钽掺杂对二氧化钒多晶薄膜相变特性的影响

将Ta_2O_5与V_2O_5均匀混合,压制成溅射靶,用离子束增强沉积方法在二氧化硅衬底上沉积掺Ta氧化钒薄膜.在氮气中适当退火,形成掺杂二氧化钒多晶薄膜.X射线衍射结果显示,薄膜具有单一的(002)取向.XPS测试表明,膜中V为+4价,Ta以替位方式存在.温度-电阻率测试表明,薄膜具有明显的相变行为,原子比为3%的Ta掺杂后,二氧化钒多晶薄膜相变温度降低到约48℃.Ta原子的半径大于V原子的半径,Ta的掺入在薄膜中引入了张应力;5价Ta 替代4价V,在d轨道中引入多余电子,产生施主能级,这些是掺钽二氧化钒多晶薄膜相变温度降低的原因.     

BeO瓷的金属化和封接

综述了氧化铍瓷的金属化及其封接技术,指出氧化铍瓷和Al2O3瓷在金属化工艺上的差异,论文最后汇集了国内外常用烧结金属粉末法15种配方和工艺参数,以资同行专家参考.     

电化学法制备CdSexTey薄膜及其光电性能

以Cd(NO3)2·4H2O,Na2 SeO3和Na2TeO3的混合液为电解液,采用电化学共沉积法在氧化铟锡(ITO)玻璃基底上制备了CdSexTey薄膜样品.探讨了沉积电压、水浴温度、沉积时间以及Cd,Te和Se物质的量比等制备条件对样品在模拟太阳光下的开路电压的影响.结果表明,在沉积电压为3.0V,水浴温度为50℃,沉积时间为30 min,n(Cd)∶n(Te)∶n(Se)=5.6∶1∶1时制备的CdSexTey薄膜具有较高的开路电压,其值可达到0.464 1 V.X射线衍射(XRD)分析结果显示,CdSexTey样品中含单质态Se,CdSexTey的3个主要衍射峰对应的晶粒尺寸分别为43.07,44.56和44.03 nm.能谱分析(EDS)结果显示,样品中Cd,Te,Se元素的质量分数分别是6.53％,6.25％和14.52％,原子数分数分别为1.68％,1.42％和5.32％.对Cd元素原子数分数进行归一化处理,则样品CdSexTey中x为3.17(其中有化合态Se2-为0.15,单质态Se为3.02),y为0.85.     

Epitaxy of Si:C on Si(001) via methyldichlorosilane

Methyldichlorosilane (CH₃SiHCl₂) is compared to methylsilane (CH₃SiH₃) for vapor phase epitaxy of cubic silicon - carbon (NO :) (Si:C) alloys on Si (001). Parameters of interest are growth rate, percent carbon and crystallinity. Carbon incorporation efficiency and experimental window for epitaxial growth are similar for both precursors. The two precursors differ in Si contribution to the film growth rate.     

全密封超薄碳纳米管玻璃平板字符显示器件制造工艺的初步探讨

利用自制的场助热丝化学气相沉积设备，在不锈钢电极的部分选取表面上，摸索出了直接生长碳纳米管（CNT’s）勿须涂敷催化剂的新方法。利用得到的高定向多壁碳纳米管薄膜，研究出一种制造大面积实用碳纳米管阵列场发射（CNT’s／FEA）阴极的新方法。经真空条件下的发射特性测量及SEM等检测手段肯定了这种CNT’s／FEA阴极的实用性。从工艺流程角度出发，初步探讨了静态工作制式下，采用碳纳米管做电极后，实现一种全密封超薄碳纳米管玻璃真空字符（或图像）显示器件的可能性。10多只封离管共显示过3种类型的字型（图像），全部管厚仅为2．7mm。实验结果不仅提供了一种碳纳米管阴极在玻璃真空平板型器件内应用的方法，也摸索出了一条实现小尺寸双色（或多色）字符（图像）静态（或动态）显示的廉价、节能途径。     

Ultralow Dielectric Constant Tetravinyltetramethylcyclotetrasiloxane Films Deposited by Initiated Chemical Vapor Deposition (iCVD)

