负性化学放大胶的光刻模型及模拟

在Ferguson的负性化学放大胶（CAR）后烘反应动力学模型基础上，增加了后烘过程中光致酸扩散模型，通过后烘模型的简化，得到了简化的后烘反应扩散动力学模型。将模拟图形与Ferguson的实验图形进行了比较，结果显示，简化的后烘反应扩散动力学模型比单纯的后烘反应动力学模型更准确，且程序运行占用的电脑资源更少。另外，通过不同曝光时间下的显影过程模拟，清晰地反映了光刻胶显影的过程，其结果与实际相符，对实际光刻工艺有较好的参考意义。     

电子束液态曝光技术的甩胶原理研究

在研究液体抗蚀剂受力分析的基础上，对液体抗蚀荆的甩胶原理，甩胶后抗蚀剂的液面形状、抗蚀剂涂层厚度与抗蚀剂黏度和马达转速之间的关系等进行了研究。结果表明，涂层表面形状为平面；随着马达转速的增加，涂层厚度逐渐减小；而随着抗蚀剂黏度的增大，涂层厚度却逐渐增大。在此基础上，以Epoxy618为液体抗蚀剂进行了甩胶实验，得出了不同黏度下的转速．厚度曲线，验证了研究结果的正确性。最后给出了3μm厚的液体抗蚀剂Epoxy618经SDS—Ⅱ型电子束曝光机曝光后固化所得线条的JXA-8800R电子探针图。     

电子束三维光刻技术的研究

在IH(Integrated Harden Polymer Stereo Lithography)技术和电子束光刻技术的基础上提出了电子束微三维光刻技术新概念。对其实现方法的可行性进行了简要的理论分析，并使用SDV—Ⅱ型真空腔在约1．33Pa的真空下对环氧618、WSJ-202和苏州2号抗蚀剂进行了气化试验，得出了它们在真空中的气化实验结果，证明了电子束液态光刻的可行性。     

浸没式光刻向22nm挺进

简述了光学光刻技术在双重图形曝光、高折射率透镜材料及浸没介质、32nm光刻现状及22nm浸没式光刻技术的进展,指出了光学光刻技术的发展趋势及进入22nm技术节点的前景。     

Anomalous acid diffusion in a triphenylene molecular resist with melamine crosslinker

Next generation lithography will require next generation resists. Molecular resists, based on small non-polymeric molecules, promise improvements in line width roughness and resolution control for high resolution lithographic patterns. However, these materials are generally not sensitive enough for commercial application. We have investigated the application of a common chemical amplification scheme to molecular resists. The triphenylene derivative C5/C0 (symmetrical 2,6,11-trihydroxy-3,7,11-tris(pentyloxy)triphenylene), mixed with the crosslinker hexamethoxymethyl melamine and the photoacid generator triphenylsulfonium triflate shows a substantial sensitivity enhancement, requiring a dose of only 5 μC/cm² compared with the pure triphenylene sensitivity of 6500 μC/cm² at 20 keV. Previous work has indicated that the acid diffusion length of the photoacid generator used here is around 350 nm and that the diffusion length decreases with film thickness. However, in this molecular resist system anomalous levels of acid diffusion were observed, indicating that previous results for polymeric systems may not hold true for these new materials. Initial results indicate that the acid diffusion length in this system may be on the order of microns. Furthermore, there is some evidence that the excessive diffusion is occurring in the surface layers of the resist or at the air: resist interface itself.     

Multifaceted and Nanobored Particle Arrays Sculpted Using Colloidal Lithography

A novel method of fabricating multifaceted and nanobored particle arrays via colloidal lithography using colloidal‐crystal layers as masks for anisotropic reactive‐ion etching (RIE) is reported. The shape of the sculpted particles is dependent on the crystal orientation relative to the etchant flow, the number of colloidal layers, the RIE conditions, and the matrix (or mask) structure in colloidal lithography. Arrays of non‐spherical particles with sculpted shapes, which to date could not otherwise be produced, are fabricated using a tilted anisotropic RIE process and the layer‐by‐layer growth of a colloidal mask. These non‐spherical particles and their ordered arrays can be used for antireflection surfaces, biosensors, and nanopatterning masks, as well as non‐spherical building blocks for novel colloidal crystals. In addition, polymeric particles with patterned holes of controlled depths obtained by the present method can be applied to the fabrication of functional composite particles.     

