Novel technique for characterizing feature profiles in photolithography process

A novel angle-resolved scatterometer based on pupil optimization for feature profile measurement in a photolithography process is proposed.The impact of image sensor errors is minimized by optimizing the intensity distribution of the incident light using a spatial light modulator.The scatterometry sensitivity of feature measurement at different polarization conditions is calculated using the rigorous coupled-wave and first-order analyses,and the reproducibility of the scatterometer is evaluated.The results show that the sensitivity and reproducibility of the angle-resolved scatterometer increase by 90% and 40% with pupil optimization,respectively.