Crystal growing device

Abstract

The embodiment of the specification discloses a crystal growing device, comprising: a crucible; a cavity is formed in the heat preservation assembly, and the crucible is located in the cavity; the sleeve is located between the outer wall of the crucible and the inner wall of the heat preservation assembly. The sleeve can achieve the beneficial effects of prolonging the service life of the crucible, reducing energy consumption and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of seed crystal growth, and in particular to a crystal growth device. Background Art

[0002] Crystal growth technology is a technology that uses the physical and chemical properties of substances (liquid, solid or gaseous) to control the phase change process and obtain crystals with certain structure, size, shape and properties. The crystal growth process is generally carried out in a crucible. Crystal growth methods include melt growth method, solution growth method, gas phase growth method and solid phase growth method.

[0003] The graphite crucible is used as a heating device in the crystal growth process, in which graphite reacts with the raw materials in the crucible. However, due to the uneven reaction, the internal corrosion of the graphite crucible is also uneven, so the graphite crucible is quickly scrapped and cannot be used multiple times, resulting in huge consumption of materials.

[0004] Therefore, it is necessary to provide an improved crystal growth apparatus. Utility Model Content

[0005] One of the embodiments of the present specification provides a crystal growth device, which includes: a crucible; a heat preservation component, wherein a cavity is provided inside the heat preservation component, and the crucible is located in the cavity; and a sleeve, wherein the sleeve is located between the outer wall of the crucible and the inner wall of the heat preservation component.

[0006] In some embodiments, the sum of the thickness of the side wall of the sleeve and the corresponding thickness of the side wall of the crucible is in the range of 15 mm to 40 mm.

[0007] In some embodiments, the absolute value of the difference between the sum of the thicknesses at different positions of the side wall of the sleeve is no more than 5 mm.

[0008] In some embodiments, a mid-section shape of the inner wall of the crucible in the axial direction of the crucible is U-shaped.

[0009] In some embodiments, along the axial direction, the wall thickness of the crucible gradually increases from top to bottom, and the wall thickness of the sleeve gradually decreases from top to bottom.

[0010] In some embodiments, the inner wall of the crucible has a first recessed area and / or a first raised area, and in a direction perpendicular to the axial direction of the crucible, the outer wall of the sleeve has a second raised area corresponding to the first recessed area and / or a second recessed area corresponding to the first raised area.

[0011] In some embodiments, a hole is formed in the side wall of the sleeve, a first thickness of a first crucible region corresponding to the hole is greater than a second thickness of a second crucible region, and the second crucible region is a region outside the first crucible region of the crucible.

[0012] In some embodiments, the outer wall of the crucible has a protective layer, and the inner wall of the crucible has a carbon coating.

[0013] In some embodiments, the device further comprises a radio frequency coil, which is disposed around the outside of the heat preservation component to provide an induced current and an induced magnetic field for the sleeve.

[0014] In some embodiments, the crucible and the sleeve are made of graphite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] This specification will be further described in the form of exemplary embodiments, which will be described in detail by the accompanying drawings. These embodiments are not restrictive, and in these embodiments, the same number represents the same structure, wherein:

[0016] Figure 1 It is a schematic diagram of the structure of a crystal growth device according to some embodiments of the present specification.

[0017] Figure 2A-2C Schematic diagram of a crucible and a sleeve according to some embodiments of the present specification.

[0018] Figure 3 Schematic diagram of a sleeve according to some embodiments of the present specification.

[0019] Figure 4 It is a melt velocity streamline diagram of crystal growth according to some embodiments of the present specification.

[0020] Figure 5 It is a melt temperature gradient isovalue diagram of crystal growth according to some embodiments of the present specification.

[0021] Figure 6 It is a melt velocity contour diagram of crystal growth according to some embodiments of the present specification.

[0022] Explanation of reference numerals: 100 is a crystal growing device; 110 is a crucible; 120 is a heat preservation component; 130 is a sleeve; 140 is a radio frequency coil. DETAILED DESCRIPTION

[0023] In order to more clearly illustrate the technical solutions of the embodiments of this specification, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of this specification. For ordinary technicians in this field, this specification can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0024] As shown in this specification and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "comprise" and "include" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0025] Figure 1 It is a schematic diagram of the structure of a crystal growth device according to some embodiments of the present specification.

[0026] like Figure 1 As shown, the crystal growth apparatus 100 includes a crucible 110 , a heat preservation assembly 120 , and a sleeve 130 .

