A Novel Process to Reduce Roughness in Chemically Amplified Resist (CAR) for Next-Generation Lithography

To achieve miniaturization in high-volume manufacturing (HVM), reducing the roughness of the chemically amplified resist (CAR) is highly desired. In a previous paper, post-development treatment (PDT) under development could reduce the low-frequency roughness of the 28 nm pitch line and space (L/S) [1], but the mechanism was unclear. Therefore, to understand the effect of PDT on the CAR, we performed a basic evaluation using CAR films that were either unexposed or exposed to KrF flood exposure. The results of the CAR surface roughness by atomic force microscopy (AFM) revealed a similar trend to the roughness reduction observed for 28 nm pitch L/S. Furthermore, our investigation into the PDT's impact on etch process resistance suggested an enhancement in etching resistance while maintaining a smooth surface of the CAR. This potential dual benefit of the PDT, which involves reducing roughness and improving, could significantly impact HVM.