CN115547818A - Boron diffusion method - Google Patents
Boron diffusion method Download PDFInfo
- Publication number
- CN115547818A CN115547818A CN202211194270.1A CN202211194270A CN115547818A CN 115547818 A CN115547818 A CN 115547818A CN 202211194270 A CN202211194270 A CN 202211194270A CN 115547818 A CN115547818 A CN 115547818A
- Authority
- CN
- China
- Prior art keywords
- diffusion furnace
- boron
- silicon wafer
- diffusion
- temperature
- 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.)
- Pending
Links
- 238000009792 diffusion process Methods 0.000 title claims abstract description 234
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 title claims abstract description 139
- 229910052796 boron Inorganic materials 0.000 title claims abstract description 139
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 114
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 114
- 239000010703 silicon Substances 0.000 claims abstract description 114
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 57
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 47
- 239000001301 oxygen Substances 0.000 claims abstract description 47
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 47
- 230000008021 deposition Effects 0.000 claims abstract description 22
- 239000007795 chemical reaction product Substances 0.000 claims abstract description 10
- 230000003647 oxidation Effects 0.000 claims abstract description 8
- 238000007254 oxidation reaction Methods 0.000 claims abstract description 8
- 238000007599 discharging Methods 0.000 claims abstract description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 100
- 229910052757 nitrogen Inorganic materials 0.000 claims description 38
- FAQYAMRNWDIXMY-UHFFFAOYSA-N trichloroborane Chemical compound ClB(Cl)Cl FAQYAMRNWDIXMY-UHFFFAOYSA-N 0.000 claims description 32
- 229910001873 dinitrogen Inorganic materials 0.000 claims description 24
- 239000007789 gas Substances 0.000 claims description 22
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 claims description 10
- 229910001882 dioxygen Inorganic materials 0.000 claims description 10
- 239000012298 atmosphere Substances 0.000 claims description 6
- 239000012299 nitrogen atmosphere Substances 0.000 claims description 4
- 238000000605 extraction Methods 0.000 claims description 3
- 238000009826 distribution Methods 0.000 abstract description 8
- 235000012431 wafers Nutrition 0.000 description 95
- 238000012360 testing method Methods 0.000 description 33
- 238000000034 method Methods 0.000 description 11
- 229910052810 boron oxide Inorganic materials 0.000 description 10
- JKWMSGQKBLHBQQ-UHFFFAOYSA-N diboron trioxide Chemical compound O=BOB=O JKWMSGQKBLHBQQ-UHFFFAOYSA-N 0.000 description 10
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 9
- 239000000126 substance Substances 0.000 description 9
- 239000007788 liquid Substances 0.000 description 7
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 6
- 238000001514 detection method Methods 0.000 description 6
- 239000001257 hydrogen Substances 0.000 description 6
- 229910052739 hydrogen Inorganic materials 0.000 description 6
- 239000010410 layer Substances 0.000 description 6
- 235000012239 silicon dioxide Nutrition 0.000 description 6
- 239000010453 quartz Substances 0.000 description 5
- 229910021419 crystalline silicon Inorganic materials 0.000 description 4
- 238000005137 deposition process Methods 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 3
- 229910052801 chlorine Inorganic materials 0.000 description 3
- 239000000460 chlorine Substances 0.000 description 3
- 230000003749 cleanliness Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 238000004364 calculation method Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 238000010835 comparative analysis Methods 0.000 description 2
- 229910052814 silicon oxide Inorganic materials 0.000 description 2
- 239000002344 surface layer Substances 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 description 1
- 241000282414 Homo sapiens Species 0.000 description 1
- 229910021417 amorphous silicon Inorganic materials 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 1
- 239000004327 boric acid Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000009828 non-uniform distribution Methods 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/22—Diffusion of impurity materials, e.g. doping materials, electrode materials, into or out of a semiconductor body, or between semiconductor regions; Interactions between two or more impurities; Redistribution of impurities
- H01L21/223—Diffusion of impurity materials, e.g. doping materials, electrode materials, into or out of a semiconductor body, or between semiconductor regions; Interactions between two or more impurities; Redistribution of impurities using diffusion into or out of a solid from or into a gaseous phase
-
- 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
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Electromagnetism (AREA)
- Manufacturing & Machinery (AREA)
- Formation Of Insulating Films (AREA)
Abstract
The invention relates to the technical field of photovoltaic cells, and provides a boron diffusion method, which comprises the steps of putting a silicon wafer into a diffusion furnace, and adjusting the temperature and the pressure in the diffusion furnace; carrying out pre-oxidation operation on the silicon wafer to form an oxide layer on the surface of the silicon wafer; introducing oxygen and a boron source into the diffusion furnace for deposition treatment; discharging gaseous reaction products and residual boron source during the deposition treatment to the outside of the diffusion furnace; raising the temperature in the diffusion furnace, and performing primary propelling treatment until the target amount of boron is diffused into the silicon wafer; introducing water vapor into the diffusion furnace to clean the surface of the silicon wafer; raising the temperature in the diffusion furnace, and performing secondary propelling treatment; and adjusting the temperature and the pressure in the diffusion furnace, and taking the silicon wafer out of the diffusion furnace. With the adoption of the arrangement, the problem of uneven distribution of boron content when the boron content is reduced in the prior art is solved.
