Crystal growing device

Abstract

The utility model discloses a crystal growing device which at least comprises an upper cover and a lower cover, the seed crystal cover is arranged opposite to the upper cover; the crucible barrel is arranged between the upper cover and the seed crystal cover in a surrounding manner; the porous isolation plate and the seed crystal cover are oppositely arranged in the crucible barrel; the raw material area is positioned in the crucible barrel between the porous isolation plate and the upper cover; and the growth area is positioned in the crucible barrel between the porous isolation plate and the seed crystal cover. According to the growing device provided by the utility model, raw materials can be conveniently filled into the growing device, and the filling efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of crystal growth technology, and specifically to a crystal growth apparatus. Background Technology

[0002] Silicon carbide (SiC) is an important wide-bandgap semiconductor material with excellent properties such as high thermal conductivity, high breakdown electric field, and high electron saturation drift velocity. It is widely used in power electronics, radio frequency devices, optoelectronic devices, and high-temperature, high-voltage, and high-frequency applications. As the diameter and thickness of SiC crystals increase, the amount of growth material required in crystal growth equipment increases. However, existing growth equipment suffers from problems such as inconvenient material loading, low loading efficiency, and uneven gas flow distribution near the seed crystal, which are detrimental to crystal growth. Utility Model Content

[0003] The purpose of this invention is to provide a crystal growth apparatus that facilitates the loading of raw materials into the growth apparatus, thereby improving loading efficiency and crystal quality.

[0004] To achieve the above-mentioned and other related objectives, this utility model is implemented through the following technical solution.

[0005] This invention provides a crystal growth apparatus, comprising at least:

[0006] Top cover;

[0007] The seed crystal cover is positioned opposite to the upper cover;

[0008] A crucible bucket is arranged around the upper cover and the seed crystal cover;

[0009] A porous isolation plate is disposed inside the crucible, opposite to the seed crystal cover;

[0010] The raw material zone is located within the crucible barrel between the porous partition plate and the upper cover; and the growth zone is located within the crucible barrel between the porous partition plate and the seed crystal cover.

[0011] In one embodiment of this utility model, the porous isolation plate is provided to protrude in the direction of the upper cover.

[0012] In one embodiment of the present invention, the porous isolation plate comprises multiple layers of single plates stacked together, and each layer of the single plate is provided with multiple rings of holes distributed in a preset array.

[0013] In one embodiment of this utility model, the holes in the same ring are staggered or aligned in adjacent single boards.

[0014] In one embodiment of this utility model, between the same ring of holes in two adjacent single boards, there is a preset angle between the line connecting the centers of the upper and lower holes and the axis of the single board.

[0015] In one embodiment of this utility model, the preset included angle is 10°-90°.

[0016] In one embodiment of the present invention, the growth apparatus further includes a limiting ring, which surrounds the inner wall of the crucible and is disposed between the porous isolation plate and the seed crystal cover.

[0017] In one embodiment of the present invention, the inner diameter of the limiting ring is increased in the direction from the upper cover to the seed crystal cover.

[0018] In one embodiment of the present invention, the growth apparatus further includes a heater, which is disposed outside the crucible and includes an upper surface and a lower surface disposed opposite to each other.

[0019] In one embodiment of this utility model, the plane containing the lower surface is located between the seed crystal cover and the upper cover, or is aligned with the seed crystal cover.

[0020] In summary, this invention provides a crystal growth apparatus. By improving the structure of the apparatus, it facilitates the loading of growth materials by operators, thereby increasing loading efficiency. Furthermore, the growth apparatus provided by this invention can filter the decomposition products of the raw materials and control the diffusion rate of these products onto the seed crystal, thus optimizing the crystal quality.

[0021] Of course, implementing any of the methods of this utility model does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of a crystal growth apparatus in one embodiment of the present invention.

[0024] Figure 2 for Figure 1 A schematic diagram of the upper and middle covers.

[0025] Figure 3 for Figure 1 A schematic diagram of the crucible bucket and seed crystal cover.

[0026] Figure 4 for Figure 1 A schematic diagram of the central isolation plate.

[0027] Figure 5 for Figure 1 A schematic diagram of the middle confinement ring.

[0028] Figure 6 for Figure 1 A schematic diagram of the seed crystal cap.

[0029] Figure 7 for Figure 4 Enlarged view of the holes on two adjacent single-layer panels.

