Hybrid integrated optical device
A method of fabricating a composite integrated optical device includes providing a substrate comprising a silicon layer, forming a waveguide in the silicon layer, and forming a layer comprising a metal material coupled to the silicon layer. The method also includes providing an optical detector, forming a metal-assisted bond between the metal material and a first portion of the optical detector, forming a direct semiconductor-semiconductor bond between the waveguide, and a second portion of the optical detector.
1. A hybrid integrated optical device comprising:
a silicon-on-insulator substrate that includes a silicon handle portion, an oxide layer, and a silicon layer, and wherein a first portion of the silicon layer forms a recess relative to a second portion of the silicon layer;
a first pad, disposed within the recess and bonded to the first portion of the silicon layer;
a device comprising a compound semiconductor material;
a second pad, disposed on a first region of the device and bonded to the device; and
a bonding metal, wherein:
the bonding metal comprises In 0.7 Pd 0.3 ;
the bonding metal is disposed between the first pad and the second pad;
the bonding metal is bonded to the first pad and the second pad; and
the bonding metal, the first pad, and the second pad secure the device to the substrate;
and wherein a height of the device is coplanar with or exceeds a height of the second portion of the silicon layer.
2. The hybrid integrated optical device of claim 1 , wherein:
the first pad comprises at least one of Ti, Cr, Pt, Ni or W; and
the second pad comprises at least one of Ti, Cr, Pt, Ni or W.
3. The hybrid integrated optical device of claim 1 , wherein:
the substrate comprises a waveguide; and
the device is a compound semiconductor device that emits light, wherein the light is optically coupled into the waveguide.
4. The hybrid integrated optical device of claim 1 , wherein the first portion of the silicon layer forms a recess proximate the first pad, and wherein a top surface of the device is coplanar with the second portion of the silicon layer.
5. The hybrid integrated optical device of claim 1 , further comprising a planarizing material.
6. The hybrid integrated optical device of claim 5 , wherein at least a portion of the planarizing material is removed, and further comprising an interconnect metal that provides electrical connectivity to at least one of the device and the silicon layer, at a location where the portion of the planarizing material is removed.
7. The hybrid integrated optical device of claim 5 , wherein the planarizing material extends over at least a portion of the silicon-on-insulator substrate and over at least a portion of the device.
8. The hybrid integrated optical device of claim 1 , wherein the recess extends from an upper surface of the silicon layer through a portion of the silicon layer, but does not extend to a lower surface of the silicon layer.
9. A hybrid integrated optical device wherein comprising:
a silicon-on-insulator substrate comprising a silicon handle portion, an oxide layer, and a silicon layer;
a first pad, disposed on a first region of the substrate and bonded to the substrate, wherein the first region of the substrate is a first region of the silicon layer;
a compound semiconductor optical device;
a second pad, disposed on a first region of the compound semiconductor optical device and bonded to the compound semiconductor optical device; and
a bonding metal, wherein:
the bonding metal forms a first bond;
the bonding metal comprises In 0.7 Pd 0.3 ;
the bonding metal is disposed between the first pad and the second pad;
the bonding metal is bonded to the first pad and the second pad;
the bonding metal, the first pad, and the second pad secure the compound semiconductor optical device to the substrate; and
the substrate and the device form a second bond, the second bond comprising a direct semiconductor/semiconductor bond between a second region of the silicon layer and a second region of the compound semiconductor optical device.
10. The hybrid integrated optical device of claim 9 , wherein the compound semiconductor optical device is a light-emitting device that is operable to emit light through the direct semiconductor/semiconductor bond.
11. The hybrid integrated optical device of claim 9 , wherein the light-emitting device is an optical generator.
12. The hybrid integrated optical device of claim 9 , wherein light propagates parallel to an interface between the second region of the silicon layer and the second region of the compound semiconductor optical device, such that the light evanescently couples across the direct semiconductor/semiconductor bond, between the silicon layer and the compound semiconductor optical device.
13. The hybrid integrated optical device of claim 9 , wherein the silicon layer is characterized by a first coefficient of thermal expansion (CTE) and the device is characterized by a second CTE, wherein the first CTE and the second CTE are different from one another.
14. The hybrid integrated optical device of claim 9 , wherein the substrate and the device form a third bond comprising a direct semiconductor/semiconductor bond between a third region of the silicon layer and a third region of the device.