Resist Removal by using Atomic Hydrogen

Resist removal technology by using atomic hydrogen generated by tungsten (W) catalyzer was evaluated. This removal method is the dry process which does not use chemicals, so it was expected that the environmental burden and the cost can decrease. The resist removal rate has increased by raising W current and the substrate temperature. The removal rate of the positive type of novolak resist was over 1 μm/min at the current of 30A (W catalyzer was 2000°C) and at the substrate temperature of 230&deg:C. Polyvinyl phenol (PVP) and poly methylmethacrylate (PMMA) which were used as the shorter wavelength resist were able to be removed as well as the positive type of novolak resist. In these three polymers, PMMA removal rate was about three times as fast as those of others. It is thought that polymer with high removal rate has no benzene ring and is main chain scission type polymer.