USH2207H1 - Additional post-glass-removal processes for enhanced cell efficiency in the production of solar cells - Google Patents
Additional post-glass-removal processes for enhanced cell efficiency in the production of solar cells Download PDFInfo
- Publication number
- USH2207H1 USH2207H1 US11/650,595 US65059507A USH2207H US H2207 H1 USH2207 H1 US H2207H1 US 65059507 A US65059507 A US 65059507A US H2207 H USH2207 H US H2207H
- Authority
- US
- United States
- Prior art keywords
- wafer
- wet
- chemical etching
- etching process
- phosphorous
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000000034 method Methods 0.000 title claims abstract description 32
- 238000004519 manufacturing process Methods 0.000 title abstract description 7
- BHEPBYXIRTUNPN-UHFFFAOYSA-N hydridophosphorus(.) (triplet) Chemical compound [PH] BHEPBYXIRTUNPN-UHFFFAOYSA-N 0.000 claims abstract description 19
- 238000009792 diffusion process Methods 0.000 claims abstract description 12
- 239000011521 glass Substances 0.000 claims abstract description 12
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 10
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 10
- 239000010703 silicon Substances 0.000 claims abstract description 10
- 229910004205 SiNX Inorganic materials 0.000 claims abstract description 9
- 239000011248 coating agent Substances 0.000 claims abstract description 7
- 238000000576 coating method Methods 0.000 claims abstract description 7
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 4
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 4
- 239000001301 oxygen Substances 0.000 claims abstract description 4
- 238000007704 wet chemistry method Methods 0.000 claims abstract description 4
- 238000003631 wet chemical etching Methods 0.000 claims description 12
- 238000000151 deposition Methods 0.000 claims description 11
- 238000001465 metallisation Methods 0.000 claims description 10
- 238000010304 firing Methods 0.000 claims description 5
- 239000002243 precursor Substances 0.000 claims description 5
- 238000007650 screen-printing Methods 0.000 claims description 5
- 230000000977 initiatory effect Effects 0.000 claims description 4
- 238000000137 annealing Methods 0.000 claims description 2
- 230000001590 oxidative effect Effects 0.000 claims description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims 1
- 230000008021 deposition Effects 0.000 abstract description 5
- 239000000126 substance Substances 0.000 abstract description 5
- 239000000463 material Substances 0.000 abstract description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 abstract description 2
- 230000007547 defect Effects 0.000 abstract description 2
- 230000010354 integration Effects 0.000 abstract description 2
- 230000003647 oxidation Effects 0.000 abstract description 2
- 238000007254 oxidation reaction Methods 0.000 abstract description 2
- 229910052814 silicon oxide Inorganic materials 0.000 abstract description 2
- 235000012431 wafers Nutrition 0.000 description 31
- 239000012535 impurity Substances 0.000 description 2
- 238000001039 wet etching Methods 0.000 description 2
- 238000000608 laser ablation Methods 0.000 description 1
- 229910021426 porous silicon Inorganic materials 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/18—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
- H01L31/1804—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof comprising only elements of Group IV of the Periodic Table
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/547—Monocrystalline silicon PV cells
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Definitions
- This invention relates to the process sequence in the production of solar cells from raw crystalline p-type silicon wafer material.
- FIG. 1 The process sequence of the existing production lines is shown in FIG. 1 .
- the saw-damage and impurities present on the raw silicon wafers are removed with a wet etching. Simultaneously with this process a defined surface texture is obtained.
- a phosphorous containing precursor is deposited that serves as the phosphorous source during the emitter diffusion in a horizontal passage furnace.
- a phosphorous glass layer is formed during diffusion. This layer is removed with wet etching prior to the deposition of a SiNx anti-reflection coating.
- Front- and back-side metallization is realized by screen printing and firing of metallization pastes. Finally, laser ablation electrically isolates the emitter and collector at the edge of the wafer.
- the cell efficiency obtained with the process sequence described in FIG. 1 is limited by the surface condition that is obtained after the phosphorous glass removal.
- the non-ideal surface condition may originate from:
- a process for producing solar cells from a silicon wafer comprising the steps of:
- a process for producing a solar cell from a silicon wafer comprising the steps of:
- FIG. 1 shows the process sequence of the existing production lines
- FIG. 2 shows two sequence embodiments with additional process steps, in accordance with the invention.
