CN112877778A - Protective special-shaped graphite crucible and using method thereof - Google Patents
Protective special-shaped graphite crucible and using method thereof Download PDFInfo
- Publication number
- CN112877778A CN112877778A CN202110268810.5A CN202110268810A CN112877778A CN 112877778 A CN112877778 A CN 112877778A CN 202110268810 A CN202110268810 A CN 202110268810A CN 112877778 A CN112877778 A CN 112877778A
- Authority
- CN
- China
- Prior art keywords
- crucible
- shell
- sub
- protective
- graphite
- 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
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
- C30B28/00—Production of homogeneous polycrystalline material with defined structure
- C30B28/12—Production of homogeneous polycrystalline material with defined structure directly from the gas state
- C30B28/14—Production of homogeneous polycrystalline material with defined structure directly from the gas state by chemical reaction of reactive gases
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Crystallography & Structural Chemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Silicon Compounds (AREA)
Abstract
A protective special-shaped graphite crucible and a using method thereof relate to a special-shaped graphite crucible and a using method thereof, and aim to solve the technical problems that the existing graphite crucible is easy to wear and the purity of polycrystalline powder is low. The graphite crucible comprises an upper cover, a crucible main body, a sub-crucible and an external thread graphite tube; the crucible body is internally provided with a stand column which is reduced in a step shape, the sub-crucibles are placed on the steps of the stand column, air holes are uniformly distributed in the cylinder wall of the crucible body, and the upper cover is connected with the crucible body through an external thread graphite pipe. The use method comprises the following steps: placing silicon at the bottom of the shell; putting carbon powder in the sub-crucible, and then putting the sub-crucible on the ladder of the upright post; the upper cover and the shell are screwed by an external thread graphite pipe and then are placed in a high temperature furnace; and introducing gas to the bottom of the shell through the external thread graphite pipe, and heating for reaction to obtain the high-purity silicon carbide polycrystalline powder. The graphite crucible has low wear rate, the purity of the silicon carbide polycrystal prepared by using 7N-9N silicon particles or silicon blocks is 6N, and the graphite crucible can be used in the field of preparation of silicon carbide polycrystal powder.
Description
Technical Field
The invention relates to a special-shaped graphite crucible, and relates to the field of preparation of SiC polycrystalline powder.
Background
With the rapid development of the semiconductor field, the SiC material is considered as an ideal material for the third generation semiconductor due to its advantages of larger forbidden bandwidth, higher thermal conductivity, larger electron saturation drift rate, higher critical breakdown electric field, lower dielectric constant, good chemical stability, and the like. With the development of single crystal technology, the market demand of high-purity silicon carbide polycrystalline powder is increasing. At present, high-purity silicon carbide polycrystalline powder is mainly prepared by a carbothermic method, a chemical vapor infiltration method and a chemical vapor deposition method. The prepared polycrystalline powder is greatly influenced by the purity of the raw materials, and the conventional method is difficult to highly purify the powdery raw materials, so that the purity of the polycrystalline powder is difficult to improve. Moreover, a high-purity graphite crucible is usually used as a reaction container, the structure of the universal graphite crucible is in a hollow cylindrical shape, the wall of the crucible and the bottom of the crucible form a right angle, the stress borne in the use process is small, the stress is increased when Si is converted from a solid state to a molten state, the crucible can be cracked under severe conditions, meanwhile, the universal crucible is generally corroded by Si at high temperature, the graphite crucible can be scrapped after being used for several times, and the use times seriously influence the production cost.
Disclosure of Invention
The invention aims to solve the technical problems that the existing graphite crucible is easy to wear and the purity of polycrystalline powder is low, and provides a protective special-shaped graphite crucible and a using method thereof.