Description
Technical Field
The invention relates to the technical field of photovoltaic cells, in particular to a boron diffusion method.
Background
In the preparation process of the N-type crystalline silicon solar cell, a PN junction is generally manufactured by adopting a boron diffusion process. For the boron diffusion process, not only the boron content in the prepared PN junction has important influence on the performance and efficiency of the N-type crystalline silicon solar cell, but also the uniformity of boron diffusion influences the parameter control of the subsequent manufacturing process.
In order to ensure the performance and efficiency of the N-type crystalline silicon solar cell, the boron content in the N-type crystalline silicon solar cell is generally controlled to prevent the boron content from being too high, so that the square resistance value is improved. However, in the prior art, when the boron content is reduced and the square resistance value is improved, the conditions of non-uniform distribution of boron sources and the like are often easy to occur, so that the boron content in a single silicon wafer is not uniformly distributed, and the consistency of the boron content of different silicon wafers in the same diffusion furnace is poor. The non-uniformity of the boron content is more pronounced as the throughput increases and the wafer size increases.
Therefore, how to solve the problem of uneven distribution of boron content when reducing the boron content in the prior art becomes an important technical problem to be solved by those skilled in the art.
Disclosure of Invention
The invention provides a boron diffusion method, which is used for solving the defect of uneven distribution of boron content when the boron content is reduced in the prior art.
The invention provides a boron diffusion method, which comprises the following steps:
putting a silicon wafer into a diffusion furnace, and adjusting the temperature and the pressure in the diffusion furnace;
carrying out pre-oxidation operation on the silicon wafer to form an oxide layer on the surface of the silicon wafer;
introducing oxygen and a boron source into the diffusion furnace for deposition treatment;
discharging gaseous reaction products generated in the deposition treatment and the residual boron source to the outside of the diffusion furnace;
raising the temperature and the pressure in the diffusion furnace, and performing primary propelling treatment until the target amount of boron is diffused into the silicon wafer;
introducing water vapor into the diffusion furnace to clean the surface of the silicon wafer;
raising the temperature in the diffusion furnace, and performing secondary propelling treatment;
and adjusting the temperature and the pressure in the diffusion furnace, and taking the silicon wafer out of the diffusion furnace.
According to the boron diffusion method provided by the invention, the introducing of water vapor into the diffusion furnace comprises the following steps:
and introducing nitrogen and water vapor into the diffusion furnace, wherein the flow rate of the nitrogen is greater than that of the water vapor.
According to the boron diffusion method provided by the invention, the volume flow of the water vapor is 100-2000sccm.
According to the boron diffusion method provided by the invention, the boron source is boron trichloride gas, the volume flow of the boron trichloride gas is 50-1000sccm, and the volume flow of the oxygen gas is 100-5000sccm.
According to the boron diffusion method provided by the invention, the primary drive treatment is carried out in a nitrogen atmosphere.
According to the boron diffusion method provided by the invention, the secondary propelling treatment is carried out in the atmosphere of nitrogen and oxygen.
According to the boron diffusion method provided by the invention, the step of introducing oxygen and a boron source into the diffusion furnace comprises the following steps:
and introducing mixed gas of nitrogen, the oxygen and the boron source into the diffusion furnace.
According to the boron diffusion method provided by the invention, when the silicon wafer is put into the diffusion furnace and taken out from the diffusion furnace, nitrogen is continuously introduced into the diffusion furnace.
According to the boron diffusion method provided by the invention, the adjusting of the temperature and the pressure in the diffusion furnace comprises the following steps:
performing air extraction treatment on the diffusion furnace to reduce the pressure in the diffusion furnace to a target pressure;
raising the temperature within the diffusion furnace to a target temperature.
According to the boron diffusion method provided by the present invention, after the pressure in the diffusion furnace is reduced to the target pressure, the method further includes:
and detecting the air tightness of the diffusion furnace.
