Patent ID: 8287751
Filing Date: 2012-10-16
Classification: H01L

Abstract:
1. A method for extending an effective working life of a first chemical bath comprising a first chemical bath liquid within a first chemical bath container, the method comprising the steps of: adding an amount of fresh chemical to the first chemical bath liquid within the first chemical bath container; purging an amount of the first chemical bath liquid from the first chemical bath container, wherein the amount of fresh chemical added to the first chemical bath liquid is based on the amount of the first chemical bath liquid purged from the first chemical bath container; providing the amount of the purged first chemical bath liquid to a second chemical bath comprising a second chemical bath liquid within a second chemical bath container, wherein the second chemical bath liquid comprises contaminants contained in the amount of the purged first chemical bath liquid; and using the first and second chemical bath liquids in the first and second chemical baths to clean a semiconductor wafer in a wetdeck process; wherein each of the chemical bath containers comprises an independent structure that is separated from other chemical bath containers; and wherein the chemical baths are used to clean the semiconductor wafer in order of decreasing amounts of contamination in the chemical bath liquids of the chemical baths.