High Speed Silicon Wet Bulk Micromachining of Si{111} in KOH Based Solution

The etching characteristics of Si{111} in pure and NH
2
OH-added 20 wt% KOH are investigated for the fabrication of MEMS structures using silicon wet bulk micromachining. The addition of NH
2
OH favorably modifies the etching characteristics of 20 wt% KOH, which are useful for high speed silicon wet bulk micromachining for the fabrication MEMS structures such as cavities, microcantilevers, etc. In addition, the lateral undercutting rate drastically increases in NH
2
OH-added KOH, which is a desirable property for the fast release of freestanding micro/nanoelectromechanical systems (M/NEMS) structures.