直拉重掺硼硅单晶的研究进展

系统介绍了直拉重掺硼(B)硅单晶研究的最新进展。主要内容包括重掺B硅单晶的基本性质，利用重掺B籽晶进行无缩颈硅单晶生长技术，重掺B硅单晶的机械性能，重掺B硅单晶中的氧和氧沉淀，以及B的大量掺杂与大直径直拉硅单晶中空洞型(Void)原生缺陷的控制关系。在此基础上，探讨了当前直拉重掺B硅单晶生产和研究中存在的主要问题。     

高阻探测器级硅单晶

高阻探测器级硅单晶是制备核辐射探测器等特种器件必不可少的原材料,是硅单晶中的尖端品种。其纯度极高,制备难度很大。我们从多晶硅的纯度,高阻硅单晶的制备技术及高纯工艺、高阻硅单晶电学参数的测量等几方面进行了研究。几年来,陆续向国内有关单位提供了小批量p型、电阻率高于2×10~4Ω·cm的硅单晶。现已研制出一批p型电阻率高于4×10~4Ω·cm的硅单晶。     

纵向磁场拉制硅单晶的工艺研究

用常规CZ法拉制的硅单晶质量与VLSI对材料的要求有较大差距。MCZ法可以抑制硅熔体的热对流,因而改变了硅单晶的氧含量和其他性能。作者采用VMCZ法详细地研究了磁场对硅熔体波动、温度起伏的影响,进而研究了磁场对热场分布、磁场对硅单晶中杂质的分布、磁场对硅单晶中氧、碳含量、磁场对硅单晶中微缺陷等的影响。发现:VMCZ的结果与资料报导的HMCZ数据相比有较大差别。通过调整拉晶参数也只能有限度地改善硅单晶的性能。     

北京有色研究总院拉制出直径200mm的硅单晶

北京有色研究总院国家半导体材料工程研制中心继1992年拉制出第一根直径为150mm硅单晶后,日前又拉制出直径为200mm的硅单晶,这标志我国硅单晶制造技术取得新的进步。 半导体材料硅是电子信息技术的基础,被国家列为高新技术发展的重点。这根直径为200mm的硅单晶为N型,重达56kg。加大硅单晶直径,历来被认为是提高硅片产量、降低成本的有效措施,技术难度也相应     

氧沉淀对直拉硅单晶硬度的影响

研究了氧沉淀对直拉(CZ)硅单晶维氏硬度的影响.研究表明,在发生一定程度氧沉淀的情况下,硅单晶的硬度会由于氧沉淀导致的间隙氧浓度的降低而减小,此时间隙氧原子的固溶强化作用对硅单晶硬度具有显著的影响;而当氧沉淀足够显著时,由于氧沉淀的密度和尺寸较大,氧沉淀在硅单晶中的第二相强化作用得以显现,此时硅单晶的硬度不随间隙氧浓度的降低而减小,反而有较为显著的提高.     

日本研究提高硅单晶少子寿命的最新进展

众所周知,硅单晶中的少子寿命是评价硅单晶质量的重要参数之一,因而找出影响少子寿命的主要因素,从而提高少子寿命是一个具有重要意义、又很热门的课题。最近日本电报和电话大众公司发表了一篇科研报告,介绍少子寿命是与硅单晶中的氧沉淀密切有关,并深入地定量讨论了它们之间的关系。在直拉硅单晶中,由于氧浓度较高,所以硅单晶在生长后的冷却过程中或以后的热     

探测器级NTD硅单晶的研制

介绍了探测器级NTD硅单晶的制作工艺 ,并对如何保证探测器级NTD硅单晶的质量进行了讨论。     

科技简讯

我国第一台直拉大直径硅单晶炉诞生大直径硅单晶是发展大觇模集成电略的关键材科,用大直径硅单晶切制硅片可以提高生产率和材科利用率,从而降低成本。为把我国硅单晶材料的生产提高到一个新的水平,上海有色金属研究所自行设计、自行制造了一台高达6.5米的大直径硅单晶炉,为拉制大直径硅单晶准备了条件。经调试和投料11公斤试拉表明,各项性能均达到预定的指际:投料量可达16公斤以上,真空度达10~(-5)乇,温度控制情度达±0.5℃,可用于高真空、低真尘、充氩或     

