CN102912424B - Method for improving uniformity of axial resistivity of czochralski silicon and obtained monocrystalline silicon - Google Patents

Method for improving uniformity of axial resistivity of czochralski silicon and obtained monocrystalline silicon Download PDF

Info

Publication number
CN102912424B
CN102912424B CN201210382987.9A CN201210382987A CN102912424B CN 102912424 B CN102912424 B CN 102912424B CN 201210382987 A CN201210382987 A CN 201210382987A CN 102912424 B CN102912424 B CN 102912424B
Authority
CN
China
Prior art keywords
silicon
gas
czochralski
doping
czochralski silicon
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.)
Active
Application number
CN201210382987.9A
Other languages
Chinese (zh)
Other versions
CN102912424A (en
Inventor
杨德仁
陈鹏
余学功
吴轶超
陈仙子
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zhejiang University ZJU
Original Assignee
Zhejiang University ZJU
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Zhejiang University ZJU filed Critical Zhejiang University ZJU
Priority to CN201210382987.9A priority Critical patent/CN102912424B/en
Publication of CN102912424A publication Critical patent/CN102912424A/en
Application granted granted Critical
Publication of CN102912424B publication Critical patent/CN102912424B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Landscapes

  • Crystals, And After-Treatments Of Crystals (AREA)

Abstract

The invention discloses a method for improving the uniformity of axial resistivity of czochralski silicon. The method comprises the steps as follows: (1) melting a polycrystalline silicon raw material and a solid doping agent in an argon atmosphere to obtain stable molten silicon; (2) introducing seed crystals into the stable molten silicon, and conducting constant diameter growth on the crystals after necking and shouldering processes; and (3) during the constant diameter growth period, adding dopant gas with the conductive type opposite to that of the solid doping agent until the growth of the czochralski silicon is fulfilled. According to the method, the type and the usage amount of the dopant gas are convenient to control, various required impurity concentration distributions can be obtained, the utilization rate of the czochralski silicon is increased, and the uniformity of the resistivity of the czochralski silicon is remarkably improved.

