Bibliographic Details
| Title: |
Process for the manufacture of wafers for solar cells at ambient pressure |
| Document Number: |
20120178262 |
| Publication Date: |
July 12, 2012 |
| Appl. No: |
13/496498 |
| Application Filed: |
September 15, 2010 |
| Abstract: |
Solar cells are manufactured from P-type doped monocrystalline or polycrystalline silicon ingots by sawing wafers and applying an N-type doping. The wafers can be treated by etching them, in a plasma assisted process, with an etching gas containing or consisting of carbonyl fluoride. Hereby, the surface is roughened so that the degree of light reflection is reduced, or glass-like phosphorus-containing oxide coatings caused by phosphorus doping are removed. Carbonyl fluoride is also very suitable to selectively etch silicon oxide in silicon oxide/silicon composites. |
| Inventors: |
Riva, Marcello (Hannover, DE); Lopez Alonso, Elena (Dresden, DE); Linaschke, Dorit (Dresden, DE); Dani, Ines (Lichtenau, DE); Kaskel, Stefan (Dresden, DE) |
| Assignees: |
SOLVAY FLUOR GMBH (Hannover, DE) |
| Claim: |
1. A method for manufacturing a wafer for a solar cell comprising a step of plasma-assisted etching of the wafer with an etching gas comprising carbonyl fluoride at a pressure which is equal to or greater than atmospheric pressure. |
| Claim: |
2. The method of claim 1 wherein a silicon wafer for a solar cell is manufactured. |
| Claim: |
3. The method of claim 1 wherein the method is performed at atmospheric pressure. |
| Claim: |
4. The method according to claim 3 wherein the atmospheric pressure ranges between ambient pressure −300 Pa and ambient pressure +300 Pa. |
| Claim: |
5. The method according to claim 1 wherein a wafer having a phosphorus-silicon-glass coating is etched to remove the phosphorus-silicon-glass coating. |
| Claim: |
6. The method of claim 1 wherein silicon is etched. |
| Claim: |
7. The method according to claim 6 wherein the surface of the wafer is a silicon surface which is etched to roughen the surface. |
| Claim: |
8. The method according to claim 1 wherein silicon oxide or a silicon oxide/silicon composite on the surface of the wafer is treated via said plasma-assisted etching to selectively remove the silicon oxide. |
| Claim: |
9. The method according to claim 1 wherein carbonyl fluoride is applied together with at least one gas selected from the group consisting of oxygen, nitrogen, N2O, helium, and argon. |
| Claim: |
10. The method according to claim 9 wherein carbonyl fluoride is applied together with argon, nitrogen, or argon and nitrogen. |
| Claim: |
11. The method of claim 10 wherein carbonyl fluoride, argon and nitrogen are introduced separately into an etching chamber. |
| Claim: |
12. The method of claim 10 wherein carbonyl fluoride and a mixture of argon and nitrogen are introduced separately into an etching chamber. |
| Claim: |
13. The method according to claim 1 wherein the wafer has a temperature ranging from 150° C. to 350° C. |
| Claim: |
14. The method according to claim 10 wherein etching is performed with a gas mixture consisting of carbonyl fluoride, argon, and nitrogen. |
| Claim: |
15. A method for manufacturing a solar cell wherein a wafer produced by the method according to claim 1 is used in said solar cell. |
| Claim: |
16. The method according to claim 6 wherein the wafer has a temperature ranging from 150° C. to 350° C. |
| Current U.S. Class: |
438/714 |
| Current International Class: |
01 |
| Accession Number: |
edspap.20120178262 |
| Database: |
USPTO Patent Applications |
