Simplified Process for Vertical LED Manufacturing

Patent metadata

Field	Value
Publication number	US-2016284928-A1
Application number	US-201514744602-A
Country	US
Kind code	A1
Filing date	Jun 19, 2015
Priority date	Mar 25, 2015
Publication date	Sep 29, 2016
Grant date	—

Abstract

Techniques for integrating spalling into layer transfer processes involving optical device semiconductor materials are provided. In one aspect, a layer transfer method for an optical device semiconductor material includes forming the optical device semiconductor material on a first substrate; depositing a metal stressor layer on top of the optical device semiconductor material; attaching a first handle layer to the metal stressor layer; removing the optical device semiconductor material from the first substrate by pulling the first handle layer away from the first substrate; attaching a second handle layer to the optical device semiconductor material; removing the first handle layer from the stack; and forming a second substrate on the stressor layer. Vertical LED devices and techniques for formation thereof are also provided.

First claim

What is claimed is:

1 . A layer transfer method for an optical device semiconductor material, comprising the steps of:
forming the optical device semiconductor material on a first substrate; depositing a metal stressor layer on top of the optical device semiconductor material, wherein the metal stressor layer is deposited to a thickness sufficient to permit mechanically-assisted spalling of the optical device semiconductor material to occur; attaching a first handle layer to the metal stressor layer; removing the optical device semiconductor material from the first substrate by pulling the first handle layer away from the first substrate and with it a stack comprising the metal stressor layer and the optical device semiconductor material; attaching a second handle layer to the optical device semiconductor material; removing the first handle layer from the stack; and forming a second substrate on the stressor layer, wherein the second substrate comprises a metal selected from the group consisting of: nickel, copper, silver, aluminum, zinc, tin, and combinations thereof.

2 . The method of claim 1 , wherein the optical device semiconductor material comprises silicon, germanium, gallium arsenide, gallium nitride, aluminum nitride, indium phosphide, or silicon carbide.

3 . The method of claim 1 , wherein the first substrate comprises a sapphire, silicon carbide, or bulk gallium nitride growth substrate, the method further comprising the step of:
growing the optical device semiconductor material on the first substrate.

4 . The method of claim 1 , wherein the metal stressor layer comprises one or more of nickel, cobalt, chromium, and iron.

5 . The method of claim 1 , wherein the thickness sufficient to permit mechanically-assisted spalling of the optical device semiconductor material to occur comprises the metal stressor layer having a thickness of from about 1 μm to about 50 and ranges therebetween.

6 . The method of claim 1 , further comprising the steps of:
depositing a metal adhesion layer on the optical device semiconductor material; and electroplating the metal stressor layer on the adhesion layer.

7 . The method of claim 6 , wherein the metal adhesion layer comprises one or more of titanium, tungsten, chromium, and nickel.

8 . The method of claim 1 , wherein the second substrate is formed on the stressor layer using electroplating.

9 . The method of claim 1 , wherein the second substrate is formed on the stressor layer using spray coating.

10 . The method of claim 1 , further comprising the step of:
flipping the stack such that the second substrate is below the stack.

11 . A method for forming a vertical light emitting diode (LED) device, comprising the steps of:
forming an optical device semiconductor material on a first substrate; forming a vertical LED stack on top of the optical device semiconductor material; depositing a metal stressor layer on top of the vertical LED stack, wherein the metal stressor layer is deposited to a thickness sufficient to permit mechanically-assisted spalling of the optical device semiconductor material to occur; attaching a first handle layer to the metal stressor layer; removing the vertical LED stack and the optical device semiconductor material from the first substrate by pulling the first handle layer away from the first substrate and with it a stack comprising the metal stressor layer, the vertical LED stack, and the optical device semiconductor material; attaching a second handle layer to the optical device semiconductor material; removing the first handle layer from the stack; and forming a second substrate on the stressor layer, wherein the second substrate comprises a metal selected from the group consisting of: nickel, copper, silver, aluminum, zinc, tin, and combinations thereof.

12 . The method of claim 11 , further comprising the step of:
flipping the stack such that the second substrate is below the stack.

13 . The method of claim 11 , wherein the step of forming the vertical LED stack on the optical device semiconductor material comprises the steps of:
forming an n-type doped contact layer on the optical device semiconductor material; forming an active layer on the n-type doped contact layer; and forming a p-type doped contact layer on the active layer.

14 . The method of claim 13 , wherein the n-type doped contact layer, the active layer, and the p-type doped contact layer are each formed using an epitaxial growth process.

15 . The method of claim 11 , wherein the second substrate is formed on the stressor layer using electroplating.

16 . The method of claim 11 , wherein the second substrate is formed on the stressor layer using spray coating.

Assignees

• IBM

Inventors

• Bedell Stephen W
• Fogel Keith E
• Lauro Paul A
• Sadana Devendra K

Classifications

• H10H20/858

  Means for heat extraction or cooling · CPC title

• H10H20/0365

  of means for heat extraction or cooling · CPC title

• H10H20/0363

  of optical field-shaping means · CPC title

• H10H20/0362

  of encapsulations · CPC title

• H10H20/034

  of coatings · CPC title