According to the boron diffusion method provided by the invention, a silicon wafer is placed into a diffusion furnace, the temperature and the pressure in the diffusion furnace are adjusted to the target temperature and the target pressure, and then pre-oxidation operation is carried out on the silicon wafer so as to form an oxide layer on the surface of the silicon wafer. Then, oxygen and a boron source are introduced into the diffusion furnace for deposition treatment. In order to ensure that sufficient boron is deposited at each position of each silicon wafer in the diffusion furnace, the excessive introduction of the boron source can be controlled. After the deposition treatment is finished, gaseous reaction products (including boron oxide and chlorine) and residual boron sources during the deposition treatment can be discharged to the outside of the diffusion furnace, then the temperature and pressure in the diffusion furnace are increased, and the pushing treatment is carried out for one time, so that the boron elementary substance is diffused to the inside of the silicon wafer until the boron elementary substance entering the silicon wafer reaches the target amount. And after the primary propelling treatment, introducing water vapor into the diffusion furnace, cleaning the surface of the silicon wafer by using the water vapor so as to clean boron (the boron at the position not only comprises a boron simple substance but also can comprise boron oxide and a boron source which are not discharged) remained on the surface of the silicon wafer, then raising the temperature in the diffusion furnace, and performing secondary propelling treatment so as to increase the diffusion depth of the boron simple substance into the silicon wafer to the target junction depth. And finally, adjusting the temperature and the pressure in the diffusion furnace, and taking the silicon wafer out of the diffusion furnace to obtain the boron-doped silicon wafer. According to the arrangement, excessive boron source and oxygen are introduced during deposition, so that boron at each position in the diffusion furnace can meet the requirement. After the primary propelling treatment is carried out and the boron elementary substance with the required amount enters the silicon wafer, the surface of the silicon wafer is cleaned by utilizing the water vapor so as to clean the redundant boron on the surface of the silicon wafer, and the boron attached to the surface of the silicon wafer is prevented from further diffusing into the silicon wafer during the secondary propelling treatment, so that the influence of the introduced excessive boron source on the boron content in the silicon wafer is reduced, the too high boron content in the silicon wafer is avoided, and the problem of uneven boron content distribution existing in the prior art when the boron content is reduced is solved.
Drawings
In order to more clearly illustrate the technical solutions of the present invention or the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
FIG. 1 is a flow chart of a boron diffusion method provided by the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The boron diffusion method of the present invention is described below with reference to fig. 1.
As shown in fig. 1, a boron diffusion method provided in an embodiment of the present invention includes the following steps:
Before boron diffusion operation is carried out on the silicon wafer, the silicon wafer needs to be cleaned and subjected to texturing treatment.
And opening a furnace door of the diffusion furnace, inserting the silicon wafer subjected to texturing treatment on a quartz boat, and feeding the silicon wafer and the quartz boat into the diffusion furnace together.
The diffusion furnace in this embodiment may be, but is not limited to, a quartz tube.
When the silicon wafer is placed into the diffusion furnace, nitrogen can be continuously introduced into the diffusion furnace, and the introduction of the nitrogen can increase the pressure in the diffusion furnace, so that the air outside the diffusion furnace can be reduced to enter the diffusion furnace, and the influence of the outside air on the cleanliness inside the diffusion furnace is reduced. The volume flow rate of the introduced nitrogen gas may be controlled to 2000 to 20000sccm, and specifically, the volume flow rate of the introduced nitrogen gas may be 5000sccm.
It should be noted that oxygen and nitrogen are generally involved in each step of the boron diffusion method, and nitrogen is introduced into the diffusion furnace when the silicon wafer is placed into the diffusion furnace, so that the cleanliness of the interior of the diffusion furnace is not affected. Moreover, the air breathed by human beings daily contains 78% of nitrogen, and the nitrogen is introduced in the step, so that the influence on operators can be reduced compared with the other gases.
After the silicon chip is put into the diffusion furnace, the furnace door of the diffusion furnace is closed to enable the diffusion furnace to be in a sealed state, and then the temperature and the pressure in the diffusion furnace are adjusted to the target temperature and the target pressure.
The target temperature and the target pressure are required for the deposition process in the following steps, and the target temperature is generally controlled to 800 to 950 degrees celsius and the target pressure is controlled to 50 to 300mbar. Specifically, the target temperature may be 880 degrees celsius and the target pressure may be 100mbar.
And step 120, carrying out pre-oxidation operation on the silicon wafer to form an oxide layer on the surface of the silicon wafer.
And after the temperature and the pressure in the diffusion furnace are stabilized at the target temperature value and the target pressure value, carrying out pre-oxidation operation on the silicon wafer. Specifically, oxygen is introduced into the diffusion furnace to react silicon on the surface of the silicon wafer with the oxygen to generate silicon dioxide, and an oxide layer is formed on the surface of the silicon wafer.
The oxide layer has an adsorption effect on the boron source, so that the boron source is adsorbed on the surface of the silicon wafer, and the uniformity of the boron source in the diffusion furnace is improved.
In the pre-oxidation operation process, the volume flow of oxygen gas introduced into the diffusion furnace can be controlled to be 500-5000sccm, and the introduction time is controlled to be 100-1000 seconds. Specifically, in step 120, the volume flow rate of the oxygen gas introduced into the diffusion furnace is 3000sccm, and the introduction time is 500 seconds.
And step 130, introducing oxygen and a boron source into the diffusion furnace for deposition treatment.
After the oxide layer is formed on the surface of the silicon wafer, and before step 130, nitrogen and oxygen are introduced into the diffusion furnace to change the gas atmosphere in the diffusion furnace. The volume flow rate of the introduced nitrogen is controlled to be 500-5000sccm, the volume flow rate of the introduced oxygen is controlled to be 500-5000sccm, and the introduction time is controlled to be 30-1000 seconds. Specifically, the volume flow rate of the introduced nitrogen gas is 2000sccm, the volume flow rate of the introduced oxygen gas is 900sccm, and the introduction time is 30 seconds.
