Patent ID: 6486073
Filing Date: 2002-11-26
Classification: G03F,H01L

Abstract:
A method for forming an aluminum-copper alloy wiring pattern on an insulation layer which is formed on a semiconductor substrate, an entire surface of which substrate is immune to damage from plasma due to the insulation layer, comprising the steps of:forming, on the semiconductor substrate, over the insulation layer, a layer of aluminum alloy containing 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 using accelerated reactive ions in gas plasma containing at least 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 covering the semiconductor substrate; subsequent to etching the exposed layer portion, downstream ashing the resist pattern isotropically by exposing the resist pattern to an atmosphere containing only non-ionic species, said atmosphere being created by generating gas plasma from reaction gas containing oxygen by applying electromagnetic power and directing non-ionic species in said gas plasma; and after the downstream ashing step, removing the residual chlorine component from the patterned layer and the insulation layer by heating the substrate with the patterned layer thereon in vacuum between 100Â° C. and 300Â° C. by a heated stage whereon the substrate is placed.