Description

Method for improving axial resistivity uniformity of czochralski monocrystalline silicon and monocrystalline silicon obtained by same
Technical Field
The invention relates to the field of semiconductor materials, in particular to a method for improving the uniformity of the axial resistivity of czochralski monocrystalline silicon by a gas-phase doping method and the monocrystalline silicon obtained by the method.
Background
Photovoltaic power generation is the most important renewable energy technology in the foreseeable future. Photovoltaic power generation in 2030 will meet nearly 10% of the global power demand as predicted by the European Photovoltaic Industry Association (EPIA).
The current solar cell is mainly manufactured based on a boron-doped monocrystalline silicon material, but because the monocrystalline silicon contains boron and oxygen at the same time, a boron-oxygen complex is formed in the use process of the solar cell, so that the photoelectric conversion efficiency of the solar cell is reduced by more than 10%, and the performance of the solar cell is remarkably reduced. To solve this problem, researchers have invented gallium-doped monocrystalline silicon solar cells.
Although the gallium-doped monocrystalline silicon solar cell has no light attenuation phenomenon, the gallium-doped monocrystalline silicon solar cell has great defects, because the segregation coefficient of gallium in silicon is extremely low (about 0.008), the axial resistivity difference is great in the growth process of the gallium-doped monocrystalline silicon, the resistivity of the finally grown monocrystalline silicon in the monocrystalline silicon cannot meet the requirement, and the actual utilization rate of the gallium-doped monocrystalline silicon is only about 80%.
In addition, the resistivity distribution of the gallium-doped czochralski silicon is wide, so that the efficiency distribution of the solar cell is also wide, and the consistency of the power output of the solar cell module is seriously influenced.
These drawbacks result in gallium-doped solar cells that are expensive and difficult to implement on a large scale in the industry. So far, no effective means is published at home and abroad to obtain the gallium-doped Czochralski silicon with uniformly distributed axial resistivity.
In the field of microelectronics, the heavily antimony-doped Czochralski monocrystalline silicon is also an important material, and an n/n + epitaxial wafer prepared from the heavily antimony-doped Czochralski monocrystalline silicon has the advantages of narrow transition region, steep junction gradient, small diffusion coefficient of antimony at high temperature and the like, so that the antimony-doped monocrystalline silicon becomes an important substrate.
However, like gallium-doped single crystal silicon, the equilibrium segregation coefficient of antimony in silicon is also very small (about 0.023), again resulting in poor uniformity of the axial resistivity of antimony-doped czochralski silicon.
Disclosure of Invention
The invention provides a method for improving the uniformity of the axial resistivity of czochralski silicon, which greatly improves the uniformity of the axial resistivity of the czochralski silicon by a gas-phase doping method, is simple and practical and has good industrial application prospect.
A method for improving the uniformity of the axial resistivity of czochralski silicon comprises the following steps:
(1) melting a polycrystalline silicon raw material and a solid dopant in an argon atmosphere to obtain stable molten silicon;
(2) introducing seed crystals into the stable molten silicon, and leading the crystal growth to enter an isodiametric growth stage through necking and shouldering processes;
(3) and in the isometric growth stage, introducing doping gas with the conductivity type opposite to that of the solid dopant until the growth of the Czochralski silicon is finished.
In the normal equal-diameter growth process of the czochralski silicon single crystal, doping gas is continuously and uniformly introduced to realize gas-phase doping, and the distribution of gas-phase impurities introduced by the doping gas in the silicon single crystal obeys the following equation:
C s = ak V ( 1 + k ) [ ( 1 - g ) k - 1 - 1 ] - - - ( 1 )
wherein,
Csis the doping concentration of impurities in the silicon single crystal;
a is the doping rate of the doping gas;
v is the growth rate of the czochralski silicon;
k is the segregation coefficient of impurities introduced by the doping gas;
g is the coagulation fraction.
If p-type and n-type impurities are co-doped, the distribution of carriers in the silicon crystal obeys the following equation (taking p-type gallium and n-type phosphorus as an example):
p = C 0 k 1 ( 1 - g ) k 1 - 1 - ak 2 V ( 1 - k 2 ) [ ( 1 - g ) k 2 - 1 - 1 ] - - - ( 2 )
wherein,
p is the concentration of carriers in the silicon crystal;
C0is the initial melt concentration of gallium;
k1is the segregation coefficient of gallium;
g is the coagulation fraction;
a is a doping rate of the doping gas (amount of impurities introduced per unit time, flow rate by the doping gas);
v is the growth rate of the czochralski silicon;
