CN115198365A - Silicon carbide annealing impurity removing method - Google Patents
Silicon carbide annealing impurity removing method Download PDFInfo
- Publication number
- CN115198365A CN115198365A CN202110951347.4A CN202110951347A CN115198365A CN 115198365 A CN115198365 A CN 115198365A CN 202110951347 A CN202110951347 A CN 202110951347A CN 115198365 A CN115198365 A CN 115198365A
- Authority
- CN
- China
- Prior art keywords
- silicon carbide
- temperature
- annealing
- temperature area
- preset time
- 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
- 238000000137 annealing Methods 0.000 title claims abstract description 62
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 title claims abstract description 57
- 229910010271 silicon carbide Inorganic materials 0.000 title claims abstract description 57
- 239000012535 impurity Substances 0.000 title claims abstract description 42
- 238000000034 method Methods 0.000 title claims abstract description 22
- 239000013078 crystal Substances 0.000 claims abstract description 36
- 238000009413 insulation Methods 0.000 claims abstract description 20
- 239000000463 material Substances 0.000 claims abstract description 15
- 238000001179 sorption measurement Methods 0.000 claims abstract description 13
- 239000002245 particle Substances 0.000 claims abstract description 12
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 6
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 5
- 238000001816 cooling Methods 0.000 claims abstract description 4
- 239000011261 inert gas Substances 0.000 claims abstract description 4
- 239000010410 layer Substances 0.000 claims description 19
- 239000011229 interlayer Substances 0.000 claims description 6
- 230000000694 effects Effects 0.000 description 11
- 239000004065 semiconductor Substances 0.000 description 4
- 230000005855 radiation Effects 0.000 description 2
- 238000005452 bending Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
- C30B29/10—Inorganic compounds or compositions
- C30B29/36—Carbides
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B33/00—After-treatment of single crystals or homogeneous polycrystalline material with defined structure
- C30B33/02—Heat treatment
Abstract
The invention discloses a silicon carbide annealing impurity removal method, which comprises an annealing furnace, wherein a middle heat insulation layer is arranged in the annealing furnace, the middle heat insulation layer divides the annealing furnace into a constant temperature area and a low temperature area, and a through hole for communicating the constant temperature area and the low temperature area is formed in the middle heat insulation layer; taking a silicon carbide crystal, wrapping high-purity carbon particles or high-purity silicon carbide particles on the surface of the silicon carbide crystal, and then placing the silicon carbide crystal in a constant temperature area; taking a porous adsorption material, and placing the porous adsorption material in a low-temperature area; filling or filling inert gas into the annealing furnace in a vacuum state, raising the temperature of the constant-temperature area to an annealing temperature after a first preset time, and simultaneously making the temperature of the low-temperature area lower than the temperature of the constant-temperature area by 400-800 ℃; keeping the annealing furnace at the temperature for a second preset time; and cooling the annealing furnace for a third preset time to normal temperature to obtain the annealed silicon carbide crystal. The silicon carbide annealing impurity removal method provided by the invention effectively reduces the impurity content and eliminates the internal stress.
Description
Technical Field
The invention relates to the technical field of silicon carbide, in particular to a silicon carbide annealing impurity removal method.
Background
The silicon carbide is a high-temperature semiconductor material, has the characteristics of wide forbidden band width (the forbidden band width is more than 2.2 ev), high thermal conductivity, high breakdown electric field, high radiation resistance, high electronic saturation rate and the like, and is suitable for manufacturing high-temperature, high-frequency, radiation-resistant and high-power devices.
In the process of growing the silicon carbide crystal, a small amount of unintentionally doped impurities enter the crystal, the defect density of the crystal growth is seriously influenced, the size of the crystal is greatly limited, and even in some semiconductor crystals, the unintentionally introduced impurities in the part can cause the collapse effect of current, so that the resistivity of the semiconductor becomes extremely large, and the use efficiency of the semiconductor is greatly influenced.
Because the source of the partial impurities cannot be avoided, only the impurities can be removed, the existing crystal impurity removal technology is mainly realized by annealing, and the annealing can also eliminate stress while removing the impurities, so that the cracks of the crystals in the subsequent processing process are avoided. Impurities remain in the annealing heating container in the process, and the impurity removal effect is influenced by the overhigh impurity concentration.
Disclosure of Invention
The invention aims to provide a silicon carbide annealing impurity removal method, which effectively reduces the impurity content and eliminates the internal stress.
