Silicon carbide crystal growth furnace

Abstract

The utility model discloses a silicon carbide crystal growth furnace, which relates to the technical field of crystal growth and comprises a furnace body and a temperature measuring component. A temperature measuring window is arranged on a furnace cover of the furnace body; a crucible is arranged in the furnace body; the temperature measuring assembly comprises an infrared thermometer arranged on a temperature measuring window of the furnace cover; the isolation pipe is arranged in the furnace body, and at least part of the upper end of the isolation pipe penetrates through the hole in the temperature measuring window and is aligned with the infrared thermometer; and the lower end of the isolation pipe is arranged above the crucible. According to the utility model, the isolation pipe is adopted to effectively isolate high-temperature sublimation atmosphere and various impurities from polluting or accumulating and blocking the temperature measuring window and the temperature measuring channel, so that infrared rays are prevented from being shielded, and the infrared thermometer can effectively and accurately measure the temperature in the silicon carbide crystal growth furnace.

Description

Technical Field

[0001] The utility model relates to the technical field of crystal growth, in particular to a silicon carbide crystal growth furnace. Background Art

[0002] The existing PVT method silicon carbide crystal growth furnace uses an induction coil to induction heat the graphite heating barrel or crucible in the heat preservation field, so that the raw materials at the bottom of the crucible are sublimated at high temperature and gradually crystallized at the seed crystal at the top of the crucible. There are two main modes of process control: (1) power control mode: the curing power is set by formula, and the actual temperature in the heat field is unknown; (2) temperature control mode: holes are opened on the crucible top cover and the upper and lower insulation felts, and the power and the temperature in the heat field are controlled by the top infrared thermometer. The axial temperature gradient of the heat field is understood by the temperature difference between the top and bottom.

[0003] Regarding (1) power control mode, due to the full power control, the actual temperature in the hot field during operation is unknown, and the formula cannot be adjusted according to the temperature ratio of the hot field. The only way to judge whether the temperature field in the crucible meets the crystal growth requirements is to look at the appearance and quality of the crystal after the furnace is opened. (2) temperature control mode: although infrared thermometers are installed on the top and bottom of the hot field furnace, due to the holes in the insulation material, the high-temperature sublimation atmosphere inside the hot field and the volatile carbon felt and graphite impurities are polluted through the holes. In severe cases, the holes in the insulation material are blocked by accumulation, completely blocking the infrared laser, making it impossible to measure the crucible cover temperature in a timely and accurate manner. The bottom temperature measurement is also low and will cause heat dissipation at the bottom of the crucible, affecting the high-temperature sublimation rate of the raw materials.

[0004] Therefore, the current mainstream power control mode of the PVT method silicon carbide induction crystal growth furnace has an unknown temperature in the thermal field, and the temperature control mode of infrared temperature measurement is extremely inaccurate, so both modes cannot meet the process requirements and cannot stably measure the temperature of the top and bottom of the crucible. Utility Model Content

[0005] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model provides a silicon carbide crystal growth furnace.

[0006] According to an embodiment of the utility model, a silicon carbide crystal growth furnace is provided, comprising:

[0007] A furnace body; a temperature measuring window is arranged on the furnace cover of the furnace body, and a crucible is arranged in the furnace body;

[0008] Temperature measuring component; the temperature measuring component comprises:

[0009] Infrared thermometer; the infrared thermometer is arranged on the temperature measuring window of the furnace cover;

[0010] An isolation tube; the isolation tube is arranged in the furnace body, the upper end of the isolation tube at least partially penetrates the hole on the temperature measuring window and is aligned with the infrared thermometer, and the lower end of the isolation tube is arranged above the crucible.

[0011] In an optional manner, the isolation tube includes an inner tube and an outer tube, and the inner tube can move up and down along the inner wall of the outer tube.

[0012] In an optional manner, the outer tube includes a first outer tube having a hollow cavity; the inner tube includes a first inner tube having a hollow cavity, and the inner diameter of the first outer tube is greater than or equal to the outer diameter of the first inner tube.

