Piezoelectric film transfer for acoustic resonators and filters
A method for forming an acoustic resonator comprising: forming a piezoelectric material on a first substrate; and applying the piezoelectric material to a second substrate on which the acoustic resonator is fabricated upon.
1. A method for forming an acoustic resonator comprising;
forming a piezoelectric material on a first substrate, wherein forming the piezoelectric material comprises:
growing a single crystal aluminum nitride film directly on a sapphire substrate; and
depositing an electrode material on a first surface of the single crystal aluminum nitride film forming a first electrode;
forming a reflector device on a semiconductor substrate separate from the sapphire substrate;
bonding the first electrodes to the reflector device formed on the semiconductor substrate so that the first electrode formed on the single crystal aluminum nitride film on the sapphire substrate attaches to the reflector device; and
removing the sapphire substrate.
2. The method of claim 1 , further comprising forming acoustic reflectors on the piezoelectric material on the first substrate.
3. The method of claim 1 , wherein the piezoelectric material is grown by epitaxial deposition.
4. The method of claim 1 , wherein removing the sapphire substrate further comprises removing the sapphire substrate from the single crystal aluminum nitride film by laser liftoff.
5. The method of claim 1 , wherein forming a reflector device further comprises attaching a Braggs reflector to the semiconductor substrate separate from the sapphire substrate before applying the piezoelectric material.
6. The method of claim 1 , further comprising:
forming an indentation in the semiconductor substrate separate from the sapphire substrate; and
applying the piezoelectric material over the indentation on the semiconductor substrate separate from the sapphire substrate.
7. The method of claim 1 , wherein growing the single crystal aluminum nitride film on a sapphire substrate is grown through one of metal organic chemical vapor deposition (MOCVD) or hydride vapor phase epitaxy (HVPE).
8. The method of claim 1 , further comprising applying a contact metal deposition to the single crystal aluminum nitride film prior to bonding the metal electrodes on the aluminum nitride film to the reflector device.
9. A method for forming an acoustic resonator comprising:
forming a single crystal aluminum nitride film directly on a sapphire substrate;
forming a metal electrode on the single crystal aluminum nitride film;
forming a reflector device on a second substrate, the second substrate separate and apart from the sapphire substrate;
bonding the metal electrode on the single crystal aluminum nitride film to the reflector device formed on the second substrate, the second substrate being a different material from the sapphire substrate;
removing the sapphire substrate from the single crystal aluminum nitride film by laser liftoff.
10. The method of claim 9 , wherein forming a single crystal aluminum nitride film is grown by epitaxial deposition.
11. The method of claim 9 , wherein the reflector is a Braggs reflector.
12. The method of claim 9 , further comprising:
forming an indentation in the second substrate; and
forming the single crystal aluminum nitride film over the indentation on the second substrate.