Patent ID: 6086946
Filing Date: 2000-07-11
Classification: C23C,H05K,Y10S,Y10T

Abstract:
A method for electroless gold deposition, comprising:providing a substrate;forming copper circuit features on said substrate by an additive process employing a catalyst material having palladium, wherein the palladium is a primary component to initiate the deposition of copper on said substrate;treating said substrate with an alkaline cleaner;rinsing said substrate subsequent to said treatment with an alkaline cleaner;treating said rinsed substrate with sodium persulfate;rinsing said substrate subsequent to said sodium persulfate treatment;treating said rinsed substrate with diluted sulfuric acid;rinsing said substrate subsequent to said diluted sulfuric acid treatment;immersing said rinsed substrate in a gold deposition solution whereby gold is directly deposited on exposed surfaces of the copper circuit features in the presence of detectable amounts of said palladium catalyst on said sides of the copper circuit features;rinsing said substrate subsequent to immersion in said gold deposition solution; anddrying said rinsed substrate.