反应离子束刻蚀二氧化硅和硅研究

应用CF_4、C_4F_8、CF_3I等反应气体SiO_2、单晶硅进行刻蚀研究.研究了刻蚀速率与离子能量、束流密度、入射角的关系、所得 SiO_2对单晶硅刻蚀选择比分别为 9:1(CF_4)、15:1(C_4F_8).刻蚀后,观察到表面有微量氟碳聚合物,但可用适当方法将氟碳沾污物予以消除.实验表明,C_4F_8反应气体是用于刻蚀SiO_2-Si 系统的较好气体,而CF_3I气体则否. 本文主要报道应用CF_4、C_4F_8在反应离子束刻蚀、镀膜装置(RIBC)中刻蚀SiO_2和Si的实验结果.     

用俄歇电子能谱分析Y-Ba-Cu-O超导薄膜与衬底的界面互作用

高T_c的Y-Ba-Cu-O超导材料在弱电方面进入实用的一个重要条件,就是需要制备出优质的超导薄膜。已有多种制备超导薄膜的方法见报道。用蓝宝石或Si衬底制备超导薄膜,通常会由于薄膜与衬底强烈的界面反应使其零电阻温度大为降低,严重时甚至变成非超导。而我们在实验中发现,YSZ(掺钇稳定立方氧化锆)衬底在高温下与薄膜的界面反应也较为严重。在YSZ衬底上沉积一层Ag缓冲层则可以减轻薄膜与村底的相互作用。     

SUPERCONDUCTING PROPERTIES AND STRUCTURAL PERFECTION OF EPITAXIAL YBa2Cu3O7-x THIN FILMS

High quality epitaxial YBa₂Cu₃O_7-x thin films have been succcessfully prepared by dc magnetron sputtering deposition, on (100) and (110) aligned SrTiO₃, LaAlO₃ and yttria-stabilized zirconia (YSZ) substrates. The films showed zero resistance around 90 K and had a J_c (at 77 K, H=0) over 10⁶A/cm². It was found that superconducting properties and structures of the films were strongly dependent on oxygen pressure and substrate temperature. The epitaxial structure of the films have been studied by X-ray diffraction. Rutherford backscattering and channeling spectroscopy, X-ray double-crystal diffraction and transmission election microscopy. The experimental results demonstrated that the epitaxial YBa₂Cu₃O_7-x films had excellent superconducting properties and quite perfect structure.     

SUPERCONDUCTING PROPERTIES AND STRUCTURAL PERFECTION OF EPITAXIAL YBa2Cu3O7-x THIN FILMS

The photoconductivity spectra of semimagnetic semiconductor Cd_0.7Mn_0.3Se have been measured at 50-300 K and in the wavelength range of 5500? to 8000?. It is found that the energy gap of Cd_0.7Mn_0.3Se changes with the temperature linearly, and the temperature coefficient (dE_g/dT) is about -7×10^-4 eV/K. A photoconductivity peak which is related to Mn²⁺ is also found. This peak is located around 1.85 eV, nearly unshifted with variation of the temperature. The possible transition mechanisms in Cd_1-xMn_xSe have been discussed in the light of group theory and crystal field theory, and the results are in good agreement with experiments.     

离子束溅射刻蚀

离子束溅射刻蚀、离子刻蚀、离子铣以及离子磨削等实属同一概念。离子束能刻蚀任何材料并能加工精细的几何图形。其刻蚀精度仅取决于光刻的水平及其掩膜的性质。目前,离子束溅射刻蚀已能加工出80埃的线条,而化学腐蚀所能达到的极限则为2微米线宽,且有边界轮廓模糊不清、钻蚀、沾污等缺点。离子束溅射刻蚀最突出的优点是窗壁的角度可以控制。这是通过选择入射角度和旋转靶子来完成的,这对金属化覆盖台阶来说极为重要。例如,对镍铁合金,当离子束以0～15度的入射角射到旋转着的靶板时可刻蚀出近于垂直的壁,而其它相关的刻蚀工艺都不能控制窗壁的角度。     

单片集成透镜高速1×4InGaAs/InPpin探测器阵列研究

设计并制作了带有集成透镜的1×4 InGaAs/InP pin探测器阵列.对器件纵向和横向结构参数及集成InP透镜几何参数进行了模拟设计与优化.器件带宽达1.0GHz,对宽带波分复用、光互连以及光计算网络有重要应用价值.     

铁电薄片的损耗角正切

本文研究粗磨、细磨、机械抛光和离子研磨四种不同的表面处理方法对LiNbO_3和LiTaO_3铁电晶体薄片损耗角正切的影响,对所得到的结果进行了简略的讨论。实验发现,对离子研磨样品进行中温热处理可以有效地降低薄片的损耗角正切。     

YBa_2Cu_3O_(7-x)超导薄膜的离子束改性

本文主要研究了离子注入对YBa_7Cu_3O_(7-x)薄膜超导性质的影响.测量了Ar离子注入剂量与超导转变温度T_c之间的关系.实验结果表明,高质量的YBa_2Cu_3O_(7-x) 超导薄膜具有一定的抗辐照性.随着注入剂量的增加,临界电流密度I_c下降很快,但零电阻转变温度T_c却下降较慢.分析和讨论了离子注入对YBa_2Cu_3O_(7-x)中一维Cu-O链和二维Cu-O面的影响,探讨了离子束改性手段在YBa_2Cu_3O_(7-x)超导薄膜图形加工中应用的可能性.     

用MOCVD法在YSZ衬底上制备YBCO膜

用低压ＭＯＣＶＤ多源法在单晶ＹＳＺ和具有双轴取向ＩＢＡＤＹＳＺ的金属基带上沉积了ＹＢＣＯ膜,它们的Ｊｃ（７７．３Ｋ,０Ｔ）分别为～２×１０６Ａ／ｃｍ２和～７×１０４Ａ／ｃｍ２．分析了本试验中的Ｊｃ差别原因．在单晶ＹＳＺ上ＹＢＣＯ高Ｊｃ数值显示了用ＭＯＣＶＤ制备涂层膜导体的潜力     

SUPERCONDUCTING PROPERTIES AND STRUCTURAL PERFECTION OF EPITAXIAL YBa2Cu3O7-x THIN FILMS

High quality epitaxial YBa₂Cu₃O_7-x thin films have been succcessfully prepared by dc magnetron sputtering deposition, on (100) and (110) aligned SrTiO₃, LaAlO₃ and yttria-stabilized zirconia (YSZ) substrates. The films showed zero resistance around 90 K and had a J_c (at 77 K, H=0) over 10⁶A/cm². It was found that superconducting properties and structures of the films were strongly dependent on oxygen pressure and substrate temperature. The epitaxial structure of the films have been studied by X-ray diffraction. Rutherford backscattering and channeling spectroscopy, X-ray double-crystal diffraction and transmission election microscopy. The experimental results demonstrated that the epitaxial YBa₂Cu₃O_7-x films had excellent superconducting properties and quite perfect structure.