Silicon carbide crystal growth crucible and device

Abstract

The utility model discloses a crucible and a device for growing silicon carbide crystals, which belong to the technical field of semiconductor materials, the crucible is provided with a crucible cover, a crucible wall, a crucible bottom and a cavity enclosed by the crucible wall and the crucible bottom, the crucible cover covers the cavity, and the crucible cover covers the cavity. The crucible cover is provided with a seed crystal bonding position on one side in the cavity; the cavity comprises a growth chamber and a raw material chamber which are communicated with each other, and a first porous cylindrical part and a second porous cylindrical part which extend from the bottom of the crucible to the top of the cavity are arranged in the raw material chamber; the first porous barrel-shaped piece comprises a first barrel wall and a through middle barrel, the top of the middle barrel is communicated with the growth chamber, and the second porous barrel-shaped piece is arranged between the first porous barrel-shaped piece and the crucible wall; the problem of carbon coating can be effectively solved, a large amount of polycrystalline deposition in the growth cavity is effectively avoided, the crystallization problem of silicon carbide is effectively solved, and the utilization rate of raw materials is increased.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of semiconductor material, specifically relates to a silicon carbide crystal growth crucible, device. BACKGROUND

[0002] Silicon carbide (SiC) as the third generation semiconductor material, because its unique big band gap width, high critical breakdown field strength and so on, has wide application prospect in new energy automobile, 5G communication, aerospace and so on.

[0003] With the growth demand of large size sic crystal, the carbon package problem caused by the increase of gaseous C in the later period has been slowly amplified.

[0004] In view of this, the present application is proposed. UTILITY MODEL CONTENT

[0005] In order to achieve the above purpose, the first aspect of the present application provides a silicon carbide crystal growth crucible, the crucible has a crucible cover, a crucible wall, a crucible bottom and a cavity surrounded by the crucible wall and the crucible bottom, the crucible cover covers the cavity, and the crucible cover is provided with a seed crystal bonding site on one side inside the cavity.

[0006] The cavity includes a growth chamber and a raw material chamber in communication with each other, a first porous cylindrical member and a second porous cylindrical member extending from the crucible bottom to the top of the cavity are arranged in the raw material chamber, the first porous cylindrical member includes a first cylindrical wall and a middle cylinder in communication, and the top of the middle cylinder is in communication with the growth chamber, and the second porous cylindrical member includes a second cylindrical wall arranged between the first porous cylindrical member and the crucible wall.

[0007] Among them, the first area between the second cylindrical wall and the crucible wall is used for placing silicon carbide raw materials, and the second area between the first cylindrical wall and the second cylindrical wall is used for placing tantalum particles.

[0008] The second aspect of the present application provides a silicon carbide crystal growth device, the growth device includes a furnace body provided with a furnace cavity, a heat preservation cylinder is arranged in the furnace cavity, the growth crucible of the above-mentioned silicon carbide crystal is arranged in the heat preservation cylinder, a first heating device and a second heating device are further arranged in the furnace cavity, the first heating device is arranged at the periphery of the heat preservation cylinder, and the second heating device is arranged at the top of the heat preservation cylinder, a second annular barrier is further arranged in the furnace cavity, the second annular barrier is arranged at the top edge of the heat preservation cylinder, and the second annular barrier is used for reducing the heat conduction between the first heating device and the second heating device.

[0009] The utility model discloses a beneficial effect lies in: the utility model discloses a raw material chamber is provided with the first porous cylinder piece and the second porous cylinder piece from the bottom of the crucible and the top extension of the cavity, the first porous cylinder piece includes the first cylinder wall and the middle cylinder of the middle communication and the top of the middle cylinder is connected with the growth chamber, the second porous cylinder piece includes the second cylinder wall between the first porous cylinder piece and the crucible wall, so setting, increase the tantalum particle, can effectively trap gaseous carbon, prevent excessive carbon formation carbon package, can simultaneously inhibit the edge formation polycrystal, and can make the center heat transfer receive the hindrance to a certain extent, adjust the distribution of isotherm to a certain extent, effectively improve the raw material area heat distribution, adjust evaporation rate, and effectively control silicon carbide crystal quality, improve raw material utilization. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 It is the structure schematic drawing of silicon carbide crystal growth crucible of some embodiments of the utility model.

[0011] Figure 2 It is the structure schematic drawing of silicon carbide crystal growth crucible of some other embodiments of the utility model.

[0012] Figure 3 It is the structure schematic drawing of silicon carbide crystal growth crucible of some other embodiments of the utility model.