The invention discloses a silicon carbide annealing impurity removal method which adopts the technical scheme that:
a silicon carbide annealing impurity removal method comprises the steps of taking an annealing furnace, wherein a middle heat insulation layer is arranged in the annealing furnace and divides the annealing furnace into a constant temperature area and a low temperature area, and a through hole for communicating the constant temperature area with the low temperature area is formed in the middle heat insulation layer; taking a silicon carbide crystal, wrapping high-purity carbon particles or high-purity silicon carbide particles on the surface of the silicon carbide crystal, and then placing the silicon carbide crystal in a constant temperature area; taking a porous adsorption material, and placing the porous adsorption material in a low-temperature area; filling or filling inert gas into the annealing furnace in a vacuum state, raising the temperature of the constant-temperature area to an annealing temperature after a first preset time, and simultaneously making the temperature of the low-temperature area lower than the temperature of the constant-temperature area by 400-800 ℃; keeping the annealing furnace at the temperature for a second preset time; and cooling the annealing furnace for a third preset time to normal temperature to obtain the annealed silicon carbide crystal.
Preferably, the annealing temperature is 1200-1800 ℃.
Preferably, in the first preset time and the third preset time, the temperature change speed of the constant temperature area does not exceed 10 ℃/min.
Preferably, the second preset time is 8h-30h.
Preferably, the size of the silicon carbide crystal is smaller than that of the constant temperature area.
Preferably, the through holes are provided in plurality, and the through holes extend in a bending manner in the middle heat insulation layer.
Preferably, the intermediate heat insulation layer comprises at least two interlayers, and the through holes on the adjacent interlayers are arranged in a staggered manner.
Preferably, the constant temperature area is communicated with an air outlet channel, and the low temperature area is communicated with an air inlet channel.
The silicon carbide annealing impurity removal method disclosed by the invention has the beneficial effects that: divide into constant temperature district and low temperature region with the annealing stove through middle heat insulation layer, the constant temperature district heats to annealing temperature, makes the silicon carbide crystal anneal, and the porous adsorption material that is in the low temperature region simultaneously can be better keeps original adsorption performance, makes the volatile impurity in constant temperature district adsorbed to this reduces its impurity concentration, and then improves its edulcoration effect.
Drawings
FIG. 1 is a schematic view of the structure of an annealing furnace of the present invention.
FIG. 2 is a schematic structural view of an intermediate heat-insulating layer of the annealing furnace of the present invention.
Detailed Description
The invention will be further elucidated and described with reference to a specific embodiment and the drawings of the specification:
a silicon carbide annealing impurity removal method comprises the following steps:
s100, taking an annealing furnace 10, referring to FIGS. 1 and 2, a middle heat insulation layer 11 is arranged in the annealing furnace 10, the annealing furnace 10 is divided into a constant temperature area 12 and a low temperature area 13 by the middle heat insulation layer 11, and a through hole 111 for communicating the constant temperature area 12 and the low temperature area 13 is formed in the middle heat insulation layer 11.
The constant temperature area 12 is communicated with an air outlet channel 14, and the low temperature area 13 is communicated with an air inlet channel 15.
The number of the through holes 111 is plural, and the aperture and the number thereof can be set as required. It should be noted that the through hole 111 extends linearly, and in another embodiment, the through hole 111 extends in a curved manner. The through hole 111 may have a bell mouth shape with one end thereof being large and the other end thereof being small.
The intermediate thermal insulation layer 11 includes at least two insulation layers 112, and through holes 111 on adjacent insulation layers 112 are arranged in a staggered manner.
S200, taking a silicon carbide crystal 20, wrapping high-purity carbon particles or high-purity silicon carbide particles on the surface of the silicon carbide crystal 20, and then placing the silicon carbide crystal in a constant temperature area 12. The size of the silicon carbide crystal 20 is smaller than that of the constant temperature area 12, and when the silicon carbide crystal 20 is placed in the center of the constant temperature area 12, the silicon carbide crystal 20 is uniformly heated as much as possible.
S300, taking a porous adsorption material, and placing the porous adsorption material in the low-temperature region 13.
S400, filling or inert gas into the annealing furnace 10 in a vacuum state, raising the temperature of the constant temperature area 12 to an annealing temperature after a first preset time, and simultaneously making the temperature of the low temperature area 13 lower than the temperature of the constant temperature area 12 by 400-800 ℃. Wherein the annealing temperature of the constant temperature region 12 is 1200-1800 ℃. The ultimate vacuum degree of the annealing furnace 10 is 8 x 10 -4 pa, but normal atmospheric pressure or slightly negative pressure when in use.
S500 the annealing furnace 10 is insulated for a second preset time. The second preset time is specifically 8-30 h.
S600, cooling the annealing furnace 10 for a third preset time to normal temperature to obtain the annealed silicon carbide crystal.
