A crystal growing apparatus

Abstract

The utility model discloses a kind of crystal growing apparatus, including rack, heat preservation cover, crucible, lower heater and upper heater;Upper heater includes resistance strip, resistance strip includes first end and second end, the first end to the middle section is bent and coiled in plane and forms a plurality of concentric settings and sequentially head-to-tail connection first arc section, the second end to the middle section is bent and coiled in plane and forms a plurality of concentric settings and sequentially head-to-tail connection second arc section, a plurality of first arc section is sequentially spaced apart along the circumferential direction of pointing to the center of circle, a plurality of second arc section is sequentially spaced apart along the circumferential direction of pointing to the center of circle, the number of turns of first arc section and second arc section is same and radius corresponding equal, for mutually cooperatingly surrounding and forming multiple turns of resistance;The cross-sectional area of each turn resistance sequentially increases from outside to inside.The utility model crystal growing apparatus not only can accurately set axial temperature difference, but also can greatly reduce radial temperature difference, ensure crystal growing quality.

Description

Technical Field

[0001] This utility model relates to a crystal growth device. Background Technology

[0002] Currently, when growing large-sized silicon carbide crystals, a bottom heater is generally used to create a temperature difference between the bottom and top surfaces of the crucible to meet the crystal growth requirements. During crystal growth, the crucible is slowly raised to maintain the required temperature difference. The disadvantages of this structure are that not only is the temperature difference range narrow, but the movement of the crucible is also detrimental to crystal growth.

[0003] In the prior art, this shortcoming is compensated by designing an upper heater. However, since the heat dissipation is slower at the center of the upper heater than at the edge, a radial temperature gradient still exists, resulting in relatively poor growth quality and surface flatness of large-sized crystals. Utility Model Content

[0004] The purpose of this invention is to provide a crystal growth device that can not only accurately set the axial temperature difference, but also significantly reduce the radial temperature difference, thereby ensuring the growth quality and surface flatness of large-size crystals.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] A crystal growth apparatus includes a frame, a heat insulation cover with a hollow inner cavity disposed in the frame, a crucible disposed in the heat insulation cover, a lower heater in the shape of a cup and arranged around the outside of the crucible, and an upper heater disposed above the crucible, wherein the lower heater has an opening facing upward.

[0007] The upper heater includes a resistance bar, which includes a first end and a second end, multiple concentrically arranged and sequentially connected first arc-shaped sections formed by bending and coiling a section from the first end to the middle in a plane, and multiple concentrically arranged and sequentially connected second arc-shaped sections formed by bending and coiling a section from the second end to the middle in a plane. The multiple first arc-shaped sections are arranged at intervals along the circumference towards the center, and the multiple second arc-shaped sections are arranged at intervals along the circumference towards the center. The number of turns of the first arc-shaped sections and the second arc-shaped sections are the same and their radii are correspondingly equal. They are used to cooperate with each other to form a multi-turn resistor; the cross-sectional area of ​​each turn of the resistor increases sequentially from the outside to the inside.

[0008] Preferably, the first arc-shaped portion and the corresponding second arc-shaped portion of each ring are spaced apart along their circumference and each has two first intervals; the first arc-shaped portion and the second arc-shaped portion of the innermost ring are connected in series.

[0009] Preferably, the width of each resistor ring is the same, and its thickness increases sequentially from the outside to the inside.

[0010] Preferably, the thickness of each resistor ring is the same, and its width increases sequentially from the outside to the inside.

[0011] Preferably, the width and thickness of each resistor ring increase sequentially from the outside to the inside.

[0012] Preferably, the plurality of first arc-shaped portions are each 180° and are all located on one side of the circumference, and the plurality of second arc-shaped portions are each 180° and are all located on the opposite side of the circumference.

[0013] Preferably, the first end and the second end are respectively located at the two ends of the outermost resistor that are radially opposite each other.

[0014] More preferably, the crystal growth device further includes a pair of first electrodes and second electrodes respectively disposed in the heat insulation cover, a first bolt for connecting the first electrode and the first end, and a second bolt for connecting the second electrode and the second end.

[0015] Preferably, the crystal growth apparatus further includes a heat-insulating ring disposed between the upper heater and the crucible, wherein the inner diameter of the heat-insulating ring is smaller than the inner diameter of the lower heater.

[0016] More preferably, the crucible includes a crucible body and a crucible lid covering the crucible body, wherein the inner diameter of the heat-insulating ring is larger than the diameter of the crucible lid.