上海市举行上海市企业标准《硅单晶》审定会

在国家标准总局的指导下,在上海市经委、科委的领导下,上海市企业标准《硅单晶》审定会于1981年2月底在上海第二冶炼厂举行。与会代表115人,他们来自领导机关、主管部门、硅单晶与器件生产单位、科研单位、高等院校及报刊杂志等。代表们认为上海地区硅单晶的生产形势很好,20多年来,我市硅单晶的产量在国内占有较大比     

直拉法生长硅单晶时采用减压工艺与气体导流

直拉硅单晶历来都是在真空或氩气氛条件下生长的。在真空中生长,有利于杂质挥发,但电阻率不易控制;在氩气氛条件下生长,则恰好相反,但需消耗大量氩气。特别在硅单晶生产进入大容量化之后,氩气的消耗是相当惊人的。如果高纯氩气的售价不能大幅度下降,硅单晶的成本也就无法降低。另外,直拉硅单晶工艺中用到石英坩埚。石英即二氧化硅,在熔硅与石英的反应中势必有大量氧被溶解,从而增加了硅单晶中的氧     

Growth of ZnO Single Crystal by Chemical Vapor Transport Method

ZnO crystals were grown by CVT method in closed quartz tube under seeded condition. Carbon was used as a transport agent to enhance the chemical transport of ZnO in the growth process. ZnO single crystals were grown by using GaN/sapphire and GaN/Si wafer as seeds. The property and crystal quality of the ZnO single crystals was studied by photoluminescence spectroscopy and X-ray diffraction technique.     

Low-temperature electrical characteristics of the Au/Si interface

An investigation has been conducted on the irregular electrical behavior of eutectic and polyimide die-attached NMOS devices at low temperatures. The nature of the Au/Si interface on the back side of each die is the focus of this study. A test structure consisting of alloyed gold films on both sides of the wafer was fabricated. Models of the structure were proposed to explain the observed low-temperature behavior. The Au/Si interface was assumed to be a Schottky junction. This assumption was confirmed in conjunction with measurements on another test structure which consists of Au on the back side and Al on the front side. It had been suspected that contamination introduced from the eutectic die-attach materials was solely responsible for the observed behavior. However, tests conducted on heat-treated polyimide die-attached NMOS devices produced similar observation. Solutions to the problem were discussed and a simple technique to eliminate the rectifying behavior of Au/p-Si contacts was described.     

Si/Nanocrystalline Diamond Film Heterojunction Diodes Preparation

With electron assisted hot filament chemical vapor deposition technology, nanocrystalline diamond films were deposited on polished n-(100)Si wafer surface. The deposited films were characterized and observed by Raman spectrum, X-ray diffraction, semiconductor characterization system and Hall effective measurement system. The results show that with EA-HFCVD, not only an undoped nanocrystalline diamond films with high-conductivity (p-type semiconducting) but also a p-n heterojunction diode between the nanocrystalline diamond films and n-Si substrate is fabricated successfully. The p-n heterojunction has smaller forward resistance and bigger positive resistance. The p-n junction effective is evident.     

Lattice distortion of holmium doped bismuth ferrite nanofilms

Single-phase multiferroic BiFeO3 and rare-earth metal of holmium （Ho） doped BiFeO3 nanofilms were prepared on Pt （100）/Ti/SiO2/Si wafer via solution-gelation technique. It was suggested that the lattice distortion happened with the lattice parameter of d decreasing after doping rare-earth metal of Ho. Meanwhile, the structure of nanofilms transformed from hexahedron phase to tetragonal phase after doping Ho. The analysis on X-ray photoelectron spectroscopy （XPS） indicated that the ratio of Fe3~ cations to Fe2＋ cations increased with the increase of binding energy between Fe and O and decrease of that between Bi and O after doping Ho. The present work provided an available way on enhancing multiferroic of BiFeO3 nanofilms.     

Nanocrystalline Diamond Films Deposited by Electron Assisted Hot Filament Chemical Vapor Deposition

Nanocrystalline diamond films were deposited on polished Si wafer surface with electron assisted hot filament chemical vapor deposition at 1 kPa gas pressure, the deposited films were characterized and observed by Raman spectrum, X-ray diffraction, atomic force microscopy and semiconductor characterization system. The results show that when 8 A bias current is applied for 5 h, the surface roughness decreases to 28.5 nm. After 6 and 8 A bias current are applied for 1 h, and the nanocrystalline films deposition continue for 4 h with 0 A bias current at 1 kPa gas pressure. The nanocrystalline diamond films with 0.5×109 and 1×1010 Ω·cm resistivity respectively are obtained. It is demonstrated that electron bombardment plays an important role of nucleation to deposit diamond films with smooth surface and high resistivity.     

