etch rate ratio R(100)/R(110) > 1 is obtained. The (110) surface roughness is significantly decreased when Triton is added to the solution, too. Therefore, the {110} sidewall planes could be used as micromirrors inclined at 45° towards the (100) substrate. The {110} surface roughness is low in a wide range of Triton concentration, which gives some flexibility in the choice of surfactant concentration for fabrication of smooth micromirrors. Better understanding of etching processes with surfactants could help select a composition of the etching solution which yields little rough {110} planes. For that reason, the adsorption of Triton molecules on Si surface is investigated using contact angle measurements. The results show that the (110) surface is more hydrophilic as well as better wetted by the surfactant solution than the (100) one, though both the planes are rather hydrophobic. This suggests that a little more hydrophilic surface should be more advantageous to the surfactant adsorption. The explanation, based on literature reports and theoretical considerations, is proposed and associated with the etching results.

This paper is focused on manufacture technology of molecular self-assembled monolayers (SAM) using microcontact printing (μCP) techniqe. This technique, due to its low-cost and simplicity, is a very attractive one for further development of molecular electronics and nanotechnology. The SAM can be produced on gold or silicon oxide using thiol and silane based chemistry respectively[1]. The μCP techniques allow the imposition of molecular structures in specific areas. The chemical properties of the fabricated layers depend on the functional groups of tail molecules. Such structures can be used as chemical receptors or as interface between the substrate and the biosensor receptors [2]. Architecture of the tail molecule determines the chemical reactivity and hydrophilic or hydrophobic properties. In addition it modifies the tribological properties [4] and electrical structure parameters, such as contact potential diference (CPD) [5]. The height of the SAM structure containing carbon chain is highly dependent on the length and type of binding molecules to the substrate, which enables application of the μCP SAM structures in height metrology. The results of these studies will be presented in the work.

In this paper authors present two methods of determining the cantilever displacement sensitivity. In both cases the cantilevers are examined in dynamic condition for cantilever vibrating with frequency range close to resonance frequency. One of the method uses as measurement tool a white light interferometer, the another one uses the laser interferometric vibrometer. For adequate comparing methods, obtained results refer to the same cantilever with piezoresistive Wheatstone bridge. In this paper authors also present the fabrication process of piezoresistive cantilevers with planar tip adapted for working in a shear force [1]. Additionally the piezoresistive circuit characterization by impedance spectroscopy is presented. Finally the spring constant is determined basing on frequency response of the cantilever measured from thermal noise density [2]. Basing on obtained results authors made a conclusion that both methods can be successfully used for accurate characterization piazoresistive cantilevers work in a non-contact resonance mode.

The study shows an analysis of numerical models of MEMS transducers used for magnetic field measurements. Movable silicon microbeam structures attached from one side were considered. A ferromagnetic NiFe layer was deposited on the microbeams’ surfaces by magnetron sputtering. In a magnetic field, there is a torque acting on a beam with NiFe layer. There is a change in a deflection angle of a free end of the beam according to the magnetic field strength. The impact of the beam parameters and its attachment on the deflection was analyzed for the tested numerical models of the transducers. An optoelectronic test system can be used to measure the beam’s end deflection. Experimental characteristics obtained from a test system for rotation angle transducers were shown. Range of measurements corresponds to the tested models.

Noise properties of thick-film resistors made of various resistive and conductive materials, including Pb-rich and Pb/Cd-free, have been studied. Power spectral density of voltage fluctuations has been measured using different methods which have been described and discussed, including ac and dc bridge configuration, cross-correlation technique and low-frequency noise spectroscopy (LFNS). In temperature range from 0.3 up to 350 K, for all studied samples 1/f noise resulting from resistance fluctuations has been found to be dominated noise component. Using LFNS thermally activated noise sources (TANSs) have been detected. Their interesting properties have been described and activation energies of TANSs have been extracted, which occurred to be below 1eV. Second spectra analysis has been applied revealing non-Gaussian noise components in 1/f noise. On the other hand, it has been found that noise intensity in TFRs, including devices designed for temperature sensing, increases rapidly when temperature drops below a few K. Model of conduction transport, involving hopping mechanism and electro-thermal feedback, has been used for explanation of noise suppression by excitation power, what was observed in temperatures below 1K, in the framework of inhomogeneous heating. Integral measure of noise has been introduced which was then used for qualitatively description of bulk noise generated by resistive layer and noise of contacts. Detailed comparison of material noise intensities obtained for various resistive materials has been shown. Conclusions concerning TFRs optimization with respect to noise have been given. Compatibility criteria for materials used for thick-film technology have been formulated and systems of compatible materials have been evaluated. The conclusions might be useful in further improvement of materials systems for thick-film technology in order to fabricate low-noise, reliable and stable resistors.