[0017] Due to the application of the above technical solution, this utility model has the following advantages compared with the prior art: The crystal growth device of this utility model has the following advantages:

[0018] By placing a heater above the crucible lid, the axial temperature difference can be precisely set to meet the growth requirements of large-size crystals;

[0019] Multiple first arc sections and multiple second arc sections are connected in series to form a multi-turn resistor. The cross-sectional area of ​​each resistor is set to increase sequentially from the outside to the inside, so that temperature compensation can be performed ring by ring from the outside to the inside, reducing the temperature difference between the center and the edge of the upper heater, thereby significantly reducing the radial temperature difference and ensuring the growth quality and surface flatness of large-size crystals. Attached Figure Description

[0020] Appendix Figure 1 This is a cross-sectional structural schematic diagram of the crystal growth device according to a specific embodiment of the present invention;

[0021] Appendix Figure 2 For the appendix Figure 1 A magnified schematic diagram of the upper and middle heaters.

[0022] The components are: 1. Frame; 2. Insulation cover; 3. Crucible; 31. Crucible body; 32. Crucible lid; 4. Lower heater; 5. Upper heater; 51. First end; 52. Second end; 53. First arc-shaped part; 54. Second arc-shaped part; 55. Central connecting part; 56. First gap; 6. First electrode; 7. Second electrode; 8. First bolt; 9. Second bolt; 10. Insulation ring; 11. Crucible shaft; 12. Crucible tray. Detailed Implementation

[0023] The technical solution of this utility model will be further described below with reference to specific embodiments and accompanying drawings.

[0024] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0025] In the description of the embodiments of this utility model, it should be understood that the terms "length", "inner", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the embodiments of this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the embodiments of this utility model.

[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0027] In this embodiment of the invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment of the invention according to the specific circumstances.

[0028] In this embodiment of the invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0029] The following disclosure provides many different implementations or examples for different structures of the embodiments of the present invention. To simplify the disclosure of the embodiments of the present invention, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the embodiments of the present invention. Furthermore, reference numerals and / or reference letters may be repeated in different examples of the embodiments of the present invention; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various implementations and / or arrangements discussed.

[0030] See Figure 1 As shown, this embodiment provides a crystal growth apparatus, including a frame 1, a heat insulation cover 2 with a hollow inner cavity disposed in the frame 1, a crucible 3 disposed in the heat insulation cover 2, a lower heater 4 arranged in a cup shape around the outside of the crucible 3, and an upper heater 5 disposed above the crucible 3, with the lower heater 4 opening upward.

[0031] The lower heater 4 and the upper heater 5 are located in the heat insulation cover 2, respectively; the crucible shaft 11, which is rotatable around its own axis and is mounted on the frame 1, passes upward into the heat insulation cover 2 and the lower heater 4, respectively, and carries the crucible 3 through the crucible tray 12 located on top of it.

[0032] See Figure 2 As shown, the upper heater 5 includes a resistance bar, which includes a first end 51 and a second end 52, multiple concentrically arranged and sequentially connected first arc-shaped portions 53 formed by bending and coiling a section from the first end 51 to the middle in a plane, and multiple concentrically arranged and sequentially connected second arc-shaped portions 54 formed by bending and coiling a section from the second end 52 to the middle in a plane. The multiple first arc-shaped portions 53 are arranged at intervals along the circumference pointing towards the center, and the multiple second arc-shaped portions 54 are arranged at intervals along the circumference pointing towards the center. The first arc-shaped portions 53 and the second arc-shaped portions 54 have the same number of turns and correspondingly equal radii, and are used to cooperate to form multiple turns of resistance; the cross-sectional area of ​​each turn of resistance increases sequentially from the outside to the inside.

[0033] This setup allows for temperature compensation ring by ring from the outside in, reducing the temperature difference between the center and edge of the upper heater 5, thereby significantly reducing the radial temperature difference and ensuring the growth quality and surface flatness of large-size crystals.

[0034] In this embodiment, the first arc-shaped portion 53 and the corresponding second arc-shaped portion 54 of each ring are spaced apart circumferentially, and each has two first intervals 56. The first arc-shaped portion 53 and the second arc-shaped portion 54 of the innermost ring are connected in series through a central connecting portion 55.

[0035] In this embodiment, the width of each resistor loop is the same, and its thickness increases sequentially from the outside to the inside.

[0036] In Example 2, the thickness of each resistor ring is the same, and its width increases sequentially from the outside to the inside.

[0037] In Example 3, the width and thickness of each resistor loop increase sequentially from the outside to the inside.

[0038] See Figure 2 As shown, in this embodiment, multiple first arc-shaped portions 53 are each 180° and located on one side of the circumference, and multiple second arc-shaped portions 54 are each 180° and located on the opposite side of the circumference. All first intervals 56 are arranged along the same straight line direction.