Then oxygen and boron source are introduced into the diffusion furnace for deposition treatment. In order to ensure that sufficient boron is deposited at each position in the diffusion furnace, the boron source can be controlled to be excessively introduced.
Specifically, boron trichloride gas may be used as the boron source. The following description will be made by taking the introduced boron source as boron trichloride gas as an example.
In the deposition treatment process, boron trichloride gas, oxygen and silicon react, and reaction products comprise a boron simple substance, silicon oxide, boron oxide and chlorine. The boron simple substance and the silicon oxide are attached to the surface of the silicon wafer, the boron simple substance is used for diffusing to the interior of the silicon wafer, and the chlorine and the boron oxide are distributed in the diffusion furnace.
In the deposition process, the volume flow of oxygen gas introduced into the diffusion furnace is controlled to be 100-5000sccm, the volume flow of boron trichloride gas is controlled to be 50-1000sccm, and the deposition time is controlled to be 30-2000 seconds. Specifically, in step 130, the volume flow rate of the oxygen gas introduced into the diffusion furnace is 900sccm, the volume flow rate of the boron trichloride gas is 210sccm, and the deposition time is 700 seconds.
The volume flow of boron trichloride gas and oxygen is small, the problem of insufficient distribution of boron trichloride at certain positions in the diffusion furnace is easy to occur, and the distribution uniformity of boron trichloride and oxygen in the diffusion furnace is not easy to ensure. In this embodiment, when oxygen and boron trichloride are introduced into the diffusion furnace, nitrogen is also introduced into the diffusion furnace, that is, the introduction of oxygen and boron trichloride into the diffusion furnace is realized by introducing a mixed gas of nitrogen, oxygen and boron trichloride into the diffusion furnace.
The nitrogen is used as a carrying gas of the oxygen and the boron trichloride gas, the nitrogen is required to have relatively large volume flow, and the flow rate and the reaction rate of the oxygen and the boron trichloride gas are adjusted, so that the uniform diffusion of the boron trichloride gas and the oxygen at each position in the diffusion furnace is facilitated.
In step 130, the volume flow rate of the nitrogen gas introduced into the diffusion furnace is controlled to be 1000-5000sccm, and specifically, the volume flow rate of the nitrogen gas can be 3200sccm.
And step 140, discharging gaseous reaction products and residual boron sources during the deposition treatment to the outside of the diffusion furnace.
After the deposition treatment is completed, unreacted boron trichloride, chlorine gas, boron oxide and other gaseous reaction products are distributed in the diffusion furnace, and before the promotion treatment, the gaseous reaction products and the residual boron trichloride need to be discharged to the outside of the diffusion furnace so as to prevent the boron oxide and the residual boron trichloride from influencing the subsequent process.
Specifically, the gaseous reaction product and the remaining boron trichloride during the deposition treatment can be discharged by introducing nitrogen and oxygen into the diffusion furnace under the condition of keeping the temperature and the pressure in the diffusion furnace constant.
In step 140, the volume flow rate of nitrogen gas introduced into the diffusion furnace is controlled to be 1000-5000sccm, the volume flow rate of oxygen gas is controlled to be 500-5000sccm, and the introduction time is controlled to be 30-1000 seconds. Specifically, the volume flow of nitrogen gas was 4000sccm, the volume flow of oxygen gas was 900sccm, and the flow time was 30 seconds.
And 150, raising the temperature and the pressure in the diffusion furnace, and performing primary propelling treatment until the target amount of boron is diffused into the silicon wafer.
And (3) after discharging gaseous reaction products and residual boron trichloride during deposition treatment, raising the temperature in the diffusion furnace to 900-1000 ℃, and raising the pressure in the diffusion furnace to 200-900mbar. Specifically, the temperature in the diffusion furnace was raised to 950 degrees Celsius and the pressure was raised to 500mbar.
The pressure in the diffusion furnace may be increased by introducing nitrogen gas into the diffusion furnace. In step 150, the volume flow rate of the nitrogen gas introduced into the diffusion furnace is controlled to be 2000-20000sccm, and the introduction time is controlled to be 100-1000 seconds. Specifically, the volume flow of nitrogen gas introduced into the diffusion furnace is 10000sccm for 80 seconds, and then the volume flow of nitrogen gas introduced into the diffusion furnace is 15000sccm for 100 seconds.
And after the temperature and the pressure in the diffusion furnace are increased, introducing nitrogen into the diffusion furnace, and performing primary propelling treatment in the nitrogen atmosphere to diffuse boron on the surface of the silicon wafer into the silicon wafer until the boron entering the silicon wafer reaches a target amount.
And 160, introducing water vapor into the diffusion furnace to clean the surface of the silicon wafer.
