用于高频声表面波器件的CVD金刚石衬底的研究

Research substrates of CVD diamond for high frequency surface acoustic wave device

使用纳米金刚石粉研磨工艺预处理硅片衬底抛光面,在低气压成核的条件下,以丙酮和氢气为反应物,采用传统的热丝辅助化学气相沉积法,制备了自支撑金刚石膜;通过射频磁控溅射法沉积氧化锌薄膜在自支撑金刚石膜的成核面,形成氧化锌/自支撑金刚石膜结构.通过光学显微镜、扫描电镜及原子力显微镜测试自支撑金刚石膜成核面的表面形貌.研究结果表明:成核期的低气压有助于提高成核密度,成核面表面粗糙度约为1.5 nm;拉曼光谱显示1334 cm-1附近尖锐的散射峰与金刚石SP3键相对应,成核面含有少量的石墨相,且受到压应力的作用;ZnO/自支撑金刚石膜结构的XRD谱显示,氧化锌薄膜有尖锐的(002)面衍射峰,是c轴择优取向生长的.

With the polishing sides of silicon substrates being scratched by 100 nm powder of diamond, freestanding diamond films were prepared by hot filament chemical vapor deposition （HFCVD） using acetone carried by hydrogen at the nucleation condition of low pressure. After ZnO thin films were grown on nucleation sides of freestanding diamond by RF reactive magnetron sputtering, the structure of ZnO/freestanding diamond film was formed. The surface morphologies of the nucleation sides were characterized by optical microscope, scanning electron microscopy （SEM）, and atom force microscope （AFM）. The results indicate low pressure during nucleation helps to increase nucleation density, and surface roughness of nucleation sides is about 1.5 nm. Raman spectrum shows a sharp peak at 1334 cm^-1 , which is associated with sp3 bond of diamonds. The amount of graphite in the nucleation sides is small, and the nucleation sides are in compressive stress. X-ray diffraction （XRD） pattern of the structure of ZnO/freestanding diamond shows a sharp diffraction peak for ZnO （002）, which indicates that as-sputtered film is highly c -axis oriented.