Hafnium-zirconium oxide (HZO) ferroelectric transducer and method of making the same
A nano-mechanical acoustical resonator is designed and fabricated with CMOS compatible techniques to apply to mm-wave RF front-ends and 5G wireless communication systems which have extreme small scale and integrated in 3D sensors and actuators.
1. A two-port acoustic resonator, comprising:
a substrate;
a first aluminum nitride (AlN) layer disposed on the substrate;
a first molybdenum (Moly) layer disposed on the first AlN layer;
a first transducer formed on the first Moly layer, wherein the first transducer comprises:
a second AlN layer disposed on the first Moly layer, and
a second Moly layer disposed on the second AlN layer; and
a second transducer formed on the second Moly layer, wherein the second transducer comprises:
a first hafnium zirconium oxide (HZO) layer disposed on the second Moly layer,
a first titanium nitride (TiN) layer on top of the first HZO layer, and
a first conductive layer deposited on the first HZO layer,
wherein the second transducer is located in the vicinity of the first transducer, and
wherein the second transducer comprises a second conductive layer disposed on the first Moly layer.
2. The two-port acoustic resonator according to claim 1 , wherein the HZO layer is formed by applying atomic layer deposition (ALD).
3. The two-port acoustic resonator according to claim 1 , wherein the HZO layer has a thickness ranging from 2 nm to 20 nm.
4. The two-port acoustic resonator according to claim 1 , wherein a titanium nitride (TiN) layer is disposed on top of the HZO and the second Moly layer.
5. The two-port acoustic resonator according to claim 1 , wherein the first conductive layer includes one of platinum (Pt), aluminum (Al), gold (Au), and silver (Ag).
6. The two-port acoustic resonator according to claim 1 , wherein the second conductive layer includes one of platinum (Pt), aluminum (Al), gold (Au), and silver (Ag).
7. The two-port acoustic resonator according to claim 1 , wherein the first AlN layer is a seed layer and the second AIN layer is a c-axis oriented crystalline layer.
8. The two-port acoustic resonator according to claim 1 , wherein the substrate is a SOI having a device layer on a BOX layer.
9. The two-port acoustic resonator according to claim 1 , wherein the second layer of AlN is a crystalline layer and have a thickness ranging from 50 nm to 5 um.
10. A method of fabricating a two-port acoustic resonator, comprising,
providing a silicon-on-insulator substrate;
depositing a first aluminum nitride (AlN) layer on the substrate, wherein the first AlN layer is a seed layer;
depositing a first molybdenum (Moly) layer on the first AlN layer;
depositing a second AlN layer on the first Moly layer;
depositing a second Moly layer on the second AlN layer;
patterning the second Moly layer to define a first transducer;
depositing a first hafnium zirconium oxide (HZO) layer;
depositing a first titanium nitride (TiN) layer on the HZO layer;
depositing a first conductive film on the first TiN layer;
patterning the first conductive film, the first TiN layer and the first HZO layer to form the first transducer;
patterning the second AlN layer to define a second transducer;
depositing a second conductive layer on the second transducer; and
releasing the two-port acoustic resonator by etching a trench around and removing the substrate.
11. The method of fabricating the two-port acoustic resonator as in claim 10 , wherein the first HZO layer is deposited by applying atomic layer deposition.
12. The method of fabricating the two-port acoustic resonator as in claim 10 , wherein the second HZO layer is deposited by applying atomic layer deposition.
13. The method of fabricating the two-port acoustic resonator as in claim 10 , wherein the first HZO layer has a thickness ranging from 2 nm to 20 nm, and wherein the second HZO layer has a thickness ranging from 2 nm to 20 nm.
14. A one-port acoustic resonator, comprising:
a substrate;
a first conductive layer disposed on the substrate;
a first titanium nitride (TiN) layer disposed on the first conductive layer;
a one-port transducer formed on the first TiN layer, wherein the one-port transducer comprises:
an HZO layer disposed on the first TiN layer,
a molybdenum (Moly) layer disposed on the HZO layer, and
a second TiN layer disposed on the Moly layer; and
a second conductive layer disposed on the second TiN layer.
15. The one-port acoustic resonator according to claim 14 , wherein the HZO layer is formed by applying atomic layer deposition (ALD).
16. The one-port acoustic resonator according to claim 14 , wherein the HZO layer has a thickness ranging from 2 nm to 20 nm.
17. The one-port acoustic resonator according to claim 14 , wherein the first conductive layer includes one of platinum (Pt), aluminum (Al), gold (Au), and silver (Ag).
18. The one-port acoustic resonator according to claim 14 , wherein the second conductive layer includes one of platinum (Pt), aluminum (Al), gold (Au), and silver (Ag).
19. A method of fabricating the one-port acoustic resonator as in claim 14 , comprising,
providing the substrate;
depositing the first conductive layer on the substrate;
depositing the first TiN layer on the first conductive layer;
depositing the HZO layer on the first TiN layer;
depositing the Moly layer on the HZO layer;
depositing the second TiN layer on the HZO layer;
depositing the second conductive layer on the second TiN layer;
patterning the second conductive layer, the second TiN layer and the HZO layer to form the one-port transducer; and
releasing the one-port acoustic resonator by etching a trench around and removing the substrate.
20. The method of fabricating the one-port acoustic resonator as in claim 19 , wherein the HZO layer is deposited by applying atomic layer deposition (ALD).