光学薄膜的误差灵敏度和允差分析

Computerized control of error sensibility and tolerance analysis

实际生产出的薄膜的光学特性和理论计算得到的光学特性常常存在差别,这些差别的来源有多种,诸如理论模型假设时忽略的一些因素;薄膜久置引起的薄膜结构改变或吸潮、污染;制造过程中的制造误差(光学监控系统引起的薄膜厚度和折射率的误差)等。针对各种误差的来源有相应的改善方法。本文就光学监控系统引起的薄膜厚度和折射率的误差进行分析,同时提出膜系的允差分析,以尽量减小由于监控设备引起的误差,最后介绍了实际生产的计算机优化监控程序。

The optical property of the thin films actually produced often differ from those calculated theoretically in some fields. These differences are formed from different sources, such as some influencing factors which were neglected in theoretical models, the structural variation of film due to moisture/pollution when stored for long and the errors in production, eg. film thickness error and refractivity error due to improper optical monitoring system. Some measures are proposed to take to improve different error sources, with the stress put on the errors originated from the optical monitoring system. The tolerance analysis is thus suggested for optical thin films with the aim to minimize such errors. A control program to optimize monitoring process for film production is introduced.