KrF准分子激光移相光刻在HEMT栅加工中的应用

将KrF准分子激光无铬接触式移相光刻应用于深亚微米HEMT栅图形加工，自行设计、组装了一套实验系统，很好地解决了这一器件制作的关键工艺问题。分别采用石英版移相和衬底移相方式，可重复可靠地得到剖面陡直的（0．30—0．35）μm和（0．2—0．25）μm胶阴线条，这一工艺技术完全与现有器件工艺技术兼容，为HEMT深亚微米栅加工提供了一个新的可供选择的方法，文中还从计算机模拟角度对上述两种移相光刻方式作了分析。     

光源步进扫描实现大面积光刻

介绍了一种大面积接近、接触式光刻的新方法,通过光源步进拼接扫描提供一个高均匀度的大面积的照明光源。主要论述了小面积扫描单元的形状及步进扫描拼接原理、应用及其优点,分析了扫描面的不均匀度。     

用近贴式软X射线光刻术研究DCPA光刻胶的曝光性能

采用软X射线近贴式光刻术,对DCPA光刻胶的曝光性能进行了系统研究,得到了一些新的实验结果。     

Effect of nanobubbles on friction forces between hydrophobic surfaces in water

Micro- and nanoscale combined hierarchical polymer structures were fabricated by UV-assisted capillary force lithography. The method is based on the sequential application of engraved polymer molds with a UV-curable resin of polyurethane acrylate (PUA) followed by surface treatment with a trichloro(1H,1H,2H,2H-perfluorooctyl) silane in vapor phase. Two distinct wetting states were observed on these dual-roughness structures. One is “Cassie–Wenzel state” where a water droplet forms heterogeneous contact with microstructures and homogeneous contact with nanostructures. The other is “Cassie–Cassie state” where a droplet makes heterogeneous contact both with micro- and nanostructures. A simple thermodynamic model was developed to explain static contact angle, hysteresis, and wetting transition on dual-roughness structures.     

Spatiotemporal sub-cellular biopatterning using an AFM-assisted electrochemical system

The integration of electrochemical-based biolithography (ECBL) with an ordinary atomic force microscope (AFM) enables in situ lithography adjacent to a single, cultured cell, consequently allowing the morphological shape of the cell to be manipulated. The tip of a commercially available AFM cantilever was modified to serve as an electrode that could generate the oxidant HBrO for local, controlled etching of a cytophobic material (heparin or albumin) previously layered adjacent to a living cell. A NIH-3T3 fibroblast, initially confined to a patterned area, extended along a bioadhesive surface that had been newly exposed using the ECBL-AFM system.     

Surface-energy-anisotropy-induced orientation effects on Rayleigh instabilities in sapphire

Arrays of controlled-geometry, semi-infinite pore channels of systematically varied crystallographic orientation were introduced into undoped m-plane sapphire substrates using microfabrication techniques and ion-beam etching and subsequently internalized by solid-state diffusion bonding. A series of anneals at 1700 °C caused the breakup of these channels into discrete pores via Rayleigh instabilities. In all cases, channels broke up with a characteristic wavelength larger than that expected for a material with isotropic surface energy, reflecting stabilization effects due to surface-energy anisotropy. The breakup wavelength and the time required for complete breakup varied significantly with channel orientation. For most orientations, the instability wavelength for channels of radius R was in the range of 13.2R-25R, and complete breakup occurred within 2-10 h. To first order, the anneal times for complete breakup scale with the square of the breakup wavelength. Channels oriented along a direction had a wavelength of ≈139R, and required 468 h for complete breakup. Cross-sectional analysis of channels oriented along a direction showed the channel to be completely bounded by stable c(0 0 0 1), , and facets.     

光学光刻的极限

讨论了光学光刻技术的各种分辨力增强技术(RETs),根据各类光刻设备的开发进展,探讨了光学光刻技术的加工极限。     

IC制造工艺与光刻对准特性关系的研究

针对光刻对准特性,从单项工艺和工艺集成的角度,分析了影响光刻对准的各个主要因素,包括对准标记、工艺层、隔离技术等,提出了一些改善光刻对准效果的方法。     

Selective formation of silicon nanowires on pre-patterned substrates

In this paper, the selective growth of silicon nanowires (SiNWs) was studied. With the aid of photolithography, the vertically aligned silicon nanowires were selectively formed on the patterned substrates via an electroless metal deposition (EMD) method under normal conditions (room temperature, 1 atm). Low-pressure chemical vapor deposition (LPCVD) silicon nitride was used as the masking layer for SiNWs preparation. The scanning electron microscope was used to examine the etching results. Both the patterned and the unpatterned silicon substrates were used for study. The results indicated that the growth rates of the SiNWs upon the patterned and the unpatterned substrates are different. For the patterned substrates, the growth rate of SiNWs is dependent upon the pattern shape. The influence of length-to-width ratio for the rectangular-shaped patterns was studied. It is concluded that by designing the proper length-to-width ratio, the nanowires with different lengths can be fabricated simultaneously on the same substrate.     

Surface plasmon resonance in near-field coupled gold cylinder arrays fabricated by EUV-interference lithography and hot embossing

Arrays of metal nanoparticles with nanometer-scale gaps between the particles is highly interesting for plasmonic field enhancement applications. We report a simple method to fabricate arrays of closely spaced Au particles with inter-particle separation down to 20 nm. We used extreme ultraviolet interference lithography (EUV-IL) and a mechanical press to fabricate two-dimensional arrays of Au nanoparticles. Lithographically produced particle arrays were modified by hot pressing in a nanoimprint machine and the gap was varied in a range from 50 nm to below 20 nm. Optical measurement shows two resonances at 520 nm and 620 nm, with the latter gaining strength as the gap is reduced. The experimental and theoretical investigations using a FDTD algorithm demonstrate that the low-energy resonance can be assigned to a collective surface plasmon resonance arising from the strong near-field coupling between the nanoparticles. Surface Enhanced Raman Spectroscopy (SERS) experiments performed on a model molecule (BPE) show a large gain in signal intensity as a result of the reduced gaps between the particles.