Nano-imprint lithography (NIL) is an emerging high-resolution parallel patterning method, mainly aimed towards fields in which high-end photolithography methods are costly and do not provide sufficient resolution at reasonable throughput. High resolution stamp patterning can currently be performed by electron and ion dual beam system. By scanning the focused electron beam (or ion beam) while injecting a suitable organometallic precursor gas around the location of e-beam (or ion beam) and just above the stamp substrate, a high-density and high-uniformity hard mask for subsequent etching without use proximity-effect correction techniques. Furthermore, this technique can also directly deposit a metal pattern for interconnect or a dielectric pattern on NIL stamp without the need for separate metal or dielectric deposition, photoresist etch-mask, and etching processes. FEI Helios Nano Lab™ 1200 and Nova Nano Lab™ 600 dual beam system are used in this work for NIL stamp inspection and fabrication.
Nano-imprinting lithography (NIL) technology, as one of the most promising fabrication technologies, has been demonstrated to be a powerful tool for large-area replication up to wafer-level, with features down to nanometer scale. The cost of resists used for NIL is important for wafer-level large-area replication. This study aims to develop capabilities in patterning larger area structure using thermal NIL. The commercial available Poly (Methyl Methacrylate) (PMMA) and Polystyrene (PS) polymers possess a variety of characteristics desirable for NIL, such as low material cost, low bulkvolumetric shrinkage, high spin coating thickness uniformity, high process stability, and acceptable dry-etch resistance. PMMA materials have been utilized for positive electron beam lithography for many years, offering high resolution capability and wide process latitude. In addition, it is preferable to have a negative resist like PMMA, which is a simple polymer with low cost and practically unlimited shelf life, and can be dissolved easily using commercial available Propylene glycol methyl ether acetate (PGMEA) safer solvent to give the preferred film thickness. PS is such a resist, as it undergoes crosslinking when exposed to deep UV light or an electron beam and can be used for NIL. The result is a cost effective patterning larger area structure using thermal nano-imprint lithography (NIL) by using commercial available PMMA and PS ploymers as NIL resists.
Novel wafer stepper by using contact or proximity printing will be developed, using violet LED light source to replace Hg Arc. lamp or laser. Mirror, filter and condenser lens for Hg Arc. Lamp or laser and reduction lens for projection printing can be discarded. Reliability and manufacturing cost of wafer stepper can be improved. Exposure result by using IP3600 resist and wafer stepper with violet LED light source (wave-length 360nm to 410 nm) will be obtained. This novel wafer stepper can be used for 3DIC, MEMS and bio-chip lithography application by using thin and thick resist with sub-micron to 100 micron thickness.
Nano-pillars pattern on PDMS were fabricated by using highly ordered and density nano-pore arrays of anodic aluminum
oxide film as template. We used cyclohexane to dilute polydimethylsiloxane then filled it to template, the pillars
diameters range from 100 to 200 nm, pillars height about 3 to 5 μm. The morphologies of template membrane and nanopillars
arrays were investigated by scanning electron microscopy and atomic force microscopy. This process offered a
cheaper and easier method to develop a large area and highly ordered nanostructure mold, this mold can be used in a
broad range applications such as, optoelectronic devices, semiconductor devices, bio devices, field emission displays,
data storage and so on.
Gray level 3D resist process were developed by using negative e-beam resist and multiple coating
multiple electron beam wafer direct write alignment, and are now going into be used to create
complex 3D structures in thick resist. Gray level resist process to create 3D structure in thick resist
can be used as mold for manufacturing Fly's-eye lens array, Fresnel lens, Prism, Flat prism and
Light guiding plate. Such optical devices can be used for TFT LCD display, solar concentrator and
Highly ordered and highly density nanopore arrays of anodic aluminum oxide template was prepared by a two-step
anodization method and with the assistance of ultrasonic. Well-aligned nanopore arrays were obtained perpendicular
to the surface of aluminum. The first step anodization was carried out under 0.4 M oxalic acid for one hour, and the
anodized film was removed by chemical etching, than the sample was anodized again for 40 minute under the same
conditions as the first anodization and with ultrasonic. The results of aluminum oxide films were characterized by
scanning electron microscopy, and the microstructure of the anodic aluminum oxide membrane indicating that the
nanochannel arrays prepared with the assistance of ultrasonic are better than those in ordinary way related to the pore
aligned and pore density.