- FIG. 2 shows two sequence embodiments with additional process steps, in accordance with the invention.
- the wafer is submitted to a thermal anneal under oxygen atmosphere followed by a wet-chemical oxide removal.
- the anneal reduces the surface phosphorous concentration by diffusion, reduces lattice defects in the emitter and oxidizes the silicon surface.
- both a surface oxide is obtained and subsequently removed with wet chemistry.
- This sequence allows for an integration of the phosphorous glass removal, the wet-channel oxidation, and the SiOx removal into a single machine.
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Electromagnetism (AREA)
- General Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Photovoltaic Devices (AREA)
Abstract
A method is provided for the production of solar cells from raw crystalline p-type silicon wafer material. The surface condition prior to SiNx deposition is improved by providing additional process steps following the phosphorous glass removal and prior to the SiNx anti-reflection coating deposition. In one embodiment, the wafer is submitted to a thermal anneal under oxygen atmosphere followed by a wet-chemical oxide removal. The anneal reduces the surface phosphorous concentration by diffusion, reduces lattice defects in the emitter and oxidizes the silicon surface. In another embodiment, both a surface oxide is obtained and subsequently removed with wet chemistry. This sequence allows for an integration of the phosphorous glass removal, the wet-chemical oxidation, and the SiOx removal into a single machine.
Description
This invention relates to the process sequence in the production of solar cells from raw crystalline p-type silicon wafer material.
Process tests show that the cell efficiencies obtained with the current production lines can be improved significantly by inserting one or more additional process steps.
The process sequence of the existing production lines is shown in FIG. 1. The saw-damage and impurities present on the raw silicon wafers are removed with a wet etching. Simultaneously with this process a defined surface texture is obtained. A phosphorous containing precursor is deposited that serves as the phosphorous source during the emitter diffusion in a horizontal passage furnace. A phosphorous glass layer is formed during diffusion. This layer is removed with wet etching prior to the deposition of a SiNx anti-reflection coating. Front- and back-side metallization is realized by screen printing and firing of metallization pastes. Finally, laser ablation electrically isolates the emitter and collector at the edge of the wafer.
The cell efficiency obtained with the process sequence described in FIG. 1 is limited by the surface condition that is obtained after the phosphorous glass removal. The non-ideal surface condition may originate from:
-
- (a) an excessively large phosphorous concentration;
- (b) residues left from the preceding processes that are not removed by the standard wet chemical glass removal;
- (c) segregation of impurities from the bulk to the surface during preceding processes that are not removed by the standard wet chemical glass removal; and
- (d) nanometer-scale surface roughness (e.g. porous silicon).
It is, therefore, an object of the present invention to provide an improved process sequence for the production of solar cells from raw crystalline p-type silicon wafer material.
In a first embodiment of the invention, a process is provided for producing solar cells from a silicon wafer, comprising the steps of:
-
- (a) removing any saw-damage on the wafer by a wet-chemical etching process, thereby defining surface texture on the wafer;
- (b) depositing a phosphorous containing precursor on the wafer;
- (c) placing the wafer in a furnace, thereby initiating emitter diffusion;
- (d) removing a phosphorous glass layer, formed on the surface of the wafer during the emitter diffusion step, by a wet-chemical etching process;
- (e) thermally annealing the wafer under an oxygen atmosphere;
- (f) removing oxides from the wafer by a wet-chemical etching process;
- (g) depositing a SiNx anti-reflection coating on the wafer;
- (h) screen printing metallization pastes on the surface of the wafer;
- (i) firing the metallization pastes formed on the surface of the wafer; and
- (j) laser ablating the wafer, thereby isolating the emitters and collectors formed at the edges of the wafer.
In a second embodiment of the invention, a process for producing a solar cell from a silicon wafer, comprising the steps of:
-
- (a) removing any saw-damage on the wafer by a wet-chemical etching process, thereby defining surface texture on the wafer;
- (b) depositing a phosphorous containing precursor on the wafer;
- (c) placing the wafer in a furnace, thereby initiating emitter diffusion;
- (d) removing a phosphorous glass layer, formed on the surface of the wafer during the emitter diffusion step, by a wet-chemical etching process;
- (e) oxidizing the surface of the wafer by a wet-chemical process;
- (f) removing oxides from the wafer by a wet-chemical etching process;
- (g) depositing a SiNx anti-reflection coating on the wafer;
- (h) screen printing metallization pastes on the surface of the wafer;
- (i) firing the metallization pastes formed on the surface of the wafer; and
- (j) laser ablating the wafer, thereby isolating the emitters and collectors formed at the edges of the wafer.
