Abstract
Using environmentally friendly wet ozone instead of conventional chemical methods, we removed positive-tone novolak resists. In wet ozone process, resists were decomposed and were removed in the process of the ozonolysis reaction of resists and the hydrolysis reaction of the ozonolysis products. Wet ozone process has the combination of wet ozone temperature and substrate temperature which photoresist removal rate becomes maximum rate. The maximum photoresist removal rates are 1.8μm/min at wet ozone temperature was 74℃ and substrate temperature was 66℃, 1.6μm/min at wet ozone temperature was 68℃ and substrate temperature was 62℃, 0.9μm/min at wet ozone temperature was 46℃and substrate temperature was 44℃. It was revealed that temperature difference (= “wet ozone temperature (TWO)”. “substrate temperature (TIS)”) to control water requirements for the hydrolysis strongly influences the resist removal rate. Also, the reaction of photoresist removal using wet ozone accedes to arrhenius low, and activation energy was 28.0kJ/mol.
