国际上一般采用任意取向的多晶薄膜作为探测级材料,所以电荷收集效率较低以至于灵敏度受到限制。本实验采用不同取向的多晶金刚石薄膜制作紫外光探测器,研究了薄膜取向性对探测器性能的影响,为进一步提高金刚石薄膜紫外光探测器的性能提供理论和实验依据。采用热丝辅助化学气相沉积(HFCVD)法,获得了晶粒尺寸接近的不同取向的金刚石薄膜。通过微电子加工工艺制备了不同取向的金刚石薄膜紫外光叉指结构探测器。研究表明,探测器性能与金刚石薄膜晶粒取向密切相关,使用(100)取向薄膜所获得的探测器性能明显得到改善,在225nm紫外光下的光电流~暗电流之比以及190-700nm波长范围内的紫外/可见分辨率均优于其它取向。
Different orientation polycrystalline diamond thin films are fabricated into UV detectors and the influence of film orientation on detector performance is investigated, which provides theoretical and experimental reference to enhance the performance of diamond thin film UV detectors. By using different deposition conditions,three CVD diamond films with different orientation and similar grain size are grown by hot-filament CVD technique. Through micro-electronic process technology,ultra-violet detectors with interdigital patterns are fabricated in above diamond films. It is shown that,the performance of detectors are closely related with the film orientation,and much enhanced by using (100) diamond films,with a larger lightcurrent/dark-current ratio and a better resolution in the range of 190-700 nm.