[0039] The first end 51 and the second end 52 are respectively located at the two radially opposite ends of the outermost resistor ring. In this embodiment, the crystal growth device further includes a pair of first electrodes 6 and second electrodes 7 respectively inserted into the heat insulation cover 2, a first bolt 8 for connecting the first electrode 6 and the first end 51, and a second bolt 9 for connecting the second electrode 7 and the second end 52. The first electrode 6 and the second electrode 7 extend upwards through the heat insulation cover 2 to facilitate heating by energizing the upper heater 5.

[0040] See Figure 1 As shown, the crystal growth apparatus further includes a heat-insulating ring 10 disposed between the upper heater 5 and the crucible 3. The inner diameter of the heat-insulating ring 10 is smaller than the inner diameter of the lower heater 4 to prevent a large amount of temperature loss from the lower heater 4 upwards. In this embodiment, the crucible 3 includes a crucible body 31 and a crucible lid 32 covering the crucible body 31. The inner diameter of the heat-insulating ring 10 is larger than the diameter of the crucible lid 32, so that the upper heater 5 can completely and uniformly heat the crucible lid 32.

[0041] By setting the heat-insulating ring 10 above the crucible 3, large temperature field fluctuations during crystal growth can be avoided, which is beneficial to crystal growth. The heat-insulating ring 10 adopts a constricted structure (i.e., the inner diameter of the heat-insulating ring 10 is smaller than the inner diameter of the heat-insulating cover 2), so that the axial temperature gradient has a thicker axial isothermal zone at the crucible cover 32 below the constricted structure. This ensures that the axial temperature and axial gradient at the crucible cover 32 will not be significantly changed during crystal growth (e.g., when the heat of crystal crystallization dissipates), thereby ensuring the growth conditions of large-sized crystals, making the crystal growth surface flat, and obtaining more slices during crystal slicing, thus improving the yield.

[0042] The above embodiments are only for illustrating the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be included within the scope of protection of this utility model.

Claims

1. A crystal growth apparatus, characterized in that: It includes a frame, a heat insulation cover with a hollow inner cavity disposed in the frame, a crucible disposed in the heat insulation cover, a cup-shaped lower heater disposed around the outside of the crucible, and an upper heater disposed above the crucible, wherein the lower heater has an opening facing upward; The upper heater includes a resistance bar, which includes a first end and a second end, multiple concentrically arranged and sequentially connected first arc-shaped sections formed by bending and coiling a section from the first end to the middle in a plane, and multiple concentrically arranged and sequentially connected second arc-shaped sections formed by bending and coiling a section from the second end to the middle in a plane. The multiple first arc-shaped sections are arranged at intervals along the circumference towards the center, and the multiple second arc-shaped sections are arranged at intervals along the circumference towards the center. The number of turns of the first arc-shaped sections and the second arc-shaped sections are the same and their radii are correspondingly equal. They are used to cooperate with each other to form a multi-turn resistor; the cross-sectional area of ​​each turn of the resistor increases sequentially from the outside to the inside.

2. The crystal growth apparatus according to claim 1, characterized in that: The first arc-shaped portion and the corresponding second arc-shaped portion of each ring are spaced apart along their circumference and each has two first intervals; the first arc-shaped portion and the second arc-shaped portion of the innermost ring are connected in series.

3. The crystal growth apparatus according to claim 1, characterized in that: The resistors described in each loop have the same width, and their thickness increases sequentially from the outside to the inside.

4. The crystal growth apparatus according to claim 1, characterized in that: The thickness of each resistor is the same, and its width increases sequentially from the outside to the inside.

5. The crystal growth apparatus according to claim 1, characterized in that: The width and thickness of the resistors in each ring increase sequentially from the outside to the inside.

6. The crystal growth apparatus according to claim 1, characterized in that: The multiple first arc-shaped portions are each 180° and are all located on one side of the circumference, and the multiple second arc-shaped portions are each 180° and are all located on the opposite side of the circumference.

7. The crystal growth apparatus according to claim 1, characterized in that: The first end and the second end are respectively located at the two radially opposite ends of the outermost ring of the resistor.

8. The crystal growth apparatus according to claim 7, characterized in that: The crystal growth device also includes a pair of first and second electrodes respectively inserted into the heat insulation cover, a first bolt for connecting the first electrode and the first end, and a second bolt for connecting the second electrode and the second end.

9. The crystal growth apparatus according to claim 1, characterized in that: The crystal growth apparatus further includes a heat-insulating ring disposed between the upper heater and the crucible, wherein the inner diameter of the heat-insulating ring is smaller than the inner diameter of the lower heater.

10. The crystal growth apparatus according to claim 9, characterized in that: The crucible includes a crucible body and a crucible lid covering the crucible body, wherein the inner diameter of the heat-insulating ring is larger than the diameter of the crucible lid.

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