The invention discloses a protective special-shaped graphite crucible, which comprises an upper cover, a crucible main body, a sub-crucible and an external thread graphite tube;
the upper cover consists of a cylindrical cover body and an interlayer positioned in the middle of the cover body, an internal thread hole is arranged on the interlayer, the upper part of the interlayer and the cover body form an upper cavity, and the lower part of the interlayer and the cover body form a lower cavity; the upper cavity is used for containing silicon-carbon mixed protective materials;
the crucible main body consists of a shell, at least 3 upright columns which are reduced in a step shape and a protective groove,
the outer wall of the shell is cylindrical;
the inner wall of the shell is cylindrical, and the bottom inside the shell is arc-shaped; an annular boss is arranged at the intersection of the bottom and the inner wall, upright columns which are reduced in a step shape are uniformly distributed on the boss, and the upright columns and the inner wall of the shell are connected into a whole or fixedly connected together;
air holes are uniformly distributed in the wall of the shell; the upper opening of the air hole is arranged on the upper end surface of the shell, and the lower opening of the air hole is arranged on the side wall of the annular boss;
the bottom and the wall of the sub-crucible are made of sieve plates, and the sub-crucible is placed on the ladder of the upright post; taking the upright column as a support body of the sub-crucible;
the protective groove is arranged along the outer edge of the upper opening of the shell in a circle, and the upper opening of the protective groove is higher than the contact surface of the upper cover and the shell; the protective groove is used for containing silicon-carbon mixed protective materials; embedding the contact surface of the upper cover and the shell into a silicon-carbon mixed protective material;
an internal thread is arranged at the upper opening of the air hole in the cylinder wall of the shell, the upper opening of the air hole corresponds to the position of the internal thread hole of the upper cover, and the upper opening of the air hole is matched with the external thread of the external thread graphite pipe; the external thread graphite pipe not only enables the upper cover to be connected with the shell, but also can be communicated with the air hole through the cavity of the external thread graphite pipe.
The use method of the protective special-shaped graphite crucible comprises the following steps:
firstly, placing 7N-9N high-purity silicon particles or silicon blocks at the bottom of a shell;
secondly, putting carbon powder into the sub-crucible, and then putting the sub-crucible on the ladder of the upright post; the upright posts play a role of fixing the sub-crucible, and a certain space is formed between the inner wall of the shell and the sub-crucible, so that silicon vapor is convenient to diffuse;
covering the upper cover on the shell, keeping the upper opening of the air hole of the shell corresponding to the position of the internal thread hole of the upper cover, and screwing the upper cover by using an external thread graphite tube;
fourthly, placing the protective special-shaped graphite crucible in a high-temperature furnace;
connecting the external thread graphite pipe with an air source; the gas source is argon or hydrogen;
sixthly, putting the silicon-carbon mixed protective material into a protective groove of the crucible main body and an upper cavity of the upper cover;
and seventhly, opening a gas source valve, introducing gas to the bottom of the shell through the external thread graphite pipe, raising the temperature of the high-temperature furnace to 1600-2100 ℃, and keeping the temperature for 6-12 hours to obtain the high-purity silicon carbide polycrystalline powder.
The protective special-shaped graphite crucible provided by the invention utilizes the wide-mouth upper cover and the protective groove of the crucible to contain silicon-carbon mixed protective materials; the sieve plate sub-crucible is supported by the upright columns which are reduced in a step shape, the step-shaped upright columns can ensure that silicon vapor is filled in the crucible, a gas channel is arranged in the deep part of the cylinder wall of the shell 2-1, and the Si vapor is fully contacted with the C powder through gas disturbance; the bottom of the shell is in an arc shape, so that the stress born by the shell is larger, the heating is faster and more uniform, and the gasification speed of silicon and the concentration of silicon steam are ensured; the sieve plate sub-crucible adopts a honeycomb porous structure, so that the mechanical property of the sub-crucible is ensured, the sub-crucible is simultaneously air-permeable, and the sub-crucible is convenient to lift by using tools; one or more sub-crucibles can be placed in the shell, so that raw materials are contacted more uniformly, a certain space is reserved between the inner wall of the shell and the sub-crucibles, silicon vapor diffusion is facilitated, after production is finished, the sub-crucibles are put forward to collect products, the product purity is improved, the wear rate of the graphite crucibles is reduced, the use times are increased, and the production cost is reduced. Meanwhile, the use of silicon particles or silicon blocks with higher purity is beneficial to removing impurities introduced in the charging process by using high vacuum in the early stage of reaction, so that the content of the impurities in the system can be ensured to be lower than 1ppm, and the purity of the SiC polycrystalline powder is further improved.