k2is the segregation coefficient of phosphorus;
represents the impurity concentration introduced by the solid dopant;
indicating the concentration of the dopant gas introduced impurity.
By adjusting the concentration and the flow of the doping gas, the optimal gas phase doping amount can be obtained, and the axial resistivity of the czochralski silicon single crystal is kept uniformly distributed.
The optimal gas doping amount is as follows:
a V optim . = C 0 k 1 ( 1 - k 1 ) ( 2 - k 1 ) k 2 ( 2 - k 2 ) - - - ( 3 )
wherein,
C0is the initial melt concentration of the solid dopant;
k1is the segregation coefficient of the solid dopant;
a is the doping rate of the doping gas;
v is the growth rate of the czochralski silicon;
k2is the segregation coefficient of impurities in the doping gas.
According to this formula, a suitable amount of phosphane to be doped in compensated crystals of gallium and phosphorus is 0.0268C0(C0Initial melt concentration of gallium), preferably not more than 0.0326C0Over 0.0404C0A small part of inversion can occur; for antimony and boron compensated crystals, a suitable amount of borane to be doped is 0.0463C0(C0Initial melt concentration of antimony) ofPreferably more than 0.0569C0Over 0.0775C0A small fraction of inversion will occur. In practice the optimum gas doping level may vary within a range above and below the desired value.
In the manufacturing process of the czochralski silicon single crystal, polycrystalline silicon raw materials are placed in a quartz crucible, and a corresponding amount of solid phase dopant is added according to target resistivity, after the czochralski silicon is grown, the resistivity of the head part (the part where the crystal grows firstly) and the tail part (the part where the crystal grows and ends) of the crystal is different, so that the axial resistivity distribution is not uniform.
In order to improve the axial resistivity of the czochralski silicon single crystal, doping gas with the conductivity type opposite to that of the solid dopant is continuously and uniformly introduced in the constant-diameter growth stage of the czochralski silicon single crystal, after the constant-diameter growth is finished, the introduction of the doping gas is stopped, and the processes of ending, cooling and the like are continuously carried out under the protection of argon gas, so that the growth process of the whole silicon crystal is finished. The doping amount of the doping gas is 0.001-0.1 times of the initial melt concentration of the solid dopant. The specific value is calculated according to formula (3).
Preferably, when the solid dopant is gallium, the doping gas is phosphine, and the doping amount of the phosphine is 0.025-0.03 times of the initial melt concentration of the gallium.
The utilization rate of the produced czochralski silicon single crystal is close to 100 percent (the head and the tail of the crystal are removed), compared with 80 percent of czochralski silicon single crystal without doping gas, the utilization rate is obviously improved, and the resistivity of more than 90 percent of the area is controlled within the range of 0.5-3 omega.
Preferably, when the solid dopant is antimony, the doping gas is diborane, and the doping amount of the diborane is 0.045-0.055 time of the initial melt concentration of the antimony.
The axial resistivity variation of the produced Czochralski silicon single crystal in a region of 80% or more is controlled within a range of 25%.
Preferably, the doping gas in the step (3) is mixed with an inert gas.
The inert gas is used to dilute the dopant gas, and a gas that does not affect the crystal growth, such as argon, which is generally used as a protective gas for the crystal growth, or nitrogen, which is stable in properties, should be selected.
The mixed doping gas can be directly introduced into the crystal growth chamber, as shown in fig. 1, or the mixed doping gas can be introduced into the crystal growth chamber 6 through a high-purity quartz glass pipeline 7 after the mixed doping gas with a determined proportion is obtained by respectively arranging an inert gas source 2 and a doping gas source 4 and adjusting an inert gas flowmeter 1, a doping gas flowmeter 3 and a mixed gas flowmeter 5.
Preferably, the volume percentage of the inert gas in the doping gas is 1-99.9%. The volume percentage of the inert gas in the doping gas is not strictly limited, and the inert gas dilutes the doping gas, so that the inversion caused by the excessive local doping gas concentration in the czochralski silicon single crystal due to the excessive doping gas concentration is avoided.
Preferably, the flow rate of the doping gas introduced into the growth chamber is 1-1000 sccm (standard condition milliliters per minute).
The flow rate of the doping gas is determined according to the type and concentration of the doping gas and the type and concentration of the solid dopant in the crystal, the doping speed of the doping gas is required to be ensured to be adaptive to the growth speed of the crystal, the doping gas with opposite conductivity types is used for compensating the solid dopant, and the czochralski silicon single crystal with uniform axial resistivity is obtained.
