MICROMACHINING OF (HHL) SILICON STRUCTURES - EXPERIMENTS AND 3D SIMULATION OF ETCHED SHAPES

The micromachining of various (hhl) silicon plates in a 35% KOH-water etchant is studied. Experimental shapes for membranes and mesa etched with initially circular masks are discussed. Theoretical 3D etched sha pes for such microstructures are derived from a numerical simulation b ased on the tensorial model for the anisotropic wet etching. Experimen tal and theoretical shapes show a fair agreement, indicating a satisfa ctory adjustment of the dissolution slowness surface related to the et ching of silicon in KOH etchant. The interest of the 3D simulation for designing mask patterns is outlined.