Photo-resist removal using highly concentrated ozone gas - Removal characteristics of various resists

Abstract

New processing technologies are demanded which produce hyperfine structures for electronic devices and which do not exacerbate environmental problems. We specifically examined photoresist removal technology for this study. Ozone gas of nearly 100% concentration was applied to various photoresists and ion-implanted-photoresists. Results showed that reactivity with ozone gas differs between a novolac resist, which has a benzene ring structure on a main chain, a KrF resist with this structure on a side chain, and an ArF resist which has no such structure. The activation energy of the KrF resist indicates a value close to that of the novolac resist; the value for the ArF resist was larger than these. Irrespective of the ionic species, the ion-implanted- photoresist of amount Ie 16 cm-2 of the dose can be removed with 0.7 μm/min or less in the ashing of 400°C in processing temperature. Additionally, results showed that the removal speed slows in order of B, As, and P. ©2008 CPST.