The gallium-phosphorus-compensated Czochralski silicon for the solar cell prepared by the method for improving the uniformity of the axial resistivity of the Czochralski silicon has the axial resistivity of 0.5-3 omega cm in more than 90% of the area, and the antimony-boron-heavily-doped Czochralski silicon for the micro-electronics has the axial resistivity variation of less than 25% in more than 80% of the area.
The manufacturing method of the czochralski silicon provided by the invention has the following advantages:
(1) the type and the dosage of the doping gas are convenient to control, and various required impurity concentration distributions can be obtained;
(2) the utilization rate of the czochralski silicon single crystal is improved;
(3) the resistivity uniformity of the crystal is significantly improved.
Drawings
FIG. 1 is a schematic view of an apparatus for producing a Czochralski silicon single crystal by carrying out the method of the present invention;
FIG. 2 is a resistivity profile of a Czochralski silicon single crystal prepared in example 1;
FIG. 3 is a resistivity distribution diagram of a Czochralski silicon single crystal prepared in example 2.
Detailed Description
Example 1
60kg of high purity polysilicon feedstock was charged into a quartz crucible while 2.982g of high purity gallium (control head target resistivity 1.8 ohm. cm) was doped.
Under the protection of argon, the high-purity polysilicon is gradually heated to a temperature higher than 1420 ℃ so as to completely melt the high-purity polysilicon. Seeding and shouldering according to conventional crystal growth parameters, entering an equal-diameter growth stage, and controlling the crystal pulling rate to be 1.2mm/min and the crystal diameter to be 150 mm.
The furnace pressure was controlled at 20Torr and the argon flow was controlled at 70slpm (standard liters per minute).
Setting the parameters of the doping gas:
1) adopting phosphine diluted by argon as doping gas, wherein the volume ratio of the phosphine to the argon is 1: 1000;
2) assuming that the doping efficiency is 100% (the impurities introduced by the doping gas can be all introduced into the Czochralski silicon single crystal), the flow rate of the doping gas is set to 21.14 sccm.
And (4) closing the doping gas after the isometric growth is finished, normally ending, and cooling.
Samples were taken from different parts of the grown Czochralski silicon single crystal, and the resistivity distribution was measured using a four-probe resistivity meter, with the results shown in FIG. 2.
If the resistivity of the silicon wafer for the solar cell is controlled to be 0.5-3 ohm.cm, the utilization rate of the gallium-doped silicon single crystal is 75 percent; however, for the gallium and phosphorus co-doped single crystal silicon (i.e., the single crystal silicon into which the doping gas is introduced), the utilization rate can be increased to 93%, which means that the gallium and phosphorus co-doped single crystal silicon can be fully utilized after the head and tail portions are removed. Meanwhile, the resistivity distribution of the gallium-doped silicon single crystal is very uneven. For the gallium and phosphorus co-doped silicon single crystal, most of the resistivity is very uniform, the resistivity is reduced only in a very small part of the tail part, and the obtained silicon wafers can be used for preparing solar cells with high efficiency and no light attenuation.
Example 2
60kg of high purity polysilicon material was charged into a quartz crucible while 416.64g of high purity antimony (head target resistivity controlled to 0.016 ohm. cm) was doped.
Under the protection of argon, the polycrystalline silicon is heated to 1420 ℃ or higher gradually to be completely melted. Seeding and shouldering according to conventional crystal growth parameters, entering an equal-diameter growth stage, and controlling the crystal pulling rate to be 0.8mm/min and the crystal diameter to be 150 mm.
The furnace pressure was controlled at 20Torr and the argon flow was controlled at 70 slpm.
Setting the parameters of the doping gas:
1) adopting diborane diluted by argon, wherein the volume ratio of the diborane to the argon is 1: 100;
2) assuming a doping efficiency of 100%, the dopant gas flow rate was set to 97.58 sccm.
And after the isometric growth is finished, closing the doping gas, normally ending, and cooling.
Samples were taken from different parts of the grown single crystal silicon and the resistivity distribution was measured using a four-probe resistivity meter, the results of which are shown in FIG. 3.
If the requirement of a microelectronic manufacturer for 25% fluctuation of resistivity is met, the utilization rate of the antimony-doped monocrystalline silicon is only about 40%, and the utilization rate of the antimony-boron-codoped monocrystalline silicon (namely the monocrystalline silicon with doping gas introduced) can reach about 80%, which is increased by nearly 1 time, the utilization rate of the monocrystalline silicon is obviously improved, the resistivity uniformity is obviously improved, and the quality control of an integrated circuit is facilitated.

