Thirty years ago, when I began working in lithography for semiconductor manufacturing, the bellwether of our industry was DRAM. Resolution was defined by the smallest DRAM half-pitch, and our technology nodes were named after DRAM densities. DRAM costs often determined the affordability of a personal computer, and everyone wanted more memory. By the 1990s, microprocessors began to dominate the business, and the frequency wars pushed gate length as the most important feature size (smaller gate lengths meant faster transistors). Logic gate lengths shrank faster than pitch, and two resolution measures were needed: minimum feature size and minimum half pitch. Nodes came to be named after the feature size.

This year marks the second year of the Special Section on Alternative Lithographic Technologies. Our issue features papers on emerging lithographic technologies that are potentially both cost-effective and scalable to high-volume manufacturing (HVM).

Poly(styrene)-block-poly(methylmethacrylate) (PS-b-PMMA) block-copolymers (BCP) systems synthesized on an industrial scale and satisfying microelectronic’s requirements for metallic contents specifications are studied in terms of integration capabilities for lithographic applications. We demonstrate in particular that this kind of polymer can efficiently achieve periodic features close to 10 nm. These thin films can be transferred in various substrates through dry-etching techniques. The self-assembly optimization for each polymer is first performed on freesurface, leading to interesting properties, and the changes in self-assembly rules for low molecular-weight polymers are investigated and highlighted through different graphoepitaxy approaches. The improvements in self-assembly capabilities toward low periodic polymers, as well as the broad range of achievable feature sizes, make the PS-b-PMMA system very attractive for lithographic CMOS applications. We conclude by showing that high-χ polymer materials developed in Arkema’s laboratories can be efficiently used to reduce the pattern’s size beyond the ones of PS-b-PMMA based BCP’s capabilities.

We report on the development of a new measurement method, resonant critical-dimension small-angle x-ray scattering (res-CDSAXS), for the characterization of the buried structure of block copolymers (BCP) used in directed self assembly (DSA). We use resonant scattering at the carbon edge to enhance the contrast between the two polymer blocks and allow the determination of the three-dimensional shape of the native lamella in a line–space pattern by CDSAXS. We demonstrate the method by comparing the results from conventional CDSAXS to res-CDSAXS on a 1:1 DSA BCP sample with a nominal 50-nm pitch. The res-CDSAXS method provides substantially improved uncertainty in the fit of the line shape and allows the determination of the buried structure.

Extremely large-area roll-to-roll (R2R) manufacturing on flexible substrates is ubiquitous for applications such as paper and plastic processing. It combines the benefits of high speed and inexpensive substrates to deliver a commodity product at low cost. The challenge is to extend this approach to the realm of nanopatterning and realize similar benefits. In order to achieve low-cost nanopatterning, it is imperative to move toward high-speed imprinting, less complex tools, near zero waste of consumables, and low-cost substrates. We have developed a roll-based J-FIL process and applied it to a technology demonstrator tool, the LithoFlex 100, to fabricate large-area flexible bilayer wire-grid polarizers (WGPs) and high-performance WGPs on rigid glass substrates. Extinction ratios of better than 10,000 are obtained for the glass-based WGPs. Two simulation packages are also employed to understand the effects of pitch, aluminum thickness, and pattern defectivity on the optical performance of the WGP devices. It is determined that the WGPs can be influenced by both clear and opaque defects in the gratings; however, the defect densities are relaxed relative to the requirements of a high-density semiconductor device.

The lithographic requirements for the thin film head (TFH) industry are comparable to the semiconductor industry for certain parameters such as resolution and pattern repeatability. In other aspects such as throughput and defectivity, the requirements tend to be more relaxed. These requirements match well with the strengths and weaknesses reported concerning nanoimprint lithography (NIL) and suggest an alternative approach to optical lithography. We demonstrate the proof of concept of using NIL patterning, in particular Jet and Flash™ Imprint Lithography (J-FIL™) (Imprio, Jet and Flash Imprint Lithography, and J-FIL trademarks are the property of Molecular Imprints, Inc.), to build functional TFH devices with performance comparable to standard wafer processing. An Imprio™ 300 tool from Molecular Imprints, Inc. (MII) was modified to process the AlTiC ceramic wafers commonly used in the TFH industry. Templates were produced using commercially viable photomask manufacturing processes and the AlTiC wafer process flow was successfully modified to support NIL processing. Future work is identified to further improve lithographic performance including residual layer thickness uniformity, wafer topography, NIL→NIL overlay, and development of a large imprint field that exceeds what is available in optical lithography.

