KrF Excimer Laser Micromachining of Silicon for Micro-Cantilever Applications

The conventional photolithography of crystalline silicon techniques is limited to two-dimensional and structure scaling. This can be overcome by using laser micromachine, a technique capable of producing three-dimensional structure and simultaneously avoiding the needs for photomasks. In this paper, we report on the use of RapidX-250 excimer laser micromachine with 248 nm KrF to create in-time mask design and assisting in the fabrication of micro-cantilever structure. Three parameters of the laser micromachine used to aid the fabrication of the micro-cantilever have been investigated; namely the pulse rate (i.e. number of laser pulses per second), laser energy and laser beam size. Preliminary results show that the 35 um beam size and 15 mJ energy level is the most effective parameter to structure the desired pattern. The parallel lines spacing of the structure can be reached up to 10 um while cutting, holes drilling and structuring the cantilever using the laser beam can be accomplished to as low as 50 um in dimension.