Novolak Resist Removal by Laser Irradiation (532 nm) and Adhesion between Resist and Substrate

A diazonaphthoquinone/novolak resist on a 42-alloy substrate was irradiated by the second harmonic wave (532 nm) of a pulsed Nd3+YAG laser. The resist was removed, despite the existence of hexamethyldisilane (HMDS). There was no apparent damage to the substrate. In contrast, the resist on a Si wafer could not perfectly be removed. In some cases, there was damage to the substrate. The peeling strength of the resist with HMDS was about three times than that without HMDS. The width of the resist removed by laser irradiation without HMDS was 1.02–1.03 times larger than that with HMDS. The use of this process will benefit the environment, since expensive and toxic chemicals are not used.