Stripping of High-Dose Ion-Implanted Photoresist Using a Combination of Dry and Wet Single-Wafer Processing

Abstract

High dosed ion implanted (HDI) photoresist is well-known to be difficult to remove by conventional wet stripping e.g. sulfuric–peroxide mixture without substrate loss because of their carbonized crust layer. To overcome this issue, several methods are proposed such as dry etch + wet, assist of physical cleaning. In this paper, a new method to strip HDI photoresist using a combination of dry and wet processing in the same chamber is introduced to achieve HDI photoresist removal without substrate loss. A new process consists of two steps. The first process removes the carbonized crust layer by atmospheric-pressure inductively coupled hydrogen plasma, and the second process removes remaining the bulk photoresist by a sulfuric–ozone mixture. The new process enables removal of the HDI photoresist without any substrate loss, and with significantly shorter times.