The protective special-shaped graphite crucible is used in the field of preparation of silicon carbide polycrystalline powder.
Drawings
FIG. 1 is a schematic view showing the overall structure of a protective shaped graphite crucible of example 1;
FIG. 2 is a schematic sectional structure view of the upper cap 1 of embodiment 1;
FIG. 3 is a schematic view showing the structure of a crucible main body 2 of a protective type special-shaped graphite crucible of example 1;
FIG. 4 is a schematic perspective sectional view of a protective shaped graphite crucible according to example 1;
FIG. 5 is a schematic sectional view showing the structure of the protective shaped graphite crucible of example 1;
FIG. 6 is a schematic view showing the structure of a sub-crucible of example 1;
FIG. 7 is a schematic sectional view showing a protective shaped graphite crucible according to example 2.
In the figure: 1 is an upper cover, 1-1 is a cover body, 1-2 is an interlayer, 1-3 is an internal threaded hole, 1-4 is an upper cavity, and 1-5 is a lower cavity; 2 is a crucible main body, 2-1 is a shell, 2-1-1 is an air hole, 2-2 is an upright post, 2-3 is a protection groove, and 2-4 is a boss;
3 is a sub-crucible and 4 is an external thread graphite tube.
Detailed Description
The first embodiment is as follows: (see attached figures 1-6) the protective special-shaped graphite crucible of the embodiment comprises an upper cover 1, a crucible main body 2, a sub-crucible 3 and an external thread graphite tube 4;
the upper cover 1 consists of a cylindrical cover body 1-1 and an interlayer 1-2 positioned in the middle of the cover body, an internal thread hole 1-3 is arranged on the interlayer 1-2, the upper part of the interlayer 1-2 and the cover body form an upper cavity 1-4, and the lower part of the interlayer 1-2 and the cover body form a lower cavity 1-5; the upper cavity 1-4 is used for containing silicon-carbon mixed protective materials;
the crucible body 2 consists of a shell 2-1, at least 3 upright posts 2-2 which are reduced in a step shape and a protective groove 2-3,
the bottom of the shell 2-1 is arc-shaped;
the outer wall of the shell 2-1 is cylindrical;
the inner wall of the shell 2-1 is cylindrical, the upright posts 2-2 which are reduced in a step shape are uniformly distributed on the cylindrical inner wall, and the upright posts 2-2 are connected with the inner wall of the shell into a whole or fixedly connected together;
at least 3 air holes 2-1-1 are uniformly distributed in the wall of the shell 2-1; the upper opening of the air hole 2-1-1 is arranged on the upper end surface of the shell 2-1, and the lower opening of the air hole 2-1-1 is arranged on the lower part of the inner wall of the shell 2-1;
the bottom and the wall of the sub-crucible 3 are made of sieve plates, and the sub-crucible 3 is placed on the ladder of the upright post 2-2; the upright column 2-2 is used as a supporting body of the sub-crucible 3;
the protective groove 2-3 is arranged along the outer edge of the upper opening of the shell 2-1 in a circle, and the upper opening of the protective groove 2-3 is higher than the contact surface of the upper cover 1 and the shell 2-1; the protective groove 2-1-2 is used for containing silicon-carbon mixed protective materials; burying the contact surface of the upper cover 1 and the shell 2-1 into a silicon-carbon mixed protective material;
an internal thread is arranged at the upper opening of the air hole 2-1-1 in the cylinder wall of the shell 2-1, the upper opening of the air hole 2-1-1 corresponds to the position of the internal thread hole 1-3 of the upper cover 1, and the upper opening and the internal thread hole are matched with the external thread of the external thread graphite tube 4; the external thread graphite pipe 4 not only connects the upper cover 1 with the shell 2-1, but also communicates with the air hole 2-1-1 through the cavity of the external thread graphite pipe 4.
