膜厚监控误差及监控片不均匀对膜厚监控的影响

借助于VC 编程从理论上模拟分析了膜厚监控误差以及监控片不均匀性对光学膜厚监控的影响。结果表明,膜厚监控误差和监控片的不均匀性都对监控曲线有影响;随着膜层层数的增加,监控片不均匀性逐渐增大。实验制备了多层规整薄膜并对其监控曲线进行了分析,分析表明考虑到膜厚监控误差和监控片不均匀性后计算的光学监控曲线和镀膜过程实测光学监控曲线吻合较好。这说明膜厚监控误差和监控片不均匀性是引起监控曲线与理论值偏离的重要因素。介绍了如何计算考虑膜厚监控误差和监控片不均匀性后的理论监控曲线。这将对膜厚自动监控,尤其是对非规整膜系的自动监控具有重要的指导意义。

Effect of Thickness Monitoring Error and Inhomogeneity of Witness Glass on Film Thickness Monitoring

By the aid of VC ,the influence of thickness monitoring error and witness glass inhomogeneity on the thickness monitoring of optical films is analyzed.It is found that both thickness monitoring error and witness glass inhomogeneity have effect on the thickness monitoring of optical thin films,and the inhomogeneity of witness glass increases with increase of coating layers.Then a multi-layer coating is fabricated and its monitoring curve is analyzed,it is shown that the theoretical monitoring curve which takes thickness monitoring error and inhomogeneity of witness glass into account is close to the experimental monitoring curve,and such a conclusion is got that thickness monitoring error and witness glass inhomogeneity are the important factors which cause the deviation of experimental monitoring curve from theoretical one.In the end,the calculation method of theoretical monitoring curve is proposed,in which thickness monitoring error and witness glass inhomogeneity error are taken into account.The results are of importance for the automatic thickness monitoring of thin films,especially of non-quarter wave coatings.