Plasma treatment between deposition processes

• US 7,741,144 B2
• Filed: 10/31/2008
• Issued: 06/22/2010
• Est. Priority Date: 11/02/2007
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Li, Liwei, Choi, Soo Young, Sheng, Shuran, Chae, Yong-Kee
• Primary Examiner(s): Fourson; George
• Application Number:
  US12/263,253
• Publication Number:
  US 20090142878A1
• Time in Patent Office: 599 Days
• Field of Search: 438/96, 438/482, 438/57, 438/63, 438/76, 257/E31.045, 257/E31.048, 257/E27.125, 257/E25.007, 136/250
• US Class Current: 438/57
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02576 N-type
• CPC Class Codes: H01L 21/02595 polycrystalline
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 21/02667 Crystallisation or recrystallisation of non-monocrystalline semiconductor materials, e.g. regrowth
• CPC Class Codes: H01L 31/0236 Special surface textures
• CPC Class Codes: H01L 31/02366 of the substrate or of a layer on the substrate, e.g. textured ITO/glass substrate or superstrate, textured polymer layer on glass substrate
• 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 31/076 Multiple junction or tandem solar cells
• CPC Class Codes: H01L 31/186 Particular post-treatment for the devices, e.g. annealing, impurity gettering, short-circuit elimination, recrystallisation
• CPC Class Codes: H01L 31/202 including only elements of Group IV of the Periodic Table
• 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

Embodiments of the present invention include an improved method of forming a thin film solar cell device using a plasma processing treatment between two or more deposition steps. Embodiments of the invention also generally provide a method and apparatus for forming the same. The present invention may be used to advantage to form other single junction, tandem junction, or multi-junction solar cell devices.

Claims

1. A method of forming a thin film solar cell, comprising:

transferring a substrate into a plasma enhanced chemical vapor deposition chamber;

depositing an n-doped amorphous silicon layer over the substrate;

providing a plasma treatment to the n-doped amorphous silicon layer disposed on the substrate;

depositing an n-doped microcrystalline silicon layer over the n-doped amorphous silicon layer;

removing the substrate from the chamber; and

forming a p-i-n junction over the n-doped microcrystalline silicon layer, wherein forming the p-i-n junction comprises;

depositing a p-doped microcrystalline silicon layer over the n-doped microcrystalline silicon layer;

depositing an n-doped amorphous silicon layer over the p-doped silicon layer; and

depositing an intrinsic microcrystalline silicon layer between the p-doped microcrystalline silicon layer and the n-doped amorphous silicon layer.

2. The method of claim 1, wherein providing a plasma treatment comprises generating a plasma using a hydrogen gas.

3. The method of claim 1, wherein the intrinsic microcrystalline silicon layer has a thickness of greater than about 1,000 Å

.

4. The method of claim 1, wherein the p-doped microcrystalline layer is deposited on the surface of the deposited n-doped microcrystalline silicon layer.

12. The method of claim 1, wherein depositing the n-doped amorphous silicon layer further comprises:

depositing a first n-doped layer on the intrinsic microcrystalline silicon layer; and

depositing a second n-doped amorphous layer on the first n-doped layer.

14. The method of claim 1, further comprising:

transferring the substrate into a second plasma enhanced chemical vapor deposition chamber, wherein depositing the p-doped microcrystalline silicon layer over the n-doped microcrystalline silicon layer is performed in the second plasma enhanced chemical vapor deposition chamber; and

transferring the substrate into a third plasma enhanced chemical vapor deposition chamber, wherein depositing the n-doped amorphous silicon layer and depositing the intrinsic microcrystalline silicon layer is performed in the third plasma enhanced chemical vapor deposition chamber.

5. A method of forming a thin film solar cell, comprising:

transferring a substrate into a first plasma enhanced chemical vapor deposition chamber disposed in a first system;

depositing a p-doped silicon layer over a surface of the substrate in the first plasma enhanced chemical vapor deposition chamber;

transferring a substrate from the first plasma enhanced chemical vapor deposition chamber into a second plasma enhanced chemical vapor deposition chamber disposed in the first system;

depositing an intrinsic amorphous silicon layer in the second plasma enhanced chemical vapor deposition chamber over the p-doped silicon layer;

depositing an n-doped amorphous silicon layer over the intrinsic amorphous silicon layer;

exposing the n-doped amorphous silicon layer to a plasma treatment;

depositing an n-doped microcrystalline silicon layer over the n-doped amorphous silicon layer;

removing the substrate from the second plasma enhanced chemical vapor deposition chamber; and

forming a p-i-n junction over the n-doped microcrystalline silicon layer, wherein forming the p-i-n junction comprises;

depositing a p-doped microcrystalline silicon layer over the n-doped microcrystalline silicon layer;

depositing an n-doped amorphous silicon layer over the p-doped silicon layer; and

depositing an intrinsic microcrystalline silicon layer between the p-doped microcrystalline silicon layer and the n-doped amorphous silicon layer.

6. The method of claim 5, wherein exposing the n-doped amorphous silicon layer to a plasma treatment plasma treatment comprises generating plasma using a hydrogen gas.

7. The method of claim 5, further comprising transferring the substrate from the second plasma enhanced chemical vapor deposition chamber in the first system to a first plasma enhanced chemical vapor deposition chamber disposed in a second system before depositing a p-doped microcrystalline silicon layer over the n-doped microcrystalline silicon layer.

13. The method of claim 5, wherein depositing the n-doped amorphous silicon layer further comprises:

depositing a first n-doped layer on the intrinsic microcrystalline silicon layer; and

depositing a second n-doped amorphous layer on the first n-doped layer.

15. The method of claim 5, further comprising:

transferring the substrate into a third plasma enhanced chemical vapor deposition chamber disposed in a second system, wherein depositing the p-doped microcrystalline silicon layer over the n-doped microcrystalline silicon layer is performed in the third plasma enhanced chemical vapor deposition chamber; and

transferring the substrate from the third plasma enhanced chemical vapor deposition chamber into a fourth plasma enhanced chemical vapor deposition chamber disposed in the second system, wherein depositing the n-doped amorphous silicon layer and depositing the intrinsic microcrystalline silicon layer is performed in the fourth plasma enhanced chemical vapor deposition chamber.

8. A method of forming a thin film solar cell, comprising:

depositing an amorphous silicon layer over a surface of a transparent substrate;

providing a plasma treatment to the amorphous silicon layer disposed on the transparent substrate;

depositing an microcrystalline silicon layer over the amorphous silicon layer; and

forming a p-i-n junction over the microcrystalline silicon layer, wherein forming the p-i-n junction comprises;

depositing a p-doped microcrystalline silicon layer over the n-doped microcrystalline silicon layer;

depositing an n-doped amorphous silicon layer over the p-doped silicon layer; and

depositing an intrinsic microcrystalline silicon layer between the p-doped microcrystalline silicon layer and the n-doped amorphous silicon layer.

9. The method of claim 8, wherein providing a plasma treatment comprises providing a gas selected from the group consisting of hydrogen, helium, argon and carbon dioxide.

10. The method of claim 8, further comprising depositing a transparent conductive oxide layer on the surface of the transparent substrate before depositing the amorphous silicon layer.

11. The method of claim 8, wherein depositing the n-doped amorphous silicon layer further comprises:

depositing a first n-doped layer on the intrinsic microcrystalline silicon layer; and

depositing a second n-doped amorphous layer on the first n-doped layer, wherein the second n-doped amorphous layer is degenerately doped.