USE OF CHAINED IMPLANTS IN SOLAR CELLS

• US 20090227094A1
• Filed: 03/04/2009
• Published: 09/10/2009
• Est. Priority Date: 03/05/2008
• Status: Active Grant

• Current Assignee: Varian Semiconductor Equipment Associates Incorporated (Applied Materials Incorporated)
• Original Assignee: Varian Semiconductor Equipment Associates Incorporated (Applied Materials Incorporated)
• Inventors: Sullivan, Paul, Gupta, Atul, Murphy, Paul, Bateman, Nicholas
• Granted Patent: US 7,727,866 B2
• Time in Patent Office: Days
• US Class Current: 438/514
• CPC Class Codes: H01J 2237/0827 for producing different ions sequentially
• CPC Class Codes: H01J 2237/202 Movement
• CPC Class Codes: H01J 2237/31711 using mask
• CPC Class Codes: H01J 37/3171 for ion implantation plasma immersion ion implantation H01J37/32412
• CPC Class Codes: H01J 37/32412 Plasma immersion ion implantation
• CPC Class Codes: H01L 21/26506 in group IV semiconductors
• CPC Class Codes: H01L 21/26513 of electrically active species
• CPC Class Codes: H01L 21/266 using masks H01L21/26586 takes precedence
• 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 31/0682 back-junction, i.e. rearside emitter, solar cells, e.g. interdigitated base-emitter regions back-junction 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 31/1804 comprising only elements of Group IV of the Periodic Table
• 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

The manufacture of solar cells is simplified and cost reduced through by performing successive ion implants, without an intervening thermal cycle. In addition to reducing process time, the use of chained ion implantations may also improve the performance of the solar cell. In another embodiment, two different species are successively implanted without breaking vacuum. In another embodiment, the substrate is implanted, then flipped such that it can be and implanted on both sides before being annealed. In yet another embodiment, one or more different masks are applied and successive implantations are performed without breaking the vacuum condition, thereby reducing the process time.

Claims

1. A method of manufacturing a solar cell using a substrate, comprising:

creating a vacuum wherein said substrate is implanted;

performing a first ion implantation on first surface of said substrate using a first species;

introducing a mask pattern so as to cover a portion of said first surface of said substrate; and

performing a second ion implantation on said surface using a second species, whereby only an uncovered portion of said first surface of said substrate is implanted with said second species, and wherein said first and second ion implantations are performed without breaking said vacuum.

2. The method of claim 1, wherein said first and second species are the same species.

3. The method of claim 1, wherein said first and second species comprise dopants.

4. The method of claim 1, wherein said first and second species are different species.

5. The method of claim 1, wherein said first species or said second species comprises a non-dopant.

6. The method of claim 1, wherein a second mask pattern is introduced prior to said first ion implantation, such that only a portion of said substrate is implanted by said first species.

7. A method of manufacturing a solar cell using a substrate, comprising:

creating a vacuum wherein said substrate is implanted;

performing a first ion implantation on a first surface of said substrate using a first species;

flipping said substrate so as to expose a second surface;

introducing a mask pattern so as to cover a portion of said second surface of said substrate; and

performing a second ion implantation on said second surface using a second species, whereby only an uncovered portion of said second surface of said substrate is implanted with said second species, and wherein said first and second ion implantations are performed without breaking said vacuum.

8. The method of claim 7, wherein said first and second species are the same species.

9. The method of claim 7, wherein said first and second species comprise dopants.

10. The method of claim 7, wherein said first and second species are different species.

11. The method of claim 7, wherein said first species or said second species comprises a non-dopant.

12. The method of claim 7, wherein a second mask pattern is introduced prior to said first ion implantation, such that only a portion of said first surface of said substrate is implanted by said first species.

13. A method of manufacturing a solar cell using a substrate, comprising:

creating a vacuum wherein said substrate is implanted;

performing a first ion implantation on a first surface of said substrate using a first species;

flipping said substrate so as to expose a second surface; and

performing a second ion implantation on said second surface using a second species, wherein said first and second ion implantations are performed without breaking said vacuum.

14. The method of claim 13, wherein said first and second species are the same species.

15. The method of claim 13, wherein said first and second species comprise dopants.

16. The method of claim 13, wherein said first and second species are different species.

17. The method of claim 13, wherein said first species or said second species comprises a non-dopant.

18. The method of claim 13, wherein a first mask pattern is introduced prior to said first ion implantation, such that only a portion of said first surface of said substrate is implanted by said first species.

19. The method of claim 17, wherein a second mask pattern is introduced prior to said second ion implantation, such that only a portion of said second surface of said substrate is implanted by said second species.

20. The method of claim 13, wherein a mask pattern is introduced prior to said second ion implantation, such that only a portion of said second surface of said substrate is implanted by said second species.