离子束辅助沉积非晶硅薄膜红外光学特性研究

为了得到非晶硅（a-Si）薄膜红外光学常数与工艺参数之间的关系,采用Ar离子束辅助电子束热蒸发技术制备a-Si薄膜,并利用椭偏仪和分光光度计测量了薄膜的光学常数,分析了薄膜沉积速率、基底温度和工作真空度对a-Si薄膜折射率和消光系数的影响.实验结果表明：影响a-Si薄膜光学常数的主要工艺因素是沉积速率和基底温度,工作真空度的影响最小.当沉积速率和基底温度升高时,薄膜的折射率先增大后减小;当工作真空度升高时,薄膜的折射率增大.在波长1~5μm之间,a-Si薄膜的折射率变化范围为2.47~3.28.

Study on Infrared Optical Properties of Amorphous Silicon Films Deposited by Ion Beam Assisted Deposition

In order to get the relationship between the infrared optical constants and the process parameters of the amorphous silicon（a-Si）film,the a-Si films are prepared by electron beam evaporation and Ar ion beam assisted deposition and their optical constants are measured with an ellipsometer and a spectrophotometer.The effects of deposition rate,substrate temperature and working pressure on the film refractive index and extinction coefficient are analyzed.The experimental results show that deposition rate and substrate temperature strongly influence optical properties of a-Si films,and working pressure has the least influence.With an increase in deposition rate and substrate temperature,the refractive index of a-Si film increases first and then decreases;the refractive index increases with an increase in the vacuum.The a-Si film refractive index changes from 2.47 to 3.28 when the wavelength ranges from 1 to 5 μm.