[0027] The crucible 110 has a storage space for placing raw materials. A heating structure may be provided inside or outside the crucible 110 to heat the crucible 110 and the raw materials therein. In some embodiments, the heating structure is provided outside the crucible 110, and the heating structure may heat the crucible 110 and / or the raw materials from the circumference and / or bottom of the crucible 110. The heating structure may include a resistance heater, a gas or flame heater, an electron beam heater, a laser heater, a microwave heater, a radio frequency coil, a heating belt, etc.

[0028] In some embodiments, the crucible 110 may further include an opening connecting the accommodation space with the outside. In some embodiments, a closed structure (such as a crucible cover) may be provided at the opening. The closed structure is used to close the opening to isolate the accommodation space from the outside.

[0029] In some embodiments, the crucible 110 is made of graphite material. The graphite crucible is composed of carbon elements, so in some embodiments, the graphite crucible can provide a carbon source for the crystal growth reaction process. For example, the graphite crucible can provide the required carbon for the crystal growth reaction of silicon carbide carried out therein.

[0030] In some embodiments, the outer wall of the crucible 110 has a protective layer. The protective layer may be an iridium protective layer or the like. The iridium protective layer can enhance the mechanical strength of the crucible, and iridium has excellent corrosion resistance, so that the iridium protective layer on the outer wall of the crucible can maintain the mechanical strength of the crucible and ensure the sealing of the internal environment of the crucible during the crystal growth process when a part of the crucible is corroded, thinned or even penetrated.

[0031] In some embodiments, the inner wall of the crucible 110 has a carbon coating. The carbon coating can prevent the inner wall of the crucible from directly contacting the reacting substance and can be used as the first consumed carbon source, thereby reducing the loss of the graphite crucible and extending the service life of the graphite crucible.

[0032] The heat preservation component 120 is a component used to reduce heat loss or control temperature. The heat preservation component 120 can be made of ceramic fiber insulation material, graphite paper, graphite felt, ceramic fiberboard, silicone mastic, and other materials.

[0033] like Figure 1 As shown, a cavity is provided inside the heat preservation component 120, and the crucible 110 is located in the cavity. The crucible 110 is placed in the cavity formed by the heat preservation component 120, so that the crucible 110 can be thermally insulated and the temperature inside the crucible 110 can be kept stable. The distance between the crucible 110 and the inner wall of the heat preservation component 120 can be determined based on experience and / or demand.

[0034] The sleeve 130 is located between the outer wall of the crucible and the inner wall of the insulation component. The distance between the crucible 110 and the inner wall of the sleeve 130 can be determined based on experience and / or demand. For example, the outer wall of the crucible 110 is placed in close contact with the inner wall of the sleeve 130 to prevent vibration or movement, improve heat conduction efficiency, and achieve more uniform heating or cooling. For another example, the outer wall of the crucible 110 is kept at a preset distance from the inner wall of the sleeve 130 to meet thermal isolation requirements and avoid stress or damage caused by thermal expansion of the crucible 110. The sleeve can achieve beneficial effects such as extending the life of the crucible and reducing energy consumption. For specific corresponding effects, please refer to other parts of this specification, for example, Figure 4-Figure 6 Description.

[0035] In some embodiments, the sleeve 130 is made of graphite. Since graphite is a conductive material, the inductance effect can be used to generate current inside the graphite sleeve, thereby heating the sleeve, the crucible, and the raw materials inside the crucible.

[0036] like Figure 1As shown, in some embodiments, the crystal growth device 100 may further include a radio frequency coil 140. In some embodiments, the radio frequency coil 140 is spirally arranged around the circumference of the sleeve 130. The radio frequency coil 140 can provide an induced current and an induced magnetic field for the crucible 110 and / or the sleeve 130. For example, the radio frequency coil 140 can pass an alternating current of a certain frequency and generate an alternating electromagnetic field of a certain frequency, and the alternating electromagnetic field can be used to heat graphite, thereby achieving the function of heating the crucible 110 and / or the sleeve 130. The heated crucible 110 and / or the sleeve 130 can be used to heat the raw material.

[0037] By adding a heating graphite sleeve outside the graphite crucible, the temperature inside the crucible can be effectively maintained stable. Compared with the crucible serving as both a heat source and a consumption source, the setting of the graphite sleeve can reduce the impact of the dissolution and consumption of the inner wall of the crucible on the heat.

[0038] Figure 2A-2C Schematic diagram of a crucible and a sleeve according to some embodiments of the present specification.