Claims (6)

1. A method for improving the uniformity of the axial resistivity of Czochralski silicon comprises melting a polycrystalline silicon raw material and a solid dopant in an argon atmosphere to obtain stable molten silicon; introducing seed crystals into the stable molten silicon, and leading the crystal growth to enter an isodiametric growth stage through necking and shouldering processes; the method is characterized in that doping gas with the conductivity type opposite to that of the solid dopant is introduced in the equal-diameter growth stage until the growth of the czochralski silicon is finished; the doping amount of the doping gas is 0.001-0.1 times of the initial melt concentration of the solid dopant.
2. The method of claim 1 wherein when the solid dopant is gallium, the dopant gas is phosphane in an amount of 0.025 to 0.03 times the initial melt concentration of gallium.
3. The method for improving the axial resistivity uniformity of czochralski silicon as claimed in claim 1, wherein when the solid dopant is antimony, the doping gas is diborane, and the doping amount of the diborane is 0.045-0.055 times of the initial melt concentration of the antimony.
4. The method for improving the axial resistivity uniformity of czochralski silicon as claimed in any one of claims 1 to 3, wherein an inert gas is mixed in the doping gas.
5. The method of improving the axial resistivity uniformity of czochralski silicon as claimed in claim 4 wherein the volume percent of inert gas in the dopant gas is 1 to 99.9%.
6. The method of improving the axial resistivity uniformity of czochralski silicon as claimed in claim 5, wherein the dopant gas is introduced into the growth chamber at a flow rate of 1 to 1000 sccm.
CN201210382987.9A 2012-10-10 2012-10-10 Method for improving uniformity of axial resistivity of czochralski silicon and obtained monocrystalline silicon Active CN102912424B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201210382987.9A CN102912424B (en) 2012-10-10 2012-10-10 Method for improving uniformity of axial resistivity of czochralski silicon and obtained monocrystalline silicon

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201210382987.9A CN102912424B (en) 2012-10-10 2012-10-10 Method for improving uniformity of axial resistivity of czochralski silicon and obtained monocrystalline silicon

Publications (2)

Publication Number Publication Date
CN102912424A CN102912424A (en) 2013-02-06
CN102912424B true CN102912424B (en) 2015-05-13

Family

ID=47610987

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201210382987.9A Active CN102912424B (en) 2012-10-10 2012-10-10 Method for improving uniformity of axial resistivity of czochralski silicon and obtained monocrystalline silicon

Country Status (1)

Country Link
CN (1) CN102912424B (en)

Families Citing this family (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10724148B2 (en) * 2014-01-21 2020-07-28 Infineon Technologies Ag Silicon ingot and method of manufacturing a silicon ingot
US9312338B2 (en) * 2014-06-30 2016-04-12 Infineon Technologies Ag Semiconductor device containing chalcogen atoms and method of manufacturing
US10337117B2 (en) 2014-11-07 2019-07-02 Infineon Technologies Ag Method of manufacturing a silicon ingot and silicon ingot
CN105951173A (en) * 2016-05-30 2016-09-21 上海超硅半导体有限公司 N type monocrystalline silicon crystal ingot and manufacturing method thereof
CN105887194A (en) * 2016-05-30 2016-08-24 上海超硅半导体有限公司 Growth method of type-n monocrystalline silicon
CN106400106B (en) * 2016-08-31 2019-07-12 内蒙古中环光伏材料有限公司 A kind of method and device improving pulling of silicon single crystal axial direction resistivity evenness
CN106222742B (en) * 2016-09-12 2019-01-29 江西赛维Ldk太阳能高科技有限公司 A kind of crystalline silicon and preparation method thereof
CN106222743A (en) * 2016-09-19 2016-12-14 江西赛维Ldk太阳能高科技有限公司 A kind of polycrystal silicon ingot and preparation method thereof and for preparing the ingot furnace of polycrystal silicon ingot
JP6699797B2 (en) * 2017-02-28 2020-05-27 株式会社Sumco Silicon single crystal ingot manufacturing method and silicon single crystal ingot
CN108330538A (en) * 2018-04-13 2018-07-27 内蒙古中环光伏材料有限公司 Disk and method are matched in a kind of nitrogen control for pulling single crystal silicon process
CN109505005B (en) * 2018-12-26 2021-02-05 徐州鑫晶半导体科技有限公司 Method for preparing n-type monocrystalline silicon and monocrystalline furnace
CN110158148A (en) * 2019-04-29 2019-08-23 江苏协鑫软控设备科技发展有限公司 Crystal silicon and its crystal growth technique
CN110528066A (en) * 2019-09-03 2019-12-03 宁夏隆基硅材料有限公司 A kind of doping method, monocrystalline device and single crystal growing furnace
CN114622278B (en) * 2020-12-08 2024-04-05 内蒙古中环晶体材料有限公司 Silicon single crystal and preparation method thereof, silicon wafer, solar cell and assembly
CN112831828B (en) * 2021-01-07 2021-12-07 杭州晶宝新能源科技有限公司 Growth method of gallium-doped Czochralski monocrystalline silicon, gallium-doped monocrystalline silicon and application
CN113355739B (en) * 2021-05-12 2023-01-24 晶澳太阳能有限公司 Monocrystalline silicon and method for producing same
CN115341271A (en) * 2021-05-13 2022-11-15 内蒙古中环协鑫光伏材料有限公司 Method for controlling axial decay rate of resistivity of single crystal
CN115341266A (en) * 2021-05-13 2022-11-15 内蒙古中环协鑫光伏材料有限公司 Method for automatically controlling resistivity of monocrystalline silicon
CN115613124A (en) * 2021-07-15 2023-01-17 内蒙古中环协鑫光伏材料有限公司 High-quality N-type single crystal pulling process and single crystal
CN114540950B (en) * 2022-01-10 2023-04-28 浙江大学 Method for growing n-type Czochralski silicon by reducing furnace pressure
CN116288658B (en) * 2023-05-22 2023-10-24 苏州晨晖智能设备有限公司 Single crystal furnace with intermittent doping at top and doping method thereof

