硅基底上生长金刚石层细晶粒的研究

金刚石/硅声表面波基片的金刚石层晶粒的细化有利于传播损耗的降低,本文采用热丝化学气相沉积法进行了硅基体上沉积细晶粒金刚石工艺的初步探索.探讨了基体温度、气压、氩气和甲烷浓度等因素对金刚石细晶粒生长的影响.对相应样品进行了扫描电镜和拉曼散射谱分析.结果表明:在低气压范围,相同氩气浓度,随着气压的降低,甲烷浓度也要相应降低,能保证金刚石结晶质量.同时,降低气压达到一定值后,金刚石晶粒尺寸变小,经测试可达到纳米级.

Synthesis of Fine Grain Diamond Film on Silicon

We used hot filament chemical vapor deposition method to synthesize fine grain diamond films on silicon wafers aiming to exploit diamond's acoustic properties. The smaller grain size is contributed to achieving lower propagation loss.There are some important factors that can control the grain size such as gas pressure, the concentration of argon and methane and substrate temperature.In order to investigate how the factors have effect on the growth of fine grain, we measured the diamond film samples that deposited in different conditions through SEM and Raman spectrum. The results show that in the range of low pressure (below 2000Pa), with the gas pressure lower, the concentration of methane decreases. So in that way we can grow the uniform quality diamond films and the non-diamond component carbon (such as graphite and amorphous carbon) can be restrained. When the gas pressure reach some level, the grain size turns into fine and even is in the nanometer range.