Novel Wet Anisotropic Etching Process for the Realization of New Shapes of Silicon MEMS Structures

In this work, we have developed a novel anisotropic wet etching process for the fabrication of MEMS microstructures with rounded concave and sharp convex corners, grooves for chip isolation, mesa structures with bent V-grooves, and 45deg mirrors by using a single etching mask. Tetra Methyl Ammonium Hydroxide (TMAH) at various concentrations with and without the non-ionic surfactant NC-200 at 0.1% of the total volume of the etchant has been used. In order to fabricate the microstructures with rounded concave corners, round shape mask pattern was used. Mesa structures and grooves for chip isolation were realized using spatially efficient convex corner compensation structures.