Patent ID: 8481142

Claim:
A method comprising the steps of: placing a semiconductor wafer in a total X-ray reflection fluorescence tool; scanning said semiconductor wafer using total X-ray reflection fluorescence; determining a chlorine content and a copper content of said semiconductor wafer through surface profiling of said semiconductor wafer, wherein said surface profiling determines said chlorine content and said copper content through said total X-ray reflection fluorescence; and using said determination of said chlorine content of said semiconductor wafer and chlorine contents and copper contents for a plurality of semiconductor wafers previously exposed to a metal etch process to select a value of chlorine concentration for said metal etch process to etch said semiconductor wafer that will not create metal chloride corrosion on the semiconductor wafer; wherein said plurality of semiconductor wafers were previously exposed to said metal etch process with a plurality of chlorine concentrations; and wherein said total X-ray reflection fluorescence creates a copper concentration map showing quantitative and spatial information for copper on a surface of said semiconductor wafer.