A Novel Method of Fabricating Optical Gratings Using the One Step DRIE Process on SOI Wafers

This paper describes a novel technique for manufacturing optical gratings using the one step DRIE (Deep Reactive Ion Etching) process. Utilising the notching effect documented in previous work when working with silicon on insulator (SOI) wafers, fully released, intact gratings have now been produced without the requirement for additional releasing processes. The one step process eliminates the possibility of stiction which can occur when “wet” processing chemistry is used in the release of microstructures. It should be noted that all DRIE etching in this work was performed using a Surface Technology Systems DRIE which uses a process developed from the Bosch process (R B Bosch Gmbh 1994 US Patent Specification 4855017 and German Patent Specification 4241045CI) termed ‘time multiplexed deep etching’ (TMDE) [1].