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.
© 2012 Chinese Optics LettersPDF Article