Inductively coupled plasma etching of bulk molybdenum

Abstract

Molybdenum is a promising material for bulk MEMS applications for its high melting point, radiation resistance, high strength and conductivity. This paper reports on the development of wafer level bulk molybdenum ICP etching. Various etching chemistry are explored. The influence of process parameters (coil power/ICP power, platen power/RIE power and gas flow rate) on the etching rate, selectivity to SU-8 mask and etching profile anisotropy are investigated. With an optimized recipe, an etching rate of 2.63μm/min has been achieved with a profile of 70° and samples are employed as electrodes in micro Electrical Discharge Machining (μEDM).