Method and system of heterogeneous substrate bonding for photonic integration
A hybrid integrated optical device includes a substrate comprising a silicon layer and a compound semiconductor device bonded to the silicon layer. The device also includes a bonding region disposed between the silicon layer and the compound semiconductor device. The bonding region includes a metal-semiconductor bond at a first portion of the bonding region. The metal-semiconductor bond includes a first pad bonded to the silicon layer, a bonding metal bonded to the first pad, and a second pad bonded to the bonding metal and the compound semiconductor device. The bonding region also includes an interface assisted bond at a second portion of the bonding region. The interface assisted bond includes an interface layer positioned between the silicon layer and the compound semiconductor device, wherein the interface assisted bond provides an ohmic contact between the silicon layer and the compound semiconductor device.
1. A hybrid integrated optical device comprising:
a substrate comprising a silicon layer on a CMOS substrate;
a compound semiconductor device bonded to the silicon layer; and
a bonding region disposed between the silicon layer and the compound semiconductor device, wherein the bonding region comprises:
a metal-semiconductor bond at a first portion of the bonding region, wherein the metal-semiconductor bond includes a first pad bonded to the silicon layer, a bonding metal bonded to the first pad, and a second pad bonded to the bonding metal and the compound semiconductor device; and
an interface assisted bond at a second portion of the bonding region, wherein the interface assisted bond includes an interface layer positioned between the silicon layer and the compound semiconductor device, wherein the interface assisted bond provides an ohmic contact between the silicon layer and the compound semiconductor device.
2. The hybrid integrated optical device of claim 1 wherein the substrate comprises a silicon on insulator wafer including a silicon substrate, an oxide layer disposed on the silicon substrate, and the silicon layer disposed on the oxide layer.
3. The hybrid integrated optical device of claim 1 wherein the compound semiconductor device comprises a III-V optical device.
4. The hybrid integrated optical device of claim 1 wherein the III-V optical device comprises an InP semiconductor laser.
5. The hybrid integrated optical device of claim 1 wherein the first pad and the second pad comprise Ti.
6. The hybrid integrated optical device of claim 1 wherein the interface layer comprises In x Pd y .
7. The hybrid integrated optical device of claim 6 wherein x=0.7 and y=0.3.
8. The hybrid integrated optical device of claim 1 wherein a thickness of the interface layer is less than 100 Å.
9. The hybrid integrated optical device of claim 8 wherein the thickness is less than 50 Å.
10. The hybrid integrated optical device of claim 1 wherein a region of the second portion of the bonding region is substantially free from the interface layer.