Simultaneous improvement of mechanical properties and lowering of the dielectric constant occur when films grown from the cyclic monomer tetravinyltetramethylcyclotetrasiloxane (V4D4) via initiated chemical vapor deposition (iCVD) are thermally cured in air. Clear signatures from silsesquioxane cage structures in the annealed films appear in the Fourier transform IR (1140 cm^?1) and Raman (1117 cm^?1) spectra. The iCVD method consumes an order of magnitude lower power density than the traditional plasma‐enhanced CVD, thus preserving the precursor's delicate ring structure and organic substituents in the as‐deposited films. The high degree of structural retention in the as‐deposited film allows for the beneficial formation of intrinsically porous silsesquioxane cages upon annealing in air. Complete oxidation of the silicon creates ‘Q’ groups, which impart greater hardness and modulus to the films by increasing the average connectivity number of the film matrix beyond the percolation of rigidity. The removal of labile hydrocarbon moieties allows for the oxidation of the as‐deposited film while simultaneously inducing porosity. This combination of events avoids the typical trade‐off between improved mechanical properties and higher dielectric constants. Films annealed at 410 °C have a dielectric constant of 2.15, and a hardness and modulus of 0.78 and 5.4 GPa, respectively. The solvent‐less and low‐energy nature of iCVD make it attractive from an environmental safety and health perspective.     

The growth of InAsSb/InAsP strained-layer superlattices for use in infrared emitters

We describe the metalorganic chemical vapor deposition of InAsSb/InAsP strained-layer superlattice (SLS) active regions for use in mid-infrared emitters. These SLSs were grown at 500°C, and 200 Torr in a horizontal quartz reactor using TMIn, TESb, AsH₃, and PH₃. By changing the layer thickness and composition, we have prepared structures with low temperature (≤20K) photoluminescence wavelengths ranging from 3.2 to 4.4 μm. Excellent performance was observed for a SLS light emitting diode (LED) and both optically pumped and electrically injected SLS lasers. An optically pumped, double heterostructure laser emitted at 3.86 μm with a maximum operating temperature of 240K and a characteristic temperature of 33K. We have also made electrically injected lasers and LEDs utilizing a GaAsSb/InAs semi-metal injection scheme. The semi-metal injected, broadband LED emitted at 4 μm with 80 μW of power at 300K and 200 mA average current. The InAsSb/InAsP SLS injection laser emitted at 3.6 μm at 120K.     

Effects of a-Si:H resist vacuum-lithography processing on HgCdTe

A vacuum-compatible process for carrying out lithography on Hg_1−xCd_xTe and CdTe films was previously demonstrated. It was shown that hydrogenated amorphous silicon (a-Si:H) could be used as a dry resist by projecting a pattern onto its surface using excimer laser irradiation and then developing that pattern by hydrogen plasma etching. Pattern transfer to an underlying Hg_1−xCd_xTe film was then carried out via Ar/H₂ plasma etching in an electron cyclotron resonance (ECR) reactor. Despite the successful demonstration of pattern transfer, the possibility of inducing harmful effects in the Hg_1−xCd_xTe film due to this vacuum lithography procedure had not been explored. Here we present structural and surface compositional analyses of Hg_1−xCd_xTe films at key stages of the a-Si:H vacuum lithography procedure. X-ray diffraction double crystal rocking curves taken before and after a-Si:H deposition and after development etching were identical, indicating that bulk structural changes in the Hg_1−xCd_xTe film are not induced by these processes. Cross-section transmission electron microscopy studies show that laser-induced heating in the 350 nm thick a-Si:H overlayer is not sufficient to cause structural damage in the underlying Hg_1−xCd_xTe surface. In vacuo surface analysis via Auger electron spectroscopy and ion scattering spectroscopy suggest that the hydrogen plasma development process produces Hg-deficient surfaces but does not introduce C contamination. However, after ECR plasma etching into the Hg_1−xCd_xTe film, the measured x value is much closer to that of the bulk.     

激光直写布线技术的现状与展望

本文归纳了激光直写布线技术的特点,重点综述了该技术在电子线路板的应用及在国内外发展的现状,并展望了激光直写技术的应用前景。     

Ge_xC_(1-x)非均匀增透保护膜系的设计和制备

用射频磁控反应溅射法 (RS)制备出 Gex C1-x薄膜 ,其折射率可以在 1 .7～ 4.0之间变化。设计出单层 Gex C1-x非均匀增透保护膜和含有 Gex C1-x非均匀膜的多层增透保护膜系 ,并在 Zn S基片上制备出 Gex C1-x单层非均匀增透保护膜。设计和实验结果表明 ,Zn S衬底上制备的非均匀膜实现了宽波段的增透 ,在 5 0 0 0～ 85 0 cm-1波数范围内 ,平均透过率从 6 7.1 9%提高到 78.70 % ,比未镀膜净增加 1 1 .5 1 %。