[0013] Figure 4 It is the structure schematic drawing of silicon carbide crystal growth device of some embodiments of the utility model. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical scheme and advantage of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely below, obviously, the described embodiments are some embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application.

[0015] In the present application, the technical features described in an open way include both the closed technical solution consisting of the listed features and the open technical solution containing the listed features.

[0016] In the present application, if no special description is provided, the numerical range is considered to be continuous and includes the minimum value and the maximum value of the range, and each value between the minimum value and the maximum value. Further, when the range refers to an integer, each integer between the minimum value and the maximum value of the range is included. In addition, when multiple ranges are provided to describe a feature or a characteristic, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed herein should be understood to include any and all sub-ranges subsumed therein.

[0017] Unless otherwise specified, the components raw materials or instruments used in the embodiments and comparative examples of the present application are commercially available raw materials or instruments, and the component raw materials used in each parallel experiment are of the same kind.

[0018] In addition, the terms "first", "second" are only used for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0019] As shown in Figure 1 The present application provides a silicon carbide crystal growth crucible, which has a crucible cover 101, a crucible wall 102, a crucible bottom 103, and a cavity 104 enclosed by the crucible wall and the crucible bottom, the crucible cover covers the cavity, and the crucible cover is provided with a seed crystal bonding site 105 on one side inside the cavity.

[0020] As shown in Figure 2 The cavity includes a growth chamber 1 and a raw material chamber 2 in communication with each other, the raw material chamber is provided with a first porous cylindrical member 3 and a second porous cylindrical member 4 extending from the crucible bottom to the top of the cavity, the first porous cylindrical member includes a first cylindrical wall 301 and a middle cylindrical member 302 in communication, and the top of the middle cylindrical member is in communication with the growth chamber, and the second porous cylindrical member includes a second cylindrical wall 401 arranged between the first porous cylindrical member and the crucible wall.

[0021] The first region between the second cylindrical wall and the crucible wall is used to place silicon carbide raw materials, and the second region between the first cylindrical wall and the second cylindrical wall is used to place tantalum particles.

[0022] The first porous cylinder and the second porous cylinder are arranged in the raw material chamber, extend from the bottom of the crucible to the top of the cavity, the first porous cylinder comprises a first cylinder wall and a middle cylinder which is communicated with the growth chamber, the second porous cylinder comprises a second cylinder wall arranged between the first porous cylinder and the crucible wall, the arrangement increases the tantalum particles, can effectively trap gaseous carbon, prevent excessive carbon from forming carbon coating, can inhibit the formation of polycrystal on the edge, can hinder the heat transfer in the center to a certain extent, can adjust the distribution of isotherm to a certain extent, effectively improve the heat distribution of the raw material area, adjust the evaporation rate, effectively control the silicon carbide crystal quality, and improve the raw material utilization rate.

[0023] In some embodiments, the second porous cylinder is a straight cylinder with equal diameter.

[0024] In some embodiments, the second porous cylinder is a straight cylinder with equal diameter.

[0025] Since the cylinder wall of the first porous cylinder is not in contact with the crucible wall, and the cylinder wall of the second porous cylinder is not in contact with the crucible wall, the gas flow can be effectively inhibited from passing through, so that the gas flow passes through the porous cylinder.

[0026] In some embodiments, an annular blocking piece 5 is further arranged in the crucible, and the annular blocking piece covers the first area and the second area.

[0027] In some embodiments, the material of the annular blocking piece is graphite coated with a metal coating, and the metal coating is at least one of tungsten coating, molybdenum coating, niobium coating and tantalum coating. By using graphite coated with a metal coating as the material of the first annular blocking piece, the first annular blocking piece can be effectively prevented from being corroded by the silicon atmosphere, the formation of gaseous C can be avoided, the formation of carbon coating of the crystal can be avoided, the quality of the silicon carbide crystal can be controlled, and the formation of polycrystal can be avoided.

[0028] In some embodiments, the tantalum particles have a diameter of 1-2 mm.

[0029] In some embodiments, the tantalum particles are in a cylindrical shape.

[0030] In some embodiments, the tantalum particles have a height of 1-2 mm.

[0031] In some embodiments, in the first region, from the bottom of the crucible to a first height of the crucible chamber, a first raw material 6 is placed, from the first height of the crucible to the top edge of the second porous cylindrical member, a second raw material 7 is placed, the first raw material is silicon carbide particles of a first particle size, the first raw material is silicon carbide particles of a second particle size, wherein the first particle size is smaller than the second particle size, the utility model adopts the way of edge filling silicon carbide, and controls the first particle size to be smaller than the second particle size, effectively prevents the crystallization of silicon carbide atmosphere in the tantalum particles, slows down the evaporation speed of the raw material, avoids a large number of polycrystals from being formed at the edge of the growth chamber, effectively improves the crystallization problem of silicon carbide, and improves the utilization rate of raw materials.