Arrays of metal nanoparticles, typically gold or silver, exhibit localized surface plasmon resonance, a phenomenon that has many applications, such as chemical and biological sensing. However, fabrication of metal nanoparticle arrays with high uniformity and repeatability, at a reasonable cost, is difficult. Nanosphere lithography (NSL) has been used before to produce inexpensive nanoparticle arrays through the use of monolayers of self-assembled microspheres as a deposition mask. However, control over the size and location of the arrays, as well as uniformity over large areas is poor, thus limiting its use to research purposes. In this paper, a new NSL method, called here geometrically confined NSL (GCNSL), is presented. In GCNSL, microsphere assembly is confined to geometric patterns defined in photoresist, allowing high-precision and large-scale nanoparticle patterning while still remaining low cost. Using this new method, it is demonstrated that 400 nm polystyrene microspheres can be assembled inside of large arrays of photoresist patterns. Results show that optimal microsphere assembly is achieved with long and narrow rectangular photoresist patterns. The combination of microsphere monolayers and photoresist patterns is then used as a deposition mask to produce silver nanoparticles at precise locations on the substrate with high uniformity, repeatability, and quality.

The digital pattern generator (DPG) is a complex electron-optical MEMS that pixelates the electron beam in the reflective electron beam lithography (REBL) e-beam column. It potentially enables massively parallel printing, which could make REBL competitive with optical lithography. The development of the REBL DPG, from the CMOS architecture, through the lenslet modeling and design, to the fabrication of the MEMS device, is described in detail. The imaging and printing results are also shown, which validate the pentode lenslet concept and the fabrication process.

IMS Nanofabrication realized a 50 keV electron multibeam proof-of-concept (POC) tool confirming writing principles with 0.1 nm address grid and lithography performance capability. The POC system achieves the predicted 5 nm 1 sigma blur across the 82  μm×82  μm array of 512×512 (262,144) programmable 20 nm beams. 24-nm half pitch (HP) has been demonstrated and complex patterns have been written in scanning stripe exposure mode. The first production worthy system for the 11-nm HP mask node is scheduled for 2014 (Alpha), 2015 (Beta), and first-generation high-volume manufacturing multibeam mask writer (MBMW) tools in 2016. In these MBMW systems the max beam current through the column is 1 μA. The new architecture has also the potential for 1× mask (master template) writing. Substantial further developments are needed for maskless e-beam direct write (EBDW) applications as a beam current of <;2  mA is needed to achieve 100 wafer per hour industrial targets for 300 mm wafer size. Necessary productivity enhancements of more than three orders of magnitude are only possible by shrinking the multibeam optics such that 50 to 100 subcolumns can be placed on the area of a 300 mm wafer and by clustering 10 to 20 multicolumn tools. An overview of current EBDW efforts is provided.

A primary limitation in nanoimprint lithography is lack of alignment consistency between multiple fields. Simultaneous imprinting of several fields is highly desirable for enhanced throughput, yet placement errors in template fabrication and other factors limit field-to-field accuracy. Here, we describe a method to improve overlay simultaneously across many fields via continuous, in situ control of localized temperature distributions. In this method, interferometric moiré alignment signals from an array of microscopes are analyzed to form a map of distortion and control the distribution of heat in real time. Thermal cross-talk between fields is minimized using a microchannel wafer chuck. We demonstrate simultaneous operation of feedback loops that stabilize alignment over a 100-mm span to 0.5 nm (3σ).

