用透过率测试曲线确定半导体薄膜的光学常数和厚度

Determination of Optical Constants and Thickness of Semiconductor Thin Films by Transmission Measurement

介绍了一种简单而准确地确定薄膜光学常数和厚度的方法 .借助于Forouhi Bloomer物理模型 ,用改进的单纯形法拟合分光光度计透过率测试曲线 ,获得半导体薄膜的光学常数和厚度 .对射频磁控溅射和直流反应溅射制备的玻璃基板上的α Si和ZnO薄膜进行了实验 ,拟合的理论曲线和实验曲线吻合得非常好 .计算得到的结果与文献报道的结果和台阶仪的测量结果一致 ,误差小于 4 % .该方法对无定形或多晶的半导体薄膜都适用 ,也可以用于计算厚度较薄的薄膜 .

A simple and accurate method is presented for determination of the optical constants and physical thickness of semiconductor films.The method consists in fitting the experimental transmission curve with the help of the physical model proposed by Forouhi and Bloomer.The fit is made using the modified ‘downhill’ simplex method to determine of the film thickness and the model parameters.This method is applied for amorphous Si deposited by RF sputtering and amorphous ZnO deposited by reactive sputtering on glass substrate.The calculated transmission curves fit the experimental ones well.And the results agree with those reported in the literature and from step profiler,the errors are less than 4%.The method is suitable for amorphous and crystalline semiconductor films,and those with thinner thickness as well.