R-F Electrode type workholder and methods of supporting workpieces during R-F powered reactive treatment

摘要

Workpieces (11), such as semiconductor wafers, are treated in a plasma reaction apparatus (10). The wafers are loaded onto a workholder (18), where they become seated in contact with facing surfaces of a plurality of spaced, parallel plates (19, 21). Plasma is generated in each of the spaces (23) between two adjacent ones of the plates by coupling such adjacent plates to opposite terminals (31, 32) of an R-F generator (29). Each of the plates is comprised of a base structure (41) of a thermally stable, conductive material, such as graphite. The base structure is covered with a first layer (43) of a hard material, such as silicon carbide to impart wear resistance to the graphite. The layer (43), in turn, is covered by an outer, conductive layer (44) which, in the described embodiment is a layer of aluminum.