Bit-patterned media (BPM) fabrication sets a high bar for nanopatterning especially in the aspects of lithography resolution and pattern transfer. Directed self-assembly (DSA) of spherical block copolymers (BCPs) provides promising pattern resolution extendibility and pattern layout flexibility as long as proper pre-pattern designs are provided. Polystyrene-block-polydimethylsiloxane in the form of monolayered spheres is used as a vehicle to form either globally densely packed nanodot arrays in the data zone or locally densely packed nanodot arrays in the servo zone on a BPM template. Skew compatibility of spherical BCPs is also discussed. The BCP dot template is then applied as the scaffold for pattern transfer into quartz to make a nanoimprint mold and further into magnetic storage media. Distributions of both dot sizes and dot spacings are closely monitored after DSA pattern formation and pattern transfer.

Going “beyond the CMOS information-processing era,” taking advantage of quantum effects occurring at sub-10-nm level, requires novel device concepts and associated fabrication technologies able to produce promising features at acceptable cost levels. Herein, the challenge affecting the lithographic technologies comprises the marriage of down-scaling the device-relevant feature size towards single-nanometer resolution with a simultaneous increase of the throughput capabilities. Mix-and-match lithographic strategies are one promising path to break through this trade-off. Proof-of-concept combining electron beam lithography (EBL) with the outstanding capabilities of closed-loop electric field current-controlled scanning probe nanolithography (SPL) is demonstrated. This combination, whereby also extreme ultraviolet lithography (EUVL) is possible instead of EBL, enables more: improved patterning resolution and reproducibility in combination with excellent overlay and placement accuracy. Furthermore, the symbiosis between EBL (EUVL) and SPL expands the process window of EBL (EUVL) beyond the state of the art, allowing SPL-based pre- and post-patterning of EBL (EUVL) written features at critical dimension levels with scanning probe microscopy-based pattern overlay alignment capability. Moreover, we are able to modify the EBL (EUVL) pattern even after the development step. The ultra-high resolution mix-and-match lithography experiments are performed on the molecular glass resist calixarene using a Gaussian e-beam lithography system operating at 10 keV and a home-developed SPL setup.

As design rule shrinks, it is essential that the capability to detect smaller and smaller defects should improve. There is considerable effort going on in the industry to enhance immersion lithography using directed self-assembly (DSA) for the 14-nm design node and below. While the process feasibility is demonstrated with DSA, material issues as well as process control requirements are not fully characterized. The chemical epitaxy process is currently the most-preferred process option for frequency multiplication, and it involves new materials at extremely small thicknesses. The image contrast of the lamellar line/space pattern at such small layer thicknesses is a new challenge for optical inspection tools. The study focuses on capability of optical inspection systems to capture DSA unique defects such as dislocations and disclination clusters over the system and wafer noise. The study is also extended to investigate wafer-level data at multiple process steps and to determine the contribution from each process step and materials using defect source analysis methodology. The added defect pareto and spatial distributions of added defects at each process step are discussed.

Nanopatterning of an ecofriendly antiglare film derived from biomass using an ultraviolet curing nanoimprint lithography is reported. Developed sugar-related organic compounds with liquid glucose and trehalose derivatives derived from biomass produced high-quality imprint images of pillar patterns with a 230-nm diameter. Ecofriendly antiglare film with liquid glucose and trehalose derivatives derived from biomass was indicated to achieve the real refraction index of 1.45 to 1.53 at 350 to 800 nm, low imaginary refractive index of <0.005 and low volumetric shrinkage of 4.8% during ultraviolet irradiation. A distinctive bulky glucose structure in glucose and trehalose derivatives was considered to be effective for minimizing the volumetric shrinkage of resist film during ultraviolet irradiation, in addition to suitable optical properties for high-definition display.