[0039] In some embodiments, the sum of the thickness of the sidewall of the sleeve and the thickness of the corresponding sidewall of the crucible is in the range of 15 mm to 40 mm.

[0040] The side wall thickness refers to the thickness of the sleeve or crucible in the middle section, perpendicular to the axial direction ( Figure 2A The distance from the inner surface of the side wall to the corresponding outer surface of the side wall in the z-axis direction (as shown in ).

[0041] In some embodiments, the thickness of the sidewall of the sleeve may be the same or different at different locations. Figure 2A As shown, the side wall thickness thS1 of the sleeve at point M1 is the distance from point M1 to point O1, where M1 and O1 are on a straight line x1 perpendicular to the axial direction (z axis) of the sleeve, M1 is on the inner surface of the sleeve side wall, and O1 is the point on the outer surface of the sleeve side wall corresponding to M1. For another example, the side wall thickness thS2 of the sleeve at point M2 is the distance from point M2 to point O2, where M2 and O2 are on a straight line x2 perpendicular to the axial direction (z axis) of the sleeve, M2 is on the inner surface of the sleeve side wall, and O2 is the point on the outer surface of the sleeve side wall corresponding to M2.

[0042] In some embodiments, the thickness of the side wall of the crucible may be the same or different at different locations. Figure 2AAs shown, the side wall thickness thC1 of the crucible at point I1 is the distance from point I1 to point N1, where I1 and N1 are on a straight line x1 perpendicular to the axial direction (z axis) of the crucible, I1 is on the inner surface of the side wall of the crucible, and N1 is the point on the outer surface of the side wall of the crucible corresponding to I1. For another example, the side wall thickness thC2 of the crucible at point I2 is the distance from point I2 to point N2, where I2 and N2 are on a straight line x2 perpendicular to the axial direction (z axis) of the crucible, I2 is on the inner surface of the side wall of the crucible, and N2 is the point on the outer surface of the side wall of the crucible corresponding to I2.

[0043] The sum of the thickness of the side wall of the sleeve and the thickness of the corresponding side wall of the crucible refers to the sum of the thickness of the side wall of the sleeve and the thickness of the side wall of the crucible along a straight line perpendicular to the axial direction. For example, the sum of thickness T1 = thS1 + thC1, and the sum of thickness T2 = thS2 + thC2.

[0044] The crucible and sleeve are both made of graphite material. Under the action of the induced magnetic field, both will generate induced current. Therefore, the heat distribution in the axial direction is related to the thickness and thickness of the crucible and sleeve. Setting the thickness and thickness in the range of 15mm-40mm can achieve more stable and consistent experimental results or production processes.

[0045] like Figure 4-Figure 6 As shown in the figure, the heat inside the crucible is related to the thickness of the side wall of the sleeve. The thicker the side wall of the sleeve, the greater the density and number of magnetic induction lines passing through the graphite sleeve, the more heat is provided, the faster the melt flow rate in the crucible, and the easier it is for the components inside the solution to flow; the higher the temperature, the more uniform the temperature gradient. When the thickness of the sleeve reaches 20mm, the melt velocity and melt temperature gradient in the crucible can achieve similar effects to those without a sleeve and at a power of 30KW.

[0046] Figure 4 It is a melt velocity streamline diagram of crystal growth according to some embodiments of the present specification.

[0047] Figure 4 The attached figure on the left shows an experiment with a sleeve. The heating power is 18KW. When the sleeve thickness is 10mm, a circulating eddy current is generated in the lower right corner. As the sleeve thickness gradually increases, the influence range of the eddy current is also gradually expanding.

[0048] Figure 4 The figure on the right shows the experiment without a sleeve. The experimental power is gradually increased in steps of 4KW. When the power reaches 26KW, the melt velocity streamline distribution similar to that when the sleeve thickness is 15mm can be achieved. When the power reaches 30KW, the melt velocity streamline distribution similar to that when the sleeve thickness is 20mm can be achieved.

[0049] By arranging a sleeve between the outer wall of the crucible and the inner wall of the heat preservation component, the melt velocity streamline can meet the production conditions at a lower power consumption, that is, arranging the sleeve can save energy.

[0050] Figure 5 It is a melt temperature gradient isovalue diagram of crystal growth according to some embodiments of the present specification.