The second embodiment is as follows: the first difference between the embodiment and the specific embodiment is that the number of the upright columns 2-2 which are reduced in a step shape is 3-6; the rest is the same as the first embodiment.
The third concrete implementation mode: the first or second embodiment is different from the first or second embodiment in that the number of steps of the upright post 2-2 which is reduced in a step shape is 2-6; the other is the same as in the first or second embodiment.
In this embodiment, one sub-crucible 3 may be placed on each step. Can increase the yield and improve the uniformity of the product.
The fourth concrete implementation mode: the difference between the present embodiment and one of the first to third embodiments is that the columns 2-2 and the air holes 2-1-1 are arranged alternately on the circumference of the shell 2-1; the others are the same as in one of the first to third embodiments.
The fifth concrete implementation mode: the difference between the present embodiment and one of the first to fourth embodiments is that the number of the air holes 2-1-1 is 3 to 6; the other is the same as one of the first to fourth embodiments.
The sixth specific implementation mode: the difference between this embodiment and the first to the fifth embodiment is that the sieve plate of the sub-crucible is a honeycomb porous structure; the other is the same as one of the first to fifth embodiments.
The sieve plate of the sub-crucible of the embodiment adopts a honeycomb porous structure, so that the mechanical property of the sub-crucible is ensured, and the sub-crucible is simultaneously air-permeable.
The seventh embodiment: the difference between the present embodiment and one of the first to sixth embodiments is that the thickness of the side wall and the bottom of the sub-crucible 3 is 5mm to 10 mm; the other is the same as one of the first to sixth embodiments.
The specific implementation mode is eight: the difference between the present embodiment and one of the first to seventh embodiments is that the aperture of the honeycomb-shaped hole of the sub-crucible 3 is 0.01 to 0.5 mm; the other is the same as one of the first to seventh embodiments.
The specific implementation method nine: the use method of the protective special-shaped graphite crucible according to the first embodiment specifically comprises the following steps:
firstly, placing 7N-9N high-purity silicon particles or silicon blocks at the bottom of a shell;
secondly, putting carbon powder into the sub-crucible, and then putting the sub-crucible on the ladder of the upright post; the upright posts play a role of fixing the sub-crucible, and a certain space is formed between the inner wall of the shell and the sub-crucible, so that silicon vapor is convenient to diffuse;
covering the upper cover on the shell, keeping the upper opening of the air hole of the shell corresponding to the position of the internal thread hole of the upper cover, and screwing the upper cover by using an external thread graphite tube;
fourthly, placing the protective special-shaped graphite crucible in a high-temperature furnace;
connecting the external thread graphite pipe with an air source; the gas source is argon or hydrogen;
sixthly, putting the silicon-carbon mixed protective material into a protective groove of the crucible main body and an upper cavity of the upper cover;
and seventhly, opening a gas source valve, introducing gas to the bottom of the shell through the external thread graphite pipe, raising the temperature of the high-temperature furnace to 1600-2100 ℃, and keeping the temperature for 6-12 hours to obtain the high-purity silicon carbide polycrystalline powder.
The detailed implementation mode is ten: the difference between this embodiment and the ninth embodiment is that the purity of the gas source is not less than 6N, and the rest is the same as the ninth embodiment.