After the primary propelling treatment, redundant boron (including a boron simple substance, and possibly boron oxide and boron trichloride which are not discharged) is remained on the surface of the silicon wafer, at the moment, water vapor is introduced into the diffusion furnace, the surface of the silicon wafer is cleaned by the water vapor so as to clean the boron remained on the surface of the silicon wafer, the boron attached to the surface of the silicon wafer can be prevented from further diffusing into the silicon wafer during the secondary propelling treatment, and the content of boron in the silicon wafer can be reduced. In addition, the boron-rich region can be prevented, the damage to the crystal lattice on the surface of the silicon wafer is reduced, and the passivation effect is improved.
In step 160, the volume flow rate of the water vapor introduced into the diffusion furnace is controlled to be 100-2000sccm, and the introduction time is controlled to be 50-2000 seconds. Specifically, the volume flow rate of the steam introduced into the diffusion furnace was 500sccm, and the introduction time was 900 seconds.
The volume flow of the water vapor is small, so that the diffusion of the water vapor to each position in the diffusion furnace is not facilitated, and the effective cleaning of the silicon wafers at each position in the diffusion furnace is not easy to ensure. In this embodiment, when the water vapor is introduced into the diffusion furnace, nitrogen gas is also introduced into the diffusion furnace, that is, the water vapor is introduced into the diffusion furnace by introducing a mixed gas of nitrogen gas and water vapor into the diffusion furnace.
The nitrogen is used as the carrying gas of the water vapor, and needs to have a relatively large volume flow, and particularly, the volume flow of the nitrogen can be larger than that of the water vapor, which is beneficial to uniform diffusion of the water vapor to various positions in the diffusion furnace.
The volume flow rate of the nitrogen gas introduced into the diffusion furnace in step 160 is controlled to be 2000-20000sccm, and specifically, the volume flow rate of the nitrogen gas may be 5000sccm.
The water vapor may be obtained by heating liquid water at a high temperature or by reacting hydrogen and oxygen using an ignition device.
Specifically, the diffusion furnace may be externally connected with a water vapor delivery pipe.
For the mode of obtaining water vapor by heating liquid water, a container can be connected at the inlet end of a water vapor conveying pipe, liquid water is added into the container, and the water vapor conveying pipe extends to be higher than the liquid level of the container. The container is also connected with a nitrogen conveying pipe which extends to the position below the liquid level in the container. Liquid water in the container is heated to about 90 ℃ through the heater, nitrogen is conveyed through the nitrogen conveying pipe, and the nitrogen can carry water vapor after passing through the liquid water and enters the diffusion furnace through the water vapor conveying pipe.
As for the mode of obtaining water vapor by using the reaction mode of hydrogen and oxygen, a reactor can be connected at the inlet end of a water vapor conveying pipe, and a hydrogen inlet pipe and an oxygen inlet pipe are also externally connected to the reactor. Hydrogen and oxygen are added into the reactor through a hydrogen inlet pipe and an oxygen inlet pipe, and the hydrogen and the oxygen react in an ignition or heating mode to generate water vapor. The generated steam enters the diffusion furnace through a steam conveying pipe.
In alternative embodiments, water vapor generated at other locations in the plant may also be used in step 160 of the boron diffusion method provided in this embodiment.
And 170, raising the temperature in the diffusion furnace, and performing secondary propulsion treatment.
After the boron remained on the surface of the silicon wafer is cleaned, the pressure in the diffusion furnace is ensured to be unchanged, and the temperature in the diffusion furnace is increased to the temperature required by high-temperature propelling treatment, so that the boron in the silicon wafer is further diffused into the silicon wafer.
The temperature in the diffusion furnace needs to be controlled to 1000-1100 ℃. Specifically, the temperature within the diffusion furnace may be increased to 1030 degrees celsius.
In the secondary propelling treatment process, nitrogen and oxygen are required to be introduced into the diffusion furnace, and secondary propelling treatment is carried out under the oxygen atmosphere so as to increase the diffusion depth of boron into the silicon wafer to the target junction depth.
The volume flow of the introduced nitrogen is controlled to be 0-20000sccm, the volume flow of the introduced oxygen is controlled to be 0-20000sccm, and the introduction time is controlled to be 1000-10000 seconds. Specifically, the volume flow of the introduced nitrogen is 5000sccm, the volume flow of the introduced oxygen is 3000sccm, and the introduction time is 6500 seconds.
After boron remaining on the surface of the silicon wafer is cleaned, nitrogen gas must be introduced into the diffusion furnace to remove water vapor in the diffusion furnace and change the atmosphere in the diffusion furnace before the temperature in the diffusion furnace is raised. The volume flow rate of nitrogen gas introduced into the diffusion furnace is controlled to be 2000-20000sccm, and the introduction time is controlled to be 100-1000 seconds. Specifically, the volume flow rate of the introduced nitrogen gas was 5000sccm, and the introduction time was 500 seconds.
And step 180, adjusting the temperature and the pressure in the diffusion furnace, and taking the silicon wafer out of the diffusion furnace.
After the secondary propelling treatment is completed, the temperature in the diffusion furnace is reduced to 750-850 ℃, specifically to 750 ℃. And increasing the pressure in the diffusion furnace to be consistent with the atmospheric pressure so as to prepare for taking the silicon wafer out of the diffusion furnace.
