活性成分对金刚石膜沉积速率和质量的影响

摘要

采用微波等离子体化学气相法合成的金刚石膜质量好,但采用常规CH4-H2气体体系,金刚石膜的沉积速率低.为此,实验研究了C2 H5OH-H2、CH4-H2-Ar和CH4-H2-N2等含有活性成分的体系下,微波功率、碳源浓度、气体压力对金刚石膜沉积速率、表面形貌、电阻率的影响.结果表明:使用含氧、氩、氮等活性成分的体系,金刚石膜生长速率分别达0.57、0.59、0.58 μm/h,较常规CH4-H2体系提高了近一倍；并且金刚石膜的纯度高(薄膜表层金刚石C含量80％以上)、晶型好、电阻率高(约为1010 Ω·cm)；同时,氩、氮的加入可显著降低金刚石的晶粒尺寸.因此,引入活性成分是一种提高金刚石膜沉积速率和质量的有效方法.%The diamond film with excellent quality can be synthesized by using microwave plasma chemical vapor deposition ( MPCVD) method. However, the growth rate of diamond film is very low with the conventional gas system of CH4-H2. In order to improve its growth rate and quality, the influence of different microwave power, different concentration of carbon radicals and gas pressure in C2H5OH-H2 ,CH4-H2-Ar CH4-H2-N2 gas systems on the resistivity, growth rate and surface morphology of diamond film were studied. The results show that the growth rate of diamond film is up to 0. 57,0. 59,0. 58 μm/h respectively with gas systems containing active compositions (0, Ar, N) , which nearly double that of CH4-H2 gas system, and the diamond film is of high purity (that relative content of diamond C-C bond is more than 80% ) , perfect crystal shape and high resistivity(1010 Ω · Cm). In addition, the grain size of diamond can be reduced by doping argon and nitrogen. Accordingly, the addition of active compositions is an effective method to improve the growth rate and quality of MPCVD diamond film.