Wafer-scale etch process for precision frequency tuning of MEMS gyros

A technique which retains wafer-scale processing and packaging compatibility is described for customizing the dynamics of individual silicon resonators. The approach uses laser ablation of a protective conformal layer (parylene) to expose silicon in regions that are targeted for mass removal by subsequent DRIE. The technique is demonstrated on a planar axisymmetric resonator design whereby the frequency mismatches of a subset of the wafer´s resonators are reduced to less than 100 mHz.