One of the major concerns with nanoimprint lithography is defectivity. One source of process-specific defects is associated with template separation failure. The addition of fluorinated surfactants to the imprint resist is an effective way to improve separation and template lifetime. This study focuses on the development of new reactive fluorinated additives, which function as surfactants and also have the ability to chemically modify the template surface during the imprint process and thereby sustain a low surface energy release layer on the template. Material screening indicated that the silazane functional group is well suited for this role. The new reactive surfactant, di-(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl)silazane (F-silazane) was synthesized and tested for this purpose. The material has sufficient reactivity to functionalize the template surface and acceptable stability (and thus shelf-life) in the imprint formulation. Addition of F-silazane to a standard imprint resist formulation significantly improved template release performance and allowed for significantly longer continuous imprinting than the control formulation. A multiple-imprint study using an Imprio® 100 tool confirmed the effectiveness of this new additive.

Superresolving configurations that integrate two digital mirror devices (DMDs) in the aperture and/or in the intermediate image plane are presented. The usage of DMDs allows obtaining geometric resolution improvement, enhancing field of view (FOV), and reducing aberrations such as defocusing and blurring (obtained due to relative movement during the integration time of the camera). The idea behind all the above-mentioned applications is to use the DMDs to properly encode the space and the spatial frequency domains such that the object’s information can be separated from the above mentioned aberrations, distortions, limitations, and noises. The compressed sensing concept is applied in order to allow capturing in time-less images than the obtainable improvement factor (of resolution, of FOV, or of aberration correction).

Lithography has been faced with a challenge to bring resolution down to the 10-nm level. One of the promising approaches for such ultra-high-resolution printing is self-imaging Talbot lithography with extreme ultraviolet (EUV) radiation. However, as the size of structures on the mask approaches the wavelength of the radiation, diffraction influence needs to be evaluated precisely to estimate the achievable resolution and quality of the patterns. Here, the results of finite-difference time-domain simulations of the diffraction on EUV transmission masks in dependence to the period (pitch) of the mask are presented with the aim to determine the resolution that can be realistically achieved with the EUV Talbot lithography. The modeled experimental setup is utilizing partially coherent EUV radiation with the wavelength of 10.9 nm from Xe/Ar discharge plasma EUV source and Ni/Nb-based amplitude transmission mask. The results demonstrate that the method can be used to produce patterns with resolution down to 7.5-nm half-pitch with 2∶1 mask demagnification utilizing achromatic Talbot effect and transverse electric (TE)-polarized light.

The advance of lithographic resolution has made it necessary to adopt extremely thin photoresist films for the fabrication of “2× nm” structures in order to mitigate problems such as resist collapse during development but limiting achievable etch depths at the same time. By using multilayer hardmask stacks, a considerable increase in achievable aspect ratio is possible. We have previously presented a fullerene-based spin-on carbon hardmask material capable of high-aspect-ratio etching. We report our latest findings in material characterization of an original and a modified formulation. By using a higher adduct derivative fullerene, the solubility in industry-friendly solvents and thermal stability could be improved. The etching performance and materials characteristics of the new higher-adduct fullerene hardmask were found to be comparable to those of the original hardmask.

The resist filling behavior is crucial to the quality of the final imprinted pattern in micro/nanolithography. To obtain resist flow fields, a three-dimensional (3-D) defocusing digital particle image velocimetry (DDPIV) system was set up to realize the visualization of the resist filling process. Three-dimensional motion trajectories and velocity vectors of tracer particle sets were calculated to characterize this microscale flow phenomena. The results show that the particles’ maximum velocity is located in the region below the mold corner, and the region leans to the mold cavity. Meanwhile, the squeezed resist will first move along the mold moving direction, and then fills the mold cavity in an upward moving tendency when it passes through the mold corner. The feasibility of using the DDPIV system to investigate the resist filling behavior was confirmed. The results will help to understand the resist filling behavior and provide useful instruction for the selection of process parameters and mold structure optimization.

Multioriented bilayer nanowire polarizers are integrated with photodetectors using only one-time nanoimprint lithography and metal deposition process. In order to keep the position of peak external quantum efficiency of the photodetector unchanged, the bilayer nanowire polarizer is designed to have the highest transmission at 440 nm. The photodetector is integrated with the polarizer after surface treatment. The performance of the fabricated device is then tested, and three characteristics are realized: light-intensity sensitive, polarization sensitive, and blue-light sensitive. The proposed integration method simplified the fabrication process, and the fabricated device avoids the alignment error which would be produced by using discrete elements. The results demonstrate that the proposed integration process is a promising method for fabricating photodetectors with polarization function.

