Method of fabricating a solar cell with a tunnel dielectric layer

Patent metadata

Field	Value
Publication number	US-9537030-B2
Application number	US-201514725939-A
Country	US
Kind code	B2
Filing date	May 29, 2015
Priority date	Jul 2, 2010
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

Methods of fabricating solar cells with tunnel dielectric layers are described. Solar cells with tunnel dielectric layers are also described.

First claim

What is claimed is:

1. A method of fabricating a solar cell, the method comprising:
forming, at a first temperature, a surface oxide layer disposed on the substrate by thermal oxidation; and
heating, the surface oxide layer from a temperature below 500 degrees Celsius, to a second temperature above 500 degrees Celsius, wherein the first and second temperature are approximately the same.

2. The method of claim 1 , wherein the first and the second temperature are approximately 565 degrees Celsius.

3. The method of claim 1 , wherein the surface oxide layer is formed by a low-pressure thermal oxidation process.

4. The method of claim 1 , wherein the low-pressure thermal oxidation process is performed in an atmosphere comprising oxygen (O2).

5. The method of claim 1 , further comprising forming a polysilicon layer during the heating.

6. The method of claim 5 , further comprising forming a metal contact above the polysilicon layer.

7. The method of claim 1 , wherein the substrate comprises silicon and the oxide layer comprises silicon oxide.

8. A method of fabricating a solar cell, the method comprising:
consuming a portion of a substrate of the solar cell to provide a surface oxide layer of the substrate, wherein the consuming comprises exposing the substrate to a wet chemical solution; and
heating the surface oxide layer from a temperature below 500 degrees Celsius, to a temperature above 500 degrees Celsius.

9. The method of claim 8 , further comprising, subsequent to heating the surface oxide layer to a temperature above 500 degrees Celsius, cooling back to a temperature below 500 degrees Celsius.

10. The method of claim 8 , wherein heating the surface oxide layer to the temperature above 500 degrees Celsius comprises heating to a temperature of approximately 565 degrees Celsius.

11. The method of claim 8 , wherein the wet chemical solution comprises an oxidizer selected from the group consisting of ozone (O 3 ) and hydrogen peroxide (H 2 O 2 ).

12. The method of claim 8 , wherein the substrate comprises silicon and the oxide layer comprises silicon oxide.

13. The method of claim 8 , further comprising forming a polysilicon layer during the heating.

14. The method of claim 13 , further comprising forming a metal contact above the polysilicon layer.

15. A method of fabricating a solar cell, the method comprising:
consuming a portion of a substrate of the solar cell to provide a surface oxide layer of the substrate, wherein the consuming comprises performing a thermal oxidation process; and
heating the surface oxide layer from a temperature below 500 degrees Celsius, to a temperature above 500 degrees Celsius.

16. The method of claim 15 , further comprising, subsequent to heating the surface oxide layer to a temperature above 500 degrees Celsius, cooling back to a temperature below 500 degrees Celsius.

17. The method of claim 15 , wherein the surface oxide layer is formed by a low-pressure thermal oxidation process.

18. The method of claim 15 , wherein the low-pressure thermal oxidation process is performed in an atmosphere comprising oxygen (O 2 ).

19. The method of claim 15 , further comprises forming a polysilicon layer during the heating.

20. The method of claim 19 , further comprising forming a metal contact above the polysilicon layer.

Assignees

• Sunpower Corp

Inventors

• Dennis Tim
• Harrington Scott
• Manning Jane
• Smith David D
• Waldhauer Ann

Classifications

• Y02E10/547

  Monocrystalline silicon PV cells · CPC title

• Y02E10/546

  Polycrystalline silicon PV cells · CPC title

• H10F71/00

  Manufacture or treatment of devices covered by this subclass (patterning processes to connect thin photovoltaic cells in integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/33; manufacture or treatment of encapsulations or containers for integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/80; manufacture or treatment of integrated devices, or assemblies of multiple devices, comprising at least one element in which radiation controls the flow of current H10F39/00) · CPC title

• H10F71/131

  Recrystallisation; Crystallization of amorphous or microcrystalline semiconductors · CPC title

• H10F71/1221

  comprising polycrystalline silicon · CPC title