As attached, I know basic concept between Positive and Negative PR But, I confirm this message; Negative resists were popular in the early history of integrated circuit processing, but positive resist gradually became more widely used since they offer better process controllability for small geometry features. Positive resists are now the dominant type of resist used in VLSI fabrication process. 1. Why Positive PR is the better than negative PR in VLSI? 2. Why Positive PR is the better than negative PR about "Resolution" ? R=K*λ/NA (Rayleigh criterion) Please.. Answer to me, I'm so curiosity... with Engineertic answer..