System and method for manufacturing photovoltaic structures with a metal seed layer

• US 10,181,536 B2
• Filed: 08/08/2017
• Issued: 01/15/2019
• Est. Priority Date: 10/22/2015
• Status: Active Grant

• Current Assignee: Tesla Inc.
• Original Assignee: Tesla Inc.
• Inventors: Wang, Wei
• Primary Examiner(s): Everhart, Caridad
• Application Number:
  US15/672,010
• Publication Number:
  US 20170338356A1
• Time in Patent Office: 525 Days
• CPC Class Codes: C23C 14/34 Sputtering
• CPC Class Codes: C23C 14/50 Substrate holders
• CPC Class Codes: C25D 17/001 Apparatus specially adapted for electrolytic coating of wafers, e.g. semiconductors or solar cells
• CPC Class Codes: C25D 7/126 for solar cells
• CPC Class Codes: H01L 21/67 Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere processes per se H01L21/30, H01L21/46, H01L23/00; simple temporary support means, e.g. using adhesives, electric or magnetic means H01L21/68, H01L21/302; apparatus for manufacturing arrangements for connecting or disconnecting semiconductor or solid-state bodies and for methods related thereto H01L24/74;
• CPC Class Codes: H01L 31/022425 for solar cells
• CPC Class Codes: H01L 31/022466 made of transparent conductive layers, e.g. TCO, ITO layers
• CPC Class Codes: H01L 31/0747 comprising a heterojunction of crystalline and amorphous materials, e.g. heterojunction with intrinsic thin layer
• CPC Class Codes: H01L 31/075 the potential barriers being only of the PIN type, e.g. amorphous silicon PIN solar cells
• CPC Class Codes: H01L 31/18 Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
• CPC Class Codes: H01L 31/1864 Annealing
• CPC Class Codes: H01L 31/1884 Manufacture of transparent electrodes, e.g. TCO, ITO
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• 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

One embodiment of the present invention can provide a system for fabrication of a photovoltaic structure. The system can include a physical vapor deposition tool configured to sequentially deposit a transparent conductive oxide layer and a metallic layer on an emitter layer formed in a first surface of a Si substrate, without requiring the Si substrate to be removed from the physical vapor deposition tool after depositing the transparent conductive oxide layer. The system can further include an electroplating tool configured to plate a metallic grid on the metallic layer and a thermal annealing tool configured to anneal the transparent conductive oxide layer.

Claims

1. A method for fabricating a photovoltaic structure, the method comprising:

depositing, inside a physical vapor deposition chamber, a transparent conductive oxide layer on an emitter layer of the photovoltaic structure;

depositing, within the same physical vapor deposition chamber and without requiring the photovoltaic structure to be removed from the physical vapor deposition chamber after deposition of the transparent conductive oxide layer, a metallic seed layer on the transparent conductive oxide layer;

depositing, using a plating technique, a metallic grid on the metallic seed layer; and

simultaneously annealing the transparent conductive oxide layer the metallic grid, and the metallic seed layer.

2. The method of claim 1, wherein the annealing is performed in an environment comprising:

air;

vacuum;

forming gas;

or

inert gases.

3. The method of claim 1, further comprising:

depositing, within the same physical vapor deposition chamber, a second transparent conductive oxide layer on a surface-field layer of the photovoltaic structure; and

depositing one or more metallic layers on the second transparent conductive oxide layer.

4. The method of claim 1, wherein the physical vapor deposition chamber comprises a sputtering chamber or an evaporation chamber.

5. The method of claim 1, further comprising depositing one or more metallic adhesive layers on the transparent conducive oxide layer, wherein the one or more metallic adhesive layers includes:

Cu, Ni, Ag, Ti, Ta, W, TiN, TaN, WN, TiW, NiCr, or any combination thereof.

6. The method of claim 1, wherein the transparent conductive oxide layer includes:

indium-tin-oxide (ITO), aluminum-doped zinc-oxide (ZnO;

Al), gallium-doped zinc-oxide (ZnO;

Ga), tungsten-doped indium oxide (IWO), Zn—

In—

Sn—

O (ZITO), or any combination thereof.

7. The method of claim 1, wherein depositing the transparent conductive oxide layer is performed at a temperature lower than 100°

C.

8. The method of claim 1, wherein annealing the transparent conductive oxide layer and the one or more metallic layers comprises subjecting the photovoltaic structure to a temperature between 150°

C. and 400°

C.

9. The method of claim 8, wherein annealing the transparent conductive oxide layer and the one or more metallic layers comprises subjecting the photovoltaic structure to the temperature for a time period between 5 seconds and 5 minutes.