Plasma Strip of Cold Implant Photoresist

This paper reports on the formation of highly carbonized crust layer on top of high dose implanted photoresist (PR) at cold implant temperature (-50°C) as well as room temperature. The differences between the crusts formed at different implant temperatures and the effects to the subsequent resist plasma strip were investigated. Thinner crust formed at cold implant temperature led to faster and more uniform crust and PR removal. The changes of the photoresist chemical bonding after ion implantation at different temperatures were also studied, and difference of chemical bonding between resist wafers implanted at different temperature was observed. Test results demonstrated that the resist implanted at cold temperature beneficially affects crust formation and PR plasma strip processes.