Compensation Research of the Thin Film Absorption in Thin-Film Thickness Wideband Monitoring System

During the course of thin film deposition,the thin-film thickness wideband monitoring system is utilized,the correction of thickness monitoring depends on overlapping stage of the theoretical transmittance curve and the measured one. The absorption of thin-film material results in the measured spectrum curve deviation from the theoretical spectrum curve. A method in software brings forward, namely before the next layer will be deposited, its theoretical transmittance curve is corrected so that the absorption of layers which have been deposited has no effect on this layer, as such, the theoretical transmittance curve of the layer which will be deposited is corrected until the deposition ends.By experiment, the monitoring error of thin-film thickness is less than 10-3, the result indicates that this method can satisfy the practical requirement.