The following examples are used to demonstrate the beneficial effects of the present invention:
example 1: the protection type special-shaped graphite crucible of the embodiment comprises an upper cover 1, a crucible main body 2, a sub-crucible 3 and an external thread graphite tube 4;
the upper cover 1 consists of a cylindrical cover body 1-1 and an interlayer 1-2 positioned in the middle of the cover body, an internal thread hole 1-3 is arranged on the interlayer 1-2, the upper part of the interlayer 1-2 and the cover body form an upper cavity 1-4, and the lower part of the interlayer 1-2 and the cover body form a lower cavity 1-5; the upper cavity 1-4 is used for containing silicon-carbon mixed protective materials;
the crucible body 2 consists of a shell 2-1, 3 upright columns 2-2 which are reduced in a step shape and a protective groove 2-3;
the inner wall of the shell 2-1 is cylindrical, and the bottom inside the shell 2-1 is arc-shaped; an annular boss 2-4 is arranged at the intersection of the bottom and the inner wall, 3 upright columns 2-2 which are reduced in a step shape are uniformly distributed on the boss 2-4, the number of steps of each upright column 2-2 is 2, and the upright columns 2-2 are fixedly connected with the inner wall of the shell;
3 air holes 2-1-1 are uniformly distributed in the wall of the shell 2-1; the upper opening of the air hole 2-1-1 is arranged on the upper end surface of the shell 2-1, and the lower opening of the air hole 2-1-1 is arranged on the side wall of the annular boss 2-4;
the bottom and the wall of the sub-crucible 3 are made of a sieve plate with honeycomb holes, the thickness of the sieve plate is 5mm, the aperture of the honeycomb holes is 0.5mm, and the sub-crucible 3 is arranged on the ladder of the upright post 2-2; the upright column 2-2 is used as a supporting body of the sub-crucible 3;
the protective groove 2-3 is arranged along the outer edge of the upper opening of the shell 2-1 in a circle, and the upper opening of the protective groove 2-3 is higher than the contact surface of the upper cover 1 and the shell 2-1; the protective groove 2-1-2 is used for containing silicon-carbon mixed protective materials; burying the contact surface of the upper cover 1 and the shell 2-1 into a silicon-carbon mixed protective material;
an internal thread is arranged at the upper opening of the air hole 2-1-1 in the cylinder wall of the shell 2-1, the upper opening of the air hole 2-1-1 corresponds to the position of the internal thread hole 1-3 of the upper cover 1, and the upper opening and the internal thread hole are matched with the external thread of the external thread graphite tube 4; the external thread graphite pipe 4 not only connects the upper cover 1 with the shell 2-1, but also can be communicated with the air hole 2-1-1 through the cavity of the external thread graphite pipe 4;
the preparation of high-purity silicon carbide polycrystalline powder by using the protective special-shaped graphite crucible in the embodiment 1 comprises the following specific steps:
firstly, placing 7N high-purity silicon particles at the bottom of a shell 2-1;
secondly, placing the powder C in a sub-crucible 3, and then placing the sub-crucible 3 on a step of the upright post 2-2; the upright post 2-2 plays a role of fixing the sub-crucible, and a certain space is formed between the inner wall of the shell 2-1 and the sub-crucible, so that silicon vapor is convenient to diffuse;
thirdly, covering the upper cover 1 on the shell 2-1, keeping the upper opening of the air hole 2-1-1 of the shell 2-1 corresponding to the position of the internal thread hole 1-3 of the upper cover 1, and screwing the external thread graphite tube 4;
fourthly, placing the protective special-shaped graphite crucible in a high-temperature furnace;
connecting the external thread graphite tube 4 with an argon gas source;
sixthly, putting the silicon-carbon mixed protective material into a protective groove 2-3 of the crucible main body 2 and an upper cavity 1-4 of the upper cover 1;
and seventhly, opening an argon gas source valve, introducing argon with the purity of 6N to the bottom of the shell 2-1 through the external thread graphite tube 4, heating the high-temperature furnace to 2000 ℃, and keeping the temperature for 12 hours to obtain the high-purity silicon carbide polycrystalline powder.
The purity of the high-purity silicon carbide polycrystalline powder prepared by using the protective special-shaped graphite crucible in the embodiment 1 reaches 6N, the preparation process of the high-purity silicon carbide polycrystalline powder has no abrasion to the protective special-shaped graphite crucible, and the protective special-shaped graphite crucible can be repeatedly used.
