Piezoelectric devices and methods for their preparation and use
Methods for fabricating a piezoelectric device are provided. The methods can include providing a substrate and forming a nanocrystalline diamond layer on a first surface of the substrate. The methods can also include depositing a piezoelectric layer on a first surface of the nanocrystalline diamond layer.
1. A method for fabricating a piezoelectric device, the method comprising:
providing a substrate;
forming a nanocrystalline diamond (NCD) layer on a first surface of the substrate; and
depositing a piezoelectric layer directly on a first surface of the NCD layer, wherein the piezoelectric layer has a perovskite structure, wherein the perovskite piezoelectric layer is selected from the group consisting of lead lanthanum zirconate titanate (PLZT) and lead zirconate titanate (PZT); and
annealing the perovskite piezoelectric layer at a temperature of 525° C. to 600° C. for 30 minutes to 2 hours in an atmosphere comprising 0.4 mbar to 0.6 mbar oxygen gas.
2. The method of claim 1 , wherein the substrate comprises silicon.
3. The method of claim 1 , wherein the forming the NCD layer comprises using a chemical vapor deposition (CVD) technique.
4. The method of claim 3 , wherein the CVD technique comprises a hot filament chemical vapor deposition (HFCVD) or a microwave plasma chemical vapor deposition (MPCVD) technique.
5. The method of claim 3 , wherein the forming the NCD layer comprises:
cleaning the substrate and seeding the substrate with diamond nano particles;
placing the seeded substrate in a CVD reactor;
heating the seeded substrate to a deposition temperature by an array of hot filament; and
chemically vapor depositing the NCD layer onto the first surface of the heated substrate by passing a gaseous mixture of a hydrocarbon and hydrogen into the CVD reactor.
6. The method of claim 1 , wherein the depositing the piezoelectric layer comprises using a pulsed laser deposition (PLD) technique.
7. The method of claim 6 , wherein the depositing the piezoelectric layer comprises exposing a piezoelectric target placed within a PLD chamber to a laser source.
8. The method of claim 7 , wherein a deposition temperature within the PLD chamber is about 525° C. to about 600° C.
9. The method of claim 8 , wherein the deposition temperature is about 550° C.
10. The method of claim 7 , wherein a deposition pressure within the PLD chamber is about 0.4 mbar to about 0.6 mbar.
11. A method for fabricating a piezoelectric device, the method comprising:
providing a base substrate;
chemically vapor depositing a nanocrystalline diamond (NCD) layer on a first surface of the substrate to form a diamond substrate;
depositing a lead zirconate titanate (PZT) layer directly on a first surface of the diamond substrate such that the PZT layer is a crystalline perovskite phase layer; and
annealing the crystalline perovskite phase layer at a temperature of 525° C. to 600° C. for 30 minutes to 2 hours in an atmosphere comprising 0.4 mbar to 0.6 mbar oxygen gas.
12. The method of claim 11 , wherein the depositing the PZT layer comprises using a pulsed laser deposition (PLD) technique.
13. The method of claim 11 , wherein the chemically vapor depositing the NCD layer comprises using a chemical vapor deposition technique (CVD), wherein the CVD technique comprises a hot filament chemical vapor deposition (HFCVD) or a microwave plasma chemical vapor deposition (MPCVD) technique.
14. The method of claim 11 , wherein the base substrate comprises silicon.
15. A method of using a piezoelectric device as a surface acoustic wave (SAW) device, wherein the piezoelectric device comprises:
providing a piezoelectric device comprising:
a substrate;
a nanocrystalline diamond (NCD) layer disposed on a first surface of the substrate; and
a perovskite piezoelectric layer disposed directly on a first surface of the NCD layer, wherein the perovskite piezoelectric layer is selected from the group consisting of lead lanthanum zirconate titanate (PLZT) and lead zirconate titanate (PZT);
annealing the perovskite piezoelectric layer at a temperature of 525° C. to 600° C. for 30 minutes to 2 hours in an atmosphere comprising 0.4 mbar to 0.6 mbar oxygen gas; and
depositing an interdigital transducer (IDT) layer on the perovskite piezoelectric layer of the piezoelectric device.
16. The method of claim 15 , wherein the substrate comprises silicon.
17. The method of claim 15 , wherein the IDT layer comprises platinum or tantalum.
18. The method of claim 15 , wherein the SAW device is incorporated into a telecommunications device.
19. The method of claim 18 , wherein the SAW device is a SAW filter.
20. The method of claim 15 , wherein the SAW device is incorporated into a sensing device.
21. The method of claim 20 , wherein the SAW device is incorporated into a sound navigation and ranging (SONAR) device.