Radiation-Induced Decomposition of Water on the BeO Surface

Radiation-induced decomposition of water in the BeO-adsorbed H₂O system at room temperature (T = 300 K) under the conditions of γ-irradiation for different times was studied by Fourier IR spectroscopy. The water adsorption onto BeO was found to occur by the molecular and dissociative mechanisms. Intermediate active products of radiation-induced heterogeneous decomposition of water, beryllium hydrides and hydroxy groups, were detected. The highest radiation-chemical yield of molecular hydrogen, G(H₂), was reached at the BeO particle size d ≤ 4 μm.

     

硅应力非均匀氧化影响因素及其在纳米孔制作中的应用

在微等离子体无掩模加工研究中,单晶硅在分布应力作用下的非均匀氧化现象决定了采用各向同性刻蚀得到氧化硅空心针尖纳米孔的可行性和可靠性.以V型槽为对象,研究了单晶硅在槽尖端的非均匀氧化现象.利用高温下氧化硅的黏弹性特性,建立了硅在几何约束导致的分布应力作用下的热氧化模型.该模型表明,应力通过抑制氧元素在氧化硅层中的扩散和氧化反应速率来抑制氧化进行,从而非均匀的应力分布造成了非均匀的氧化层厚度.实验证明,硅在应力作用和几何约束下的热氧化,当氧化层厚度仅为160 nm时,不同温度下的厚度非均匀性基本一致,为72%左右;而当氧化厚度增长为1.1μm时,低温与高温下的厚度非均匀性差距显著增大,分别为42%和100%.分析表明,氧化层厚度非均匀性是应力生成与应力释放过程的综合作用结果,受到氧化温度和氧化时间两个可控因素的共同影响.在此基础上,利用硅在950℃下10 h的应力非均匀氧化及后续稀释氢氟酸的各向同性刻蚀成功制作出空心针尖阵列尖端直径为50 nm~200 nm的纳米孔.     

Impurity Distribution in Multicrystalline Silicon Growth

This paper presents experimental data on the growth of multicrystalline silicon with tailored electrical properties using starting silicon of purity better than 99.999 at %. Our calculations demonstrate that the effective distribution coefficients of Fe-group impurities decrease with increasing impurity concentration in the starting charge.     

一种硅表面化学清洗方法

本文介绍了一种温和简洁的硅表面化学清洗方法，它主要包括H2SO4：H2O2溶液清洗和HF：C2H5OH刻蚀两个过程。清洗前后的硅表面用原子力显微镜（AFM）、X射线光电子能谱（XPS）和反射高能电子衍射（RHEED）等技术进行表征。结果表明，运用此方法能得到平整清洁的Si表面。为了延缓H-Si表面在空气中被氧化的速率和防止杂质污染，我们提出用无水乙醇（C2nsOH）来保护H-Si表面。300℃除气前后XPS的对比结果表明，清洗后的Si表面不存在B，但吸附少量F，以及化学吸附和物理吸附都存在的C和O。根据Si2p芯能级的同步辐射光电子能谱（SRPES），可以确定Si氧化物薄膜的厚度只有一个单层，经1000℃退火25min后，XPS和SRPES的结果表明Si表面已经非常清洁，并且出现了两个Si的表面态。     

晶体硅电池表面钝化的研究进展

随着晶体硅太阳电池技术的不断发展,硅片的厚度不断降低,电池表面钝化对提高太阳能电池转化效率变得尤为重要。本文介绍了表面钝化膜在晶体硅太阳电池中的应用,以及几种晶体硅电池表面钝化方法,包括等离子体增强化学气相沉积法、氢化非晶硅、热氧化法、原子层沉积法以及叠层钝化,并分别介绍了它们在应用上的优缺点。分析了制备钝化膜过程中存在的问题,并提出了相应措施及发展趋势。表面钝化技术是提高晶体硅电池转换效率最有效的手段之一,今后晶体硅电池表面钝化技术仍将是国内和国际研究的热点之一。     

Experimental Determination of the Nonuniform Shape-Induced Anisotropy Field in Thin Ni–Fe Films

We have determined the nonuniform distribution of the shape-induced magnetic anisotropy field for patterned thin films of Ni-Fe. To do this, we used integrated microstrip structures with different widths on identically patterned Ni-Fe cores to act as probes of the internal magnetic field. We verified the accuracy of the field profiles by comparing them with M-H loop measurements of the magnetic films     

Temperature Dependence of Spectral Characteristics of Silicon Photodiodes in the Ultraviolet Region

Methods, measurement results, and mechanisms for the temperature dependence of the spectral sensitivity of silicon photodiodes in the ultraviolet region are examined.     

