Resist pattern collapse with top rounding resist profile

Abstract

The pattern size is reduced as the device is more integrated. The resist deformation phenomenon has been a serious problem under 100 nm line width patterns. The most applicable model for an existing empirical result is chosen to create a simulation tool by comparing the two mechanical models when a pattern receives a distributed pressure or a concentrated pressure from the rinse liquid. Based on the chosen model, the critical aspect ratio with respect to line width and space can be calculated. The simulated results show that the pattern collapse phenomenon is reduced for a rounded top resist profile rather than for a flat top profile.