Method of forming an electronic device using a separation-enhancing species

• US 7,749,884 B2
• Filed: 05/05/2009
• Issued: 07/06/2010
• Est. Priority Date: 05/06/2008
• Status: Active Grant

• Current Assignee: Applied Novel Devices, Inc.
• Original Assignee: AstroWatt, Inc.
• Inventors: Mathew, Leo, Jawarani, Dharmesh
• Primary Examiner(s): Garber; Charles D
• Assistant Examiner(s): Isaac; Stanetta D
• Application Number:
  US12/435,942
• Publication Number:
  US 20090280635A1
• Time in Patent Office: 427 Days
• Field of Search: 438/458, 438/602, 257/E21.294
• US Class Current: 438/602
• CPC Class Codes: H01L 21/26506 in group IV semiconductors
• CPC Class Codes: H01L 31/022425 for solar cells
• CPC Class Codes: H01L 31/028 including, apart from doping material or other impurities, only elements of Group IV of the Periodic Table
• CPC Class Codes: H01L 31/0304 including, apart from doping materials or other impurities, only AIIIBV compounds
• CPC Class Codes: H01L 31/0312 including, apart from doping materials or other impurities, only AIVBIV compounds, e.g. SiC
• CPC Class Codes: H01L 31/03682 including only elements of Group IV of the Periodic Table
• CPC Class Codes: H01L 31/03762 including only elements of Group IV of the Periodic Table
• CPC Class Codes: H01L 31/03765 including AIVBIV compounds or alloys, e.g. SiGe, SiC
• CPC Class Codes: H01L 31/068 the potential barriers being only of the PN homojunction type, e.g. bulk silicon PN homojunction solar cells or thin film polycrystalline silicon PN homojunction solar cells
• CPC Class Codes: H01L 31/1864 Annealing
• 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: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A method of forming an electronic device can include forming a metallic layer by an electrochemical process over a side of a substrate that includes a semiconductor material. The method can also include introducing a separation-enhancing species into the substrate at a distance from the side, and separating a semiconductor layer and the metallic layer from the substrate, wherein the semiconductor layer is a portion of the substrate. In a particular embodiment, the separation-enhancing species can be incorporated into a metallic layer and moved into the substrate, and in particular embodiment, the separation-enhancing species can be implanted into the substrate. In still another embodiment, both the techniques can be used. In a further embodiment, a dual-sided process can be performed.

Claims

1. A method comprising:

plating a first metallic layer over a first side of a semiconductor substrate, wherein the semiconductor substrate has at least one doped junction;

incorporating hydrogen into the first metallic layer overlying the semiconductor substrate, wherein incorporating the hydrogen occurs during plating the first metallic layer;

moving the hydrogen from the first metallic layer into the semiconductor substrate by an anneal process; and

separating a semiconductor layer and the first metallic layer from the semiconductor substrate.

4. The method of claim 1, further comprising plating the first metallic layer over a second side of the semiconductor substrate.

5. The method of claim 1, further comprising forming a second metallic layer over the semiconductor substrate before plating the first metallic layer, wherein the second metallic layer is formed by physical vapor deposition, atomic layer deposition, chemical vapor deposition, or any combination thereof.

6. The method of claim 5, wherein the second metallic layer comprises titanium, tungsten, palladium, copper, tin, nickel, silver, gold, or any combination thereof.

7. The method of claim 1, further comprising forming a second metallic layer by mechanically applying a metallic paste over the semiconductor substrate.

8. The method of claim 1, wherein separating the semiconductor layer and the first metallic layer from the semiconductor substrate is caused at least in part by moving the hydrogen from the first metallic layer into the semiconductor substrate.

9. The method of claim 1, wherein separating the semiconductor layer and the first metallic layer from the semiconductor substrate comprises using a wire to aid in the separation.

10. The method of claim 1, further comprising adding contacts to the separated semiconductor layer to form a photovoltaic cell.

11. The method of claim 1, further comprising adding contacts to the separated semiconductor layer to form a light emitting device.

2. A method comprising:

forming a metallic layer by an electrochemical process over a first side of a semiconductor substrate, wherein the semiconductor substrate has at least one doped junction;

incorporating hydrogen into the metallic layer overlying the semiconductor substrate;

moving the hydrogen from the metallic layer into the semiconductor substrate by an anneal process; and

separating a semiconductor layer and the metallic layer from the semiconductor substrate, wherein the semiconductor substrate comprises a hydrogen-implanted region, and wherein the moving the hydrogen from the metallic layer into the semiconductor substrate is used to separate the semiconductor layer from the semiconductor substrate.

3. The method of claim 2, wherein the semiconductor substrate comprises a plurality of hydrogen-implanted regions.

12. A method comprising:

plating a first metallic layer over a first side of a semiconductor substrate wherein a separation-enhancing species is incorporated within the first metallic layer during plating;

annealing the first metallic layer and the semiconductor substrate to move at least some of the separation-enhancing species from the first metallic layer into the semiconductor substrate, wherein during heating or cooling after the anneal, stress builds within semiconductor substrate; and

separating a semiconductor layer and the first metallic layer from the semiconductor substrate, wherein the stress within the semiconductor substrate helps in separating the semiconductor layer and the first metallic layer from the semiconductor substrate.

13. The method of claim 12, wherein the separation-enhancing species includes hydrogen.

14. The method of claim 12, further comprising forming a second metallic layer over the semiconductor substrate before plating the first metallic layer, wherein the second metallic layer is formed by physical vapor deposition, atomic layer deposition, chemical vapor deposition, or any combination thereof.

15. The method of claim 14, wherein the second metallic layer comprises titanium, tungsten, palladium, copper, tin, nickel, silver, gold, or any combination thereof.

16. The method of claim 12, wherein separating the semiconductor layer comprises using a wire.

17. The method of claim 12, wherein the semiconductor substrate comprises silicon, germanium, gallium arsenide, gallium nitride, indium phosphide, or any combination thereof.

18. The method of claim 12, further comprising plating the first metallic layer over a second side of the semiconductor substrate.

19. The method of claim 12, further comprising adding contacts to the separated semiconductor layer to form a photovoltaic cell.

20. The method of claim 12, further comprising adding contacts to the separated semiconductor layer to form a light emitting device.