[0030] Marker explanation:

[0031] 100. Top cover; 101. Protrusion; 102. Threaded hole; 103. Bolt; 104. First thread; 200. Crucible barrel; 201. Protrusion; 202. First matching thread; 203. Second matching thread; 300. Raw material; 400. Porous isolation plate; 401. First layer plate; 402. Second layer plate; 403. Third layer plate; 500. Restriction ring; 501. Restriction block; 600. Seed crystal cover; 601. Seed crystal; 602. Second thread; 700. Raw material area; 800. Growth area; 900. Heater; 901. Upper surface; 902. Lower surface. Detailed Implementation

[0032] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this utility model can be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0033] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0034] In this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used only for descriptive and distinguishing purposes and should not be construed as indicating or implying relative importance.

[0035] Please see Figures 1 to 7 As shown, this utility model provides a crystal growth apparatus, including, for example, an upper cover 100, a crucible 200, a porous partition plate 400, and a seed crystal cover 600. The upper cover 100 and the seed crystal cover 600 are arranged opposite each other, the crucible 200 is arranged around the upper cover 100 and the seed crystal cover 600, and the porous partition plate 400 is arranged opposite to the seed crystal cover 600 within the crucible 200. The porous partition plate 400 divides the crucible 200 into a raw material area 700 and a growth area 800. The raw material area 700 is located within the crucible 200 between the porous partition plate 400 and the upper cover 100, and the growth area 800 is located within the crucible 200 between the porous partition plate 400 and the seed crystal cover 600. In the growth apparatus provided by this utility model, the raw material 300 is filled in the raw material zone 700, and the seed crystal 601 is placed in the growth zone 800 below the raw material zone 700. This allows the raw material 300 to be placed in the upper part of the growth apparatus and the seed crystal 601 to be placed in the lower part, facilitating the operator's loading of the raw material 300 into the growth apparatus and improving loading efficiency. The growth apparatus provided by this utility model can be widely used in the growth process of various crystals such as silicon carbide or gemstones. In this embodiment, the growth apparatus is described using the synthesis of silicon carbide crystals as an example.

[0036] Please see Figures 1 to 2 As shown, in one embodiment of this utility model, the shape and size of the upper cover 100 can be selected according to actual needs. In this embodiment, the growth device is described using a circular upper cover 100 as an example. The material of the upper cover 100 includes, for example, graphite. The upper cover 100 is provided with, for example, a protrusion 101, a threaded hole 102, a bolt 103, and a first thread 104. The protrusion 101 is arranged around one side of the upper cover 100, and the outer diameter of the protrusion 101 is equal to the diameter of the upper cover 100. The first thread 104 is provided on the inner wall of the protrusion 101. The threaded hole 102 is recessed into the upper cover 100 from the side of the upper cover 100 away from the protrusion 101. The depth of the threaded hole 102 is less than the thickness of the upper cover 100. The bolt 103 is detachably placed in the threaded hole 102, and the length of the bolt 103 is, for example, greater than the depth of the threaded hole 102.

[0037] Please see Figure 1 , Figure 2 and Figure 6 As shown, in one embodiment of this utility model, the seed cover 600 and the upper cover 100 are disposed opposite to each other. Specifically, the seed cover 600 and the upper cover 100 are disposed coaxially, for example, and the shape of the seed cover 600 is the same as the shape of the upper cover 100, for example, circular. In this embodiment, the diameter of the seed cover 600 is, for example, 200mm-1000mm.

[0038] Please see Figure 1 , Figure 2 and Figure 6 As shown, in one embodiment of this utility model, the seed cover 600 is provided with, for example, a seed crystal 601 and a second thread 602. The seed crystal 601 is placed on the side of the seed cover 600 near the upper cover 100, and the second thread 602 is provided on the side wall of the seed cover 600.

