Bulk acoustic wave resonators having convex surfaces, and methods of forming the same
In one example, an apparatus comprises an acoustic resonator, the acoustic resonator including: an electrode; and a piezoelectric layer on the electrode, in which the electrode covers entirely a surface of the piezoelectric layer, and the piezoelectric layer has a convex portion with a non-uniform thickness.
1 . An apparatus comprising:
an acoustic resonator including:
an electrode; and
a piezoelectric layer on the electrode, in which the electrode covers entirely a surface of the piezoelectric layer, and the piezoelectric layer has a convex portion with a non-uniform thickness.
2 . The apparatus of claim 1 , wherein the surface of the piezoelectric layer is a planar surface, and the convex portion has a convex surface opposing the planar surface.
3 . The apparatus of claim 1 , further comprising a substrate, and the acoustic resonator is on the substrate.
4 . The apparatus of claim 1 , further comprising an acoustic reflector, and the acoustic resonator is on the acoustic reflector.
5 . The apparatus of claim 1 , wherein the electrode is a first electrode, and the acoustic resonator includes a second electrode on the convex portion of the piezoelectric layer.
6 . The apparatus of claim 1 , wherein the piezoelectric layer includes at least one of: aluminum oxide, or zinc oxide.
7 . The apparatus of claim 1 , wherein the convex portion is configurable to perform at least one of: reducing a spurious mode, confining a main mode in a central portion of the piezoelectric layer, or reducing a leakage of acoustic energy from the acoustic resonator.
8 . The apparatus of claim 1 , further comprising a semiconductor die coupled to the acoustic resonator, and the semiconductor die and the acoustic resonator is in an integrated circuit package.
9 . The apparatus of claim 8 , wherein the acoustic resonator is configurable to provide a clock signal to the semiconductor die.
10 . The apparatus of claim 8 , wherein the acoustic resonator is mounted on the semiconductor die.
11 . The apparatus of claim 8 , wherein the acoustic resonator is coupled to the semiconductor die via bond wires.
12 . The apparatus of claim 1 , wherein the acoustic resonator is a bulk acoustic wave (BAW) resonator.
13 . An integrated circuit (IC) comprising:
an acoustic resonator including:
an electrode; and
a piezoelectric layer on the electrode, in which the electrode covers entirely a surface of the piezoelectric layer, and the piezoelectric layer has a convex portion with a non-uniform thickness.
14 . The IC of claim 13 , wherein the surface of the piezoelectric layer is a planar surface, and the convex portion has a convex surface opposing the planar surface.
15 . The IC of claim 13 , further comprising a substrate, and the acoustic resonator is on the substrate.
16 . The IC of claim 13 , further comprising an acoustic reflector, and the acoustic resonator is on the acoustic reflector.
17 . The IC of claim 13 , wherein the electrode is a first electrode, and the acoustic resonator includes a second electrode on the convex portion of the piezoelectric layer.
18 . The IC of claim 13 , wherein the piezoelectric layer includes at least one of: aluminum oxide, or zinc oxide.
19 . The IC of claim 13 , further comprising a semiconductor die coupled to the acoustic resonator.
20 . The IC of claim 19 , wherein the acoustic resonator is mounted on the semiconductor die.