Analyzing stray light on line structures of different critical dimensions based on Kirk test

The Kirks stray light simulation model is adopted to study the variation of stray light on different line structures, and the effects of stray light on imaging of different line structures are analyzed according to be image contrast. The simulation based on in-house image processing software written in Matlab indicates that, imaging of a sparser line structure has a lower image contrast and is more susceptible to stray light when the critical dimension is fixed. When the ratio of line width and space is fixed, a smaller critical dimension will lead to a lower image contrast and stronger effect of stray light on image pattern. Therefore, the stray light has great influence on the image pattern of narrow and sparse line structure.