Tringular Corner Compensation and Etch Flow Mechanism for Anisotropic TMAH Etching of (100) Silicon | Original Article

ABSTRACT:

Anisotropic wet chemical bulk-micromachining is a simple and cost-effective method for fabricating silicon micro sensors. In anisotropic etching, convex corners are attacked; therefore, a proper compensating structure design is often required when fabricating microstructures with sharp corners (convex corners). In the present work, <310• triangular compensation structures have been used for convex corner compensation with 25% wt. TA'IAH-water solution at 90.± lit temperature. Design and etch flow morphology of the compensating structure is presented. This type of compensation is use hill for the applications like micro cantilevers, where protection of convex corner is required and space is not a constraint. For 25% wt. 1111111-water solution, it was observed that throughout the etching, (311) planes were responsible for etching in all the directions curd no other planes were observed. Etch-front-attack angle remains the same as that ul <310> angle. This compensation can give perfect convex corner and mesa, but requires more space. The compensation structure is simple to design and analyze among all other types such as 10':- square. 100.' bars. and 110 bars of compensating structures.