溅射工艺参数对硅薄膜微结构影响的Raman分析

为了解决碳化硅难以进行光学加工的问题，该文采用射频磁控溅射方法，在碳化硅反射镜坯体上沉积与碳化硅具有相近热膨胀系数且易于进行光学加工的硅薄膜。利用拉曼光谱(Raman)对衬底温度、射频功率、衬底偏压等溅射工艺条件对硅膜微结构的影响进行了分析。研究发现：随着衬底温度的升高，薄膜的晶化率先增大后减小;衬底偏压的增加不利于薄膜有序结构的形成;射频功率对薄膜微结构的影响比较复杂，随着功率的升高，薄膜晶粒尺寸减小，晶化率降低，当射频功率进一步升高时，薄膜中有序团簇尺寸和晶化率逐渐升高。但过高的射频功率反而不利于薄膜的晶化。

Effect of Technological Parameters of Sputtering on the Microstructure of Silicon Film Investigated by Raman Analysis

In order to facilitate optical polishing of silicon carbide space telescope, in the present paper, silicon film, which has similar coefficient of thermal expansion with silicon carbide, was fabricated on SiC substrate by radio frequency magnetron sputtering. The effect of substrate temperature, radio frequency power, and substrate bias voltage was investigated by Raman scattering. The results indicate that at lower substrate temperature, the crystalline volume fraction of Si films increases with the increase in deposition temperature. Exceeding a certain temperature, the crystalline volume fraction decreases with further increasing deposition temperature; the increase in substrate bias voltage is bad for forming crystalline structure; the effect of radio power on microstructure of silicon film is comparatively complicated. As the rf power increases, the cluster size and crystallite volume fraction decrease, and both of them increase with further increasing the rf power. But when the rf power is too high, the crystallite volume fraction of the silicon film will decrease slightly.