热灯丝CVD金刚石膜的微结构和形貌对其电子性质的影响

利用热灯丝CVD法在硅衬底上合成出了金刚石膜。金刚石膜的质量和电子性质由扫描电子显微镜、拉曼谱、阴极发光及霍尔系数测量来表征。实验结果表明，沉积条件对金刚石膜电子性质和质量有重要影响。载流子迁移率随甲烷浓度增加而减少，但场发射随其增加而增强。压阻效应随微缺陷增多而降低。异质外延金刚石膜压阻因子在室温下100微形变时为1200，但含有大量缺陷的多晶金刚石膜压阻因子低于200，这是由于薄膜中缺陷态密度增加，并依赖于膜结构的变化。

Influence of microstructure and morphology on electronic properties of diamond films by hot filament chemical vapor deposition

The diamond films were synthesized on silicon substrate by hot filament chemical vapor de－position (HFCVD). The quality and electronic properties of the films were characterized by scanning electron microscopy(SEM), Raman spectrum, Cathodoleminesecence(CL) and the Hall effect measure－ments. The experimental results show that the deposition conditions have an important influence on the quality and electronic properties of diamond films. The carrier mobility decreases with increasing methane concentration. However, the field emission effect is enhanced with the methane concentration. The piezoresistive effect is degraded with increasing micro－defects.The gauge factor for the heteroepi－taxial p－type diamond films is found to be 1200 at 100 microstrain for room temperature, but lower than 200 for poly－crystalline diamond films with a lot of defects. This is ascribed to the increase of defect state density and also dependes on the structure changes in the films.