Specifically, the temperature in the diffusion furnace may be decreased and then the pressure in the diffusion furnace may be increased.
When the temperature in the diffusion furnace is reduced, nitrogen and oxygen can be introduced into the diffusion furnace, the volume flow of the introduced nitrogen is 10000sccm, the volume flow of the introduced oxygen is 3000sccm, and the introduction time is 2100 seconds.
When the pressure in the diffusion furnace is increased, nitrogen gas can be introduced into the diffusion furnace, the volume flow of the introduced nitrogen gas is 20000sccm, and the introduction time is 200 seconds.
When taking out the silicon chip from the diffusion furnace, after opening the furnace door, need continuously to letting in nitrogen gas in the diffusion furnace, the volume flow who lets in nitrogen gas can be 20000sccm, and the pressure in the diffusion furnace can be increased in letting in of nitrogen gas to can reduce the outside air admission diffusion furnace of diffusion furnace, reduce the influence of air to the inside cleanliness factor of diffusion furnace.
And when the silicon wafer is taken out of the diffusion furnace, taking out the quartz boat and the silicon wafer together to further cool the silicon wafer, and then taking down the silicon wafer from the quartz boat to obtain the boron-doped silicon wafer.
So set up, let in excessive boron trichloride and oxygen during the deposit to ensure that the boron of each position in the diffusion furnace satisfies the demand. After the boron is subjected to primary propelling treatment and the required amount of boron enters the silicon wafer, the surface of the silicon wafer is cleaned by utilizing water vapor, so that redundant boron on the surface of the silicon wafer is cleaned, the boron attached to the surface of the silicon wafer is prevented from further diffusing in the silicon wafer during secondary propelling treatment, the influence of introduced excessive boron trichloride on the boron content in the silicon wafer is reduced, the boron content in the silicon wafer is prevented from being too high, the sheet resistance value of the silicon wafer is ensured, and the problem of uneven distribution of the boron content existing in the prior art when the boron content is reduced is solved.
In the deposition process, when boron trichloride and oxygen react with silicon, products such as boron oxide are generated and discharged to the outside of the diffusion furnace in step 140, and the products such as boron oxide are condensed on the inner wall of the transfer line outside the diffusion furnace with a decrease in temperature, and the transfer line is easily clogged. In this embodiment, after the surface of the silicon wafer is cleaned by using the water vapor, the water vapor is discharged to the outside of the diffusion furnace, and then reacts with a product such as boron oxide when passing through the conveying pipeline to generate boric acid which has a low melting point and a low boiling point and is soluble in water, so that the problem of blockage of the conveying pipeline can be alleviated, and the maintenance period and the service life of equipment are prolonged.
In this embodiment, the primary drive treatment is performed in a nitrogen atmosphere, which is advantageous for boron to rapidly enter the surface layer of the silicon wafer. The secondary propelling treatment is carried out in the atmosphere of nitrogen and oxygen, which is beneficial to further diffusion of boron and adjusts the diffusion distribution curve of boron on the surface layer of the silicon wafer.
In this embodiment, in step 110, when adjusting the temperature and the pressure in the diffusion furnace, the diffusion furnace may be first subjected to an air extraction process to reduce the pressure in the diffusion furnace to a target pressure, and then the temperature in the diffusion furnace may be increased to a target temperature. The air suction treatment can be realized by an air suction pump, and the air suction time is controlled to be 100-1000 seconds.
After the pressure in the diffusion furnace is reduced to the target pressure, the airtightness of the diffusion furnace also needs to be checked. Specifically, the air suction pump can be closed, any gas is not introduced into the diffusion furnace, the pressure change condition in the diffusion furnace is observed for 60 seconds, and if the pressure increase in the diffusion furnace is not more than 2mbar, the air tightness of the diffusion furnace is good.
And after the temperature of the diffusion furnace is raised to the target temperature, introducing nitrogen into the diffusion furnace to discharge air entering the diffusion furnace due to opening and closing of a furnace door. In the process of introducing the nitrogen, the air pump can be opened to maintain the pressure in the diffusion furnace to be stable. The volume flow of the introduced nitrogen is controlled to be 1000-5000sccm, and the introduction time is controlled to be 100-1000 seconds.
In step 110, after the temperature and the pressure are adjusted to the target temperature and the target pressure, the temperature is stabilized for a certain time, so that the power of the heating wire of the diffusion furnace and the actual temperature in the diffusion furnace are stabilized.
The following is a further description of the effect of the boron diffusion method in the examples of the present invention with reference to the data of the test group and the control group.
Two test groups and a control group were set up and boron diffusion treatment was performed, respectively.
The data of the first test set and the second test set are strictly performed according to the steps of the boron diffusion method provided by the embodiment of the invention, the first test set and the second test set are only different in the time for introducing the water vapor in the step 160 (the volume flow rate of the introduced water vapor is the same), and the time for introducing the water vapor in the second test set is 100 seconds shorter than that in the first test set.