Other objects, features, and advantages of one or more embodiments of the present invention will seem apparent from the following detailed description, and accompanying drawings, and the appended claims.
Embodiments of the present invention will now be disclosed, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, in which
The surface condition prior to SiNx deposition is improved by providing additional process steps following the phosphorous glass removal and prior to the SiNx anti-reflection coating deposition. FIG. 2 shows two sequence embodiments with additional process steps, in accordance with the invention.
In the first embodiment, as shown in FIG. 2(a), the wafer is submitted to a thermal anneal under oxygen atmosphere followed by a wet-chemical oxide removal. The anneal reduces the surface phosphorous concentration by diffusion, reduces lattice defects in the emitter and oxidizes the silicon surface.
In the second embodiment, as shown in FIG. 2(b), both a surface oxide is obtained and subsequently removed with wet chemistry. This sequence allows for an integration of the phosphorous glass removal, the wet-channel oxidation, and the SiOx removal into a single machine.
A combination of the two sequences described above is also envisioned.
While the specific embodiments of the present invention have been described above, it will be appreciated that the invention may be practiced otherwise than described. The description is not intended to limit the invention.
Claims (2)
1. A process for producing a solar cell from a silicon wafer, comprising the steps of:
(a) removing any saw-damage on the wafer by a wet-chemical etching process, thereby defining surface texture on the water;
(b) depositing a phosphorous containing precursor on the wafer;
(c) placing the wafer in a furnace, thereby initiating emitter diffusion;
(d) removing a phosphorous glass layer, formed on the surface of the wafer during the emitter diffusion step, by a wet-chemical etching process;
(e) thermally annealing the wafer under an oxygen atmosphere;
(f) removing oxides from the wafer by a wet-chemical etching process;
(g) depositing a SiNx anti-reflection coating on the wafer;
(h) screen printing metallization pastes on the surface of the wafer;
(i) firing the metallization pastes formed on the surface of the wafer; and
(j) laser ablating the wafer, thereby isolating the emitters and collectors formed at the edges of the wafer.
2. A process for producing a solar cell from a silicon wafer, comprising the steps of:
(a) removing any saw-damage on the wafer by a wet-chemical etching process, thereby defining surface texture on the wafer;
(b) depositing a phosphorous containing precursor on the wafer;
(c) placing the wafer in a furnace, thereby initiating emitter diffusion;
(d) removing a phosphorous glass layer, formed on the surface of the wafer during the emitter diffusion step, by a wet-chemical etching process;
(e) oxidizing the surface of the wafer by a wet-chemical process;
(f) removing oxides from the wafer by a wet-chemical etching process;
(g) depositing a SiNx anti-reflection coating on the wafer;
(h) screen printing metallization pastes on the surface of the wafer;
(i) firing the metallization pastes formed on the surface of the wafer; and
(j) laser ablating the wafer, thereby isolating the emitters and collectors formed at the edges of the wafer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US11/650,595 USH2207H1 (en) | 2007-01-05 | 2007-01-05 | Additional post-glass-removal processes for enhanced cell efficiency in the production of solar cells |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US11/650,595 USH2207H1 (en) | 2007-01-05 | 2007-01-05 | Additional post-glass-removal processes for enhanced cell efficiency in the production of solar cells |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| USH2207H1 true USH2207H1 (en) | 2007-12-04 |
Family
ID=38775578
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US11/650,595 Abandoned USH2207H1 (en) | 2007-01-05 | 2007-01-05 | Additional post-glass-removal processes for enhanced cell efficiency in the production of solar cells |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | USH2207H1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100035409A1 (en) * | 2008-08-05 | 2010-02-11 | Joel P De Souza | Crystalline silicon substrates with improved minority carrier lifetime |
