ION BEAM STUDY ON EPITAXIAL GROWTH FEATURES OF YBaCuO FILMS

The epitaxial growth features of YBa2Cu3O7-x (YBCO) films on (100) SrTiO3 substrates have been studied by Rutherford backscattering spectrometry and axial channeling technique. A typical minimum yield value, Xmin, of Ba yielded in channeling spectrum is 4.6 % for the film of 166 nm. Only (00L) peaks appeared in X ray diffraction patterns of the films. The results indicate that the YBCO films have good epitaxial growth quality with c- axis orientation perpendicular to the substrate surface. Simulation of RB process in films and substrates have also been performed using RUMP program, and analysis shows that compositions of the films are uniform with near (123) stoichiometry. The higher interface yields in the aligned spectrum reveal that there are extra defects in the interface layer owing to lattice mismatch and interface interaction.     

离子束合成法形成的Si／CoSi2／Si／SiO2／Si（100）结构

用离子束合成法先后在Si(100)衬底中形成了连续的SiO_2及CoSi_2埋层,从而形成了复合的Si/CoSi_2/Si/SiO_2/Si(100)结构。卢瑟福背散射、沟道技术及用扫描电镜所作的电子通道花样被用来对这一结构形成的各个阶段进行分析。这一结构可望用于今后新型的微电子器件、光电器件及三维集成电路等。     

反应溅射氮化钨薄膜特性研究

本文采用两种溅射系统:射频磁控溅射系统和S枪溅射系统淀积了氮化钨薄膜。X射线衍射方法(XRD)、俄歇电子谱(AES)和电学测量等方法用来分析了氮化钨薄膜的组分、晶体结构和薄膜的电阻率。并研究了氮在氮、氩混合气体中的不同流量比对氮化钨薄膜特性的影响。用卢瑟福背散射(RBS)方法对比研究了纯钨薄膜和氮化钨薄膜在Al/W/Si和Al/WN_x/Si两种金属化系统中的扩散势垒特性。分析结果表明,Al/W/Si金属化系统经500℃、30分钟热退火后,出现了明显的互扩散现象;而Al/WN_x/Si金属化系统在550℃、30分钟热退火后,没有发现互扩散的迹象,说明氮化钨在硅集成电路中是一种有效的扩散势垒材料。