Compared with the test group one and the test group two, the volume flow of the boron trichloride and the oxygen is reduced in the step 130 by the comparison group, the step 160 is reduced, and the data in the rest steps are consistent with those in the test group.
After the boron diffusion treatment is completed in the test group one, the test group two and the control group, the sheet resistance of the middle position, the lower right position, the lower left position, the upper left position and the upper right position (corresponding to the detection point one, the detection point two, the detection point three, the detection point four and the detection point five respectively) of each silicon wafer of each group is tested, and the following data are obtained:
data for test set one are shown in the following table:
data for test group two are shown in the following table:
the data for the control group are shown in the following table:
since the boron content in the silicon wafer cannot be directly measured, the square resistance value is taken as the representation of the boron content in the embodiment. The square resistance value is in inverse proportion to the boron content, and the larger the square resistance value is, the less the boron content in the silicon wafer is; the smaller the sheet resistance value, the more boron content in the silicon wafer.
The above-mentioned average value of sheet internal sheet square resistance means the average value of the square resistance of each detection point of a single silicon wafer.
The above in-chip sheet resistance uniformity refers to the uniformity of sheet resistance in a single silicon chip, and the calculation formula is:
that is, a smaller value of the sheet internal sheet resistance uniformity indicates a better sheet resistance uniformity.
The sheet resistance average value refers to an average value of sheet resistance average values in each sheet.
The above total sheet internal sheet resistance uniformity refers to the average value of the internal sheet resistance uniformity of each sheet.
The above inter-wafer sheet resistance uniformity refers to the uniformity of sheet resistance of each silicon wafer, and the calculation formula is:
that is, the smaller the value of the sheet-to-sheet resistance uniformity, the better the sheet-to-sheet resistance uniformity.
By comparative analysis of the above data, the following conclusions can be drawn:
as excessive boron trichloride and oxygen are introduced into the first test group and the second test group during deposition treatment, and the silicon wafer is cleaned by using water vapor after primary propulsion treatment, the uniformity of the total sheet internal sheet square resistance and the uniformity of the sheet internal sheet square resistance in the first test group and the second test group are both good.
The time for introducing the water vapor into the first test group is longer than the time for introducing the water vapor into the second test group, and the boron remained on the surface of the silicon wafer in the first test group is less than the boron remained on the surface of the silicon wafer in the second test group, so the sheet resistance of the first test group is greater than that of the second test group.
As the boron trichloride and the oxygen are not excessive and the water vapor is not introduced during the deposition treatment in the control group, the total in-sheet uniformity and the inter-sheet resistance uniformity in the control group are poor, the sheet resistance in the control group is smaller than that in the first test group, and the sheet resistance in the control group is as much as that in the second test group.
In summary, the sheet resistance, the total in-sheet uniformity and the sheet-to-sheet uniformity are related to whether the amount of boron trichloride and oxygen gas is excessive during the deposition process, whether water vapor is introduced after one drive process, and the flow rate of the introduced water vapor. Therefore, in the boron diffusion treatment process, the flow parameters of the boron trichloride and the oxygen introduced during the deposition treatment and the flow parameters of the water vapor introduced after the primary propulsion treatment can be adjusted according to the uniformity requirement of the boron content and the requirement of the boron content.
In this embodiment, after the above test is completed, 100 silicon wafers are extracted from the second test group and the control group respectively to perform a conventional TOPCon process (back etching, tunnel oxidation, amorphous silicon doping, annealing, decoating, aluminum oxide, positive film, and back film), 5 of the silicon wafers are extracted to test the hidden open circuit voltage, and then sintering is performed, and then the hidden open circuit voltage is tested again, and the rest of the printed batteries are used. The test results are shown in the following table:
by comparative analysis of the above data, the following conclusions can be drawn:
the sheet resistance of the test group II is similar to that of the comparison group, and the performance of the battery made of the silicon wafer of the test group II is superior to that of the battery made of the silicon wafer of the comparison group.
In summary, when the boron diffusion method in this embodiment is used to process a boron-doped silicon wafer, the uniformity is good when the sheet resistance of the silicon wafer is improved, and the parameters of the subsequent process after boron diffusion can be conveniently controlled. And is beneficial to improving the performance of the battery to a certain extent.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. A boron diffusion method, comprising:
putting a silicon wafer into a diffusion furnace, and adjusting the temperature and the pressure in the diffusion furnace;
carrying out pre-oxidation operation on the silicon wafer to form an oxide layer on the surface of the silicon wafer;
introducing oxygen and a boron source into the diffusion furnace for deposition treatment;
discharging gaseous reaction products generated in the deposition treatment and the residual boron source to the outside of the diffusion furnace;
raising the temperature and the pressure in the diffusion furnace, and performing primary propelling treatment until the target amount of boron is diffused into the silicon wafer;
introducing water vapor into the diffusion furnace to clean the surface of the silicon wafer;
raising the temperature in the diffusion furnace, and performing secondary propelling treatment;
and adjusting the temperature and the pressure in the diffusion furnace, and taking the silicon wafer out of the diffusion furnace.