In this work structural, optical and surface properties of gasochromic thin films based on mixtures of selected transition metal oxides have been outlined. Two sets of thin films were prepared by reactive magnetron sputtering from four-component metallic mosaic targets containing Ti, V ,Ta as a base and W or Nb as a fourth material. Neither Pd nor Pt metals were used as a catalyst. X-ray diffraction investigations revealed, that all prepared thin films were amorphous while application of x-ray photoelectron spectroscopy studies show presence of TiO₂, V₂O₅, Ta₂O₅, and WO₃ or Nb₂O₅ oxides at the surface depending on the thin films composition. Gasochromic properties were investigated through observations of the change in optical transmission response of the films exposed to reducing or oxidizing gas. Dynamic optical responses of samples were collected at room temperature. Depending on composition of the sample being investigated the change in optical transmission at room temperature ranged up to about 28 %. Based on optical transmission refraction and extinction indexes were calculated using reverse synthesis method. The obtained results are very promising for utilization of prepared thin films in optical gas sensing devices.

Electrochromic system is the one of the most popular devices using color memory effect under the influence of an applied voltage. The electrochromic system was produced based on the thin WO₃ electrochromic films. Films were prepared by RF magnetron sputtering from tungsten targets in a reactive Ar+O₂ gas atmosphere of various Ar/O₂ ratios. The technological gas mixture pressure was 3 Pa and process temperature 30°C. Structural and optical properties of WO₃ films were investigated for as-deposited and heat treated samples at temperature range from 350°C to 450°C in air. The material revealed the dependence of properties on preparation conditions and on post-deposition heat treatment. Main parameters of thin WO₃ films: thickness d, refractive index n, extinction coefficient k and energy gap Eg were determined and optimized for application in electrochromic system. The main components of the system were glass plate with transparent conducting oxides, electrolyte, and glass plate with transparent conducting oxides and WO₃ layer. The optical properties of the system were investigated when a voltage was applied across it. The electrochromic cell revealed the controllable transmittance depended on the operation voltage.

Paper assesses the greenhouse gas emissions related to the electronic sectors including information and communication technology and media sectors. While media often presents the carbon emission problem of other industries like petroleum industry, the airlines and automobile sectors, plastics and steel manufacturers, the electronics industry must include the increasing carbon footprints caused from their applications like media and entertainment, computers and cooling devices, complex telecommunications networks, cloud computing and powerful mobile phones. In that sense greenhouse gas emission of electronics should be studied in a life cycle perspective, including regular operational electricity use. Paper presents which product groups or processes are major contributors in emission. From available data and extrapolation of existing information we know that the information and communication technology sector produced 1.3% and media sector 1.7% of global gas emissions within production cycle, using the data from 2007.In the same time global electricity use of that sectors was 3.9% and 3.2% respectively. The results indicate that for both sectors operation leads to more gas emissions than manufacture, although impacts from the manufacture is significant, especially in the supply chain. Media electronics led to more emissions than PCs (manufacture and operation). Examining the role of electronics in climate change, including disposal of its waste, will enable the industry to take internal actions, leading to lowering the impact on the climate change within the sector itself.

Currently, most of gas sensors on the market are produced in thin or thick film technologies with the use of ceramic substrates. It is expected that the miniature sensors needed in portable applications will be based on one-dimensional structures due to their low power consumption, fast and stable time response, small dimensions and possibility of embedding in integrated circuit together with signal conditioning electronics. The authors manufactured resistance type gas sensors based on ZnO and WO₃ nanostructures. ZnO:Al nanorods with good cristallinity were obtained with electrodeposition method, while ZnO:Al nanofibres with varying diameters were obtained by electrospinning method. The sensors were built as a nanowire network. WO₃ films with nanocrystalline surface were manufactured by deposition of a three layer WO₃/W/WO₃ structure by RF sputtering and successive annealing of the structure in appropriate temperature range. In effect a uniform nanostructurized metal oxide layer was formed. Investigation of sensors characteristics revealed good sensitivity to nitrogen dioxide at temperatures lower than these for conventional conductometric type sensors.