电子束曝光UV3正性抗蚀剂的工艺研究

为了在体硅CMOSFinFET中用等离子体腐蚀精细凹槽图形，研究了将电子束直写曝光用于原为深紫外光学曝光的UV3正性抗蚀剂的工艺技术；详细分析了包括膜厚、曝光能量、曝光剂量、显影时间、设计尺寸和衬底材料等在内的各类工艺参数与实际曝光图形效果的关系；特别指出了曝光过程中特有的延迟效应及解决办法。采用最终的优化工艺条件，得到了合适的图形效果。     

离子束曝光技术

论述了离子束曝光技术的原理、特点，分析了其面临的关键技术问题，如掩模技术、离子源技术、图像对准技术等，并介绍了这些年来国外的一些研究机构及公司在离子束曝光技术上的研究进展及取得的一些新结果。     

类锂硅离子的软X射线放大

本文描述了最近进行的复合泵浦类锂硅离子软X射线激光增益实验结果。利用1m消像散掠入射光栅谱仪拍摄了平面硅靶线聚焦激光等离子体在5～12nm波长范围里的光谱。利用线聚焦激光等离子体轴向和非轴向光谱的时间积分强度比求得Si~(11+)5f-3d(8.89nm)和5d-3p(8.73nm)跃迁的增益系数分别为1.4和0.9cm~(-1);用轴向强度随线聚焦激光等离子体长度的变化得到离靶面300μm处的增益系数分别为1.5和1.4cm~(-1)。     

Microfabrication processes on cylindrical substrates - Part II: Lithography and connections

Cylindrical microfabrication offers the opportunity to fabricate electrical or mechanical devices around the surfaces of cylinders. Standard processes developed for planar substrates such as silicon wafers must be adapted to curved surfaces. This paper focuses on lithography of and connections to cylinders. Results from lithographic testing includes dose exposure curves using laser and electron beam sources as well as the minimal effects of surface curvature on linewidth. Bonding included ultrasonic wedge bonding, silver epoxy, and solder paste. Electrical and mechanical characteristics of these bonding methods are presented.     

Fabrication and electrical performance of high-density arrays of nanometric silicon tips

We propose and demonstrate a simple and low cost process for the fabrication of large area arrays of nanometric silicon tips, for use as Field Emission Devices (FEDs). The process combines Interference Lithography (IL) with isotropic Reactive Ion Etching (RIE). Si tips with typical curvature radius of 20 nm and height of 900 nm were recorded with a periodicity of 1 μm (density of 10⁶ tips/mm²) covering a Silicon wafer of 2 in. The measurement of the electrical performance of the arrays demonstrates the feasibility of the association of these two techniques for recording Field Emission Tips.     

Auger electron spectroscopy study of reactive ion etched silicon carbide

Reactive ion etching (RIE) of bulk 4H-SiC based on CHF₃-O₂ plasma was studied by varying the rf power and process pressure. The elements on the etched surface and the surface roughness were characterized by Auger electron spectroscopy and atomic force microscopy, respectively. It was found that the surface roughening is mainly caused by Al contamination and C rich layer (C residues) induced micromasking effect. The micromasking effect is in turn determined by the dc self-bias developed at the substrates. A threshold dc self-bias exists at around −320 to −330 V, beyond which no micromasking effect was observed. This observation is explained in terms of physical ion bombardment and sputtering in the RIE process.     

Junction solar cells made with molecular beam glow discharge bombardment

The fabrication and characterization of silicon p-n junction solar cells with various glow discharge, unanalyzed, molecular implanted emitter regions is described. Total area simulated air mass one (AM1) power conversion efficiencies without AR coatings or back surface fields are at best 8.2% compared to 9.1% for conventionally implanted or POC1₃ thermally diffused cells on similar substrates. To achieve optimum performance, Q-switched ruby laser light was incorporated into the molecular implant annealing procedure. Conversion efficiencies greater than 8% were achieved with the four dopants BC1₃, PC1₃ AsF₃ and POC1₃. For similar processing, conversion efficiency with BF₃ implants was less than those of previous investigations, most likely due to poor crystalline regrowth of the heavily doped emitter regions. Cell quantum efficiency and mesa junction ideality are shown to be similar to those of conventional cells while molecular implant sheet resistance values varied, generally being directly related to the dopant molecular weight. Work submitted in partial fulfillment of Ph.D. in Electrical Engineering at the Univ. of Missouri, Columbia, MO 65211     

Improved photovoltaic properties of amorphous silicon thin-film solar cells with an un-doped silicon oxide layer

