SiO2衬底上PECVD-Si1-xGex薄膜研究

摘要

在覆盖SiO2的n-Si(100)衬底上,采用等离子体增强化学沉积法(PECVD)制备Si1-xGex薄膜材料.薄膜Ge含量x及元素的深度分布由俄歇电子谱(AES)测定.对Si1-xGex进行热退火处理,以考察退火温度和时间对薄膜特性的影响.薄膜的物相通过X射线衍射(XRD)确定.基于XRD图谱,利用Scherer公式计算平均晶粒大小.Si1-xGex薄膜载流子霍尔迁移率由霍尔效应法测定.数值拟合得到霍尔迁移率与平均晶粒尺寸为近线性关系,从而得出PECVD-Si1-xGex薄膜的电输运特性基本符合Seto模型的结论.%Silicon-germanium (Si1-xGex) thin films were grown on SiO2-coated n-Si (100) substrates by plasma enhancement chemical vapor deposition (PECVD) method. The Ge fraction in Si1-xGex layer was determined at x=0.14～0.16 intervals by Auger electron spectroscopy (AES). The samples were thermally annealed in a conventional furnace. The temperature and duration were studied to explore the annealing effects on some physical and electrical properties of Si1-xGex thin films. Phase identification was performed by X-ray diffractometry (XRD). Based on XRD, the average grain size was calculated in terms of Scherer's formula. It is obtained that the hole mobility has a nearly linear correlation with the average grain size. It can be inferred that the electrical transport property of PECVD-Si1-xGex film in this study follows Seto's model fairly well.