Substrate Temperature Dependence of the Photoresist Removal Rate Using Atomic Hydrogen Generated by a Hot-Wire Tungsten Catalyst

Instead of photoresist removal methods using chemicals, we investigated an environmentally friendly removal method using atomic hydrogen generated by decomposing hydrogen molecules by contact with a hot-wire tungsten catalyst. We set the distance between the catalyst and the photoresist substrate (D(CS)) at 20, 60, 100 and 120 mm and evaluated the apparent activation energy (E(AP)) for the reaction between photoresist and atomic hydrogen at each D(CS). The E(AP) was determined from Arrhenius plots of the photoresist removal rate against the average substrate temperature. When D(CS) was 20 and 60 mm, E(AP) decreased with increasing catalyst temperature (WT = 2040-2420 degrees C) and was not constant. However, when D(CS) was 100 and 120 mm, E(AP) was nearly constant at 19 +/- 1 kJ/mol without depending on WT. We might obtain the activation energy of about 19 kJ/mol in the reaction of photoresist with atomic hydrogen. (C) 2010 The Japan Society of Applied Physics