[0051] like Figure 5 As shown in the figure, when there is a sleeve, the heating power is 18KW. As the thickness of the sleeve gradually increases, the higher the melt temperature is, the more uniform the melt temperature gradient is. When there is no sleeve, when the power reaches 30KW, the melt temperature gradient distribution similar to that when the sleeve thickness is 20mm can be achieved.

[0052] Figure 6 It is a melt velocity contour diagram of crystal growth according to some embodiments of the present specification.

[0053] Similar, such as Figure 6 As shown in the figure, in the case of no sleeve, when the power reaches 30KW, the melt velocity distribution similar to that when the sleeve thickness is 20mm can be achieved. In addition, when adding a graphite heat cylinder of corresponding thickness to reach the corresponding power without a heat cylinder, the streamlines of the melts of the two are almost the same, but the melt velocity of the melt with the addition of the graphite heat cylinder is improved overall, which has a positive significance for the material transfer in the crystal growth process and is conducive to crystal growth.

[0054] In some embodiments, the absolute value of the difference between the sum of the thicknesses at different positions of the side wall of the corresponding sleeve is no more than 5 mm.

[0055] Maintaining the thickness at different locations and the absolute value of the difference no more than 5 mm can achieve uniform heat transfer and temperature distribution, which is beneficial to avoid local overheating or overcooling problems and ensure the stability of the production process.

[0056] In some embodiments, the middle cross-section of the inner wall of the crucible in the axial direction of the crucible is U-shaped. Figure 2A and Figure 2B As shown, two lower corners of the middle cross section of the inner wall of the crucible in the axial direction of the crucible have a curvature or arc shape.

[0057] Sharp lower corners usually cause turbulence and lead to problems such as unstable flow rate. A curved lower corner can reduce the generation of turbulence, allowing the fluid to pass more smoothly, reducing or avoiding problems caused by turbulence and instability.

[0058] In some embodiments, along the axial direction, the wall thickness of the crucible increases from top to bottom, and the wall thickness of the sleeve decreases from top to bottom. Figure 2AAs shown, along the axial direction, the wall thickness of the crucible gradually increases from top to bottom. For example, the wall thicknesses thC1, thC2, and thC3 of the crucible gradually increase from top to bottom, and the wall thicknesses thS1, thS2, and thS3 of the sleeve gradually decrease from top to bottom.

[0059] The wall thickness of the crucible gradually increases while the wall thickness of the sleeve gradually decreases, which can achieve the complementarity of the crucible and the sleeve in thickness, and is conducive to maintaining the stability of the thickness and of the crucible and the sleeve, thereby ensuring the stability of the temperature field in the crucible.

[0060] In some embodiments, the inner wall of the crucible 110 has a first concave area and / or a first convex area. Figure 2B As shown, the inner wall of the crucible 110 has a first recessed area 211 and a second recessed area 212. Figure 2C As shown, the inner wall of the crucible 110 has a plurality of first recessed areas, for example, the first recessed areas 213 and the first recessed areas 214 ; the inner wall of the crucible 110 also has a plurality of first raised areas, for example, the first raised areas 213 and the first raised areas 214 .

[0061] In some embodiments, in a direction perpendicular to the axial direction of the crucible 110, the outer wall of the sleeve 130 has a second convex area corresponding to the first concave area and / or a second concave area corresponding to the first convex area. Figure 2B As shown, in the x3 direction perpendicular to the axial direction of the crucible 110, the outer wall of the sleeve 130 has a second convex area 221 corresponding to the first concave area 211 and a second convex area 222 corresponding to the first concave area 212. Figure 2C As shown, the outer wall of the sleeve 130 has a second raised area 223 corresponding to the first recessed area 213 , a second raised area 224 corresponding to the first recessed area 214 , a second recessed area 225 corresponding to the first raised area 215 , and a second recessed area 226 corresponding to the first raised area 216 .

[0062] The inner wall of the crucible has depressions and / or protrusions, and the outer wall of the sleeve has corresponding protrusions and / or depressions. On the one hand, the crucible and the sleeve can complement each other in thickness, which is beneficial to maintaining the stability of the thickness and of the crucible and the sleeve, thereby ensuring the stability of the temperature field in the crucible; on the other hand, the contact area between the crucible as a carbon source and the melt can be increased, thereby improving the reaction efficiency.

[0063] In some embodiments, the side wall of the sleeve is provided with a hole. In some embodiments, the hole may be a through hole on the side wall of the sleeve. Figure 3As shown, the sleeve 130 is provided with a plurality of holes, for example, hole 311, hole 312, hole 321, and hole 322. In some embodiments, the size and distribution of the holes can be determined based on experience and / or demand.

