基于评价函数的宽光谱膜厚监控系统,由于实测光谱曲线和理论光谱曲线相背离,使得评价函数发散,监控失败。利用实测的膜层透射率光谱曲线,对于已镀层,利用模拟退火算法实时拟合其实际的光学常数,据此修正目标透射率曲线,并补偿吸收的影响,重新设计膜层数及预镀层厚度,获得新的评价函数,如此对评价函数进行逐层修正。实验结果表明,薄膜厚度监控误差可以达到10-2以下,精度完全可以满足实际要求。 Based on the evaluation function of the broad-spectrum film thickness monitoring system, the deviation of the measured spectral curve from the theoretical spectral curve causes the evaluation function to diverge and the monitoring fails. The measured optical transmittance curve of the coating was used to simulate the actual optical constants of the coated layer and the simulated annealing algorithm in real time so as to correct the target transmittance curve and compensate the influence of absorption and to redesign the number of layers and the thickness of the pre-coating , Get a new evaluation function, so the evaluation function layer by layer correction. Experimental results show that the film thickness monitoring error can reach 10-2 below, the accuracy can meet the actual requirements.