In the first preset time and the third preset time, the temperature change speed of the constant temperature area 12 is not more than 10 ℃/min, and the slow and uniform temperature change can reduce the internal stress.
According to the silicon carbide annealing impurity removal method disclosed by the invention, an annealing furnace 10 is divided into a constant temperature area 12 and a low temperature area 13 through an intermediate heat insulation layer 11, the constant temperature area 12 is heated to an annealing temperature, so that silicon carbide crystals are annealed, meanwhile, a porous adsorption material in the low temperature area 13 can well keep the original adsorption performance, so that impurities volatilized from the constant temperature area 12 are adsorbed, the impurity concentration is reduced, and the impurity removal effect is further improved.
Example 1: the interlayer is provided with 3 layers, the length of the interlayer is 30cm, the diameter of the low-temperature region is 20cm, and the length of the low-temperature region is 40cm. The silicon carbide crystal was set to a size of 2 inches, and the constant temperature zone was 20cm in diameter and 60cm in length.
High-purity carbon particle materials are wrapped around the silicon carbide crystals, porous graphite is selected as the porous adsorption material, the temperature change speed of the constant-temperature area in the first preset time and the third preset time is 10 ℃/min, and the second preset time is 12h. The annealing temperature of the constant temperature area is 1800 ℃, meanwhile, the temperature of the low temperature area is 1800 ℃, which is equivalent to constant temperature annealing, and the impurity removal effect is not obvious.
Example 2: the difference from the example 1 is that the temperature of the low-temperature zone is 1400 ℃, and the impurity removal effect is better.
Example 3: the difference from the example 1 is that the temperature of the low-temperature zone is 1200 ℃, and the impurity removal effect is better.
Example 4: the difference from the example 1 is that the temperature of the low-temperature zone is 1000 ℃, and the impurity removal effect is better.
Example 5: the difference from the embodiment 1 is that the high-purity silicon carbide particle material is wrapped around the silicon carbide crystal, and the crystal impurity removal effect is not obvious.
Example 6 is different from example 2 in that the silicon carbide crystal is wrapped with high-purity silicon carbide particles, and the impurity removal effect is good.
Example 7 is different from example 3 in that the silicon carbide crystal is wrapped with high-purity silicon carbide particle material, so that the impurity removal effect is better.
Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the protection scope of the present invention, although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.
Claims (8)
1. The silicon carbide annealing impurity removing method is characterized by comprising
Taking an annealing furnace, wherein a middle heat insulation layer is arranged in the annealing furnace, the middle heat insulation layer divides the annealing furnace into a constant temperature area and a low temperature area, and a through hole for communicating the constant temperature area and the low temperature area is formed in the middle heat insulation layer;
taking a silicon carbide crystal, wrapping high-purity carbon particles or high-purity silicon carbide particles on the surface of the silicon carbide crystal, and then placing the silicon carbide crystal in a constant temperature area;
taking a porous adsorption material, and placing the porous adsorption material in a low-temperature area;
filling or filling inert gas into the annealing furnace in a vacuum state, raising the temperature of the constant temperature area to an annealing temperature after a first preset time, and simultaneously making the temperature of the low temperature area lower than the temperature of the constant temperature area by 400-800 ℃;
keeping the annealing furnace at the temperature for a second preset time;
and cooling the annealing furnace for a third preset time to normal temperature to obtain the annealed silicon carbide crystal.
2. The silicon carbide annealing impurity removal method according to claim 1, wherein the annealing temperature is 1200 ℃ to 1800 ℃.
3. The silicon carbide annealing impurity removal method according to claim 2, wherein the temperature change rate of the constant temperature region does not exceed 10 ℃/min during the first preset time and the third preset time.
4. The silicon carbide annealing impurity removal method according to claim 2, wherein the second preset time is 8h to 30h.
5. The silicon carbide annealing impurity removal method according to claim 1, wherein the size of the silicon carbide crystal is smaller than the size of the constant temperature region.
6. The silicon carbide annealing impurity removal method according to claim 1, wherein the intermediate heat insulation layer comprises at least two interlayers, and through holes on the adjacent interlayers are arranged in a staggered manner.
7. The silicon carbide annealing impurity removal method according to claim 1, wherein a plurality of through holes are provided, and the plurality of through holes extend in a bent manner in the intermediate heat insulation layer.
