Patent ID: 7850786

Claim:
A method of improving the corrosion resistance of a stainless steel surface which is used in contact with semiconductor processing fluids, consisting of: a) cleaning said stainless steel surface with a detergent or a basic reagent or a combination thereof, followed by; b) further cleaning said stainless steel surface using deionized water, followed by; c) drying said stainless steel surface using hot nitrogen gas, followed by; d) inspecting said cleaned stainless steel surface and repeating steps a) through c) until said stainless steel surface meets a criteria for surface contamination, followed by; e) treating said stainless steel with a nitric acid solution to improve the surface composition of said stainless steel, followed by; f) further cleaning said stainless steel surface using deionized water, followed by; g) treating said stainless steel surface with a detergent, followed by; h) further cleaning said stainless steel surface using deionized water, followed by; i) treating said stainless steel with a solution of citric acid to improve the surface composition of said stainless steel, followed by; j) further cleaning said stainless steel surface using deionized water, followed by; k) drying said stainless steel surface in the presence of an argon atmosphere, followed by; l) heat treating said stainless steel surface in the presence of an argon atmosphere, followed by; m) treating said stainless steel with a nitric acid solution to improve the surface composition of said stainless steel, followed by; n) further cleaning said stainless steel surface using deionized water; and o) drying said stainless steel surface using hot nitrogen gas.