Solid state optoelectronic device with preformed metal support substrate
View Patent ↗A wafer-level process for manufacturing solid state lighting (“SSL”) devices using large-diameter preformed metal substrates is disclosed. A light emitting structure is formed on a growth substrate, and a preformed metal substrate is bonded to the light emitting structure opposite the growth substrate. The preformed metal substrate can be bonded to the light emitting structure via a metal-metal bond, such as a copper-copper bond, or with an inter-metallic compound bond.
1. A method of manufacturing a plurality of solid state lighting (“SSL”) devices, the method comprising:
providing a light emitting structure having a first semiconductor material, a second semiconductor material, and an active region between the first and second semiconductor materials;
forming a metal bonding structure on the light emitting structure; and
bonding a preformed metal substrate to the metal bonding structure, wherein the light emitting structure extends continuously over a surface of the preformed metal substrate.
2. The method of claim 1 wherein the first semiconductor material, the second semiconductor material, and the active region extend continuously over a surface of the preformed metal substrate.
3. The method of claim 1 wherein bonding a preformed metal substrate to the metal bonding structure includes forming an inter-metallic compound (IMC) bond between the preformed metal substrate and the metal bonding structure.
4. The method of claim 3 wherein the IMC bond includes a first boundary region proximate the preformed metal substrate, a second boundary region proximate the light emitting structure, and a median region between the first and second boundary regions.
5. The method of claim 1 wherein bonding a preformed metal substrate to the metal bonding structure includes subjecting at least a portion of the preformed metal substrate and metal bonding structure to heat.
6. The method of claim 1 wherein providing a light emitting structure includes:
growing the light emitting structure on a growth substrate, and
after forming the metal bonding structure on the light emitting structure, removing the growth structure from the light emitting structure by at least one of grinding, post-grinding, wet etching, or dry etching.
7. The method of claim 1 , further comprising forming one or more exterior contacts for each SSL device and over the light emitting structure.
8. The method of claim 1 , further comprising attaching the preformed metal substrate to a temporary carrier with an adhesive before bonding the preformed metal substrate to the metal bonding structure.
9. The method of claim 1 , further comprising forming the preformed metal substrate by stamping the preformed metal substrate from a metal sheet.
10. The method of claim 1 wherein the metal bonding structure includes one or more of a reflective material, a barrier material, or a copper seed layer, and wherein the metal bonding structure extends continuously over the preformed metal substrate.
11. A method of manufacturing a semiconductor wafer, the method comprising:
forming a metal bonding structure on a light emitting structure having a first semiconductor material, a second semiconductor material, and an active region between the first and second semiconductor materials; and
bonding a preformed metal substrate to the metal bonding structure, wherein the first semiconductor material, the second semiconductor material, and the active region extend continuously over a surface of the preformed metal substrate.
12. The method of claim 11 wherein the wafer is at least approximately six inches in diameter, and wherein the preformed metal substrate has a thickness of approximately 50-300 μm.
13. The method of claim 11 wherein the metal bonding structure extends continuously over a surface of the preformed metal substrate.
14. The method of claim 11 wherein bonding a preformed metal substrate to the metal bonding structure includes forming an inter-metallic compound (IMC) bond.
15. The method of claim 14 wherein the metal bonding structure and the preformed metal substrate both include copper, and wherein the IMC bond is a copper-copper bond.
16. The method of claim 14 wherein the IMC bond includes a first boundary region proximate the preformed metal substrate, a second boundary region proximate the light emitting structure, and a median region between the first and second boundary regions, wherein the median region includes a metal alloy.
17. The method of claim 11 wherein bonding a preformed metal substrate to the metal bonding structure includes forming an inter-metallic compound bond made of nickel and tin between the metal bonding structure and the preformed metal substrate.
18. The method of claim 11 wherein bonding a preformed metal substrate to the metal bonding structure includes subjecting at least a portion of the preformed metal substrate and metal bonding structure to heat at a temperature less than 300° Celsius.
19. The method of claim 11 , further comprising forming a barrier material on the light emitting structure between the light emitting structure and the metal bonding structure.
20. The method of claim 11 wherein providing a light emitting structure includes:
growing the light emitting structure on a growth substrate, and
after forming the metal bonding structure on the light emitting structure, removing the growth structure from the light emitting structure by at least one of grinding, post-grinding, wet etching, or dry etching.