[0039] Please see Figures 1 to 6As shown, in one embodiment of this utility model, a crucible 200 is arranged around the upper cover 100 and the seed crystal cover 600. The crucible 200, the seed crystal cover 600, and the upper cover 100 are, for example, arranged coaxially. The inner diameter of the crucible 200 is equal to the diameter of the seed crystal cover 600, and the outer diameter of the crucible 200 is equal to the diameter of the upper cover 100. The material of the crucible 200 includes, for example, graphite. Furthermore, the crucible container 200 is provided with, for example, a protrusion 201, a first matching thread 202, and a second matching thread 203. The protrusion 201 is disposed around the inner wall of the crucible container 200 on the side of the crucible container 200 near the top cover 100. The inner diameter of the protrusion 201 is equal to the inner diameter of the crucible container 200, the outer diameter of the protrusion 201 is smaller than the outer diameter of the crucible container 200, and the height of the protrusion 201 is equal to the height of the protrusion 101. The sum of the thickness of the protrusion 201 and the thickness of the protrusion 101 is equal to the thickness of the crucible container 200. The first matching thread 202 is disposed on the outer wall of the protrusion 201, and the first matching thread 202 matches the first thread 104. By setting the protrusion 201, the raised portion 101, the first matching thread 202, and the first thread 104, the raised portion 101 can be placed on the crucible barrel 200 and fitted with the protrusion 201. The first matching thread 202 and the first thread 104 engage, which can improve the stability of the raised portion 101 and the upper cover 100 on the crucible barrel 200, making it less likely for the upper cover 100 to fall off the crucible barrel 200, thereby sealing the crucible barrel 200 and ensuring that the crystal growth process inside the crucible barrel 200 is not affected by the external environment. Furthermore, by providing a threaded hole 102, a bolt 103, a first mating thread 202, and a first thread 104, once the bolt 103 is placed inside the threaded hole 102 and engaged with it, the operator can fix external equipment to the bolt 103 exposed outside the threaded hole 102. Then, by rotating the top cover 100 in a certain direction, the engagement between the first mating thread 202 and the first thread 104 is loosened, while the engagement between the threaded hole 102 and the bolt 103 becomes tighter. Finally, by pulling the bolt 103 upwards using the external equipment, the top cover 100 can be opened. The external equipment can be, for example, a hoisting device.

[0040] Please see Figures 1 to 6 As shown, in one embodiment of this utility model, a second matching thread 203 is disposed on the inner wall of the crucible jar 200 near the seed crystal cover 600, and the second matching thread 203 matches the second thread 602. By setting the second matching thread 203 and the second thread 602 to engage, the seed crystal cover 600 is fixedly connected to the crucible jar 200, thereby sealing the crucible jar 200 and ensuring that the crystal growth process inside the crucible jar 200 is not affected by the external environment.

[0041] Please see Figures 1 to 7As shown, in one embodiment of this utility model, a porous isolation plate 400 and a seed crystal cover 600 are disposed opposite each other inside the crucible jar 200. The porous isolation plate 400 is made of materials such as isostatically pressed graphite, and it protrudes in the direction of the upper cover 100. Specifically, in this embodiment, the porous isolation plate 400 is, for example, semi-circular, and the porous isolation plate 400, the upper cover 100, the crucible jar 200, and the seed crystal cover 600 are, for example, coaxially arranged, and the diameter of the porous isolation plate 400 is equal to the inner diameter of the crucible jar 200.

[0042] Please see Figures 1 to 7 As shown, in one embodiment of this utility model, the porous isolation plate 400 includes, for example, multiple layers of single plates stacked together. The number of single plates is, for example, 2-6 layers, or 3-4 layers, and the thickness of the single plates is, for example, 5mm-20mm. In this embodiment, the porous isolation plate 400 includes, for example, three layers of single plates stacked together. The three layers of single plates include, for example, a first layer single plate 401, a second layer single plate 402, and a third layer single plate 403, etc. In the direction from the top cover 100 to the seed crystal cover 600, the first layer single plate 401, the second layer single plate 402, and the third layer single plate 403 are arranged coaxially, for example, sequentially, and each layer of single plate has multiple rings of holes (not shown in the figure) distributed according to a preset array. The diameter of the holes is, for example, greater than 0 and less than 2mm, and the preset array is, for example, a rectangular array or a circular array. In adjacent layers of single plates, the holes in the same ring are staggered or aligned. In this embodiment, the holes in the same ring are staggered in two adjacent single plates. Furthermore, there is a preset angle α between the center line of the two holes in the same ring between two adjacent single plates and the axis of the single plate. The preset angle α is, for example, 10°-90°. This can block the raw material 300 particles falling into the porous isolation plate 400 onto the single plate, and prevent the raw material 300 from falling directly onto the seed crystal 601 and forming large-scale defects on the surface of the seed crystal 601.

[0043] Please see Figures 1 to 6 As shown, in one embodiment of this invention, the growth apparatus further includes a limiting ring 500, which surrounds the inner wall of the crucible 200 and is disposed between the porous isolation plate 400 and the seed crystal cover 600. The outer diameter of the limiting ring 500 is equal to the inner diameter of the crucible 200, and the inner diameter of the limiting ring 500 increases in the direction from the upper cover 100 to the seed crystal cover 600. By setting the limiting ring 500, the diameter of the silicon carbide crystal during the growth process can be constrained, preventing polycrystalline growth and thus improving the crystal quality.

