VCSEL structure with embedded heat sink
An optoelectronic device includes a semiconductor substrate, having front and back sides and having at least one cavity extending from the back side through the semiconductor substrate into proximity with the front side. At least one optoelectronic emitter is formed on the front side of the semiconductor substrate in proximity with the at least one cavity. A heat-conducting material at least partially fills the at least one cavity and is configured to serve as a heat sink for the at least one optoelectronic emitter.
1. An optoelectronic device, comprising:
a semiconductor substrate, having front and back sides;
at least one optoelectronic emitter formed on the front side of the semiconductor substrate;
an electrically-conductive film deposited over the back side of the semiconductor substrate in ohmic contact with the semiconductor substrate; and
a heat-conducting material deposited on the back side of the semiconductor substrate over the electrically-conductive film and configured to serve as a heat sink for the at least one optoelectronic emitter.
2. The optoelectronic device according to claim 1 , wherein the electrically-conducting film serves the at least one optoelectronic emitter as an electrical contact.
3. The optoelectronic device according to claim 1 , wherein the back side of the semiconductor substrate is thinned in a vicinity of the at least one optoelectronic emitter.
4. The optoelectronic device according to claim 3 , wherein the semiconductor substrate contains a cavity extending through the back side into proximity with the at least one optoelectronic emitter, and wherein the electrically-conductive film and the heat-conducting material are deposited in the cavity.
5. The optoelectronic device according to claim 1 , wherein the at least one optoelectronic emitter comprises an array of emitters on the front side of the semiconductor substrate.
6. The optoelectronic device according to claim 1 , wherein the at least one optoelectronic emitter comprises a vertical-cavity surface-emitting laser (VCSEL).
7. A method for manufacturing an optoelectronic device, the method comprising:
forming an optoelectronic emitter by deposition and patterning of epitaxial layers on a front side of a semiconductor substrate;
depositing an electrically-conductive film over a back side of the semiconductor substrate in ohmic contact with the semiconductor substrate; and
depositing a heat-conducting material over the electrically-conductive film so as to serve as a heat sink for the optoelectronic emitter.
8. The method according to claim 7 , wherein the electrically-conductive film serves the optoelectronic emitter as an electrical contact.
9. The method according to claim 7 , and comprising thinning the back side of the semiconductor substrate in a vicinity of the at least one optoelectronic emitter.
10. The method according to claim 9 , wherein thinning the back side comprises forming a cavity extending through the back side into proximity with the at least one optoelectronic emitter, and wherein the electrically-conductive film and the heat-conducting material are deposited in the cavity.
11. The method according to claim 7 , wherein forming the optoelectronic emitter comprises forming an array of emitters on the front side of the semiconductor substrate.
12. The method according to claim 7 , wherein the optoelectronic emitter comprises a VCSEL.