Photoresist development rate can be defined microscopically (the development rate at a point) or macroscopically (the propagation rate of an average resist height). In the presence of stochastic noise, these two rates will be different. In order to properly calibrate lithography simulators, the difference between these two definitions of development rate should be quantified. Using theoretical derivations and a stochastic (Monte Carlo) development simulator, the propagation rate of a resist surface is characterized in the presence of stochastic variation in the resist deprotection concentration and a nonlinear development rate response. The resulting propagation rate (macroscopic development rate) can be more than an order of magnitude higher than for the case of no stochastic noise. Correlation in the development rate creates an effective surface inhibition over a depth into the resist proportional to the correlation length, with results that are qualitatively different for two-dimensional versus three-dimensional simulations. The differences between microscopic and macroscopic dissolution rate can have an important effect on how development rate models should be calibrated, depending on their use in continuum or stochastic lithography simulators.

A microcapillary pumped loop (MCPL) utilizing a two-phase heat transport has been investigated extensively because of its high heat transmission ability. Although the MCPL has been started up successfully, the initial amount of working liquid required to fill the system is so hard to control that the repeat operation of MCPL is not easy to initiate. In addition, the issue of Newton ring often occurs in the thermal bonding process of the chip and even causes the device to crack. An innovative method of micromatrix posts is proposed and confirmed by experiment for eliminating the initial filling and Newton’s ring effectively. This proposed method will be useful in the operation of MCPL and all thermal bonding of microchips.

We present a dynamic electrical balancing of coupling stiffness for improving the bias stability of micromachined gyroscopes, which embeds the coupling stiffness in a closed-loop system to make the micromachined gyroscope possess more robust bias stability by suppressing the variation of coupling stiffness. The effect of the dynamic electrical balancing control is theoretically analyzed and implemented using a silicon micromachined gyroscope as an example case. It has been experimentally shown that, comparing with open loop detection, the proposed method increased the stability of the amplitude of the mechanical quadrature signal by 38 times, and therefore improved the bias stability by 5.2 times from 89 to 17  deg/h , and the temperature stability of scale factor by 2.7 times from 622 to 231  ppm/°C . Experimental results effectively indicated the theoretical model of dynamic electrical balancing of coupling stiffness.

Photolithography for patterns with periodicity in the illumination plane (2.5-D lithography) has seen rapid advances over the past decade, with the introduction of holographic lithography and the further development of phase-contrast and grayscale photolithography methods. However, each of these techniques suffers from substantial difficulties preventing further integration into device fabrication: a lack of parallel processing capabilities and dimension limitations. Here, we present a demonstration of controlled layer topography through modulation of both the exposure dose and exposure focal plane yielding reproducible 2.5-D patterns which are applied to the further development of plasmonic gratings. This process is entirely compatible with commercially available i -line photolithography and etch hardware, enabling a path to ready integration.

With extreme ultraviolet lithography (EUVL) emerging as one of the top contenders to succeed from optical lithography for the production of next generation semiconductor devices, the search for suitable resists that combine high resolution, low line edge roughness (LER) and commercially viable sensitivity for high volume production is still ongoing. One promising approach to achieve these goals has been the development of molecular resists. Here we report our investigations into the EUV lithographic performance of a molecular fullerene resist showing resolution down to 20-nm half-pitch with interference lithography with a LER of <5  nm and sensitivity of about 20  mJ/cm ².