2. The boron diffusion method of claim 1, wherein said introducing water vapor into said diffusion furnace comprises:
and introducing nitrogen and water vapor into the diffusion furnace, wherein the flow rate of the nitrogen is greater than that of the water vapor.
3. The boron diffusion method according to claim 2, wherein the volume flow rate of the water vapor is 100 to 2000sccm.
4. The boron diffusion method according to claim 1, wherein the boron source is a boron trichloride gas, a volume flow rate of the boron trichloride gas is 50 to 1000sccm, and a volume flow rate of the oxygen gas is 100 to 5000sccm.
5. The boron diffusion method according to claim 1, wherein the primary drive treatment is performed under a nitrogen atmosphere.
6. The boron diffusion method according to claim 1, wherein the secondary drive treatment is performed in an atmosphere of nitrogen and oxygen.
7. The boron diffusion method of claim 1, wherein said introducing oxygen and a boron source into said diffusion furnace comprises:
and introducing mixed gas of nitrogen, the oxygen and the boron source into the diffusion furnace.
8. The boron diffusion method according to claim 1, wherein nitrogen gas is continuously introduced into the diffusion furnace while the silicon wafer is being introduced into the diffusion furnace and while the silicon wafer is being taken out of the diffusion furnace.
9. The boron diffusion method of claim 1, wherein said adjusting the temperature and pressure within said diffusion furnace comprises:
performing air extraction treatment on the diffusion furnace to reduce the pressure in the diffusion furnace to a target pressure;
raising the temperature within the diffusion furnace to a target temperature.
10. The boron diffusion method of claim 9, wherein after reducing the pressure within the diffusion furnace to a target pressure, further comprising:
and detecting the air tightness of the diffusion furnace.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211194270.1A CN115547818A (en) | 2022-09-28 | 2022-09-28 | Boron diffusion method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211194270.1A CN115547818A (en) | 2022-09-28 | 2022-09-28 | Boron diffusion method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115547818A true CN115547818A (en) | 2022-12-30 |
Family
ID=84731345
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211194270.1A Pending CN115547818A (en) | 2022-09-28 | 2022-09-28 | Boron diffusion method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115547818A (en) |
-
2022
- 2022-09-28 CN CN202211194270.1A patent/CN115547818A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7846762B2 (en) | Integrated emitter formation and passivation | |
| CN104505427B (en) | Improve method and the device of crystal silicon solar cell sheet LID and PID | |
| US20110162706A1 (en) | Passivated polysilicon emitter solar cell and method for manufacturing the same | |
| CN115094521B (en) | Boron diffusion reaction system and process method thereof | |
| CN111341649A (en) | Boron diffusion method for N-type solar cell | |
| WO2022166040A1 (en) | Boron diffusion method suitable for hbc battery | |
| CN109473508A (en) | A kind of solar battery method for annealing and device and preparation method of solar battery | |
| CN111293189A (en) | Tunneling oxidation method based on horizontally placed LPCVD (low pressure chemical vapor deposition) equipment | |
| CN116404073A (en) | Method and device for preparing amorphous silicon film in TOPCON battery | |
| CN102386277A (en) | Multi-coating technology | |
| US9437426B2 (en) | Method of manufacturing semiconductor device | |
| CN115547818A (en) | Boron diffusion method | |
| JP2636817B2 (en) | Single wafer type thin film forming method and thin film forming apparatus | |
| CN203976978U (en) | A kind of novel diffusion furnace | |
| CN110137307B (en) | High-uniformity shallow junction diffusion process in low-pressure environment | |
| CN114678265A (en) | Novel boron diffusion wet oxygen process | |
| JP2012089850A (en) | Apparatus and method for surface treatment within furnace | |
| CN118621449A (en) | Flow equalizing device, diffusion furnace, phosphorus diffusion method and sintering method | |
| JPH0693452B2 (en) | Single-wafer thin film forming method and thin film forming apparatus | |
| EP3370267A1 (en) | Method of manufacturing oxidation layer for solar cell | |
| JP2015046588A (en) | Thin film formation method and manufacturing method for solar battery element | |
| CN115117201B (en) | Silicon wafer phosphorus or boron doping method | |
| CN118367056A (en) | Wet oxidation diffusion process and equipment thereof | |
| CN107507762A (en) | A kind of technology for improving silicon nitride film and being rich in hydrogen | |
| CN116387400A (en) | Boron diffusion method and device of TOPCON battery |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20231225 Address after: 036899 No. 2-1, Wei'er Road, Pinglu Economic and Technological Development Zone, Shuozhou City, Shanxi Province Applicant after: Sany Silicon Energy (Shuozhou) Co.,Ltd. Address before: 3rd Floor, Sany Administration Center, Sanyi Industrial City, Sanyi Road, Economic Development Zone, Changsha City, Hunan Province, 410100 Applicant before: SANY GROUP Co.,Ltd. |
|
| TA01 | Transfer of patent application right |