Patent ID: 7328497

Claim:
A method of manufacturing a mechanical resonator having a desired resonant frequency, the method comprising: forming a first electrode; forming a transducer layer over the first electrode; forming a second electrode having a plurality of discrete layers of known thickness, each of the discrete layers having etching properties different from at least one other of the discrete layers; sequentially etching a calculated number of the discrete layers in order to incrementally reduce the resonator overall thickness by a known amount to adjust a resonator resonant frequency to the desired resonant frequency, wherein the step of forming the second electrode discrete layers further comprises: forming a first conductive electrode layer having a thickness calculated to produce a resonator having a first resonant frequency that is higher than the desired resonant frequency; calculating a desired thickness for an adjustment layer such that, when the adjustment layer is placed over the first conductive layer, the resonant frequency of the resonator is reduced by a selected frequency increment; forming a plurality of adjustment layers over the conductive layer sufficient to produce a second electrode thickness such that the resonant frequency of the resonator is below the desired resonant frequency, each of the adjustment layers having etching properties different from the etching properties of any adjacent adjustment layers; measuring an actual resonant frequency of the resonator and calculating a number of adjustment layers to be removed to incrementally adjust the actual resonator frequency to the desired resonant frequency; and sequentially selectively etching the calculated number of adjustment layers to adjust the resonator resonant frequency to the desired resonant frequency.