SixNy/Ni thin film green mask blanks were developed , and are now going to be used to replace general chromium film used for binary mask as well as to replace molydium silicide embedded material for AttPSM for I-line (365 nm), KrF (248 nm), ArF (193 nm) and Contact/Proximity lithography. A bilayer structure of a 1 nm thick opaque, conductive nickel layer and a SixNy layer is proposed for binary and phase-shifting mask. With the good controlling of plasma CVD of SixNy under silane (50 sccm), ammonia (5 sccm) and nitrogen (100 sccm), the pressure is 250 mTorr. and RF frequency 13.56 MHz and power 50 W. SixNy has enough deposition latitude to meet the requirements as an embedded layer for required phase shift 180 degree, and the T% in 193, 248 and 365 nm can be adjusted between 2% to 20% for binary and phase shifting mask usage. Ni can be deposited by E-gun, its sheet resistance Rs is less than 1.435 kΩ/square. Jeol e-beam system and I-line stepper are used to evaluate these thin film green mask blanks, feature size less than 200 nm half pitch pattern and 0.558 μm pitch contact hole can be printed. Transmission spectrums of various thickness of SixNy film are inspected by using UV spectrometer and FTIR. Optical constants of the SixNy film are measured by n & k meter and surface roughness is inspected by using Atomic Force Microscope (AFM).
Anodic aluminum oxide (AAO) mask was fabricated by a two-step aluminum anodizing process. Highly ordered through-holes porous anodic alumina film was obtained by oxidation of aluminum in the solution of oxalic or sulfuric acid, that were used as electrolytes. AAO mask possess hexagonally ordered porous structures with narrow size distributions of pore diameters and inter-pore space, we can control the dimensions of the AAO structure such as pore diameter, pore length, and pore density by changing the procedures and conditions of the fabrication process. In this paper, we change the etching condition, such as different kinds of etching solution, concentration of etching solution, and etching time. We hope to find out the adequate conditions to get a suitable pore size of AAO mask for different requirement. AAO mask offers a cheaper and easier method to apply to a large area and highly ordered nanostructure, such as nano-dot arrays, and nano-wire arrays with high aspect ratio, which is quite difficult to be formed by using electron beam lithography and track etching technique.
Nanoimprint technology is placed on the ITRS 04 for the 32nm and 22nm technology node (half pitch of metal 1 layer for DRAM) competing technologies, which can also reach the throughput requirements of SEMI: EUV, DUV, X-ray and Electron projection lithography. Nanoimprint technology can be used for mainstream IC, nanoelectronics, polymer electronics, optics (wave guides, switches, lenses), data storage, biochemistry, life science (DNA), μTAS and
microfluidics. However, the technology key of nanoimprint is stamp fabrication. In this paper, high resolution electron beam resist ZEP520 is used for the fabrication of 32 and 22nm nanoimprint stamp, PDMS material for nanoimprint is evaluated and the applications of nanoimprint technology using PDMS stamp for semiconductor, optoelectronics and biotechnology are presented.
The oldest lithography technique contact/proximity printing are widely used for research activity, most MEMS, Bio-Chip and Optical Electro devices can be fabricated by this method. In this paper, deep submicron 1x mask can be fabricated easily by using e-beam exposure, chemically amplified resist (CAR) and Cr dry etching, a chemical shrink method using dry/wet etching technology was proposed for nanofabrication by using Cr film as hard mask. Micro channel for biochip as well as micro lens for Optical Electro devices can easily be fabricated on glass and quartz substrates by this method.