Patent ID: 9705470
Date: 2017-07-11
CPC Classifications: H01L,H03H

Claim:
1. A microelectromechanical system (MEMS) resonator comprising: a single-crystal silicon layer doped with an impurity concentration that renders the single-crystal silicon layer sufficiently conductive to serve as a first electrode; a conductive layer to serve as a second electrode; an aluminum nitride piezoelectric layer disposed between the conductive layer and the single-crystal silicon layer; wherein a resonator axis along which the MEMS resonator exhibits a predominant motion during resonant oscillation is offset from a dominant crystallographic axis of the single-crystal silicon layer by an angle that substantially reduces at least one of first-order or second-order temperature coefficients of frequency (TCFs) of the MEMS resonator relative to first- and/or second-order TCFs that would result without angular offset between the resonator axis and the dominant crystallographic axis; and wherein the impurity concentration and angular offset are jointly controlled to substantially attenuate the first-order and second-order TCFs.