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
  • H01L31/186—Particular post-treatment for the devices, e.g. annealing, impurity gettering, short-circuit elimination, recrystallisation
  • H01L31/1864—Annealing
• • 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
  • H01L31/02—Details
  • H01L31/0216—Coatings
  • H01L31/02161—Coatings for devices characterised by at least one potential jump barrier or surface barrier
  • H01L31/02167—Coatings for devices characterised by at least one potential jump barrier or surface barrier for solar cells
  • H01L31/02168—Coatings for devices characterised by at least one potential jump barrier or surface barrier for solar cells the coatings being antireflective or having enhancing optical properties for the solar cells
• • 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
  • H01L31/02—Details
  • H01L31/0236—Special surface textures
  • H01L31/02363—Special surface textures of the semiconductor body itself, e.g. textured active layers
• • 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
  • H01L31/04—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 adapted as photovoltaic [PV] conversion devices
  • H01L31/06—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 adapted as photovoltaic [PV] conversion devices characterised by potential barriers
  • H01L31/068—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 adapted as photovoltaic [PV] conversion devices characterised by potential barriers 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
• • 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
  • H01L31/04—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 adapted as photovoltaic [PV] conversion devices
  • H01L31/06—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 adapted as photovoltaic [PV] conversion devices characterised by potential barriers
  • H01L31/068—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 adapted as photovoltaic [PV] conversion devices characterised by potential barriers 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
  • H01L31/0682—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 adapted as photovoltaic [PV] conversion devices characterised by potential barriers 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 back-junction, i.e. rearside emitter, solar cells, e.g. interdigitated base-emitter regions back-junction cells
• • 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
  • H01L31/04—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 adapted as photovoltaic [PV] conversion devices
  • H01L31/06—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 adapted as photovoltaic [PV] conversion devices characterised by potential barriers
  • H01L31/068—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 adapted as photovoltaic [PV] conversion devices characterised by potential barriers 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
  • H01L31/0684—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 adapted as photovoltaic [PV] conversion devices characterised by potential barriers 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 double emitter cells, e.g. bifacial solar cells
• • 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
• • 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
  • H01L31/186—Particular post-treatment for the devices, e.g. annealing, impurity gettering, short-circuit elimination, recrystallisation
  • H01L31/1868—Passivation
• • 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

