CTE-matched silicon-carbide submount with high thermal conductivity contacts

1. A laser diode submount, comprising:

a thermally conductive, insulating substrate; and

a first contact that comprises a first upper contact portion and a portion of a first base layer, a second contact that comprises a second upper contact portion and a portion of a second base layer, and a bonding contact situated between the first contact and the second contact, the bonding contact comprising an upper laser contact portion and a portion of the first base layer, wherein the first base layer and the second base layer are conductive layers situated at a major surface of the substrate, wherein the first upper contact portion and the upper laser contact portion are displaced from each other along the major surface to define a first gap, the second upper contact portion and the upper laser contact portion are displaced from each other along the major surface to define a second gap, the first contact and the bonding contact are electrically coupled to each other by the first base layer and insulated from the second contact, and the bonding contact includes a thermally conductive layer of thickness of at least 0.5 μm.

2. The laser diode submount of claim 1 , wherein the substrate is silicon carbide.

3. The laser diode submount of claim 2 , wherein the substrate is single crystal silicon carbide.

4. The laser diode submount of claim 1 , wherein the thermally conductive layer is gold.

5. The laser diode submount of claim 1 , wherein the thermally conductive layer is copper.

6. The laser diode submount of claim 1 , wherein the common base layer comprises layers of titanium, platinum, and gold.

7. The laser diode submount of claim 6 , wherein the bonding contact terminates with an AuSn layer.

8. The thermally conductive, insulating substrate of claim 1 , wherein the first contact, the second contact, and the bonding contact are side by side rectangular contacts that substantially cover the major surface of the substrate.

9. A device, comprising:

a silicon carbide substrate having a major surface;

first conductive contact layers that include a first upper contact portion and a portion of a first base layer and second conductive contact layers that include a second upper contact portion and a portion of a second base layer situated on the major surface, the first conductive contact layers and the second conductive contact layers separated by a first insulating gap and defining a first contact and a second contact that are displaced along the major surface;

a bonding contact that includes an upper laser contact portion and a portion of the first base layer situated on the major surface of the silicon carbide substrate, wherein the upper laser contact portion is displaced from the first upper contact portion by a second insulating gap, and conductively coupled to the first conductive contact layers, the bonding contact including at least one conductive layer of thickness greater than 0.5 μm; and

a laser diode secured and electrically coupled to the bonding contact.

10. The device of claim 9 , further comprising a solder layer that secures the laser diode to the bonding contact.

11. The device of claim 9 , wherein the first conductive contact layers and second conductive contact layers include a common set of conductive base layers.

12. The device of claim 11 , wherein the common set of conductive base layers includes layers of Ti, Pt, and Au.

13. The device of claim 12 , wherein a thickness of the Au layer of the common set of conductive base layers is greater than 0.5 μm.

14. The device of claim 11 , wherein the common set of conductive layers includes a copper layer having a thickness greater than 0.5 μm.

15. The device of claim 9 , wherein the first conductive contact layers and the second conductive contact layers include at least one layer of gold and one layer of copper, each of thickness greater than or equal 0.5 μm.

16. The device of claim 9 , wherein the first conductive contact layers and the second conductive contact layers include, from the major surface of the substrate, layers of Ti, Pt, and Au, wherein the Au layer has a thickness of at least 1 μm.

17. The device of claim 16 , wherein the bonding contact includes layers of Ti, Pt, and Au, and a thickness of the Au layer is greater than 0.5 μm.

18. A method, comprising:

forming a first set of conductive base layers on a major surface of a SiC substrate, the first set of conductive base layers defining an insulating gap between a first area and a second area of the major surface; and

defining a first contact and a second contact in a second set of conductive base layers by forming the second set of conductive base layers to cover a portion of the first set of conductive base layers associated with the first area of the major surface, wherein the covered portion is not adjacent the insulating gap between the first area and the second area of the major surface and to cover the portion of the first set of conductive base layers associated with the second area of the major surface, wherein the first set of conductive base layers includes layers of Ti, Pt, and Au and the second set of conductive base layers has a thickness of at least 5 μm.

19. The method of claim 18 , further comprising bonding and electrically coupling at least one laser diode to an uncovered portion of the first set of base layers associated with the first area of the major surface.

20. The method of claim 18 , wherein the first set of conductive base layers includes a Ti layer of thickness of 0.1 μm, a Pt layer of thickness 0.2 μm, and an Au layer of thickness of 10 μm, and the second set of conductive base layers includes an Au layer, a Cu layer, or an AuSn layer.

21. The method of claim 18 , wherein the first contact, the second contact, and an uncovered portion of the first set of conductive base layers associated with the first area of the major surface of the substrate are rectangular areas covering the major surface of the substrate except at the insulating gap.