This paper proposes the use of undoped hydrogenated microcrystalline silicon oxide (μc-SiO_x:H) deposited on the n-μc-Si:H layer of amorphous silicon single-junction superstrate configuration thin-film solar cells produced through 40 MHz very high frequency plasma-enhanced chemical vapor deposition. Raman spectroscopy and optoelectronic analyses of the undoped μc-SiO_x:H thin film revealed that adding a small amount of oxygen into a μc-network results in a low optical absorption, wide band gap, high optical band gap E₀₄, high refractive index, reasonable conductivity, and crystalline volume fraction, which are advantageous properties in solar cells. Compared with a standard cell, the current density–voltage (J–V) characteristics of the cell with an undoped μc-SiO_x:H/n-μc-Si:H structure showed an enhancement in short-circuit current density J_sc from 13.32 to 13.60 mA/cm², and in conversion efficiency from 8.53% to 8.61%. The increased J_sc mechanism can be attributed to an improved light-trapping capability in the long wavelength range between 510 and 660 nm, as demonstrated by the external quantum efficiency.     

New method for boron removal from silicon by electron beam injection

A new method for boron removal from silicon using electron beam injection (EBI) is proposed. After thermal oxidation on monocrystalline silicon (100) wafer at 1000 °C for 1 h, EBI was used to induce thermal and negative charging effects to enhance boron diffusion in the oxide film and the silicon substrate. This facilitates boron removal from the silicon substrate. The boron concentration in samples was measured by secondary ion mass spectrometry. The results show that EBI reduced the boron concentration in the silicon substrate by 4.83%.     

Micro-patterning of LiPON and lithium iron phosphate material deposited onto silicon nanopillars array for lithium ion solid state 3D micro-battery

The paper deals with the methodology used to form regular pattern of sputtered thin films LiPON/LiFePO₄ material acting respectively as the solid electrolyte and the positive electrode of the lithium ion solid state 3D micro-battery. The micromachining of the silicon periodic nanopillars array (negative electrode of the micro-battery) is also reported. The proposed study clearly demonstrates a breakthrough technology in the field of lithium ion micro-battery as the ecologically friendly LiFePO₄ material has never been evaluated as the positive electrode.     

Electron beam induced current investigations of active electrical defects in silicon due to reactive ion etching and reactive ion beam etching processes

Reactive ion etching and reactive ion beam etching are common tools for anisotropic etch processes in silicon microdevice fabrication; but, unfortunately, they also create radiation damage in the etched surface. We have studied the electrically active defects by measuring the recombination of carriers with the help of the electron beam induced current (EBIC) mode of a secondary electron microscope. We have measured the temperature behavior of the samples by annealing studies and the temperature dependent EBIC signal for several p-doped silicon wafers and obtained different shaped curves. Theoretical EBIC models developed with the assumption of a reduced net carrier concentration in the etched areas agree with our experimental results.     

缩小投影电子束曝光机的调试技术

详细介绍了在透射电镜上进行缩小投影电子束曝光技术原理性实验的主要调试过程。它充分利用了透射电镜本身的功能与特点。整个调试方法不仅可获得高分辨率图形，而且为下一步的研究工作提供了比较好的工作参数。     

低温纳米压印技术制备微纳图案的研究

纳米压印需要将聚合物加热到它的玻璃化温度以上,然后用印章压印使其复制印章图案.采用低玻璃化温度的SU-82000.1和Hybrane胶体转移图案,能够在低温、甚至室温下实现微纳图案的转移.采用的印章制备方法是聚焦离子束(FIB)直接在衬底上制备图案,从而避免了传统工艺中效率较慢的电子束加工和取消了反应离子刻蚀步骤;并且采用FIB方法可同时在衬底上制备微米、纳米尺度的图案.实验结果表明用FIB方法可以得到比较均匀致密的微纳米图案印章,经过低温纳米压印后可成功地实现微纳图案的复制.     

Complexing of nitrogen with carbon and oxygen in silicon: Photoluminescence studies

We study interactions of nitrogen with carbon and oxygen in crystalline silicon by photoluminescence spectroscopy. Such processes manifest themselves in five photoluminescence lines in the spectral region around 1.6 μm emerging after nitrogen and carbon implantations and furnace annealing with 550° C optimum temperature. Nitrogen and carbon isotope shifts of the lines confirm the incorporation of these atomic species in the optical defects. Nitrogen-oxygen interactions are demonstrated by differences in the lines’ appearance between oxygen-lean float-zone and oxygen-rich pulled silicon starting materials. The data suggests similar basic nitrogen-carbon units in all five defects.