METHODS FOR SIMULTANEOUSLY FORMING DOPED REGIONS HAVING DIFFERENT CONDUCTIVITY-DETERMINING TYPE ELEMENT PROFILES

• US 20100167511A1
• Filed: 12/29/2008
• Published: 07/01/2010
• Est. Priority Date: 12/29/2008
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Bhanap, Anil, Leung, Roger Yu-Kwan, Rutherford, Nicole
• Granted Patent: US 7,820,532 B2
• Time in Patent Office: Days
• US Class Current: 438/548
• CPC Class Codes: H01L 21/2225 Diffusion sources
• CPC Class Codes: H01L 21/2255 the applied layer comprising oxides only, e.g. P2O5, PSG, H3BO3, doped oxides
• CPC Class Codes: H01L 31/022441 Electrode arrangements specially adapted for back-contact solar cells
• 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 31/1804 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

Method for simultaneously forming doped regions having different conductivity-determining type elements profiles are provided. In one exemplary embodiment, a method comprises the steps of diffusing first conductivity-determining type elements into a first region of a semiconductor material from a first dopant to form a doped first region. Second conductivity-determining type elements are simultaneously diffused into a second region of the semiconductor material from a second dopant to form a doped second region. The first conductivity-determining type elements are of the same conductivity-determining type as the second conductivity-determining type elements. The doped first region has a dopant profile that is different from a dopant profile of the doped second region.

Claims

1. A method for fabricating a semiconductor device, the method comprising the steps of:

diffusing first conductivity-determining type elements into a first region of a semiconductor material from a first liquid dopant to form a doped first region; and

simultaneously diffusing second conductivity-determining type elements into a second region of the semiconductor material from a second liquid dopant to form a doped second region, wherein the first conductivity-determining type elements are of the same conductivity-determining type as the second conductivity-determining type elements;

wherein, the doped first region has a dopant profile that is different from a dopant profile of the doped second region.

2. The method of claim 1, wherein the step of simultaneously diffusing comprises simultaneously diffusing second conductivity-determining type elements that are different from the first conductivity-determining type elements.

3. The method of claim 1, wherein the step of simultaneously diffusing comprises simultaneously diffusing second conductivity-determining type elements from the second liquid dopant that has a concentration of the second conductivity-determining type elements that is different from a concentration of the first conductivity-determining type elements of the first liquid dopant.

4. The method of claim 1, wherein the step of diffusing comprises diffusing first conductivity-determining type elements into the first region to form a doped first region having a first conductivity-determining type elements diffusion profile and wherein the step of simultaneously diffusing comprises simultaneously diffusing second conductivity-determining type elements into a second region to form a doped second region having a second conductivity-determining type elements diffusion profile that is different from the first conductivity-determining type elements diffusion profile.

5. The method of claim 1, wherein the step of diffusing comprises diffusing first conductivity-determining type elements from the first liquid dopant having a first vapor pressure and wherein the step of simultaneously diffusing comprises simultaneously diffusing second conductivity-determining elements from the second liquid dopant having a second vapor pressure that is different from the first vapor pressure.

6. The method of claim 1, wherein the step of diffusing comprises diffusing first conductivity-determining type elements into the first region to form a doped first region having a first conductivity-determining type elements concentration and wherein the step of simultaneously diffusing comprises simultaneously diffusing second conductivity-determining type elements into a second region to form a doped second region having a second conductivity-determining type elements concentration that is different from the first conductivity-determining type elements concentration.

7. The method of claim 1, wherein the step of diffusing comprises the step of depositing the first liquid dopant overlying the first region and wherein the step of simultaneously diffusing comprises depositing the second liquid dopant overlying the second region, wherein the second liquid dopant is deposited overlying the first liquid dopant.

8. The method of claim 7, wherein the step of depositing the first liquid dopant is performed using inkjet printing, aerosol jet printing, screen printing or roller printing.

9. The method of claim 7, wherein the step of depositing the second liquid dopant is performed by spinning, inkjet printing, aerosol printing, screen printing, roller printing, or spraying the second liquid dopant overlying the second region.

10. The method of claim 1, wherein the step of diffusing comprises the step of depositing the first liquid dopant overlying the first region and wherein the step of simultaneously diffusing comprises depositing the second liquid dopant overlying the second region, wherein the second region is substantially exclusive of the first region.

11. The method of claim 10, wherein the step of depositing the first liquid dopant is performed using inkjet printing, aerosol jet printing, screen printing or roller printing.

12. The method of claim 10, wherein the step of depositing the second liquid dopant is performed using inkjet printing, aerosol jet printing, screen printing or roller printing.

13. The method of claim 1, further comprising the steps of depositing the first liquid dopant onto the semiconductor material such that it has a first density and depositing the second liquid dopant onto the semiconductor material such that it has a second density that is different from the first density.

14. A method for forming doped regions in a semiconductor material, the method comprising the steps of:

depositing a first liquid dopant comprising first conductivity-determining type elements overlying a first region of the semiconductor material;

depositing a second liquid dopant comprising second conductivity-determining type elements overlying a second region of the semiconductor material, wherein the first liquid dopant is not the second liquid dopant and wherein the second conductivity-determining type elements are of the same conductivity-determining type as the first conductivity-determining type elements;

simultaneously diffusing at least a portion of the first conductivity-determining type elements into the first region and at least a portion of the second conductivity-determining type elements into the second region.

15. The method of claim 14, wherein the step of depositing a second liquid dopant comprises depositing the second liquid dopant having a concentration of second conductivity-determining type elements that is different from a concentration of first conductivity-determining type elements of the first liquid dopant.

16. The method of claim 14, wherein the step of depositing a second liquid dopant comprises depositing the second liquid dopant having a vapor pressure that is different from a vapor pressure of the first liquid dopant.

17. The method of claim 14, wherein the step of depositing a second liquid dopant comprises depositing the second liquid dopant having second conductivity-determining type elements that are different from the first conductivity-determining type elements of the first liquid dopant.

18. The method of claim 14, wherein the step of depositing a second liquid dopant comprises depositing the second liquid dopant having a composition that is different from a composition of the first liquid dopant.

19. The method of claim 14, wherein the step of depositing a second liquid dopant comprises depositing the second liquid dopant overlying the first liquid dopant.

20. The method of claim 19, wherein the step of depositing the first liquid dopant is performed using inkjet printing, aerosol jet printing, screen printing or roller printing.

21. The method of claim 19, wherein the step of depositing the second liquid dopant is performed by spinning, inkjet printing, aerosol jet printing, screen printing, roller printing, or spraying the second liquid dopant overlying the second region.

22. The method of claim 14, wherein the step of depositing a second liquid dopant overlying the second region comprises depositing the second liquid dopant such that the second region is substantially exclusive of the first region.

23. The method of claim 22, wherein the step of depositing the first liquid dopant is performed using inkjet printing, aerosol jet printing, screen printing or roller printing.

24. The method of claim 22, wherein the step of depositing the second liquid dopant is performed using inkjet printing, aerosol jet printing, screen printing or roller printing.

25. The method of claim 14, wherein the steps of simultaneously diffusing is performed by thermal annealing, infrared annealing, laser annealing, microwave annealing, or a combination thereof.