Further development of printed electronics requires investigations of new polymer composites which can be coated on flexible substrates with printing techniques. These composites should exhibit low sheet resistance and high durability to thermal stresses. In this article, the properties of polymer composites prepared by mixing a commercial solution of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) in aliphatic hydrocarbons with multi-wall carbon nanotubes or graphite platelet nanofibers were described. These composites were coated on flexible and low-cost substrates with screen printing techniques. The microstructure of fabricated layers were observed in a top and cross-sectional view and their thickness was measured with a contact profilometer. Their resistance was measured with a four-point-probe method depending on a printing multiplicity and after exposure the tested samples to the influence of temperature variation. Temperature distribution under influence of current flow in the produced layers was also examined.

Deposition technology of the three layers antireflective coatings consists of hafnium compound are presented in this paper. Oxide films were deposited by means of e-gun evaporation in vacuum of 5x10^-5 mbar in presence of oxygen and fluoride films by thermal evaporation. Substrate temperature was 250°C. Coatings were deposited onto optical lenses made from quartz glass (Corning HPFS). Thickness and deposition rate were controlled by thickness measuring system Inficon XTC/2. Simulations leading to optimization of thickness and experimental results of optical measurements carried during and after deposition process were presented. Physical thickness measurements were made during deposition process and were equal to 43 nm/74 nm/51 nm for Al₂O₃ / HfO₂ / MgF₂ respectively. Optimization was carried out for ultraviolet region from 230nm to the beginning of visible region 400 nm. In this region the average reflectance of the antireflective coating was less than 0.5% in the whole range of application.

The three-dimensional imaging system has been developed in the form of an attachment to a SEM, which consists of a combined directional electron detector, a frame-grabber and a PC-based processing unit. The detector head is integrated with the intermediate vacuum system to separate the sample chamber allowing gas pressure over 10 hPa and the electron optical column where high vacuum must be maintained. Quantitative information about the surface topography is obtained by digital processing of four input images acquired from four electron detectors. The multi-detector system developed by authors comprises two quadruple backscattered electron detectors (of the semiconductor and ionisation types) and an ionisation secondary electron one. The semiconductor detector is dedicated for imaging of nonconductive surfaces while the ionisation one can be also used for wet or even semiliquid samples.

Nanoelectronic and nanophotonic applications have created a pressure on methods of fabrication double dielectric barriers stacks with ultrathin silicon layer located between dielectric layers. Among numerous possible methods, PECVD seems to be very promising. In order to increase possible number of applications, however, the ability to transform continuous silicon layer into nanocrystalline form in dielectric matrix is required. The work described below reports on experimental efforts to form such a structure by controlled high temperature recrystallization and oxidation of ultrathin PECVD silicon layer in the stack. The effects if high temperature annealing has been studied by spectroscopic ellipsometry. The applied model allowed for identification of composition and structural changes within the silicon PECVD layer due to different high temperature annealing processes applied. As a result of this study, it has been proved that it is feasible to fabricate complete two barrier stack consisting of ultrathin dielectric and silicon layers in one PECVD system without exposing samples to the ambient atmosphere. In order to reduce the PECVD silicon layer thickness to approximately 3 nm, we proposed using plasma oxidation in PECVD instead of PECVD oxide deposition. High temperature (especially in 1100°C) annealing in argon proved to allow formation of silicon nanocrystals in oxide matrix. Other effects resulting from high temperature annealing of fabricated stacks are also studied.

Nematic liquid crystals are promising dielectrics for tunable microwave devices due to their significant birefringence and moderately low loss. Dielectric anisotropy or refractive index anisotropy of liquid crystal is one of the important parameter for the design of variety of reconfigurable devices. In this work, transmission line method is used for the broadband investigation of nematic liquid crystals in the frequency range of 1-10 GHz. For this purpose, a measurement device is proposed with a tunable liquid crystal transduces based on an inverted microstrip structure section placed between two segments of layered microstrip lines terminated by microstrip-coaxial line transitions. Measurements of the scattering parameters of the device with standard liquid crystal 6CHBT as well as with a novel highly anisotropic mixture W1825 have been conducted. Based on these measurements, a high effective refractive index anisotropy of 0.31 for the W1825 mixture compared to 0.12 for 6CHBT have been determined. These values are lower of 26% and 18% than anisotropy of the refractive indices appointed by a resonator method for W1825 and 6CHBT, respectively. Progress in highly anisotropic mixtures opens new low-cost liquid crystal applications in microwave devices.