六甲基二硅胺烷对纳米二氧化硅表面改性的研究

以六甲基二硅胺烷(HMDS)为改性剂,氮气为保护气,对纳米二氧化硅表面进行改性研究,并通过粘度测定、红外光谱分析等手段对改性的效果进行评价.结果显示,在本实验所考察的范围内,反应温度为100℃,偶联剂用量为12mL时,改性效果最好.     

线切割单晶硅表面损伤的研究

利用台阶仪、扫描电镜（ＳＥＭ）和Ｘ射线双晶衍射仪,研究了线切割硅片和内圆切割硅片的表面切割损伤和损伤层厚度。实验指出线切割硅片表面粗糙度大,外表面损伤大,但损伤层的厚度要小于常规内圆切割硅片。初步讨论了影响线切割硅片表面损伤的原因     

Assessment of the Stress Sensitivity of Magnetostriction in Grain-Oriented Silicon Steel

This paper describes a novel, versatile system for measuring the stress sensitivity of magnetostriction of Epstein strips of grain-oriented electrical steel, an analysis of results of measurements on several grades of commercial material, and an attempt to relate their stress sensitivity characteristics to material properties. The maximum value of peak magnetostriction under applied stress is proportional to the strip gauge for both conventional and high permeability grades of material. A model explains the contributions of retained stress and stress due to the forsterite coatings on grain-oriented silicon steel. This model can be used to correlate the thickness of the fosterite coating to its calculated coating stress. It is also possible to separate the effect of the phosphate and forsterite coatings. Both types of coating set up a longitudinal stress in the steel in proportion to their thickness.     

Al-Zn-Mg-Cu-Sc-Zr系富Al角相图评估

总结了近年来Al-Zn-Mg-Cu-Sc-Zr六元系相图的发展情况,分析了Al-Zn-Mg-Cu-Sc-Zr六元系中富铝角存在的中间相Al3Sc、Al3Zr、Al3(Sc1-xZrx)、W相(ScCu6.6～4Al5.4～8)、T相((Al,Zn,Cu)49 Mg32、Mg3Zn3Al2)、M相(或η相、MgZn2)及它们的相结构,概述了Sc、Zr添加对Al-Zn-Mg-Cu合金的有益作用,指出了Al-Zn-Mg-Cu-Sc-Zr六元相图的价值和研究方向.     

Nb-Mo-W-Zr-C系富Nb角相图评估

综述了Nb-Mo-W-Zr-C系富Nb角相图的研究情况,分析了Nb-Mo-W-Zr-C系富Nb角中存在的中间相NbC、Nb2C、(Nb,Mo,W,Zr)C、W2Zr、M02Zr、(W,Mo)2Zr等以及它们的相结构,概述了添加Zr、C对含W、Mo的α(Nb)合金的有益作用,指出了Nb-Mo-W-Zr-C系富Nb角相图的价值和研究方向.     

硅钢绝缘涂层的研究进展

本文系统介绍了取向硅钢与无取向硅钢表面绝缘涂层，包括有机涂层、无机涂层和半无机涂层三大类。无机涂层具有良好的耐热和焊接性能，但其冲制性和粘结性不佳。半无机涂层具有良好的冲制性和粘结性，但其耐热性和焊接性不及无机涂层。另外，最新研究的取向硅钢表面物理气相沉积ＴｉＮ、ＣｒＮ和ＴｉＣ绝缘涂层可使硅钢获得极低的铁损，大大提高了硅钢的磁通量密度，并具有优异的耐热、焊接、冲制和粘结性。     

Bidirectional Reflectance Distribution Function of Rough Silicon Wafers

The trend towards miniaturization of patterning features in integrated circuits (IC) has made traditional batch furnaces inadequate for many processes. Rapid thermal processing (RTP) of silicon wafers has become more popular in recent years for IC manufacturing. Light-pipe radiation thermometry is the method of choice for real-time temperature monitoring in RTP. However, the radiation environment can greatly affect the signal reaching the radiometer. The bidirectional reflectance distribution function (BRDF) of rough silicon wafers is needed for the prediction of the reflected radiation that reaches the radiometer and for reflective RTP furnace design. This paper presents the BRDF measurement results for several processing wafers in the wavelength range from 400 to 1100 nm with the spectral tri-function automated reference reflectometer (STARR) at the National Institute of Standards and Technology (NIST). The rms roughness of these samples ranges from 1 nm to 1 m, as measured with an optical interferometric microscope. Correlations between the BRDF and surface parameters are obtained using different models by comparing theoretical predictions with experiments.     

