中文摘要：

本文采用30kW级直流电弧等离子体喷射法沉积自支撑金刚石膜，研究了大进气量条件下不同的甲烷浓度对金刚石膜的表面形貌及晶面取向的影响，当甲烷浓度达到一定程度时，出现纳米二次晶的形核，晶粒细化，微米金刚石转变成为纳米金刚石。同时不同的氩氢配比对金刚石膜的表面形貌也产生一定的影响。在高甲烷浓度的情况下，可以得到一种具有（111）取向的微米级金刚石膜。结果表明，随着甲烷浓度和氩氢比（Ar/H2）的增加，金刚石膜表面晶粒尺寸是呈逐渐减小趋势的，此外，通过控制甲烷浓度可以得到（111）晶面的高取向金刚石膜，当甲烷浓度为20%时，金刚石膜表面晶粒的（111）晶面可以达到高取向。

英文摘要：

Free-standing diamond films were deposited by using 30 kW DC Arc Plasma Jet CVD. Influence of different concentration of methane upon the surface morphology of diamond films and crystalline plane was studied. By increasing the concentration of methane, diamond nanometer secondary nuclei began to be nucleated, and diamond ~crystalline grains were gradually diminished. Diamond crystalline grains almost turned into nanometer size diamond grains. Meanwhile,different ratio of Ar/H2 also influenced the surface morphology of diamond films. Under high methane concentration conditions, we can obtain microcrystalline diamond film of high （ 111 ） -orientation. The results indicated that by increasing the concentration of methane and radio of Ar/H2 , diamond crystalline grains were gradually diminished. Furthermore, with concentration of methane of 20%, diamond films may get high （ 111 ） -orientation.