METHOD AND STRUCTURE FOR HIGH PERFORMANCE RESONANCE CIRCUIT WITH SINGLE CRYSTAL PIEZOELECTRIC CAPACITOR DIELECTRIC MATERIAL
A method and structure for single crystal acoustic electronic device. The device includes a substrate having an enhancement layer formed overlying its surface region, a support layer formed overlying the enhancement layer and an air cavity formed through a portion of the support layer. Single crystal piezoelectric material is formed overlying the air cavity and a portion of the enhancement layer. Also, a first electrode material coupled to the backside surface region of the crystal piezoelectric material and spatially configured within the cavity. A second electrode material is formed overlying the topside of the piezoelectric material, and a dielectric layer formed overlying the second electrode material. Further, one or more shunt layers can be formed around the perimeter of a resonator region of the device to connect the piezoelectric material to the enhancement layer.
1 . An acoustic resonator device comprising:
a bond substrate;
a bonding support layer overlying the bond substrate;
a support layer overlying the bonding support layer, the support layer having an air cavity;
a first electrode overlying the air cavity and a portion of the support layer;
a first passivation layer overlying the support layer and being physically coupled to the first electrode;
a piezoelectric film overlying the support layer, the first electrode, and the air cavity, the piezoelectric film having an electrode contact via;
a second electrode formed overlying the piezoelectric film;
a top metal formed overlying the piezoelectric film, the top metal being physically coupled to the first electrode through the electrode contact via;
a first contact metal formed overlying a portion of the second electrode and the piezoelectric film;
a second contact metal formed overlying a portion of the top metal and the piezoelectric film; and
a second passivation layer formed overlying the piezoelectric film, the second electrode, and the top metal;
wherein the second passivation layer is characterized by a consistent thickness.
2 . The device of claim 1 wherein the growth substrate and bond substrate include silicon (S), silicon carbide (SiC), sapphire (Al 2 O 3 ), silicon dioxide (SiO 2 ), or other silicon materials.
3 . The device of claim 1 wherein the piezoelectric film is a single crystal or polycrystalline piezoelectric film that includes aluminum nitride (AlN), gallium nitride (GaN), Al x Ga 1-x N alloys, or other epitaxial materials; or
wherein the piezoelectric film is an upper portion of a polycrystalline piezoelectric film that includes aluminum nitride (AlN), gallium nitride (GaN), Al x Ga 1-x N alloys, or other polycrystalline epitaxial materials.
4 . The device of claim 1 wherein the first passivation layer or the second passivation layer is characterized by a thickness of about 50 nm to about 100 nm.
5 . The device of claim 1 wherein the first electrode, second electrode, and top metal include molybdenum (Mo), ruthenium (Ru), tungsten (W), or other conductive materials; and wherein the first and second passivation layers can include silicon nitride (SiN), silicon oxide (SiO), silicon dioxide (SiO 2 ), or other silicon materials.
6 . The device of claim 1 wherein the first and second contact metals include gold (Au), aluminum (Al), copper (Cu), nickel (Ni), aluminum bronze (AlCu), or other metal materials.
7 . The device of claim 1 wherein the support layer and the bonding support layer include silicon dioxide (SiO 2 ) or other silicon materials.
8 . The device of claim 1 wherein at least one of the first electrode and the second electrode includes an energy confinement structure.
9 . The device of claim 8 wherein the energy confinement structure is configured as a mass loaded area surrounding a resonator area of the piezoelectric film.
10 . The device of claim 9 wherein the resonator area includes a region where the first electrode, the piezoelectric film, and the second electrode overlap.