• the invention relates to a method for producing a solar cell made of crystalline semiconductor material, wherein in a first surface of a semiconductor substrate, a first doping region by thermal diffusion of a first dopant and in the second surface of the semiconductor substrate, a second doping region with a second
• Crystalline silicon solar cells have also recently undergone significant new developments, such as the solar cells of the o. G. Type (especially the so-called n-PERT solar cells) count.
• a prominent example is bifacial n-type solar cells with a boron-doped emitter on the front and a phosphor-doped back surface field (BSF) on the back of the cell.
• BSF back surface field
• the invention provides a method having the features of claim 1.
• Advantageous developments of the inventive concept are the subject of the dependent claims.
• the invention adopts a hybrid approach in which only the phosphorus-doped regions (or, more generally, second dopant regions) are prepared by ion implantation and in boron doping (or more generally doping with the first dopant) are based on established approaches such as gas phase diffusion or doping glasses becomes. in the
• a covering layer which acts primarily as a diffusion barrier layer is formed on that surface in which the second doping regions have been formed, in order to prevent and at least severely impede diffusion of the first dopant there.
• the efficient implementation entails a number of problems, the solution of which, based on the above-mentioned concept, ultimately leads to the implementation of the invention which is optimal from a world viewpoint.
• the preferred process sequence of the present invention is characterized in that the thermal budget of boron diffusion (or diffusion of the first dopant) is used simultaneously to activate the implanted phosphor region (or more generally, the dopant deposit layer of the second dopant).
• a key feature is that after phosphorus ion implantation and before boron diffusion, a multifunctional covering layer on the phosphorus phor Scheme is deposited.
• the cover layer has at least the property of serving as an (in) diffusion barrier for the first dopant (eg boron) and thus preventing it from penetrating into the dopant end deposit layer of the second dopant (especially phosphorus).
• the cover layer has further properties / functions:
• It can act as a (diffusion) diffusion barrier for phosphorus (or more generally, the second dopant).
• Antimony-containing group in particular phosphorus.
• the dopant combination boron / phosphorus which has been mentioned in detail several times above, is of great practical importance with a view to younger, more effectively increasing solar cell developments.
• the proposed method can be carried out as a method for producing a bilaterally contacted solar cell with front-side emitter or a solar cell with rear-side emitter or a MWT (metal wrap-through) solar cell or an IBC (Interdigitad Back Contact) solar cell.
• the first impurity region may be formed as an emitter region in the front surface of an n-type silicon substrate and the second impurity region may be formed as a back surface field in the back surface of the n-type silicon substrate.
• the doping profile of the second doping region relative to that of the first doping region is flatter and / or characterized by a higher surface concentration of the second dopant compared to the first dopant.
• the method is configured such that the formation of the first doping region comprises coating the first and optionally second surfaces with a glass containing the first dopant or providing the first dopant in the gaseous state in a process atmosphere.
• FIGURE shows a schematic cross-sectional representation in the solar cell according to the invention.
• the single figure shows schematically in a cross-sectional representation a solar cell 1 with an n-type crystalline silicon substrate 3 and a pyramid-like structured first (front) surface 3a and second (rear) surface 3b.
• a first doping region (emitter region) 5 is formed in the first surface 3a.
• a flat back surface field 7 is formed by phosphor implantation and subsequent annealing / activation as a second doping region.
• a dense silicon nitride layer or SiN-containing double layer 9a or 9b is deposited as antireflection layer in each case.
• the backside silicon nitride film 9b is a film formed in the back surface 3b after phosphorus implantation but formed in the semiconductor substrate before a step of boron diffusion and left there after a thermal diffusion step.
• the antireflection layer may be supplemented by an additional partial layer of an oxide (such as silicon oxide), which improves the passivation properties of the layer, but is not shown in the figure.
• an oxide such as silicon oxide
• the sequence of manufacture of this solar cell includes the below-mentioned process modules in this order, each process module consisting of one or more process steps.
• Process module 1 Texturing of the wafer
• the wafer can be planarized on the back side.
• several methods are prior art and not relevant to the explanation of the invention.
• Process module 2 Formation of the dopant deposit layer (Phosphor implantation) Phosphorus is implanted in the back of the cell (eg one dose
• the sheet resistance of the phosphor layer after annealing (step 4) is 10-300 ohms / square, preferably 30-120 ohms / square. In an extended embodiment, the
• Implantation selectively, so that the dose is higher below the metallization.
• the implantation may be masked such that an undoped area of 50-1000 ⁇ m width is created between the wafer edge and phosphorus doping in order to ensure electrical isolation between the BSF and the emitter.
• the wafer may optionally be cleaned to remove unwanted phosphor residue and contamination. This can be done in one embodiment by a wet chemical process with one or more steps in water, dilute HF, HN0 3 or H 2 0 2 / HCI. In another embodiment, the purification can be carried out by a plasma process with a hydrogen, oxygen and / or fluorine-containing atmosphere.
• Process module 3 Generation of the diffusion barrier layer
• the cover layer (diffusion barrier layer) on the second substrate surface prevents boron from diffusing into it and is impermeable to oxygen. Furthermore, it is intended to ensure a good passivation, as well as to act as an antireflection coating in the use of the bifacial solar cell.
• the thickness of the Layer is between 1 nm and 250 nm, preferably 30-80 nm.
• the cap layer is deposited by a PECVD process with a process chemistry of one or more gases of the group SiH 4 , N 2 , NH 3 , H 2 , Ar.
• the cover layer with other methods, such. As LPCVD, APCVD or PVD are applied.
• a layer stack in which a Si0 2 , Al 2 O 3 , TiO or SiON layer is introduced between silicon and SiN, which layer can improve the electrical passivating shafts. (0.5-50 nm, preferably 5 nm)
• a layer of amorphous or polycrystalline silicon can additionally be introduced into the layer stack. (0.5-30 nm, preferably 20 nm).
• Process module 4 boron diffusion and at the same time phosphor activation
• the boron diffusion is carried out by a furnace process in which the wafer is first covered with boron glass in a boron-containing atmosphere.
• Common procursors are BBr 3 and BCI 3 , further process gases N 2 and 0 2 .
• a drive-in step takes place in situ in an inert or oxygen-containing atmosphere.
• document and Eintreib Kunststoffe are at least partially in
• Another possibility is the deposition of a boron glass on the front of the cell (eg by APCVD or PECVD) and subsequent driving in a separate process step.
• the Bordiffusions Council is mainly characterized by the sheet resistance, which is in particular between 30 and 200 ohms / sq, preferably at 45-100 ohms / sq.
• the boron diffusion simultaneously causes the annealing and activation of the phosphorus-doped region.
• the phosphorus also diffuses deeper into the substrate, but through the process with the multifunctional layer slower than the boron.
• the depths of the diffusion regions are between 30 nm and 2500 nm, preferably 400-1000 nm, the depth of the boron preferably being greater than that of the phosphor.
• Process module 5 front side passivation
• Embodiment is not relevant to the invention.
• the boron glass possibly formed in the process module 4 may have to be removed from the front side, which according to the state of the art can be done with a dilute HF solution.
• Process Module 6 Optional Additional Backside Passivation If the diffusion barrier layer formed in process module 3 does not simultaneously act as electrical passivation of the cell backside, it must be removed and replaced with an additional passivation layer. Removal of the topcoat may be accomplished by an extended RF step along with the boron glass removal in step 5.
• an SiO / SiN or SiN layer can be used.
• Process module 7 metallization
• the metallization can be done by industry standard methods and is not relevant to the invention.
• the front side metallization is usually done with a silver grid.
• the backside metallization is also carried out with a silver grid or a full-surface aluminum metallization with local contacts, which z. B. by laser ablation and PVD is produced.

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• 2013
  • 2013-09-27 DE DE102013219603.2A patent/DE102013219603A1/de not_active Withdrawn
• 2014
  • 2014-09-26 US US15/024,879 patent/US20160240724A1/en not_active Abandoned
  • 2014-09-26 WO PCT/EP2014/070613 patent/WO2015044342A1/de active Application Filing
  • 2014-09-26 CN CN201480062121.7A patent/CN105723520A/zh active Pending
  • 2014-09-26 EP EP14776652.1A patent/EP3050118A1/de not_active Withdrawn
  • 2014-09-26 KR KR1020167010999A patent/KR20160061409A/ko not_active Application Discontinuation

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