BAW component, lamination for a BAW component, and method for manufacturing a BAW component

1. A BAW component, comprising:

a first bulk acoustic wave (BAW) resonator having a first bottom electrode, a first top electrode and a lamination between the first bottom electrode and the first top electrode, wherein:

the lamination comprises a first layer with a first piezoelectric material comprising Sc doped AlN and a second layer with a second piezoelectric material that is different from the first piezoelectric material and arranged over the first layer;

a carrier chip; and

a second BAW resonator consisting of a second bottom electrode, a second top electrode, and a piezoelectric layer between the second bottom electrode and the second top electrode, wherein:

the first BAW resonator and the second BAW resonator are arranged on the carrier chip; and

the piezoelectric layer is a layer of the first piezoelectric material, substantially free of the second piezoelectric material.

2. The BAW component of claim 1 , wherein the lamination of the first BAW resonator has first thickness, and the piezoelectric layer of the second BAW resonator has a second thickness different from the first thickness.

3. The BAW component of claim 1 , wherein the first piezoelectric material and the second piezoelectric material have a different etching selectivity with respect to an etching agent.

4. The BAW component of claim 3 , wherein the etching agent is a wet etching agent.

5. The BAW component of claim 4 , wherein the etching agent comprises 2.36% Tetramethyl ammonium hydroxyl in combination with a wetting agent.

6. The BAW component of claim 3 , wherein the etching agent is a dry etching agent.

7. The BAW component of claim 1 , wherein the second piezoelectric material is AlN.

8. The BAW component of claim 1 , wherein the BAW component is a duplexer and the first BAW resonator is a resonator of a TX filter of the duplexer.

9. A method for manufacturing a BAW component, the method comprising:

providing a carrier chip;

providing a first bottom electrode on the carrier chip;

providing a second bottom electrode on the carrier chip;

arranging a first layer of a first piezoelectric material comprising Sc doped AlN over the first bottom electrode;

arranging a second layer of the first piezoelectric material over the second bottom electrode;

arranging a first layer of a second piezoelectric material, different from the first piezoelectric material, over the first layer of the first piezoelectric material;

arranging a second layer of the second piezoelectric material over the second layer of the first piezoelectric material;

selectively removing the second layer of the second piezoelectric material;

arranging, after the selectively removing the second layer of the second piezoelectric material, a first top electrode over the second layer of the first piezoelectric material; and

arranging a second top electrode over the first layer of the second piezoelectric material.

10. The method of claim 9 , wherein the first piezoelectric material and the second piezoelectric material have a different etching selectivity with respect to an etching agent used during the selectively removing step.

11. The method of claim 10 , wherein the etching agent is a wet etching agent.

12. The method of claim 11 , wherein the etching agent comprises 2.36% Tetramethyl ammonium hydroxyl in combination with a wetting agent.

13. The method of claim 10 , wherein the etching agent is a dry etching agent.

14. The method of claim 9 , wherein the second piezoelectric material is AlN.