Patent ID: 6103633
Filing Date: 2000-08-15
Classification: H01L

Abstract:
A method of cleaning metal precipitates in the formation of metal lines in the fabrication of an integrated circuit comprising:providing semiconductor device structures in and on a semiconductor substrate;covering said semiconductor device structures with an insulating layer;depositing a barrier metal layer overlying said insulating layer;depositing an aluminum layer overlying said barrier metal layer wherein said aluminum layer is an aluminum alloy containing copper and wherein said metal precipitates form at the interface between said barrier metal layer and said aluminum layer;covering said aluminum layer with a layer of photoresist;exposing said photoresist layer to actinic light and developing and patterning said photoresist layer to form the desired photoresist mask;etching away said aluminum layer where it is not covered by said photoresist mask to form said metal lines whereby said metal precipitates are exposed on the surface of said barrier metal layer;anisotropically etching into said barrier metal layer using a high DC bias of greater than 240 volts; andthereafter isotropically etching into said barrier metal layer underlying said metal precipitates whereby said metal precipitates are stripped away from said surface of said barrier metal layer completing said cleaning of said metal precipitates in said formation of said metal lines in said fabrication of said integrated circuit.