Method for performing on-wafer tuning of thin film bulk acoustic wave resonators (FBARS)

Claim 1

A method for tuning individual ones of a plurality of Thin Film Bulk Acoustic Wave Resonators (FBARs) constructed on a wafer, each of the FBARs exhibiting at least one of a series resonance and a parallel resonance at respective frequencies before a layer is deposited over the FBAR, wherein after the layer is formed over at least a portion of the individual FBARs, the FBARs exhibit at least one of a series resonance and a parallel resonance at frequencies that are a function of a thickness of the layer, comprising the steps of: measuring frequencies at which selected ones of the FBARs exhibit one of a series resonance and a parallel resonance before the layer is formed over the FBARs; calculating an average of the measured frequencies; calculating a thickness (T) of the layer that is to be formed over at least a portion of the FBARs in order to minimize a difference between the calculated average of the measured frequencies and a reference frequency; and simultaneously forming the layer over at least a portion of each of the plurality of FBARs so that the layer has the thickness (T), thereby minimizing the difference between the reference frequency and the calculated average of the measured frequencies.

Claim 2

A method for tuning individual ones of a plurality of Thin Film Bulk Acoustic Wave Resonators (FBARs) constructed on a wafer, each of the FBARs exhibiting at least one of a series resonance and a parallel resonance at respective frequencies before a layer is deposited over the FBAR, wherein after the layer is formed over at least a portion of the individual FBARs, the FBARs exhibit at least one of a series resonance and a parallel resonance at frequencies that are a function of a thickness of the layer, comprising the steps of: measuring frequencies at which selected ones of the FBARs exhibit one of a series resonance and a parallel resonance before the layer is formed over the FBARs; calculating an average of the measured frequencies; calculating a thickness (T) of the layer that is to be formed over at least a portion of the FBARs in order to minimize a difference between the calculated average of the measured frequencies and a reference frequency; and simultaneously forming the layer over at least a portion of each of the plurality of FBARs so that the layer has the thickness (T), thereby minimizing the difference between the reference frequency and the calculated average of the measured frequencies.

Claim 8

A method for simultaneously tuning a plurality of Thin Film Bulk Acoustic Wave Resonators (FBARs) before the FBARs are separated from a wafer, comprising steps of: (i) measuring frequencies at which selected ones of the FBARs exhibit a resonance, the frequencies being a function of thicknesses of the selected ones of the FBARs; (ii) calculating an average of the measured frequencies; (iii) calculating a thickness for at least one layer which, after being deposited on the FBARs, will cause a difference between the calculated average of the measured frequencies and a reference frequency to be substantially minimized; and (iv) simultaneously forming the at least one layer having the thickness calculated in step (iii) on the plurality of FBARs before the FBARs are separated from the wafer, thereby causing the difference between the reference frequency and the calculated average of the measured frequencies to be substantially minimized.

Claim 9

A method for simultaneously tuning a plurality of Thin Film Bulk Acoustic Wave Resonators (FBARs) before the FBARs are separated from a wafer, comprising steps of: (i) measuring frequencies at which selected ones of the FBARs exhibit a resonance, the frequencies being a function of thicknesses of the selected ones of the FBARs; (ii) calculating an average of the measured frequencies; (iii) calculating a thickness for at least one layer which, after being deposited on the FBARs, will cause a difference between the calculated average of the measured frequencies and a reference frequency to be substantially minimized; and (iv) simultaneously forming the at least one layer having the thickness calculated in step (iii) on the plurality of FBARs before the FBARs are separated from the wafer, thereby causing the difference between the reference frequency and the calculated average of the measured frequencies to be substantially minimized.

Claim 12

A method for simultaneously tuning a plurality of Thin Film Bulk Acoustic Wave Resonators (FBARs) before the FBARs are separated from a wafer, comprising steps of: measuring a frequency at which selected ones of the FBARs exhibit a resonance, the frequency being a function of thicknesses of the selected FBARS; calculating an average of the measured frequencies; calculating an amount (A) by which the thicknesses of the selected FBARs need to be altered in order to substantially minimize a difference between the calculated average of the measured frequencies and a reference frequency; and simultaneously altering the thicknesses of each of the plurality of the FBARs by the amount (A) before the plurality of FBARs are separated from the wafer for reducing the difference between the reference frequency and the calculated average of the measured frequencies.

Claim 13

A method for simultaneously tuning a plurality of Thin Film Bulk Acoustic Wave Resonators (FBARs) before the FBARs are separated from a wafer, comprising steps of: measuring a frequency at which selected ones of the FBARs exhibit a resonance, the frequency being a function of thicknesses of the selected FBARS; calculating an average of the measured frequencies; calculating an amount (A) by which the thicknesses of the selected FBARs need to be altered in order to substantially minimize a difference between the calculated average of the measured frequencies and a reference frequency; and simultaneously altering the thicknesses of each of the plurality of the FBARs by the amount (A) before the plurality of FBARs are separated from the wafer for reducing the difference between the reference frequency and the calculated average of the measured frequencies.