化学法多晶硅生产工艺研究进展

随着能源危机的不断加剧,太阳能作为可再生能源已成为关注的焦点。从国内外多晶硅的生产状况,综述了化学法多晶硅的生产工艺,重点分析比较了几种潜在工业应用的流化床法生产多晶硅工艺的特点,指出未来多晶硅生产应当以流化床法为主,并耦合其它相关技术。同时展望了未来化学法生产多晶硅的发展趋势。     

Electrical characteristics of Pt-SBT-Polysilicon (MFIP) capacitors with yttrium oxide as the buffer layer

Abstract

MFIS structures with Strontium Bismuth Tantalate (SBT) as the ferroelectric thin film and yttrium oxide as the buffer layer have been fabricated on polysilicon layer as well single crystal silicon. Yttrium oxide film was deposited by electron beam evaporation and SBT was deposited by spin on MOD technique. Preliminary analysis of capacitance vs voltage (C-V) curve shows hysteresis and the direction of hysteresis corresponds to ferroelectric polarization. For an applied DC bias of ± 5 V, the C-V curve shows a memory window of ± 2 V.     

多晶硅生产中氢气的来源与净化

简述了多晶硅生产过程中氢气的几个来源,并比较了采用电解、裂解或工业尾气净化回收氢气作为多晶硅生产补充氢气来源的技术、经济性。提出了采用特定吸附剂,变压吸附净化回收可重复利用氢气的新方法。对比了几种氢气的净化回收技术的优势,认为采用变压吸附（PSA）氢气净化工艺过程最优,能耗最低,经济效益最好。     

冶金法太阳能级多晶硅的制取

硅行业是个有着复杂产业链的行业,而工业硅产业是整个硅产业链中的源头产业和基础产业;多晶硅及光伏产业是最具发展前景和近一、二年发展最快的产业。工业硅产业和多晶硅及光伏产业是同属于硅产业链的上下游产品行业,彼此存在着数量和质量间紧密的制约关系。     

Tunnelling piezoresistive effect of grain boundary in polysilicon nano-films

The experiment results indicate that the gauge factor of highly boron doped polysilicon nanofilm is bigger than that of monocrystalline silicon with the same doping concentration, and increases with the grain size decreasing.To apply the unique properties reasonably in the fabrication of piezoresistive devices, it was expounded based on the analysis of energy band structure that the properties were caused by the tunnel current which varies with the strain change forming a tunnelling piezoresistive effect. Finally, a calculation method of piezoresistance coefficients around grain boundaries was presented, and then the experiment results of polysilicon nanofilms were explained theoretically.     

一种新型半绝缘键合SOI结构

报道了一种新型半绝缘键合SOI结构,采用化学气相淀积加外延生长键合过渡多晶硅层的方法实现了该结构.研制出的这种新结构,完整率大于85%,Si-Si键合界面接触比电阻小于5×10-4Ω·cm2.这种新结构可以广泛用于高低压功率集成电路、高可靠集成电路、MEMS、硅基光电集成等新器件和电路中.     

Ni金属诱导晶化非晶硅(a-Si:H)薄膜

对在氢化非晶硅薄膜（a-Si：H）上溅射金属Ni的样品进行金属诱导晶化（MIC）／金属诱导横向晶化（MILC），制备多晶硅薄膜（p-Si）的上艺及薄膜特性进行了研究。XRD测最结果表明非晶硅在500℃退火1h后就已经全部晶化。金属诱导晶化的优选晶向为（220）．而且晶粒随退火时间的延长而长大。非晶硅薄膜样品500℃下退火6h后的扫描电镜照片显示，原金属镍覆盖区非晶硅全部晶化．晶粒均匀．平均晶粒大小约为0．3μm，而且已经发生横向晶化。EDS测试Ni在晶化的非晶硅薄膜中的原子百分含量分析表明，金属Ni在MILC过程中的作用只是催化晶化．除了少量残留在MILC多晶硅中外．其余的Ni原子都迁移至晶化的前沿。500℃下退火20h后样品的Raman测试结果也表明．金属离子向周边薄膜扩散．横向晶化了非晶硅薄膜。     

我国硅产业发展需审慎

冶炼硅需消耗大量能源,并排放很多有害气体和粉尘,与当前世界各国重视气候变暖的低碳经济相悖。对我国硅产业的发展现状、消费领域和产业发展中存在的问题进行了剖析,提出了切实可行的解决方案。     

多晶硅纳米薄膜电学特性的实验研究

用低压化学气相淀积(LPCVD)法淀积了膜厚为60～250nm的多晶硅纳米薄膜,研究了膜厚和掺杂浓度对多晶硅纳米薄膜电学特性的影响。结合扫描电镜(SEM)图片,在电阻率与电阻率温度系数测试结果的基础上,分析了膜厚和掺杂浓度对薄膜电学特性的影响。结果表明:重掺杂多晶硅纳米薄膜具有良好的温度特性,电阻率温度系数可达到1×10-4～3×10-4/℃的水平。