A contact hole shrink process using directed self-assembly lithography (DSAL) for sub-30 nm contact hole patterning is reported on. DSAL using graphoepitaxy and poly (styrene-block-methyl methacrylate) (PS-b -PMMA) a block copolymer (BCP) was demonstrated and characteristics of our process are spin-on-carbon prepattern and wet development. Feasibility of DSAL for semiconductor device manufacturing was investigated in terms of DSAL process window. Wet development process was optimized first; then critical dimension (CD) tolerance of prepattern was evaluated from three different aspects, which are DSA hole CD, contact edge roughness (CER), and hole open yield. Within 70+/−5  nm hole prepattern CD, 99.3% hole open yield was obtained and CD tolerance was 10 nm. Matching between polymer size and prepattern size is critical, because thick PS residual layer appears at the hole bottom when the prepattern holes are too small or too large and results in missing holes after pattern transfer. We verified the DSAL process on a 300-mm wafer at target prepattern CD and succeeded in patterning sub-30 nm holes on center, middle, and edge of wafer. Average prepattern CD of 72 nm could be shrunk uniformly to DSA hole pattern of 28.5 nm. By the DSAL process, CD uniformity was greatly improved from 7.6 to 1.4 nm, and CER was also improved from 3.9 to 0.73 nm. Those values represent typical DSAL rectification characteristics and are significant for semiconductor manufacturing. It is clearly demonstrated that the contact hole shrink using DSAL is a promising patterning method for next-generation lithography.

Monolithic fabrication of continuous facesheet high-aspect ratio gold microelectromechanical systems (MEMS) deformable mirrors (DMs) onto a thermally matched ceramic–glass substrate (WMS-15) has been performed. The monolithic process allows thick layer deposition (tens of microns) of sacrificial and structural materials thus allowing high-stroke actuation to be achieved. The fabrication process does not require wafer bonding to achieve high aspect ratio three-dimensional structures. A gold continuous facesheet mirror with 3.4 nm surface roughness has been deposited on a 16×16 array of X-beam actuators on a 1-mm pitch. A stroke of 6.4 μm was obtained when poking two neighboring actuators. Initial electrostatic actuation displacement results for a high-aspect ratio gold MEMS DM with a continuous facesheet will be discussed.

Due to the rich information provided by the Mueller matrices when the most general conical diffraction configuration is considered, the Mueller matrix polarimetry has demonstrated a great potential in semiconductor manufacturing. As the configurations of the incidence and azimuthal angles have different influences on the measurement accuracy, it is necessary to select an optimal one among the multitude of possible options. We introduce the norm of a configuration error propagating matrix to assess the measurement accuracy for different measurement configurations. The optimal configuration for a Si grating sample was achieved by minimizing the norm of the configuration error propagating matrix. Experimental results show the agreement between the theoretically predicted optimal configuration and the experimental exhibited one obtained by using a dual-rotating compensator Mueller matrix polarimeter and thus demonstrated the validity of the proposed optimization method.

Overlay control is becoming increasingly more important with the scaling of technology. It has become even more critical and more challenging with the move toward multiple-patterning lithography, where overlay translates into CD variability. Design rules and overlay have strong interaction and can have a considerable impact on the design area, yield, and performance. We study this interaction and evaluate the overall design impact of rules, overlay characteristics, and overlay control options. For this purpose, we developed a model for yield loss from overlay that considers overlay residue after correction and the breakdown between field-to-field and within-field overlay; the model is then incorporated into a general design-rule evaluation framework to study the overlay/design interaction. The framework can be employed to optimize design rules and more accurately project overlay-control requirements of the manufacturing process. The framework is used to explore the design impact of litho-etch litho-etch double-patterning rules and poly line-end extension rule defined between poly and active layer for different overlay characteristics (i.e., within-field versus field-to-field overlay) and different overlay models at the 14-nm node. Interesting conclusions can be drawn from our results. For example, one result shows that increasing the minimum mask-overlap length by 1 nm would allow the use of a third-order wafer/sixth-order field-level overlay model instead of a sixth-order wafer/sixth-order field-level model with negligible impact on design.

