Modulated-temperature DSC (MT-DSC): a new technique for the extensive thermal characterization of complex chemically amplified systems

Abstract

Two main parameters are expected from the thermal analysis of chemically amplified resist systems, namely the glass transition temperature and the temperature of deprotection. Due to the large heat flow involved in the deprotection reaction, this thermal event is generally easily monitored using conventional differential scanning calorimetry (DSC). Conversely, the glass transition signal, corresponding to slight changes in the heat capacity of the resist material, is often hidden by or convoluted with the deprotection reaction. This problem constitutes a limitation on the understanding and modeling of these resist systems. The recently introduced modulated temperature DSC (MT-DSC) technique allows the separation of Tg and the deprotection reaction signals, and therefore provides experimental solutions to unsolved basic questions foe each step of the lithographic process. This study presents the first results on the thermal characterization of chemically amplified systems using MT-DSC. All chemically amplified systems, both positive or negative tone, presenting or not a Tg signal convoluted with the deprotection signal, can be completely characterized using this technique.