[0032] In some embodiments, the first particle size is 20-40 mesh.

[0033] In some embodiments, the second particle size is 8-20 mesh.

[0034] In some embodiments, the first height is 1 / 10-3 / 5 of the height of the first region, and the control height H is in the range, which can improve the quality of silicon carbide crystals. Figure 2 In some embodiments, the distance between the first cylindrical wall and the crucible wall at the surface of the bottom of the crucible is A (10-15 mm), and the distance between the center point of the surface of the bottom of the crucible and the crucible wall is C (15-20 mm), and A is 2 / 3-9 / 10 of C.

[0035] In some embodiments, the distance between the second cylindrical wall and the crucible wall is B (5-8 mm), and B is 1 / 3-1 / 2 of C.

[0036] In some embodiments, the material of the first cylindrical wall is porous tantalum carbide, and the porosity of the porous tantalum carbide is 45-55%, and the porous tantalum carbide ring is used as the porous tantalum carbide ring, which can effectively isolate the tantalum particles and the growth chamber and inhibit the carbon-rich phenomenon in the growth chamber.

[0037] In some embodiments, the material of the second cylindrical wall is porous graphite, and the porosity of the porous graphite is 45-55%.

[0038] In some embodiments, the growth chamber further comprises a baffle 7, the material of the baffle is graphite coated with a metal coating, and the metal coating is at least one of tungsten coating, molybdenum coating, niobium coating and tantalum coating.

[0039] In some embodiments, the baffle 8 is annular, and the baffle encloses the growth chamber.

[0040] As Figure 3As shown, in the middle tube of the first porous cylinder, a container 9 is arranged, and the inside of the container is used to place cerium compounds 10.

[0041] In some embodiments, the cerium compound comprises at least one of cerium oxide and cerium silicide.

[0042] As Figure 4 As shown, the embodiment provides a silicon carbide crystal growth device, the growth device comprises a furnace body 100 provided with a furnace cavity, a heat preservation cylinder 11 is arranged in the furnace cavity, the growth crucible of the silicon carbide crystal is arranged in the heat preservation cylinder, a first heating device 12 and a second heating device 13 are arranged in the furnace cavity, the first heating device is arranged at the side of the heat preservation cylinder, the second heating device is arranged at the top of the heat preservation cylinder, a second annular barrier 14 is arranged in the furnace cavity, the second annular barrier is arranged at the edge of the top of the heat preservation cylinder, and the second annular barrier is used to reduce the heat conduction between the first heating device and the second heating device.

[0043] The double heating bodies are arranged, the mutual influence between the double heating bodies is small, the temperature distribution in the growth chamber can be effectively adjusted, the radial and axial temperature distributions of the raw material area are improved, and therefore the growth of the silicon carbide crystal is better controlled, and the carbon coating problem of the crystal is improved.

[0044] In some embodiments, during the crystal growth process, the heating temperature of the first heating device is configured to be 2200-2500 DEG C, and the heating temperature of the second heating device is configured to be 1800-2000 DEG C.

[0045] In some embodiments, the furnace cavity is further provided with a first heat preservation felt 14 and a second heat preservation felt 15, the first heat preservation felt is arranged at the side of the crucible, and the second heat preservation felt is arranged below the crucible.

[0046] In some embodiments, the second annular barrier is connected with the first heat preservation felt.

[0047] The first heat preservation felt and the second heat preservation felt are arranged, excellent heat preservation effect can be achieved, the mutual influence between the first heating body and the second heating body can be effectively isolated by the arrangement of the isolation felt, and the temperature distribution of the crucible assembly is more uniform by the arrangement of the uniform temperature barrel.

[0048] The third aspect of the present application provides a preparation method of a silicon carbide crystal, comprising the following steps:

[0049] A crystal growth device is provided, which comprises a crucible having a crucible cover, a crucible wall, a crucible bottom, and a cavity enclosed by the crucible wall and the crucible bottom, the crucible cover covering the cavity, and a seed crystal bonding site provided on one side of the cavity;

[0050] The cavity comprises a growth chamber and a raw material chamber in communication with each other, the raw material chamber is provided with a first porous cylindrical member and a second porous cylindrical member extending from the crucible bottom to the top of the cavity, the first porous cylindrical member comprises a cylindrical wall and a middle cylinder in communication, and the top of the middle cylinder is in communication with the growth chamber, and the second porous cylindrical member is arranged between the first porous cylindrical member and the crucible wall.