Structural, topographical and morphological changes of carbonaceous-palladium (C-Pd) films obtained by physical vapor deposition /chemical vapor deposition (PVD/CVD) method were studied. Effect of changes in these properties under the influence of CVD process temperature on the hydrogen sensitivity of these films is discussed. Scanning electron microscopy (SEM) observations were used to investigate the topography and morphology of an initial (PVD) film and the film modified in CVD process (PVD/CVD film) at different temperatures. The changes of film’s morphology after modification performed at various temperatures (500, 550, 600, 650, 700 and 750°C) caused changes in their resistance. The electrical measurements carried out in the presence of gas containing 1vol % of hydrogen showed different sensing characteristics for various films. The highest hydrogen sensitivity and the fastest response were observed for films modified at the temperature of 500°C and 550°C. In SEM images on surface of these films palladium nanograins with different sizes were observed. For films modified at the temperatures higher than 600°C Pd nanograins placed under superficial very thin carbonaceous layer were found.

The influence of growth conditions on properties of high temperature GaN (HT-GaN) buffer used in AlGaN/GaN HEMT heterostructures was studied. Many various factors are presumed to have significant impact on the concluding properties of HT-GaN buffer. In this paper the nucleation layer growth time as well as temperature during high temperature GaN layer growth was selected as a factors alleged to cause variation in final GaN layer properties. The study was designed to show step by step improvement of HT-GaN buffer with consecutive changes of particular parameters. Electrical properties of the AlGaN/GaN heterostructures were determined using impedance spectroscopy method performed with HP 4192A impedance meter equipped in two contact mercury probe. Laser reflectance traces acquired in-situ during MOVPE (Metalorganic Vapor Phase Epitaxy) growth were compered and analyzed in order to correlate growth mechanism with electrical properties of HT-GaN buffer. The improvement of HT-GaN resistivity was shown through decrement of capacitance in the depleted space-charge region.

This paper presents the design, prototype realization and measurement results of the liquid crystal bias voltage-tunable microwave band stop filter. A possible use of liquid crystals for tunable band stop filters was shown.

Dilute nitride (In, Ga)(As, N) alloys grown on GaAs substrate are a very attractive materials for optoelectronics. In this work we compare the optical properties of (In, Ga)(As, N)/GaAs triple quantum well grown by atmospheric pressure metal organic vapour phase epitaxy. As grown and annealed structures were investigated by means of photoluminescence and contactless electroreflectance spectroscopies. Energies of fundamental transition from each measurement were determined and compared, moreover the value of Stokes shift was assigned and discussed.

The work presents the results of a research carried out with Plasmalab Plus 100 system, manufactured by Oxford Instruments Company. The system was configured for deposition of diamond-like carbon films by ICP PECVD method. The deposition processes were carried out in CH₄ or CH₄/H₂ atmosphere and the state of the plasma was investigated by the OES method. The RF plasma was capacitively coupled by 13.56 MHz generator with supporting ICP generator (13.56 Mhz). The deposition processes were conducted in constant value of RF generator’s power and resultant value of the DC Bias. The power values of RF generator was set at 70 W and the power values of ICP generator was set at 300 W. In this work we focus on the influence of DLC film’s thickness on optical, electrical and structural properties of the deposited DLC films. The quality of deposited DLC layers was examined by the Raman spectroscopy, AFM microscopy and spectroscopic ellipsometry. In the investigated DLC films the calculated sp³ content was ranging from 60 % to 70 %. The films were characterized by the refractive index ranging from 2.03 to 2.1 and extinction coefficient ranging from 0.09 to 0.12.

