Method for separating a device-forming layer from a base body

• US 5,811,348 A
• Filed: 02/01/1996
• Issued: 09/22/1998
• Est. Priority Date: 02/02/1995
• Status: Expired

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Matsushita, Takeshi, Tayanaka, Hiroshi
• Primary Examiner(s): Nguyen, Tuan H.
• Application Number:
  US08/595,382
• Time in Patent Office: 964 Days
• Field of Search: 438/458, 438/459, 438/464, 438/455, 438/57, 136/244
• US Class Current: 438/455
• CPC Class Codes: H01L 21/02381 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/0245 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02488 Insulating materials
• CPC Class Codes: H01L 21/02513 Microstructure
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02658 Pretreatments cleaning in general H01L21/02041
• CPC Class Codes: H01L 21/02664 Aftertreatments planarisation in general H01L21/304
• CPC Class Codes: H01L 21/76251 using bonding techniques
• CPC Class Codes: H01L 21/76259 with separation/delamination along a porous layer
• CPC Class Codes: H01L 31/048 Encapsulation of modules
• CPC Class Codes: H01L 31/077 the devices comprising monocrystalline or polycrystalline materials
• CPC Class Codes: H01L 31/1804 comprising only elements of Group IV of the Periodic Table
• CPC Class Codes: H01L 31/1892 methods involving the use of temporary, removable substrates
• CPC Class Codes: Y02E 10/547 Monocrystalline silicon PV cells
• CPC Class Codes: Y02E 10/548 Amorphous silicon PV cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A porous Si layer is formed on a single-crystal Si substrate, and then a p⁺ -type Si layer, p-type Si layer and n⁺ -type Si layer which all make up a solar cell layer. After a protective film is made on the n⁺ -type Si layer, the rear surface of the single-crystal Si substrate is bonded to a tool, and another tool is bonded to the front surface of the protective film. Then, the tools are pulled in opposite directions to mechanically rupture the porous Si layer and to separate the solar cell layer from the single-crystal substrate. The solar cell layer is subsequently sandwiched between two plastic substrates to make a flexible thin-film solar cell.

Claims

1. A method for separating a semiconductor layer from a substrate, comprising:

forming a porous layer on a surface of a substrate by an anodic oxidization;

forming at least one semiconductor layer on said porous layer; and

separating said semiconductor layer from said substrate by forming a mechanical rupture in said porous layer or along an interface formed between the porous layer and the substrate or between the porous layer and the semiconductor layer.

2. A method for separating a semiconductor layer from a substrate according to claim 1, wherein said substrate is a Si substrate.

3. A method for separating a semiconductor layer from a substrate according to claim 1, wherein said porous layer is a Si porous layer.

4. A method for separating a semiconductor layer from a substrate according to claim 1, wherein the method further comprises a step of oxidizing said porous layer after forming said porous layer.

5. A method for separating a semiconductor layer from a substrate according to claim 4, wherein said porous layer is oxidized at a temperature of 400°

C. to 600°

C.

6. A method for separating a semiconductor layer from a substrate according to claim 1, wherein the method further comprises a step of H₂ -annealing said porous layer after forming said porous layer.

7. A method for separating a semiconductor layer from a substrate according to claim 6, wherein said porous layer is H₂ -annealed at a temperature of 950°

C. to 1000°

C.

8. A method for separating a semiconductor layer from a substrate according to claim 1, wherein the method further comprises the steps of:

forming a oxide film on a entire surface of said semiconductor layer, said porous layer and said substrate; and

removing said oxide film to form a wedge-shaped gap in an interface between said porous layer and said semiconductor layer.

9. A method for separating a semiconductor layer from a substrate, comprising:

forming a porous layer on a surface of a substrate;

H₂ -annealing said porous layer;

forming at least one semiconductor layer on said porous layer;

separating said semiconductor layer from said substrate by forming a mechanical rupture within said porous layer or along an interface formed between the substrate and the porous layer or between the porous layer and said semiconductor layer.

10. A method for separating a semiconductor layer from a substrate, comprising:

forming a porous layer on a surface of a substrate;

oxidizing said porous layer;

forming at least one semiconductor layer on said porous layer;

separating said semiconductor layer from said substrate by forming a mechanical rupture within said porous layer or along an interface formed between the substrate and the porous layer or between the porous layer and said semiconductor layer.

11. A method for manufacturing a solar cell, comprising;

forming a porous layer on a surface of a substrate by anodic oxidization;

forming a plurality of semiconductor layers on said porous layer to form the solar cell;

separating said plurality of semiconductor layers from said substrate by forming a mechanical rupture within said porous layer or along an interface formed between the substrate and the porous layer or between the porous layer and said semiconductor layer.