Example 2: (see figure 7) the protective special-shaped graphite crucible of the embodiment consists of an upper cover 1, a crucible main body 2, two sub-crucibles 3 and an external thread graphite tube 4;
the upper cover 1 consists of a cylindrical cover body 1-1 and an interlayer 1-2 positioned in the middle of the cover body, an internal thread hole 1-3 is arranged on the interlayer 1-2, the upper part of the interlayer 1-2 and the cover body form an upper cavity 1-4, and the lower part of the interlayer 1-2 and the cover body form a lower cavity 1-5; the upper cavity 1-4 is used for containing silicon-carbon mixed protective materials;
the crucible body 2 consists of a shell 2-1, 3 upright columns 2-2 which are reduced in a step shape and a protective groove 2-3;
the inner wall of the shell 2-1 is cylindrical, and the bottom inside the shell 2-1 is arc-shaped; an annular boss 2-4 is arranged at the intersection of the bottom and the inner wall, 3 upright columns 2-2 which are reduced in a step shape are uniformly distributed on the boss 2-4, the number of steps of each upright column 2-2 is 3, and the upright columns 2-2 are fixedly connected with the inner wall of the shell;
3 air holes 2-1-1 are uniformly distributed in the wall of the shell 2-1; the upper opening of the air hole 2-1-1 is arranged on the upper end surface of the shell 2-1, and the lower opening of the air hole 2-1-1 is arranged on the side wall of the annular boss 2-4;
the bottom and the wall of the sub-crucible 3 are made of a sieve plate with honeycomb holes, the thickness of the sieve plate is 5mm, the aperture of the honeycomb holes is 0.5mm, and the two sub-crucibles 3 are respectively arranged on two steps of the upright post 2-2; the upright column 2-2 is used as a supporting body of the sub-crucible 3;
the protective groove 2-3 is arranged along the outer edge of the upper opening of the shell 2-1 in a circle, and the upper opening of the protective groove 2-3 is higher than the contact surface of the upper cover 1 and the shell 2-1; the protective groove 2-1-2 is used for containing silicon-carbon mixed protective materials; burying the contact surface of the upper cover 1 and the shell 2-1 into a silicon-carbon mixed protective material;
an internal thread is arranged at the upper opening of the air hole 2-1-1 in the cylinder wall of the shell 2-1, the upper opening of the air hole 2-1-1 corresponds to the position of the internal thread hole 1-3 of the upper cover 1, and the upper opening and the internal thread hole are matched with the external thread of the external thread graphite tube 4; the external thread graphite pipe 4 not only connects the upper cover 1 with the shell 2-1, but also can be communicated with the air hole 2-1-1 through the cavity of the external thread graphite pipe 4;
the preparation of high-purity silicon carbide polycrystalline powder by using the protective special-shaped graphite crucible in the embodiment 1 comprises the following specific steps:
firstly, placing 7N high-purity silicon particles at the bottom of a shell 2-1;
secondly, placing the powder C in two sub-crucibles 3, and then respectively placing the two sub-crucibles 3 on two steps of the upright post 2-2; the upright post 2-2 plays a role of fixing the sub-crucible, and a certain space is formed between the inner wall of the shell 2-1 and the sub-crucible, so that silicon vapor is convenient to diffuse;
thirdly, covering the upper cover 1 on the shell 2-1, keeping the upper opening of the air hole 2-1-1 of the shell 2-1 corresponding to the position of the internal thread hole 1-3 of the upper cover 1, and screwing the external thread graphite tube 4;
fourthly, placing the protective special-shaped graphite crucible in a high-temperature furnace;
connecting the external thread graphite tube 4 with an argon gas source;
sixthly, putting the silicon-carbon mixed protective material into a protective groove 2-3 of the crucible main body 2 and an upper cavity 1-4 of the upper cover 1;
and seventhly, opening an argon gas source valve, introducing argon with the purity of 6N to the bottom of the shell 2-1 through the external thread graphite pipe 4, heating the high-temperature furnace to 2100 ℃, and keeping for 12 hours to obtain the high-purity silicon carbide polycrystalline powder.