| WO2012000612A3 (en) * | 2010-06-18 | 2012-12-20 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e. V. | Method for producing a selective doping structure in a semiconductor substrate in order to produce a photovoltaic solar cell |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040029334A1 (en) * | 2002-05-21 | 2004-02-12 | Otb Group B.V. | Method for passivating a semiconductor substrate |
| US20060231031A1 (en) * | 2002-12-12 | 2006-10-19 | Otb Group B.V. | Method and apparatus for treating a substrate |
| US20060292891A1 (en) * | 2003-05-21 | 2006-12-28 | Bijker Martin D | Cascade source and a method for controlling the cascade source |
-
2007
- 2007-01-05 US US11/650,595 patent/USH2207H1/en not_active Abandoned
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040029334A1 (en) * | 2002-05-21 | 2004-02-12 | Otb Group B.V. | Method for passivating a semiconductor substrate |
| US6946404B2 (en) * | 2002-05-21 | 2005-09-20 | Otb Group B.V. | Method for passivating a semiconductor substrate |
| US20060231031A1 (en) * | 2002-12-12 | 2006-10-19 | Otb Group B.V. | Method and apparatus for treating a substrate |
| US20060292891A1 (en) * | 2003-05-21 | 2006-12-28 | Bijker Martin D | Cascade source and a method for controlling the cascade source |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100035409A1 (en) * | 2008-08-05 | 2010-02-11 | Joel P De Souza | Crystalline silicon substrates with improved minority carrier lifetime |
| US7749869B2 (en) | 2008-08-05 | 2010-07-06 | International Business Machines Corporation | Crystalline silicon substrates with improved minority carrier lifetime including a method of annealing and removing SiOx precipitates and getterning sites |
| WO2012000612A3 (en) * | 2010-06-18 | 2012-12-20 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e. V. | Method for producing a selective doping structure in a semiconductor substrate in order to produce a photovoltaic solar cell |
| US8927317B2 (en) | 2010-06-18 | 2015-01-06 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Method for producing a selective doping structure in a semiconductor substrate in order to produce a photovoltaic solar cell |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN115312633B (en) | Mask-layer-free combined passivation back contact battery and preparation method thereof | |
| CN101567408B (en) | Method for manufacturing photoelectric conversion device | |
| US20100108134A1 (en) | Thin two sided single crystal solar cell and manufacturing process thereof | |
| JP6246744B2 (en) | Method for manufacturing solar battery cell | |
| JPH10233518A (en) | Solar cell and its manufacturing method, and manufacturing method of semiconductor device | |
| JP5058184B2 (en) | Method for manufacturing photovoltaic device | |
| CN115000246B (en) | P-type passivation contact battery preparation method and passivation contact battery | |
| JPH11214720A (en) | Manufacture of thin-film crystal solar cell | |
| CN101740659A (en) | Method for manufacturing buried-contact solar battery | |
| CN114005888A (en) | Solar cell and preparation method thereof | |
| JP6440853B2 (en) | Manufacturing method of solar cell | |
| JP5408009B2 (en) | Manufacturing method of solar cell | |
| CN102653887A (en) | Treatment method and etching method of crystalline silicon wafer with oil stains | |
| USH2207H1 (en) | Additional post-glass-removal processes for enhanced cell efficiency in the production of solar cells | |
| JP2006295212A (en) | Method of producing solar cell and method of producing semiconductor device | |
| JP2005129714A (en) | Manufacturing method of solar cell | |
| CN102157626B (en) | Method for reducing contact resistance between emitter and buried gate of solar battery | |
| CN114937706B (en) | Laminated passivation film for crystalline silicon solar cell and preparation method thereof | |
| WO2016129372A1 (en) | Method for manufacturing solar cell, and solar cell | |
| CN114914328B (en) | Double-sided solar cell and preparation method thereof | |
| JP5157451B2 (en) | Photovoltaic manufacturing method | |
| JP6114108B2 (en) | Manufacturing method of solar cell | |
| CN115274404A (en) | Modified tunneling oxide layer and preparation method thereof, TOPCon structure and preparation method thereof, and solar cell | |
| JP5014263B2 (en) | Photovoltaic device and manufacturing method thereof | |
| CN113659033A (en) | Preparation method of P-type back contact solar cell |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| STCF | Information on status: patent grant |
Free format text: PATENTED CASE |