非掺半绝缘LEC-GaAs晶片热处理工艺研究

为了获得高质量半绝缘砷化镓单晶片．有必要降低微缺陷密度，开展了晶片热处理工艺的研究．确定了晶片热处理的温度、时间、降温建率等一系列工艺参数，证实丁采用此项工艺能降低LEG-GaAs晶片的砷沉淀密度，郎AB-EPD，同时也保证了晶片的电学参数不受影响。通过对晶片热处理工艺过程和结果进行分析．给出了晶片热处理工艺理论模型的解释。     

Fabrication and selective surface modification of 3-dimensionally textured biomedical polymers from etched silicon substrates

A new method is described for producing biomedically relevant polymers with precisely defined micron scale surface texture in the x, y, and z planes. Patterned Si templates were fabricated using photolithography to create a relief pattern in photoresist with lateral dimensions as small as 1 micron. Electroless Ni was selectively deposited in the trenches of the patterned substrate. The Ni served as a resilient mask for transferring the patterns onto the Si substrate to depths of up to 8.5 microns by anisotropic reactive ion etching with a fluorine-based plasma. The 3-dimensional (3-D) textured silicon substrates were used as robust, reusable molds for pattern transfer onto poly (dimethyl siloxane), low density poly (ethylene), poly (L-lactide), and poly (glycolide) by either casting or injection molding. The fidelity of the pattern transfer from the silicon substrates to the polymers was 90 to 95% in all three planes for all polymers for more than 60 transfers from a single wafer, as determined by scanning electron microscopy and atomic force microscopy. Further, the 3-D textured polymers were selectively modified to coat proteins either in the trenches or on the mesas by capillary modification or selective coating techniques. These selectively patterned 3-D polymer substrates may be useful for a variety of biomaterial applications.     

高温氩退火对直拉CZ硅单晶中空洞型微缺陷的影响

研究了高温氩退火对大直径直拉硅单晶中晶体原生粒子缺陷(COP)的消除作用.分别在不同温度和保温时间下进行退火,然后利用表面扫描检测系统SPI测量退火前后硅片表面COP的密度变化,来表征退火对COP的消除作用.研究发现,在1200℃退火2h能够显著降低硅单晶表面区域的COP密度,并且随着退火时间的延长COP的密度降低得越多.然后,把所有的退火硅片抛去不同的厚度,检测COP在厚度上的分布,进而得出退火对COP消除的有效距离为0～10 μm.因此,可以得到高温氩退火只能够消除硅片表面的COP缺陷,而对于硅片内部的这些缺陷影响较小.     

Immunoassays based on surface-enhanced infrared absorption spectroscopy

A new type of biosensor for pathogens has been developed. The sensor produces spectral fingerprints of biological systems by using surface-enhanced infrared absorption (SEIRA) spectroscopy. Antibodies were immobilized onto a 10-nm-thick film of gold which had been previously deposited on a Si wafer. SEIRA spectra of the antibodies measured in the external reflection mode exhibited two new bands at 1085 and 990 cm-1. These new bands were observed with p-polarized radiation but were absent with s-polarized radiation. The spectrum of water on the surface of the sensor was observed under both directions of polarization. The sensor was first tested with a model system consisting of glucose oxidase (GOX) and the antibodies for glucose oxidase (anti-GOX). In addition to the bands due to the anti-GOX at 1085 and 990 cm-1, new bands were observed at 1397, 1275, and 930 cm-1 when the GOX antigens were present. The same type of sensor was prepared for Salmonella (SAL) by immobilizing antibodies for Salmonella (anti-SAL) on a gold-surfaced Si water. The SEIRA spectra for anti-SAL antibodies were very similar to those for anti-GOX, with bands at 1085 and 990 cm-1; however, a sharp new band was observed at 1045 cm-1 after the sensor was exposed to the SAL antigens. In addition to specific new bands due to antigens, both GOX and SAL sensors exhibited changes in the regions of water absorptions at approximately 3500 and 850 cm-1 when the antigens were present.     

晶体硅太阳能电池用硅片制备工艺及关键技术

多晶硅片或单晶硅片是光伏产业链中太阳能电池片生产的基板材料,近年光伏产业的迅猛发展极大促进了硅片制造技术和装备的飞速发展,文章介绍了当前晶体硅太阳能电池用硅片制备的主要工艺,并对其中的关键技术及发展状况进行了论述。