A process for photoresist removal after aluminum etching using plasma treatment in a gas containing hydrogen

A photoresist removal process with plasma treatment after aluminum film etching was developed. During a previous reactive ion etching step, reaction products are deposited on the sidewalls of the patterns etched in the Al film and the photoresist on top of it. The deposited material is analyzed by X-ray photoelectron spectroscopy and found to consist of chlorides of Al. It is demonstrated than the deposited film can be removed by treatment in inductively coupled plasma using hydrogen-containing gas (methyl alcohol in the present study) with a radio frequency bias applied to the substrate. The optical spectra indicate that the reactive species are hydrogen and other reactive species (e.g., CH and OH) generated by dissociation of methyl alcohol.