Publication Type:



Volume US5445705 A, Number US 08/269,865 (1995)



A contactless method and apparatus for in-situ chemical etch monitoring of an etching process during etching of a workpiece with a wet chemical etchant are disclosed. The method comprises steps of providing a base member having a reference surface; releasably securing the workpiece to the base member; providing at least two sensors disposed on the base member to be proximate to but not in contact with the outer perimeter of the workpiece surface; and monitoring an electrical characteristic between said at least two sensors, wherein a prescribed change in the electrical characteristic is indicative of a prescribed condition of the etching process.

Cite this Research Publication

S. G. Barbee, Datta, M., Heinz, T. F., Li, L., Ratzlaff, E. H., and Shenoy, R. V., “Method and apparatus for contactless real-time in-situ monitoring of a chemical etching process”, U.S. Patent US 08/269,8651995.