Our recent study reveals that the propagation of a phase defect (PD) from an extreme ultraviolet mask substrate surface through a multilayer does not always propagate in a vertical direction. To fully understand the propagation model of PDs, two types of defects on a quartz (Qz) substrate are prepared. One is space patterns fabricated by a mask patterning process followed by an etching giving a cross-sectional angle of 90 deg. The others are atomic force microscopy scratched space patterns with their cross-sectional angles as 30 deg and 60 deg. After coating a patterned Qz substrate with a multilayer, propagation of PDs through the multilayer was observed by a transmit electron microscope (TEM). As a result, the TEM images clearly exhibit a tendency that originates from the Qz substrate while the PDs propagate through the multilayer and their propagation path is inclined toward the center of the mask. The impacts of the inclination angles on the printed images on a wafer are calculated using a simulator. A PD with an inclination angle of 1 deg corresponds to a positional shift of 1 nm on a printed wafer image.

Measurement of the power spectral density (PSD) of a rough surface or a feature involves large random and systematic errors. While random errors can be reduced by averaging together many PSDs, systematic errors can be reduced only by carefully studying and understanding the sources of these systematic biases. Using both analytical expressions and numerical simulations for the measurement of the PSD of line-edge roughness, four sources of systematic errors are evaluated: aliasing, leakage, averaging, and image noise. Exact and approximate expressions for each of these terms are derived over a range of roughness exponents, allowing a measured PSD to be corrected for its systematic biases. In the absence of image noise, the smallest measurement bias is obtained when appropriate data windowing is used and when the sampling distance is set to twice the measurement signal width. Uncorrected PSD measurements are likely to systematically bias each of the PSD parameters, with the roughness exponent especially susceptible to bias.

Specimen alignment is critical for the accuracy and the reliability of micro-tensile testing. A vernier-groove carrier fabricated by bulk micromachining of silicon is developed. Through the vernier in the carrier the alignment accuracy can be detected, and the groove and the convex stands guarantee rapid alignment and high repeatability. In order to demonstrate the validity of the carrier, a micro-tensile specimen integrated with piezoresistive cells is designed. The specimen can detect axial alignment precision and tensile force simultaneously. The performances of the carrier and the specimen are tested by using a micro-tensile tester. By comparing the measured results of micro-tensile testing with the carrier and without the carrier, it is confirmed that high alignment precision and high repeatability can be obtained by the carrier. For the specimen, the sensitivity coefficient of the piezoresistive cells for tensile force measurement is equal to 0.017  mV/mN .

The datapath throughput of electron beam lithography systems can be improved by applying lossless image compression to the layout images and using an electron beam writer that contains a decoding circuit packed in single silicon to decode the compressed image on-the-fly. In our past research, we had introduced Corner2, a lossless layout image compression algorithm that achieved significantly better performance in compression ratio, encoding/decoding speed, and decoder memory requirement than Block C4. However, it assumed a somewhat different writing strategy from those currently suggested by multiple electron beam (MEB) system designers. The Corner2 algorithm is modified so that it can support the writing strategy of an MEB system.

Although microfluidic devices that integrate microfluidic chips with hollow out-of-plane microneedle arrays have many advantages in transdermal drug delivery applications, difficulties exist in their fabrication due to the special three-dimensional structures of hollow out-of-plane microneedles. A new, cost-effective process for the fabrication of a hollow out-of-plane Ni microneedle array is presented. The integration of PDMS microchips with the Ni hollow microneedle array and the properties of microfluidic devices are also presented. The integrated microfluidic devices provide a new approach for transdermal drug delivery.

Recently, microgrippers are finding more importance in the field of tissue engineering and microassembly in semiconductor electronics. Large force and, hence, large displacement, low power, and low temperature are the essential features to be considered during the design of the microgrippers. The electrical and mechanical behaviors of electrothermally actuated silicon microgrippers are presented. The effect of increasing the flexure length and the cold arm area to improve the displacement is discussed. These microgrippers are normally of the open type, in which the arms have an initial open gap of 20 μm, and they move away from each other with the applied voltage. The displacement of each arm is observed to be 24 μm for the applied voltage of 10 V. The response time of the device is less than 5 ms, and the maximum power dissipation is 110 mW. The displacement of the microgrippers can be increased with increased flexure length and cold arm length with short extended arms. This structure also shows lower stress.