[0044] Please see Figures 1 to 6As shown, in one embodiment of this utility model, a limiting ring 500 is provided with limiting blocks 501, etc. For example, there are multiple limiting blocks 501, symmetrically arranged on the side of the limiting ring 500 near the porous isolation plate 400. A preset distance is maintained between the limiting blocks 501 and the inner wall of the crucible 200, for example, a distance greater than or equal to the thickness of the porous isolation plate 400. In this embodiment, for example, there are two limiting blocks 501, and the preset distance is for example equal to the thickness of the porous isolation plate 400. By providing the limiting blocks 501, the porous isolation plate 400 can be constrained between the limiting blocks 501 and the inner wall of the crucible 200, preventing the porous isolation plate 400 from falling off the limiting ring 500, thereby improving the stability of the porous isolation plate 400 on the limiting ring 500.

[0045] Please see Figures 1 to 6 As shown, in one embodiment of this utility model, the raw material zone 700 is located inside the crucible jar 200 between the porous isolation plate 400 and the upper cover 100, and is filled with raw material 300, i.e., silicon carbide powder. The raw material 300 in the raw material zone 700 is heated and decomposed into growth gas flow. The growth gas flow enters the lower part of the crucible jar 200 through the holes in the porous isolation plate 400. The porous isolation plate 400 is used to support the raw material 300 and transmit the growth gas flow. The mass of the raw material 300 is, for example, 20Kg-200Kg, and the particle size of the raw material 300 is, for example, larger than the diameter of the holes in the porous isolation plate 400, so as to prevent solid raw material 300 from falling onto the seed crystal 601 through the holes and forming large-scale defects on the surface of the seed crystal 601. Moreover, compared with the flat porous partition plate 400, the semi-circular porous partition plate 400 has the following advantages: First, it can reduce the amount of raw material 300 contained in the center of the raw material area 700, and prevent the raw material 300 in the center of the raw material area 700 from agglomerating due to uneven heating, thereby improving the utilization rate of raw material 300. Second, it can increase the surface area of ​​the porous partition plate 400 and the holes on the porous partition plate 400, thereby facilitating the volatilization of the growth gas flow from the raw material 300 onto the seed crystal 601, and increasing the crystal growth rate. Third, it ensures that the center of each hole in the porous partition plate 400 is at the same distance from the center of the seed crystal 601, thereby ensuring that the growth gas flow passing through each hole reaches the center of the seed crystal 601 through an equal path, improving the uniformity of the growth gas flow distribution on the seed crystal 601, and thus optimizing the crystal growth.

[0046] Please see Figures 1 to 6As shown, in one embodiment of this invention, the growth zone 800 is located within the crucible jar 200 between the porous isolation plate 400 and the seed crystal cover 600. Specifically, the raw material 300 in the raw material zone 700 is heated and decomposed into a growth gas flow. The growth gas flow enters the growth zone 800 through the holes in the porous isolation plate 400 and condenses into a crystal on the seed crystal 601, thereby obtaining a silicon carbide crystal. By setting the porous isolation plate 400, placing the growth zone 800 at the lower part of the growth device and the raw material zone 700 at the upper part of the growth device, it is convenient for operators to load the raw material 300 into the growth device, improving loading efficiency. At the same time, during the crystal growth process, the upper cover 100 can be opened to replenish the raw material zone 700 without touching the crystal in the growth zone 800, ensuring that there is enough raw material 300 for crystal growth, which is beneficial for obtaining large-size crystals. Moreover, by adjusting the number of layers, the size of the holes, and the preset included angle α of the single plate in the porous isolation plate 400, the diffusion rate of the growth gas flow to the seed crystal 601 can be controlled, thereby optimizing the quality of the silicon carbide crystal.

[0047] Please see Figures 1 to 6 As shown, in one embodiment of this utility model, the growth apparatus further includes a heater 900, which is disposed outside the crucible jar 200 to provide a heat source for the decomposition of the raw material 300 in the raw material zone 700. The heater 900 includes an upper surface 901 and a lower surface 902 disposed opposite to each other. The plane containing the upper surface 901 can be located on the side of the upper cover 100 away from the raw material zone 700, or it can be aligned with the upper cover 100. The plane containing the lower surface 902 is located between the seed crystal cover 600 and the upper cover 100, or it can be aligned with the seed crystal cover 600. This allows the raw material zone 700 to be located in a high-temperature zone, while the seed crystal cover 600 and the seed crystal 601 are located in a low-temperature zone. This facilitates the decomposition of the raw material 300 into growth gas flow and the condensation of the growth gas flow on the seed crystal 601, thereby ensuring the smooth progress of the crystal growth process. Specifically, the vertical distance between the lower surface 902 and the seed crystal cover 600 is, for example, 0-90 mm, or, for example, 30 mm or 60 mm.

