Patent ID: 6184148
Filing Date: 2001-02-06
Classification: G03F,H01L

Abstract:
A method for forming an aluminum alloy pattern on a semiconductor substrate, comprising the steps of:forming, on a semiconductor substrate having an insulation layer thereon, a layer chosen to have a thickness of 1-4 .mu.m from an aluminum alloy containing 2-4% copper;forming a resist pattern on said aluminum alloy layer to create a resist layer portion and an exposed layer portion;etching the exposed layer portion using the resist pattern as a mask by reactive etching using gas plasma containing chlorine ions to form a patterned layer,wherein a residual chlorine component is sputtered by ion bombardment on the resist pattern and on the insulation layer on the semiconductor substrate, said residual chlorine component including at least one of cuprous chloride, cupric chloride and a mixture of Cu, Cl, Al, C;downstream ashing the resist pattern isotropically by exposing the resist pattern to gas plasma containing only non-ionic species from reaction gas containing oxygen to which electromagnetic power has been applied, and from the ionic species of the gas plasma; andremoving the residual chlorine component from the patterned layer and the insulation layer by heating the substrate with the patterned layer thereon in vacuum between 250.degree. C. and 300.degree. C.,wherein the downstream ashing and removing steps occur without generating aluminum oxide particles on the patterned layer, andwherein the reaction gas comprises a nitrogen containing compound and oxygen.