Patent ID: 8236580
Filing Date: 2012-08-07
Classification: H01L

Abstract:
1. A method, comprising: (a) forming a multiplicity of contamination monitors, each contamination monitor comprising an ion-implanted N-type region in a single-crystal silicon substrate, said N-type region abutting a top surface of said substrate; (b) selecting an unused contamination monitor of said multiplicity of contamination monitors and submerging, for a preset duration of time, said selected contamination monitor of said multiplicity of contamination monitors into an aqueous solution contained in a tank of a processing tool used to fabricate integrated circuits; after (b), (c) determining an amount of copper adsorbed from said aqueous solution by said region of said substrate of said selected contamination monitor; after (c), (d) if said amount of copper exceeds a preset limit, taking a corrective action to prevent copper contamination of said integrated circuits when processed in said tank before processing said integrated circuits through said tank and if said amount of copper does not exceed said preset limit then processing said integrated circuits through said tank; and (e) repeating steps (b) through (d) periodically.