The purity of the high-purity silicon carbide polycrystalline powder prepared by using the protective special-shaped graphite crucible in the embodiment 1 reaches 6N, the preparation process of the high-purity silicon carbide polycrystalline powder has no abrasion to the protective special-shaped graphite crucible, and the protective special-shaped graphite crucible can be repeatedly used.
Claims (10)
1. A protective special-shaped graphite crucible is characterized by comprising an upper cover (1), a crucible main body (2), a sub-crucible (3) and an external thread graphite tube (4);
the upper cover (1) consists of a cylindrical cover body (1-1) and an interlayer (1-2) positioned in the middle of the cover body, an internal threaded hole (1-3) is formed in the interlayer (1-2), the upper part of the interlayer (1-2) and the cover body form an upper cavity (1-4), and the lower part of the interlayer (1-2) and the cover body form a lower cavity (1-5);
the crucible main body (2) consists of a shell (2-1), at least 3 upright columns (2-2) which are reduced in a step shape and a protective groove (2-3);
the outer wall of the shell (2-1) is cylindrical;
the inner wall of the shell (2-1) is cylindrical, and the bottom inside the shell (2-1) is arc-shaped; an annular boss (2-4) is arranged at the intersection of the bottom and the inner wall, upright columns (2-2) which are reduced in a step shape are uniformly distributed on the boss (2-4), and the upright columns (2-2) are connected with the inner wall of the shell into a whole or fixedly connected together;
air holes (2-1-1) are uniformly distributed in the wall of the shell (2-1); the upper opening of the air hole (2-1-1) is arranged on the upper end face of the shell (2-1), and the lower opening of the air hole (2-1-1) is arranged on the side wall of the annular boss (2-4);
the bottom and the wall of the sub-crucible (3) are made of sieve plates, and the sub-crucible (3) is placed on the ladder of the upright post (2-2); the upright column (2-2) is used as a supporting body of the sub-crucible (3);
the protective grooves (2-3) are arranged along the outer edge of the upper opening of the shell (2-1) in a circle, and the upper opening of the protective grooves (2-3) is higher than the contact surface of the upper cover (1) and the shell (2-1);
an internal thread is arranged at the upper opening of the air hole (2-1-1) in the cylinder wall of the shell (2-1), the upper opening of the air hole (2-1-1) corresponds to the position of the internal thread hole (1-3) of the upper cover (1), and the upper opening of the air hole and the internal thread hole are matched with the external thread of the external thread graphite tube (4).
2. The protective shaped graphite crucible as claimed in claim 1, wherein the number of the pillars (2-2) decreasing in a step shape is 3-6.
3. The protective type special-shaped graphite crucible as claimed in claim 1 or 2, wherein the number of steps of the column (2-2) which is reduced in a step shape is 2-6.
4. The protective type special-shaped graphite crucible as claimed in claim 1 or 2, wherein the number of the air holes (2-1-1) is 3-6.
5. The protective type special-shaped graphite crucible as claimed in claim 1 or 2, wherein the columns (2-2) and the air holes (2-1-1) are arranged alternately on the circumference of the shell (2-1).
6. A protective shaped graphite crucible as claimed in claim 1 or 2, wherein the sub-crucible (3) is made of a sieve plate with cellular porous structure.
7. The protective shaped graphite crucible as claimed in claim 1 or 2, wherein the thickness of the side wall and the bottom of the sub-crucible (3) is 5mm to 10 mm.
8. The protective shaped graphite crucible as claimed in claim 1 or 2, wherein the aperture of the honeycomb-shaped hole of the sub-crucible (3) is 0.01-0.5 mm.
