Method for integration of electro-optical materials in a photonic integrated circuit
A method includes providing a sacrificial wafer, contacting the sacrificial wafer to a photonic device wafer, and bonding the sacrificial wafer to the photonic device wafer. The sacrificial wafer includes a substrate and an electro-optical material strip disposed within a dielectric matrix. The photonic device wafer includes a photonic device die, and the electro-optical material strip is disposed proximate to the photonic device die. A photonic device structure includes a photonic device wafer and a sacrificial wafer. The photonic device structure includes a device wafer substrate and a photonic device die fabricated in a device wafer dielectric layer. The sacrificial wafer includes a sacrificial wafer substrate and an electro-optical material strip embedded in a sacrificial wafer dielectric matrix. The sacrificial wafer dielectric matrix is bonded to the device wafer dielectric layer, and the electro-optical material strip is disposed proximate to the photonic device die.
1. A method comprising:
providing a sacrificial wafer, comprising a substrate and an electro-optical material strip disposed within a dielectric matrix deposited over the substrate;
contacting the sacrificial wafer to a photonic device wafer,
wherein the photonic device wafer comprises a photonic device die, and
wherein the electro-optical material strip is disposed proximate to the photonic device die; and
bonding the sacrificial wafer to the photonic device wafer.
2. The method of claim 1 , wherein the electro-optical material strip comprises essentially LiNbO 3 .
3. The method of claim 1 , wherein the electro-optical material strip comprises essentially BaTiO 3 .
4. The method of claim 1 , wherein providing the sacrificial wafer comprises:
placing an electro-optical material chiplet on a dielectric layer of the sacrificial wafer;
bonding the electro-optical material chiplet to the dielectric layer of the sacrificial wafer;
fabricating an electro-optical material strip from the electro-optical material chiplet;
depositing a second dielectric layer over the sacrificial wafer and the electro-optical material strip, thereby embedding the electro-optical material strip in the dielectric matrix; and
planarizing the dielectric matrix of the sacrificial wafer.
5. The method of claim 4 , wherein placing the electro-optical material chiplet on the dielectric layer of the sacrificial wafer comprises using a pick-and-place device or a wafer bonding device.
6. The method of claim 4 , wherein the electro-optical material chiplet, comprises an electrooptical material thin film deposited over a chiplet dielectric layer disposed over a chiplet substrate.
7. The method of claim 6 , wherein placing the electro-optical material chiplet on the dielectric layer of the sacrificial wafer comprises placing the electro-optical material thin film of the electro-optical material chiplet on the dielectric layer of the sacrificial wafer.
8. The method of claim 7 , further comprising:
removing the chiplet substrate; and
etching the electro-optical material thin film thereby forming the electro-optical material strip.
9. The method of claim 4 , wherein placing the electro-optical material chiplet on the dielectric layer of the sacrificial wafer comprises placing an electro-optical material die on the dielectric layer of the sacrificial wafer.
10. The method of claim 9 , wherein the electro-optical material die comprises a thick electrooptical material film, an electro-optical material thin film, and a pre-implanted damage layer therebetween, and
wherein placing the electro-optical material die on the dielectric layer of the sacrificial wafer comprises placing the electro-optical material thin film on the dielectric layer of the sacrificial wafer.
11. The method of claim 10 further comprising:
cleaving the electro-optical material die to remove the thick electro-optical material film; and
etching the electro-optical material thin film thereby forming the electro-optical material strip.
12. The method of claim 1 , wherein the sacrificial wafer further comprises an optical waveguide disposed proximate to the electro-optical material strip.
13. The method of claim 12 , wherein providing the sacrificial wafer comprises:
depositing an optical waveguide material above a dielectric layer of the sacrificial wafer, wherein the dielectric layer of the sacrificial wafer is disposed over the substrate;
patterning the optical waveguide material thereby fabricating the optical waveguide;
depositing an additional dielectric layer over the optical waveguide and the dielectric layer of the sacrificial wafer;
planarizing a surface of the additional dielectric layer;
placing an electro-optical material chiplet on the planarized surface of the sacrificial wafer proximate to the optical waveguide; and
bonding the electro-optical material chiplet to the planarized surface of the sacrificial wafer.
14. The method of claim 1 , wherein the sacrificial wafer further comprises an electrode disposed proximate to the electro-optical material strip.
15. The method of claim 14 , wherein providing the sacrificial wafer comprises:
pattern etching a dielectric layer of the sacrificial wafer, wherein the dielectric layer of the sacrificial wafer is disposed over the substrate;
depositing an electrode material in the etched pattern of the dielectric layer of the sacrificial wafer;
planarizing a surface comprising the electrode material in the etched pattern and the dielectric layer of the sacrificial wafer;
depositing an additional dielectric layer over the electrode material in the etched pattern and the dielectric layer;
placing an electro-optical material chiplet on the additional dielectric layer proximate to the electrode material in the etched pattern; and
bonding the electro-optical material chiplet to the additional dielectric layer.
16. The method of claim 1 , further comprising removing the substrate, thereby exposing a bottom surface of the dielectric matrix of the sacrificial wafer.
17. A photonic device structure, comprising:
a photonic device wafer, comprising:
a device wafer substrate; and
a photonic device die fabricated in a device wafer dielectric layer disposed over the device wafer substrate; and
a sacrificial wafer, comprising:
a sacrificial wafer substrate; and
an electro-optical material strip, wherein the electro-optical material strip is embedded in a sacrificial wafer dielectric matrix,
wherein the sacrificial wafer dielectric matrix is bonded to the device wafer dielectric layer, and
wherein the electro-optical material strip is disposed proximate to the photonic device die.
18. The photonic device structure of claim 17 , wherein the electro-optical material strip comprises essentially LiNbO 3 .
19. The photonic device structure of claim 17 , wherein the electro-optical material strip comprises essentially BaTiO 3 .
20. The photonic device structure of claim 17 , wherein the electro-optical material strip is 200 nm to 600 nm thick.
21. The photonic device structure of claim 17 , wherein the sacrificial wafer further comprises an electrode proximate to the electro-optical material strip.
22. The photonic device structure of claim 17 , wherein the sacrificial wafer further comprises an optical waveguide proximate to the electro-optical material strip.