InxGa1−xAs ohmic contacts to n-type GaAs with a tungsten nitride barrier

Significant reduction of the contact resistance of In_0.7Ga_0.3As/Ni/W contacts (which were previously developed by sputtering in our laboratory) was achieved by depositing a W₂N barrier layer between the Ni layer and W layer. The In_0.7Ga_0.3 As/Ni/W₂N/W contact prepared by the radio-frequency sputtering technique showed the lowest contact resistance of 0.2 Ωmm after annealing at 550°C for 10 s. This contact also provided a smooth surface, good reproducibility, and excellent thermal stability at 400°C. The polycrystalline W₂N layer was found to suppress the In diffusion to the contact surface, leading to improvement of the surface morphology and an increase in the total area of the In_xGa−As between metal and the GaAs substrate. These improvements are believed to reduce the contact resistance.     

Properties of Quaternary Alloy Magnetic Semiconductor (InGaMn)As Grown on InP

We have studied properties of quaternary alloy magnetic semiconductor (InGaMn)As grown on InP substrates by low-temperature molecular-beam epitaxy (LT-MBE). A large MCD peak whose intensity is larger than 500 mdeg for (InGaMn)As was observed. This peak intensity was about three times larger than that of typical (GaMn)As films. Relatively high Curie temperature of 83 K of [(In_0.53Ga_0.47)_0.88Mn_0.12]As was observed by Hall measurements. The carrier concentration of [(In_0.53Ga_0.47)_0.88Mn_0.12]As was estimated to be more than 1.0 × 10²¹ cm^–3 by using the Curie–Weiss fitting of the Hall coefficient R _H, indicating that more than 40% of Mn atoms are activated. This means that (InGaMn)As has a higher activation ratio of Mn as acceptors than (GaMn)As.     

Controlled oxygen incorporation in indium gallium arsenide and indium phosphide grown by metalorganic vapor phase epitaxy

The defect engineering in metalorganic vapor phase epitaxy In_xGa_1-xAs and InP by controlled oxygen doping using diethyl aluminum ethoxide (DEALO) was developed in this study. DEALO doping has led to the incorporation of Al and O, and the compensation of shallow Si donors in In_xGa_1−xAs: Si with 0 ≤ x ≤ 0.25. With the same DEALO mole fraction during growth, the incorporation of Al and O was found to be independent of x, but the compensation of Si donors decreases with increasing In content. Deep level transient spectroscopy analysis on a series of In_xGa_1-xAs: Si. samples with 0 ≤ x ≤ 0.18 revealed that oxygen incorporation led to a set of deep levels, similar to those found in DEALO doped GaAs. As the In composition was increased, one or more of these deep levels became resonant with the conduction band and led to a high electron concentration in oxygen doped In_0.53Ga_0.47As. Low temperature photoluminescence emission measurements at 12K on the same set of samples revealed the quenching of the near-band edge peak, and the appearance of new oxygen-induced emission features. DEALO doping in InP has also led to the incorporation of Al and O, and the compensation of Si donors due to oxygen-induced multiple deep levels.     

基于CH365型接口和MCX314As型运动控制器的PCI总线运动控制卡设计

以CH365型PCI总线接口和MCX314As型运动控制器为核心硬件,自主研发了基于运动控制器的PCI总线运动控制卡,该控制卡能够实现4轴位置、速度和S曲线的加减速控制,具有直线、圆弧、位模式插补功能及自动原位搜寻功能,同时具有4路信号输入和8路通用输出.     

Heavy arsenic doping of silicon grown by atmospheric pressure selective epitaxial chemical vapor deposition

Selective epitaxial Si with a high arsenic concentration of 2.2×10¹⁹ atoms/cm³ was deposited at a high growth rate of 3.3 nm/min under atmospheric pressure. It was confirmed that this method had excellent selectivity and produced films having good crystalline quality, abrupt dopant profiles at the interfaces, and smooth surfaces. The growth mechanism is discussed in terms of the relationship between the effects of arsenic surface segregation and etching by hydrogen chloride.     

铜电解精炼过程中砷、锑、铋的危害及脱除方式的进展

在铜电解精炼过程中 ,砷、锑、铋等杂质 ,尤其是锑、铋 ,一直来被人们认为是对阴极铜生产、影响阴极铜质量的最为有害的元素。本文结合贵冶历年的生产实践来讨论砷、锑、铋等杂质在阴极铜生产过程中的危害以及脱除方式的进展。     

As,Sb,Sn对30CrMnSiA钢力学性能的影响

在３０ＣｒＭｎＳｉＡ钢中加入不同量的Ａｓ，Ｓｂ，Ｓｎ元素，研究了这些元素单独存在及复合存在时对钢的强度，塑性，冲击韧度及韧脆转变温度的影响规律，并用扫描电镜及俄歇能谱分析了Ａｓ，Ｓｂ，Ｓｎ导致晶界脆化的机理。     

稀土镁对铸态高锰钢机械性能的影响

实验了稀土镁对铸态高锰钢机械性能的影响．结果表明，在一定的Ｃ、Ｍｎ、Ｓｉ成分中，加入ＲＥＭｇ合金均使其铸态机械性能有所提高．同时在工业设备上试验证实，加入ＲＥＭｇ的某种成分之高锰钢，在铸态时其耐磨性能、机械性能均已达ＺＧＭｎ１３－１和ＺＧＭｎ１３－２（ＧＢ５６８０－８５）水平并超过了铸态使用的７５Ｍｎ１３     

TAM胶粘剂中铅镉汞铬砷有害元素的同时测定

研究了HF +HCl消解样品 ,试液用ICP -AES法同时测定TAM胶粘剂中铅、镉、汞、铬、砷的新方法。在选定的最佳条件下测铅、镉、汞、铬、砷的检出限分别为 0 .0 0 15、0 .0 0 0 8、0 .0 0 11、0 .0 0 17、0 .0 0 0 9μg·L- 1 ,回收率为 93 .5 %～ 10 8.3 % ,RSD为 0 .62 %～ 5 .65 %。该法准确、快速、简便 ,应用于TAM胶粘剂的测定 ,结果满意     

水泥熟料形成过程中重金属价态变化分析

采用基于同步辐射光源的X射线吸收精细结构谱（XAFS）,研究了掺烧As^5＋、Cr^6＋、Cr^3＋的水泥熟料中,As和Cr在水泥熟料形成过程中价态变化行为.结果表明：掺加As^5＋和Cr^6＋的水泥生料经高温煅烧后化学价态没有发生变化,掺烧As^5＋水泥熟料中As以As^5＋的形式存在;掺烧Cr^6＋水泥熟料中Cr仅以Cr^6＋的形式存在,说明水泥生料中含有的微量Cr^3＋在煅烧过程中已完全被氧化为Cr^6＋;掺烧Cr^3＋水泥熟料中含有Cr^3＋和Cr^6＋,大部分Cr^3＋在水泥熟料形成过程中被氧化为Cr^6＋.