8. The silicon carbide annealing impurity removal method according to claim 1, wherein the constant temperature zone is communicated with an air outlet channel, and the low temperature zone is communicated with an air inlet channel.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2021103872562 | 2021-04-09 | ||
| CN202110387256 | 2021-04-09 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115198365A true CN115198365A (en) | 2022-10-18 |
Family
ID=83574252
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110951347.4A Pending CN115198365A (en) | 2021-04-09 | 2021-08-18 | Silicon carbide annealing impurity removing method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115198365A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010064919A (en) * | 2008-09-10 | 2010-03-25 | Showa Denko Kk | Method for annealing silicon carbide single crystal material, silicon carbide single crystal wafer, and silicon carbide semiconductor |
| CN104269348A (en) * | 2014-09-26 | 2015-01-07 | 安庆美晶新材料有限公司 | Method for removing impurities attached to base material surface through annealing in low-pressure environment |
| CN107699955A (en) * | 2017-08-30 | 2018-02-16 | 昆明理工大学 | It is a kind of using microwave heat remove single-crystal silicon carbide defect in and surface organic impurities method |
-
2021
- 2021-08-18 CN CN202110951347.4A patent/CN115198365A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010064919A (en) * | 2008-09-10 | 2010-03-25 | Showa Denko Kk | Method for annealing silicon carbide single crystal material, silicon carbide single crystal wafer, and silicon carbide semiconductor |
| CN104269348A (en) * | 2014-09-26 | 2015-01-07 | 安庆美晶新材料有限公司 | Method for removing impurities attached to base material surface through annealing in low-pressure environment |
| CN107699955A (en) * | 2017-08-30 | 2018-02-16 | 昆明理工大学 | It is a kind of using microwave heat remove single-crystal silicon carbide defect in and surface organic impurities method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107723798B (en) | Growth device and method for efficiently preparing high-purity semi-insulating silicon carbide single crystal | |
| CN1339072A (en) | Tungsten doped crucible and method for preparing same | |
| CN106757357B (en) | A kind of preparation method of high-purity semi-insulating silicon carbide substrate | |
| JP4697909B2 (en) | Carbon wire heating element encapsulated heater | |
| KR102331308B1 (en) | Large size, high-purity silicon carbide single crystal, substrate, and manufacturing method and device for the same | |
| CN110284199B (en) | Crystal in-situ carbonization annealing device and method | |
| CN106711022A (en) | Preparation method for growing silicon carbide epitaxial film with clear doping interface | |
| CN108707966A (en) | A kind of low nitrogen content SiC single crystal grower and its application | |
| KR20160012138A (en) | Method for producing monocrystalline silicon | |
| CN112553694A (en) | Method and device for high-temperature annealing of silicon carbide single crystal | |
| US10487417B2 (en) | Method for manufacturing a FZ silicon single crystal subject to additional gallium doping for solar cells | |
| CN115198365A (en) | Silicon carbide annealing impurity removing method | |
| CN113789573A (en) | Method for preparing AlN crystal by spontaneous nucleation through PVT method | |
| JP3312553B2 (en) | Method for producing silicon single crystal and silicon single crystal thin film | |
| JP2002249376A (en) | Low nitrogen concentration carbonaceous material and method for producing the same | |
| KR102235858B1 (en) | Manufacturing method for silicon carbide ingot and system for manufacturing silicon carbide ingot | |
| CN112457026A (en) | Copper calcium titanate ceramic reduction-oxidation atmosphere co-sintering method | |
| CN113005510B (en) | Preparation method of silicon carbide single crystal | |
| KR101692142B1 (en) | HEAT TREATING METHOD OF SiC INGOT | |
| CN113871468A (en) | Silicon carbide MIS device with stacked gate structure and preparation method thereof | |
| CN111017914B (en) | Method for preparing epitaxial graphene through laser heating | |
| CN109112634B (en) | Crucible equipment and method for preparing aluminum nitride crystal | |
| JP7239182B2 (en) | High-purity silicon carbide single crystal substrate and its manufacturing method and application | |
| CN112695486A (en) | Preparation method of high-purity graphite felt and crystal silicon furnace | |
| CN218089892U (en) | Device for preparing silicon carbide by PVT method |
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: 20230817 Address after: 543000 Guangxi Zhuang Autonomous Region Wuzhou City Wanxiu District Guangdong Guangxi Cooperation Special Experimental Zone (Wuzhou) High tech Zone Yingtian Intelligent Manufacturing Industrial Park 4th Floor of Factory Building Applicant after: Guangxi Xihui Tiancheng Technology Co.,Ltd. Address before: 518000 Room 401, Kechuang building, lingnanwan Kechuang Park, 23 Nanxin Road, Nanling village community, Nanwan street, Longgang District, Shenzhen City, Guangdong Province Applicant before: Shenzhen Tiancheng Advanced Material Technology Co.,Ltd. |
|
| TA01 | Transfer of patent application right | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20221018 |