Method for manufacturing a coupled resonator device
View Patent ↗A method for manufacturing a coupled resonator device includes forming a first BAW-device on a first substrate, forming a second BAW-device on a second substrate, and bonding the first and the second BAW-device such that the bonded first and second BAW-device are sandwiched between the first and second substrate.
1. A method for manufacturing a coupled resonator device, the method comprising:
forming a first BAW-device on a first substrate;
forming a second BAW-device on a second substrate;
bonding the first and the second BAW-device such that the bonded first and second BAW-device are sandwiched between the first and second substrate;
trimming the first BAW-device; and
trimming the second BAW-device depending on the trimmed first BAW-device.
2. The method of claim 1 , wherein the first BAW-device exhibits a first resonance frequency and wherein the second BAW-device exhibits a second resonance frequency, and wherein trimming of the first BAW-device comprises adjusting the first resonance frequency depending on the second resonance frequency.
3. The method of claim 2 , wherein the trimming is performed such that a difference between the first and the second resonance frequencies comprises a target value.
4. The method of claim 1 , wherein forming the first and second BAW-devices comprises forming a piezoelectric layer sandwiched by a first and second electrode layer.
5. The method of claim 4 , further comprising trimming the first BAW-device wherein the trimming comprises etching the first or second electrode layer.
6. The method of claim 4 , further comprising trimming the first BAW-device, wherein the trimming comprises adding further layer material to one of the first or second electrode layer.
7. The method of claim 1 , further comprising forming a coupling layer, wherein the coupling layer is arranged between the first BAW-device and the second BAW-device, such that the first and second BAW-devices are electrically isolated and acoustically coupled.
8. The method of claim 7 , wherein the first BAW-device exhibits a first resonance frequency and wherein the second BAW-device exhibits a second resonance frequency and wherein the coupling layer comprises a coupling layer thickness, the method further comprising adjusting the coupling layer thickness depending on the first or second resonance frequency.
9. The method of claim 7 , wherein the coupled resonator device shows a filter characteristic with a bandwidth and an attenuation within a certain frequency range, the method further comprising trimming an electrode layer or trimming the coupling layer, such that the filter characteristic is within target values.