[0048] To further describe in detail the crystal growth apparatus provided by this utility model, the process of crystal growth using the growth apparatus is described in detail below.

[0049] The growth apparatus is placed inside the growth chamber, and the chamber is evacuated to a first pressure. The heater is then activated, and the growth apparatus is heated to a first temperature. The chamber is then evacuated again to the first pressure, and argon gas is introduced into the chamber to a second pressure. The growth apparatus is then heated to the second temperature and held for a first time. Next, the pressure inside the growth chamber is reduced to a third pressure, and the temperature is increased to the third temperature. This temperature is held for a second time, and then the growth apparatus is cooled to room temperature to obtain the crystal. The first pressure is, for example, less than or equal to 10. -3Pa, first temperature for example 800℃-1200℃, second pressure for example 200mbar-500mbar, second temperature for example 2000℃-2100℃, first time for example 15h-25h, third pressure for example 1mbar-10mbar, third temperature for example 2100℃-2350℃, second time for example 50h-200h.

[0050] In summary, this invention provides a crystal growth apparatus. By using a porous partition plate to position the growth zone at the bottom and the raw material zone at the top, it facilitates the loading of raw materials into the growth apparatus, improving loading efficiency. Furthermore, the growth apparatus provided by this invention allows for the control of the diffusion rate of the growth gas flow onto the seed crystal by adjusting the number of layers, the size of the holes, and the preset angle within the porous partition plate, thereby optimizing the quality of the silicon carbide crystal.

[0051] Throughout this specification, the terms "one embodiment," "an embodiment," or "a specific embodiment" refer to a particular feature, structure, or characteristic described in connection with an embodiment that is included in at least one embodiment of the present invention, but not necessarily in all embodiments. Therefore, the various representations of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in different places throughout the specification do not necessarily refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic of any specific embodiment of the present invention may be combined with one or more other embodiments in any suitable manner. It should be understood that other variations and modifications of the embodiments of the present invention described and illustrated herein may be based on the teachings herein and will be considered part of the spirit and scope of the present invention.

[0052] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the utility model involved in this application is not limited to the technical solutions formed by specific combinations of the above-described technical features. It should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in this application. Except for the technical features described in the specification, the remaining technical features are known to those skilled in the art. To highlight the innovative features of this utility model, the remaining technical features will not be described further here.

Claims

1. A crystal growth apparatus, characterized in that, At least including: Top cover; The seed crystal cover is positioned opposite to the upper cover; A crucible bucket is arranged around the upper cover and the seed crystal cover; A porous isolation plate is disposed inside the crucible, opposite to the seed crystal cover; The raw material area is located inside the crucible barrel between the porous partition plate and the upper cover; as well as The growth zone is located within the crucible barrel between the porous isolation plate and the seed crystal cover.

2. The growing apparatus of claim 1, wherein, The porous isolation plate protrudes in the direction of the upper cover.

3. The growing apparatus of claim 1, wherein, The porous isolation plate comprises multiple layers of single plates, each layer of which has multiple rings of holes distributed in a preset array.

4. The growing apparatus of claim 3, wherein, In two adjacent single-layer panels, the holes in the same ring are staggered or aligned.

5. The growing apparatus of claim 4, wherein, Between the holes in the same ring of two adjacent single-layer boards, there is a preset angle between the line connecting the centers of the two holes and the axis of the single-layer board.

6. The growing apparatus of claim 5, wherein, The preset included angle is 10°-90°.

7. The growing apparatus of claim 1, wherein, The growth apparatus further includes a confinement ring, which surrounds the inner wall of the crucible and is disposed between the porous isolation plate and the seed crystal cover.

8. The growing apparatus of claim 7, wherein, The inner diameter of the limiting ring increases in the direction from the upper cover to the seed crystal cover.

9. The growing apparatus of claim 1, wherein, The growth apparatus further includes a heater disposed outside the crucible, and the heater includes an upper surface and a lower surface disposed opposite to each other.

10. The growing apparatus of claim 9, wherein, The plane containing the lower surface is located between the seed crystal cover and the upper cover, or is aligned with the seed crystal cover.

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