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101654804A (en) * 2009-09-24 2010-02-24 浙江大学 Method for controlling specific resistance of gallium-doped Czochralski silicon in crystal growth process
CN102534752A (en) * 2012-03-08 2012-07-04 天津市环欧半导体材料技术有限公司 Czochralski zone melting gas doping method for preparing zone-melted silicon single crystal

Also Published As

Publication number Publication date
CN102912424A (en) 2013-02-06

Similar Documents

Publication Publication Date Title
CN102912424B (en) Method for improving uniformity of axial resistivity of czochralski silicon and obtained monocrystalline silicon
CN102560641B (en) N-type casting policrystalline silicon with uniform doping resistivity and preparation method thereof
CN101560693A (en) Preparation method of solar-grade silicon crystal containing doping elements
EP4257734A1 (en) Crystal pulling process for single-crystal silicon
CN114540950B (en) Method for growing n-type Czochralski silicon by reducing furnace pressure
JP4723071B2 (en) Silicon crystal, silicon crystal wafer, and manufacturing method thereof
NO333319B1 (en) Silicon material for the production of solar cells
WO2015172556A1 (en) Gallium-doped polycrystalline silicon ingot and preparation method therefor
KR20130041733A (en) P-type silicon single crystal and method of manufacturing the same
CN106222742B (en) A kind of crystalline silicon and preparation method thereof
JP6749309B2 (en) Compound semiconductor wafer and photoelectric conversion element
CN105951173A (en) N type monocrystalline silicon crystal ingot and manufacturing method thereof
CN102560627B (en) N-type czochralski silicon with uniform doping resistivity and preparation method thereof
CN102560646B (en) N-type casting monocrystalline silicon with uniform doping resistivity and preparation method thereof
CN107109692A (en) The manufacture method and solar cell of study on floating zone silicon used for solar batteries
CN112831828B (en) Growth method of gallium-doped Czochralski monocrystalline silicon, gallium-doped monocrystalline silicon and application
CN105951172A (en) Manufacturing method of N type/P type monocrystalline silicon crystal ingot
US20230250549A1 (en) Method for preparing monocrystalline silicon and solar cell and photovoltaic module with monocrystalline silicon
CN105970284B (en) A kind of p type single crystal silicon piece and its manufacturing method
CN102094236B (en) Czochralski method for growing long-lifetime P-type boron-doped silicon single crystal
Ciszek et al. Silicon defect and impurity studies using float-zone crystal growth as a tool
Nakajima et al. Applications of novel effects derived from Si ingot growth inside Si melt without contact with crucible wall using noncontact crucible method to high-efficiency solar cells
Kim et al. Fast pulling of n-type Si ingots for enhanced si solar cell production
JP4607307B2 (en) Silicon single crystal for solar cell, silicon single crystal wafer for solar cell, and manufacturing method thereof
JP4723082B2 (en) Method for producing Ga-doped silicon single crystal

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant