论文部分内容阅读
采用减压化学气相沉积(RPCVD)系统,通过调节GeH4和刻蚀性气体HCl的通入速率,在Si/SiO2图形衬底上利用40 nm薄低温Ge缓冲层选择性外延生长Ge薄膜,然后H2退火20 min以减少外延Ge层中的位错及缺陷。采用化学腐蚀方法检查位错坑密度,利用扫描电子显微镜(SEM)、原子力显微镜(AFM)和高分辨率X射线衍射(HRXRD)方法表征分析了外延Ge晶体质量。测试结果表明,图形衬底上直径为10μm的圆形区域外延Ge位错密度低至1.3×10~6/cm~2,约1.5μm厚外延Ge层衍射峰的半高宽平均为240 arcsec,化学机械抛光(CMP)工艺后用AFM测得Ge膜表面粗糙度低至0.2 nm,该工艺方法制备的锗薄膜材料将有望集成应用于硅基探测器等硅基光电器件。
The Ge film was selectively epitaxially grown on a Si / SiO2 pattern substrate by using a 40 nm low-temperature Ge buffer by adjusting the access rate of GeH4 and etchant gas HCl by a reduced pressure chemical vapor deposition (RPCVD) Annealed for 20 min to reduce dislocations and defects in the epitaxial Ge layer. The density of dislocation pits was examined by chemical etching. The quality of epitaxial Ge crystals was characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and high resolution X-ray diffraction (HRXRD). The results show that the epitaxial Ge dislocation density is as low as 1.3 × 10 ~ 6 / cm ~ 2 in a circular region with a diameter of 10μm and the average half-height width of an approximately 1.5μm thick Ge layer diffraction peak is 240 arcsec, After the chemical mechanical polishing (CMP) process, the surface roughness of Ge film measured by AFM is as low as 0.2 nm. The germanium film material prepared by the process method is expected to be integrated and applied to silicon-based photoelectric devices such as a silicon-based detector.