PCVD法对碳化硅陶瓷的表面改性研究

利用等离子辉光放电化学气相沉积技术（ＰＣＶＤ），控制甲烷与磋烷质量流量比、硅烷与氨质量流量比，在碳化硅基体表面分别沉积上无定形碳化硅和氨化硅薄膜，研究其膜的组成、沉积工艺、厚度等对碳化硅陶瓷的强度改性影响．在一定的沉积条件下沉积的碳化硅薄膜可以使基体强度提高２０％达到８５０ＭＰａ，沉积氮化硅薄膜使强度提高３０％达到９００ＭＰａ，改性的效果很明显．     

光敏染料的键合及其对单晶硅的光敏化作用

用卤化法将噻－２＇－菁光敏染料共价键合于单晶硅表面。测定了键合染料硅片的表面光电压，结果表明，键合光敏染料噻－２＇－菁对单晶硅具有很强的敏化作用；利用电化学测量和紫外可见吸收光谱确定了键合光敏染料噻－２＇－菁与硅之间的相对能级位置，并对界面电子转移过程进行了讨论。     

微纳米尺度单晶硅各向异性表面的切削特性

利用纳米压痕仪和原子力显微镜,分别对单晶硅Si(100)、Si(110)、Si(111)三种晶面取向的表面进行微纳米尺度下的切削性能进行了实验研究。实验结果表明:在定载荷下,刻划速度的大小对单晶硅Si(100)、Si(110)晶面取向的切削力、摩擦系数的大小影响较小,但对单晶硅Si(111)晶体取向影响较大;在较低载荷下,单晶硅各晶面取向表面划痕细小,深度较浅且不明显,切削力大小无明显变化规律。随着载荷的逐渐增大,划痕宽度及深度也逐渐增大,切削力也相应增大,但并非呈线性增长。当载荷增大到一定值后,单晶硅各表面发生严重的塑性变形,变形积累一定程度后,沟槽两侧及探针前端形成明显的切屑堆积。     

Laser Refining of a Surface Layer with Silicon Carbide

The article discusses the effect of adding silicon carbide by laser remelting of low-carbon steel. Tests in laser remelting were carried out with energy inputs ranging between 10 and 80 J/mm² with the most favorable degree, i.e., 30%, of overlapping of individual trace. Sufficient energy input was necessary to dissolve silicon-carbide with iron. A microchemical analysis of the remelted layer confirmed the dissolution of silicon carbide and formation of a smaller portion of martensite (10-20%) and of suesite Fe₃Si (65-80%). It was found that the test-specimen deformation was smallest with the laser-beam in the zig-zag motion. The surface was also assessed visually. The choice of adequate remelting conditions reduced, i.e., prevented, the occurrence of cracks and other defects. The influence of energy input and the mode of laser-beam travel on the efficiency of remelting, i.e., refining, was described by a ratio of the width of the remelted surface layer to its depth, which should amount to around 5:1.     

电化学腐蚀多孔硅表面形貌的结构特性

多孔硅作为微电子机械系统中重要的热绝缘层和牺牲层材料,其表面形貌结构特性是影响多孔硅上薄膜器件性能的重要因素,为此,利用双槽电化学腐蚀方法制备了多孔硅薄膜,并通过原子力显微镜和场发射扫描电子显微镜对制备多孔硅的表面形貌和孔径大小分布进行了观察．结果发现：腐蚀初期,在硅表面会有大量的硅柱形成,硅柱的直径、高度、分布密度与电流密度成正比关系;硅柱在进一步腐蚀过程中会消失,多孔硅的表面粗糙度随着腐蚀的进行,先减小再增大,最后达到稳定值0．52nm;多孔硅孔径大小分布区间随腐蚀时间增加变窄．