Controlling Copper Electrochemical Deposition (ECD)

The implementation of copper processing in semiconductor manufacturing has resulted in major process development and manufacturing challenges. A fundamental understanding of the copper plating processes used in manufacturing has been limited by the lack of in‐line methods for direct measurement and control of process chemistry. Plating bath chemistry adjustments and change‐out frequencies are currently determined using a combination of indirect electrochemical monitoring techniques, off‐line analyses of wafer metrology and analytical lab measurements. There have been a number of industry reports of major process startup delays, yield management problems and reliability issues as a result of these difficulties. A new in‐process mass spectrometry (IPMS) approach enables automated, real‐time measurement of both the inorganic components and organic additives in the copper electroplating chemistry as they change during production. The tool is not only capable of real time direct quantification of the copper, c...