Wet-etchable, sacrificial liftoff layer compatible with high temperature processing

Patent metadata

Field	Value
Publication number	US-9676227-B2
Application number	US-201414201009-A
Country	US
Kind code	B2
Filing date	Mar 7, 2014
Priority date	Mar 15, 2013
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

A method for forming a wet-etchable, sacrificial lift-off layer or layers compatible with high temperature processing, a sacrificial layer, defined as consisting of a single film of one material or multiple films of multiple materials, that can tolerate high temperatures, is deposited on a substrate, called the original substrate, by sputtering or another suitable technique (e.g. evaporation, pulsed laser deposition, wet chemistry, etc.). Intermediate steps result in a lift-off layer attached to the lift-off substrate, that allow for separating the product from the original substrate.

First claim

What is claimed is:

1. A method of lift-off comprising:
depositing a sacrificial layer on an original substrate,
depositing a lift-off layer onto the sacrificial layer at a substrate temperature between 100° C. and 1000° C.,
bonding the lift-off layer to a lift-off substrate using an adhesive, and
etching the sacrificial layer to obtain the lift-off layer attached to the lift-off substrate,
wherein at least one of said depositing steps occurs under non-epitaxial conditions, and
wherein the etching is sufficient to separate the lift-off layer and the lift-off substrate from the original substrate.

2. The method of claim 1 , wherein one or both of said depositing steps occur by sputtering, evaporation, electrodeposition, pulsed laser deposition, or wet chemistry.

3. The method of claim 1 , wherein the sacrificial layer is an acid soluble glass and wherein said etching is accomplished using acid.

4. The method of claim 3 , wherein said glass is selected from the group consisting of fluoride glasses, phosphate glasses, chalcogenide glasses, and silicate glasses containing sodium silicate.

5. The method of claim 1 , further comprising depositing a diffusion barrier between said sacrificial layer and said lift-off layer, wherein said etching also removes the diffusion barrier.

6. The method of claim 1 , wherein the lift-off layer comprises copper indium gallium diselenide.

7. The method of claim 1 , further comprising patterning the lift-off layer.

8. A method of lift-off comprising:
depositing a sacrificial layer on an original substrate,
depositing a lift-off layer onto the sacrificial layer at a substrate temperature between 100° C. and 1000° C., wherein the lift-off layer comprises copper indium gallium diselenide, Cu 2 ZnSn(S,Se) 4 ), cadmium telluride, iron disulfide, or a transparent conducting oxide,
bonding the lift-off layer to a lift-off substrate using an adhesive, and
etching the sacrificial layer to obtain the lift-off layer attached to the lift-off substrate,
wherein at least one of said depositing steps occurs under non-epitaxial conditions, and
wherein the etching is sufficient to separate the lift-off layer and the lift-off substrate from the original substrate.

9. The method of claim 8 , wherein one or both of said depositing steps occur by sputtering, evaporation, electrodeposition, pulsed laser deposition, or wet chemistry.

10. The method of claim 8 , wherein the sacrificial layer is an acid soluble glass and wherein said etching is accomplished using acid.

11. The method of claim 8 , further comprising depositing a diffusion barrier between said sacrificial layer and said lift-off layer, wherein said etching also removes the diffusion barrier.

12. The method of claim 1 , wherein the lift-off layer comprises said copper indium gallium diselenide.

13. The method of claim 8 , further comprising patterning the lift-off layer.

Assignees

• Frantz Jesse A
• Myers Jason D
• Bekele Robel Y
• Sanghera Jasbinder S
• Us Navy

Inventors

• Frantz Jesse A
• Myers Jason D
• Bekele Robel Y
• Sanghera Jasbinder S

Classifications

• H10P90/00

  Preparation of wafers not covered by a single main group of this subclass, e.g. wafer reinforcement · CPC title

• Y02E10/541

  CuInSe2 material PV cells · CPC title

• B44C1/227 Primary

  by etching · CPC title

• H01L21/02002

  Electricity · mapped topic

• H01L31/1896

  Electricity · mapped topic