In this work, results of measurements of surface tension of KOH and TMAH solutions containing alcohol additives were used to assess the behavior of the alcohols during silicon anisotropic etching. Surface tension of KOH and TMAH solutions containing additives of alcohols with one or more hydroxyl groups as well as etching rates and surface roughness of Si(100) and Si(110) surfaces etched in these solutions were analyzed. An improvement in roughness of both the planes was observed after addition of the alcohols to the KOH and TMAH solutions, however reduction of etching rates of Si(110) planes occurred only in KOH solutions. Based on surface tension measurements, it was stated that reduction of etching rates results from selective adsorption of the surface active compound on Si surfaces, which is possible due to adsorption layer formed on the solution surface of KOH etchant. The adsorption layer does not appear in TMAH + alcohols solutions, which accounts for a different behavior of TMAH-based etchants.

In this paper authors present the mechanical, optical and electrical parameters of Indium Tin Oxide (ITO) Transparent Conductive Layers (TCL) deposited on flexible substrate. Layers’ properties are analyzed and verified. Investigated Transparent Conductive Oxide (TCO) was deposited, using magnetron sputtering method. Flexible polymer PET (polyethylene terephthalate) foil was used as a substrate, in order to photovoltaic (PV) cell’s emitter contact application of investigated material. ITO-coated PET foils have been dynamically bent on numerous cylinders of various diameters according to the standard requirements. Resistance changes for each measured sample were measured and recorded during bending cycle. Thermal durability, as well as temperature influence on resistance and optical transmission are verified. Presented results were conducted to verify practical suitability and to evaluate possible applications of Indium Tin Oxide as a front contact in flexible photovoltaic cell structures.

Manufacturing of semiconductor devices consists of many equally significant stages. Every improperly-performed detail may cause abnormal functioning of the device which is very undesirable. Electrical contact manufacturing guarantees the connection between the "inner world" containing phenomena on the molecular level of the device and the "outer world" including connections to other objects and enabling consumer usability. In the following thesis two kinds of pastes containing silver nanoparticles in polymer matrix have been used to make electrical contacts. Performed layers have been compared with sputtering-method made contacts.

Silicon nanowires (SiNWs) have undergone intensive research for their application in novel integrated systems such as field effect transistor (FET) biosensors and mass sensing resonators profiting from large surface-to-volume ratios (nano dimensions). Such devices have been shown to have the potential for outstanding performances in terms of high sensitivity, selectivity through surface modification and unprecedented structural characteristics. This paper presents the results of mechanical characterization done for various types of suspended SiNWs arranged in a 3D array. The characterization has been performed using techniques based on atomic force microscopy (AFM). This investigation is a necessary prerequisite for the reliable and robust design of any biosensing system. This paper also describes the applied investigation methodology and reports measurement results aggregated during series of AFM-based tests.

Reactive magnetron sputtering technique using O₂/Ar gas mixture was used to deposit Gd₂O₃ layers. Following metallization process of Al allowed to create MIS structures, which electrical parameters (κ, D_it, U_FB, ρ, etc.) were measured using high frequency C-V equipment. Created layers exhibit high permittivity (κ≈12) at 100kHz. I-V measurements point out on maximum electric break down field E_br≈0.4 MV/cm and maximum break down voltage U_br ≈ 16V. Layers were morphologically tested using AFM technique (R_a ≈ 0.5÷2nm). Layer thicknesses as well as refractive indexes (RI ≈ 1.50÷2.05) were estimated using ellipsometry measurements.

In-Ga-Zn-O thin films fabricated by reactive RF magnetron sputtering have been investigated for their compositional, structural, morphological, electrical and optical properties. All resulting films present the amorphous microstructure, and root mean square roughness below 0.6 nm. The variation of the oxygen content in the deposition atmosphere from 0% to 0.9% results in the formation of a-IGZO thin films consisting of 15-29% indium, 16-28% gallium, 10-13% zinc and 30-60% oxygen, which significantly differs from the InGaZnO₄ target composition. IGZO thin films present the transmittance in range of 75% to 90% for VIS-NIR wavelengths. Mechanism of free electrons generation via oxygen vacancies formation is proposed to determine the relation between oxygen content in the deposition atmosphere and the transport properties of the IGZO of the thin films.

