单晶金刚石膜与多晶金刚石膜的制备工艺及性能

GROWTH PROCESSES AND CHARACTERISTICS OF POLYCRYSTALLINE DIAMOND FItLMS AND EPITAXIAL DIAMOND FILMS

本文主要介绍了用微波等离子体化学气相沉积法(以下简称MP CVD法)以甲醇-氢气混合气和丙酮-氢气混合气为源气体,分别以单晶硅的(111)面和人造金刚石的(100)面为衬底材料,制备出了面积为20mm×20mm厚为10μm的多晶金刚石膜和面积为1.0mm×1.0mm厚为5μm的单晶金刚石膜。通过试验发现,源气体配比和衬底温度对薄膜质量起决定性作用。另外,衬底在反应腔中的位置对薄膜的生成也有很大影响。单晶金刚石膜制备过程中衬底金刚石的晶体取向与金刚石薄膜的生长及质量有密切的关系。在金刚石的(100),(110)和(111)面上分别获得了单晶金刚石膜和金刚石多晶粒子。选用扫描电镜、显微激光拉曼、反射电子衍射对多晶金刚石膜及单晶金刚石膜的性能进行了测试。

The growth processes and characteristics of polycrystalline diamond films and epitaxial diamond films by microwave plasma CVD (Chemical Vapor Deposition) method are presented in the paper. Polycrystalline diamond films, 20mm×20mm in area and 10μm thick, on silicon (111) substrates and epitaxial diamond films, 1.0mm×1.0mm in area and 5μm thick on (100) planes of synthesized single-crystal diamond substrates were prepared respectively. For the source gases, i.e. CH_3OH, CH_3COCH_3 and H_2 gases of different carbon concentrations (CH_3OH/H_2,CH_3COCH_3/H_2) were usel. The quality of diamond films depends on substrates temperature, CH_3OH or CH_3COCH_3 concentration of the source gas and the position of substrates in reaction chamber. The growth and the quality of the epitaxial diamond films are related to crystal orientations of dia mand substrates considerably, Different substfate orientations are necessary for different processes. Epitaxial diamond films and polycrystalline diamond grain were obtained on(100), (110) and(111) surface of synthesized single-crystal diamond substrates. The crystallinity of polycrystalline diamond films and epitaxial diamond films were examined by scanning electron microscopy (SEM), micro laser Raman spectroscopy and reflection electron diffraction (RED).