9. The use method of the protective profiled graphite crucible as set forth in claim 1, characterized in that the method is carried out by the following steps:
firstly, placing 7N-9N silicon particles or silicon blocks at the bottom of a shell;
secondly, putting carbon powder into the sub-crucible, and then putting the sub-crucible on the ladder of the upright post; the upright posts play a role of fixing the sub-crucible, and a certain space is formed between the inner wall of the shell and the sub-crucible, so that silicon vapor is convenient to diffuse;
covering the upper cover on the shell, keeping the upper opening of the air hole of the shell corresponding to the position of the internal thread hole of the upper cover, and screwing the upper cover by using an external thread graphite tube;
fourthly, placing the protective special-shaped graphite crucible in a high-temperature furnace;
connecting the external thread graphite pipe with an air source; the gas source is argon or hydrogen;
sixthly, putting the silicon-carbon mixed protective material into a protective groove of the crucible main body and an upper cavity of the upper cover;
and seventhly, opening a gas source valve, introducing gas to the bottom of the shell through the external thread graphite pipe, raising the temperature of the high-temperature furnace to 1600-2100 ℃, and keeping the temperature for 6-12 hours to obtain the high-purity silicon carbide polycrystalline powder.
10. The use method of the protective shaped graphite crucible as claimed in claim 9, wherein the purity of the gas source is greater than or equal to 6N.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110268810.5A CN112877778A (en) | 2021-03-12 | 2021-03-12 | Protective special-shaped graphite crucible and using method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110268810.5A CN112877778A (en) | 2021-03-12 | 2021-03-12 | Protective special-shaped graphite crucible and using method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112877778A true CN112877778A (en) | 2021-06-01 |
Family
ID=76041191
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110268810.5A Pending CN112877778A (en) | 2021-03-12 | 2021-03-12 | Protective special-shaped graphite crucible and using method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112877778A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114394844A (en) * | 2021-12-28 | 2022-04-26 | 华中科技大学 | Method for preparing silicon carbide ceramic by 3D printing of waste and silicon carbide ceramic |
-
2021
- 2021-03-12 CN CN202110268810.5A patent/CN112877778A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114394844A (en) * | 2021-12-28 | 2022-04-26 | 华中科技大学 | Method for preparing silicon carbide ceramic by 3D printing of waste and silicon carbide ceramic |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2008531461A (en) | Reactor and method for preparing silicon | |
| CN101643933A (en) | CZ method silicon single crystal growth furnace quartz crucible carbon protection crucible and manufacturing process thereof | |
| CN112341232B (en) | Carbon/carbon crucible and manufacturing method thereof | |
| CN214422782U (en) | Protection type abnormal shape graphite crucible | |
| CN112877778A (en) | Protective special-shaped graphite crucible and using method thereof | |
| CA1087758A (en) | Process for the manufacture of large surface area bonded to a substrate | |
| CN109280977B (en) | comprehensive utilization method of silicon carbide crystal growth residual material | |
| CN113120909A (en) | Preparation method of high-purity semi-insulating silicon carbide powder | |
| CN113089087A (en) | Method for improving quality of silicon carbide crystals | |
| WO1987005287A1 (en) | Process for manufacturing glass | |
| CN102021653A (en) | Method for growing silicon carbide single crystal by using high-density material block | |
| CN210065531U (en) | Mold capable of enabling fused quartz crucible to have seeding function | |
| CN102206855A (en) | Czochralski crystal grower graphite crucible | |
| KR20110073872A (en) | Furnace for manufacturing silicon carbide and silicon carbide manufacturing method using same | |
| CN220149233U (en) | Graphite-metal electrode for producing polycrystalline silicon | |
| CN201634795U (en) | Czochralski crystal furnace graphite crucible | |
| JPH0476925B2 (en) | ||
| CN115468419B (en) | Device and method for removing boron impurities in metallurgical grade silicon in submerged arc furnace | |
| CN110512281A (en) | The method for quickly preparing silicon carbide | |
| CN1675134A (en) | Fabrication of heavy walled silica tubing | |
| CN115520871A (en) | Synthetic method of high-purity silicon carbide powder | |
| CN114908420B (en) | Preparation method of high-purity silicon carbide polycrystalline powder | |
| EP0704559A1 (en) | Method for the preparation of a substrate material for solar cells and a solar cell prepared by using the same | |
| CN218621128U (en) | A graphite device for high-purity graphite powder nitrogen discharging | |
| KR100530889B1 (en) | Graphite crucible with the cone shape at the bottom part, which is used in growing SiC single crystal |
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 |