Thin (100 nm) nanocrystalline dielectric films of lanthanum doped barium titanate were produced on Si substrates by means of reactive impulse plasma ablation deposition (IPD) from BaTiO₃ + La₂O₃ (2 wt.%) target. Scanning electron microcopy and atomic force microscopy showed that the obtained layers were dense ceramics of uniform thickness with average roughness R_a = 2.045 nm and the average grain size of the order of 15 nm. Measurements of current-voltage (IV) characteristics of metal-insulator-semiconductor (MIS) structures, produced by evaporation of metal (Al) electrodes on top of barium titanate films, allowed to determine that the leakage current density and critical electric field intensity (E_BR) of investigated layers ranged from 10^-12 to 10^-6 A cm^-2 and from 0.2 to 0.5 MV cm^-1, respectively. Capacitance-voltage (C-V) measurements of the same structures were performed in accumulation state showing that the dielectric constant value (εri) of films is of the order of 20.

An attempt to investigate the changes of luminance of alternating-current electroluminescent lamps (ACEL) during first 12 hours of operation and the influence of moisture on this process was undertaken. A series of test ACEL lamps was degraded in dry and humid air. The changes were dependent on humidity of storage and working atmosphere.

Over the last few years, ternary and quaternary semiconductor compounds containing (Ga, In) and (N, As) elements become subject of many studies. Both, indium and nitrogen, lowers the band gap of gallium arsenide, but their influence on lattice parameter is compensated. As a result it is possible to deposit epitaxial layers of 1 eV , or less, material which is matched to GaAs substrate. GaAs technology is well known and much cheaper than more sophisticated phosphorus alloys. Optoelectronic devices composed of dilute nitrides materials can be widely used as a telecommunication lasers, photodetectors or even photovoltaic cells. Investigated samples were performed using atmospheric-pressure MOVPE system with AIXTRON AIX200 R-and-D reactor. GaNAs layers were deposited as bulk layers, while GaInNAs material grown as bulk and additionally as quantum wells with GaAs barriers. Gallium arsenide substrates were utilized. Studies were performed utilizing Raman spectroscopy at room temperature. Phonons were excited using 514 nm Ar+ laser. Characteristic for such structures GaN-like local vibrational mode was observed to change its position with changing nitrogen concentration. GaAs-like longitudinal optic phonon also was investigated. As a result an attempt to measure nitrogen concentration in mentioned materials using Raman spectroscopy was performed.

Heterostructures of GaInNAs/GaAs multiple quantum wells were characterized by high resolution x-ray diffraction. Complexity and stress compensating effect of such quaternary alloys cause many characterization problems. One of the most important issue is determination of composition of the material, which cannot be performed utilizing only one characterization method. That is why structural analysis had to be related with optical measurements which give different information correlated with composition. A comparison of theoretical calculations of energy band gap with energy of transitions in GaInNAs QWs from photoluminescence or contactless electro-reflectance measurements supplement the results of HRXRD and gives complete information about the structure required as a feedback to develop technology of heterostructures epitaxial growth.

Progress in quality of ultrathin superconducting niobium nitride films for fabrication technology of single photon detectors is here presented. The films deposited on Al₂O₃ single crystals reveal excellent both superconducting and structure properties but the films deposited on Si single crystals have really worse parameters. High epitaxial quality of NbN and NbTiN films grown on the Al2O3 substrates is proved by HRXRD and HRTEM studies. The results of the studies on both NbN and NbTiN films reveal one cubic NbN phase with NaCl-type structure, and the planes of NbN are correlated with Al₂O₃ crystal orientation. The critical temperatures of NbN and NbTiN films with thickness of few nm grown on the Al₂O₃ and Si substrates are in range 4K ÷ 7K, but post-grown annealing of the films at 1000°C in Ar increases temperature about 10K. Moreover, the NbTiN film deposited on sapphire at optimized conditions and annealed discloses the best superconducting properties - critical temperature of 14 K as well as extremely high critical current density of 12·10⁶ A/cm². This is the best results measured on so thin superconducting films and not reported up to now. The improvement in superconductor parameters is explained here due to reduced strain and defects by high temperature annealing of the film. Structural analysis on the annealed NbTiN films by XRD measurement confirms that FWHM of the 111 Bragg reflection is extremely narrow, about value of 10 arcsec characterising the best single crystals.

In this work we report the recent results of our investigations on synthesis the PMMA composite base on Al₂O₃ doped by ytterbium metal. The set of the Al₂O₃:Yb³⁺ composite samples was manufactured and examined with respect of their structural, physical and mechanical properties. The investigations have confirmed applicability of developed synthesis method to manufacturing of good structural quality, decent level of agglomeration, good homogeneity and good thermal stability consisting of nanoparticles with average size in the range of several tens of nanometers.