[0051] The first porous cylindrical member and the second porous cylindrical member are used to place tantalum particles, and the area between the cylindrical wall of the second porous cylindrical member and the crucible wall is used to place silicon carbide raw materials. In some embodiments, in the first area, from the crucible bottom to a first height of the crucible cavity, a first raw material is placed, and from the first height of the crucible to the top edge of the second porous cylindrical member, a second raw material is placed, the first raw material is silicon carbide particles of a first particle size, and the second raw material is silicon carbide particles of a second particle size, wherein the first particle size is smaller than the second particle size.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the protection scope of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present application.

Claims

1. A silicon carbide crystal growth crucible, characterized in that: The crucible comprises a crucible cover, a crucible wall, a crucible bottom, and a cavity enclosed by the crucible wall and the crucible bottom, wherein the crucible cover covers the cavity, and a seed crystal bonding position is provided on one side of the crucible cover inside the cavity; The chamber comprises a growth chamber and a raw material chamber that are interconnected. A first porous cylindrical member and a second porous cylindrical member are disposed in the raw material chamber and extend from the bottom of the crucible to the top of the chamber. The first porous cylindrical member comprises a first cylindrical wall and a through-hole middle cylinder, and the top of the middle cylinder is in communication with the growth chamber. The second porous cylindrical member comprises a second cylindrical wall disposed between the first porous cylindrical member and the crucible wall. The first area between the second barrel wall and the crucible wall is used to place silicon carbide raw materials, and the second area between the first barrel wall and the second barrel wall is used to place tantalum particles.

2. The silicon carbide crystal growth crucible according to claim 1, characterized in that: The second porous cylindrical member is in the shape of a straight cylinder with a constant diameter; And / or, the second porous cylindrical member is in the shape of a straight cylinder with a constant diameter.

3. The silicon carbide crystal growth crucible according to claim 1, characterized in that: An annular blocking member is further provided in the crucible, and covers the first region and the second region between the first porous cylindrical member and the crucible wall.

4. The silicon carbide crystal growth crucible according to claim 3, characterized in that: The material of the annular blocking member is graphite with a surface covered with a metal coating, and the metal coating is a tungsten coating, a molybdenum coating, a niobium coating or a tantalum coating.

5. The silicon carbide crystal growth crucible according to claim 1, characterized in that: In the first region, the area from the bottom of the crucible to the first height of the crucible chamber is used to place the first raw material; the area from the first height of the crucible to the top edge of the second porous cylindrical member is used to place the second raw material, the first raw material is silicon carbide particles of a first particle size, the first raw material is silicon carbide particles of a second particle size, wherein the first particle size is smaller than the second particle size.

6. The silicon carbide crystal growth crucible according to claim 5, characterized in that: The first particle size is 20 to 40 meshes; and / or, The second particle size is 8 to 20 meshes.

7. The silicon carbide crystal growth crucible according to claim 5, characterized in that: The first height is 1 / 10 to 3 / 5 of the height of the first region.

8. The silicon carbide crystal growth crucible according to claim 1, wherein: On the surface of the bottom of the crucible, the distance between the first tube wall and the crucible wall is 2 / 3-9 / 10 of the distance between the center point of the bottom surface of the crucible and the crucible wall; and / or, The distance between the second tube wall and the crucible wall is 1 / 3-1 / 2 of the distance between the center point of the bottom surface of the crucible and the crucible wall.

9. The silicon carbide crystal growth crucible according to claim 1, characterized in that: The material of the first barrel wall is porous tantalum carbide and / or; The material of the second cylinder wall is porous graphite.

10. A silicon carbide crystal growth device, characterized in that: The growth device includes a furnace body provided with a furnace cavity, an insulation tube is provided in the furnace cavity, a growth crucible for silicon carbide crystal according to any one of claims 1 to 9 is provided in the insulation tube, and a first heating device and a second heating device are also provided in the furnace cavity, the first heating device is separated from the insulation tube and the first heating device is provided on the peripheral side of the insulation tube, the second heating device is separated from the insulation tube and the second heating device is provided on the top of the insulation tube, a second annular barrier is also provided in the furnace cavity, the second annular barrier is provided on the top edge of the insulation tube, and the second annular barrier is used to reduce heat conduction between the first heating device and the second heating device.

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