[0064] In some embodiments, a first thickness of a first crucible region corresponding to the crucible and the hole is greater than a second thickness of a second crucible region, and the second crucible region is a region of the crucible other than the first crucible region.

[0065] The first crucible region corresponding to the crucible and the hole portion refers to the portion of the crucible that overlaps with the hole portion position on the sleeve. It can be understood that at the position of the sleeve where no hole is opened, both the crucible and the sleeve can generate current and heat in the magnetic field. At the position where the hole is opened, only the crucible generates current and heat. Opening the hole at the sleeve position corresponding to the first crucible region with large thickness is conducive to maintaining the stability of the thickness and of the crucible and the sleeve, thereby ensuring the stability of the temperature field in the crucible.

[0066] In some embodiments, the sleeve can be customized to achieve requirements such as temperature field control and melt flow control. For example, if the temperature at the bottom of the crucible needs to be higher, the local thickness of the sleeve corresponding to the bottom of the crucible can be increased. For another example, if the temperature at a certain point in the crucible needs to be lower, the local thickness of the sleeve corresponding to that point can be reduced, or a hole can be opened locally at the corresponding point in the sleeve.

[0067] In some embodiments of the present application, a sleeve is provided between the crucible and the insulation component, and the beneficial effects that can be achieved include: 1) using the sleeve as the main heat source to reduce or avoid the impact of structural changes of the crucible on the heat source during the reaction; 2) uniform temperature field control to make the loss of the crucible uniform and extend the service life of the crucible; 3) increasing the surface area of ​​the inner wall of the crucible, increasing the contact area between substances, and improving the reaction efficiency; 4) in the presence of a sleeve, higher power production conditions can be achieved with lower power, which can reduce energy consumption; 5) thickening or thinning the sleeve (even opening a hole) as needed, which can change the temperature gradient in the vertical direction, achieve local temperature control, and even control the direction of thermal convection of the solution, so as to achieve effective transfer of substances and improve reaction efficiency.

[0068] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only for example and does not constitute a limitation of this specification. Although not explicitly stated here, those skilled in the art may make various modifications, improvements and corrections to this specification. Such modifications, improvements and corrections are suggested in this specification, so such modifications, improvements and corrections still belong to the spirit and scope of the exemplary embodiments of this specification.

[0069] At the same time, this specification uses specific words to describe the embodiments of this specification. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of this specification. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures or characteristics in one or more embodiments of this specification can be appropriately combined.

Claims

1. A crystal growth device, characterized in that: include: Crucible; A heat preservation component, wherein a cavity is provided inside the heat preservation component, and the crucible is located in the cavity; as well as A sleeve is located between the outer wall of the crucible and the inner wall of the heat preservation component.

2. The device according to claim 1, characterized in that The sum of the thickness of the side wall of the sleeve and the corresponding thickness of the side wall of the crucible is in the range of 15 mm to 40 mm.

3. The device according to claim 2, characterized in that The absolute value of the difference between the sum of the thicknesses at different positions of the side wall of the sleeve is no more than 5 mm.

4. The device according to claim 2, characterized in that The inner wall of the crucible has a U-shaped mid-section in the axial direction of the crucible.

5. The device according to claim 4, characterized in that Along the axial direction, the wall thickness of the crucible increases gradually from top to bottom, and the wall thickness of the sleeve decreases gradually from top to bottom.

6. The device according to claim 2, characterized in that The inner wall of the crucible has a first recessed area and / or a first raised area, and in a direction perpendicular to the axial direction of the crucible, the outer wall of the sleeve has a second raised area corresponding to the first recessed area and / or a second recessed area corresponding to the first raised area.

7. The device according to claim 2, characterized in that A hole is formed on the side wall of the sleeve, a first thickness of a first crucible region of the crucible corresponding to the hole is greater than a second thickness of a second crucible region, and the second crucible region is a region outside the first crucible region of the crucible.

8. The device according to claim 1, characterized in that The outer wall of the crucible is provided with a protective layer, and the inner wall of the crucible is provided with a carbon element coating.

9. The device according to claim 1, characterized in that It also includes a radio frequency coil, which is arranged around the outside of the heat preservation component to provide an induced current and an induced magnetic field for the sleeve.

10. The device according to any one of claims 1 to 9, characterized in that The crucible and the sleeve are made of graphite material.

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