Processing effects on the dissolution properties of thin chemically amplified photoresist films

Resist film thickness is anticipated to be 60 nm in the 22 nm technology node setting significant processing challenges due to resist non-bulk behavior. The changes in the dissolution rate of a positive DUV polymer based chemically amplified resist due to various processing conditions such as film thickness, exposure dose, and thermal processing conditions, are experimentally investigated. It is quantified among others, the way an increase of PAB temperature deteriorates dissolution rate at low exposure dose, while in higher exposure doses increasing PAB temperature enhances dissolution rate. Also, an analytic model for the dissolution rate is imported on a stochastic lithography simulator and first quantitative results for thin films are reported.