应用等离子体增强化学气相淀积(PECVD)法制备SiO2薄膜, 并用折射率来表征致密性。研究了SiO2薄膜致密性与射频(RF)功率、基板温度、腔内压强、N2O/SiH4流量比的关系。通过Filmetrics薄膜测厚仪F20测量了薄膜的折射率, 用聚焦离子束扫描电镜(FIB-SEM)测量了表面微结构。利用能量弥散X射线(EDX)分析薄膜中Si、O、N元素含量随工艺参数变化对致密性的影响。进行多因子实验设计(DOE), 得出了各种条件下最优的折射率与结构的生长条件, 并研究了SiO2薄膜致密性随工艺条件变化的机理。

Plasma enhanced chemical vapor deposition (PECVD) method is applied to prepare SiO2 thin films, and the compactness is characterized by refractive index. The relationship between SiO2 thin film compactness and radio-frequency (RF) power, substrate temperature, chamber pressure, N2O/SiH4 flow rate is studied. Refractive index is measured by Filmetrics thin film thickness gauge F20 and surface microstructure is measured by focus ion beam scanning electron microscopes (FIB-SEM). Energy dispersive X-ray (EDX) is used to analyze the influence of Si, O and N element contents in thin films on the compactness with different process parameters. Design of experiments (DOE) of multi-factors is carried out. The optimum refractive index and structure growth condition under various conditions are got. The mechanism of compactness of SiO2 thin film changing with process conditions is studied.