Method and system for heterogeneous substrate bonding of waveguide receivers
A composite integrated optical device includes a substrate including a silicon layer and a waveguide disposed in the silicon layer. The composite integrated optical device also includes an optical detector bonded to the silicon layer and a bonding region disposed between the silicon layer and the optical detector. The bonding region includes a metal-assisted bond at a first portion of the bonding region. The metal-assisted bond includes an interface layer positioned between the silicon layer and the optical detector. The bonding region also includes a direct semiconductor-semiconductor bond at a second portion of the bonding region.
1. A composite integrated optical device comprising:
a complementary metal oxide semiconductor (CMOS) substrate comprising a silicon layer;
a waveguide disposed in the silicon layer;
an optical detector bonded to the silicon layer comprising; and
a bonding region disposed between the silicon layer and the optical detector, wherein the bonding region comprises:
a metal-assisted bond at a first portion of the bonding region, wherein the metal-assisted bond includes an interface layer positioned between the silicon layer and the optical detector; and
a direct semiconductor-semiconductor bond at a second portion of the bonding region.
2. The composite integrated optical device of claim 1 wherein the metal-assisted bond provides an ohmic contact between the optical detector and the silicon layer.
3. The composite integrated optical device of claim 1 wherein the metal-assisted bond provides a Schottky contact between the optical detector and the silicon layer.
4. The composite integrated optical device of claim 1 wherein the CMOS substrate comprises a silicon on insulator wafer.
5. The composite integrated optical device of claim 1 wherein the optical detector comprises a III-V optical device.
6. The composite integrated optical device of claim 1 wherein the III-V optical device comprises an APD receiver.
7. The composite integrated optical device of claim 1 wherein the interface layer comprises In x Pd y .
8. The composite integrated optical device of claim 7 wherein x=0.7 and y=0.3.
9. The composite integrated optical device of claim 1 wherein a thickness of the interface layer is less than 100 Å.
10. The composite integrated optical device of claim 9 wherein the thickness is less than 50 Å.
11. The composite integrated optical device of claim 1 wherein the waveguide supports a fundamental mode and a first portion of the waveguide associated with a maximum intensity of the fundamental mode includes a direct semiconductor-semiconductor bond and a second portion of the waveguide associated with a wing of the fundamental mode includes a metal-assisted bond.
12. The composite integrated optical device of claim 1 wherein the waveguide supports a higher order mode and a node of the higher order mode is positioned at a metal-assisted bond.