[0013] In an optional embodiment, the outer tube also includes a second outer tube having a hollow cavity arranged below the first outer tube, and the inner tube also includes a second inner tube having a hollow cavity arranged below the first inner tube, the inner diameter of the second outer tube is smaller than the outer diameter of the first inner tube, and the outer diameter of the second outer tube is greater than or equal to the outer diameter of the second inner tube.

[0014] In an optional manner, the outer diameter of the first outer tube is smaller than the outer diameter of the second outer tube.

[0015] In an optional manner, the crucible is provided with a crucible cover, and the lower end of the isolation tube is arranged above the crucible cover.

[0016] In an optional manner, at least one heat-insulating cover is disposed on the crucible cover, and a first through hole is disposed on the heat-insulating cover.

[0017] In an optional embodiment, the isolation tube includes an inner tube and an outer tube. Along the axial direction of the silicon carbide crystal growth furnace, a pressure ring is provided on the insulation cover closest to the furnace cover, and a second through hole is provided on the pressure ring; the lower end of the outer tube is provided at the upper end of the pressure ring; the inner tube passes through the insulation cover and the pressure ring, and is provided below the insulation cover and above the crucible cover.

[0018] In an optional manner, the pressure ring is detachably connected to the outer tube;

[0019] In an optional manner, along the axial direction of the silicon carbide crystal growth furnace, the length of the outer tube is smaller than the length of the inner tube.

[0020] In an optional embodiment, the isolation tube is made of a material that can withstand high temperatures above 2300 degrees.

[0021] In an optional manner, the isolation tube is made of graphite, quartz ceramic, or silicon nitride ceramic.

[0022] In an optional manner, the temperature measuring window is arranged at the center of the furnace cover.

[0023] Compared with the prior art, the utility model has the following beneficial effects:

[0024] (1) An isolation tube is used to effectively isolate the high-temperature sublimation atmosphere and various impurities from polluting or clogging the temperature measuring window and the temperature measuring channel, avoiding blocking of infrared rays, so that the infrared thermometer can effectively and accurately measure the temperature in the silicon carbide crystal growth furnace.

[0025] (2) The isolation tube adopts an inner and outer tube structure, and the inner tube is movable, so that the temperature of the entire path set by the inner and outer tubes can be effectively measured, so that the temperature distribution in the entire silicon carbide crystal growth furnace can be more effectively measured, and then the temperature gradient in the silicon carbide crystal growth furnace can be effectively controlled, effectively improving the crystal quality.

[0026] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0028] Figure 1 A schematic diagram of the front cross-sectional structure of an embodiment of a silicon carbide crystal growth furnace provided by the utility model;

[0029] Figure 2 for Figure 1 Schematic diagram of the main cross-sectional structure without the isolation tube installed;

[0030] Figure 3 A schematic diagram of the structure of the isolation tube provided by the utility model;

[0031] Reference numerals:

[0032] 10-furnace cover; 11-temperature measuring window; 20-temperature measuring assembly; 21-infrared thermometer; 22-isolation tube; 221-outer tube; 2211-first outer tube; 2212-second outer tube; 222-inner tube; 2221-first inner tube; 2222-second inner tube; 30-graphite crucible; 31-crucible cover; 40-insulation cover; 41-first through hole; 50-pressure ring; 51-second through hole. DETAILED DESCRIPTION

[0033] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0034] The disclosure below provides many different embodiments or examples for realizing different structures of the utility model. In order to simplify the disclosure of the utility model, the components and settings of specific examples are described below. Of course, they are merely examples, and the purpose is not to limit the utility model. In addition, the utility model can repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the utility model provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the applicability of other processes and / or the use of other materials.

[0035] Below, refer to the attached Figure 1 , describes a silicon carbide crystal growth furnace according to an embodiment of the utility model, the silicon carbide crystal growth furnace includes a furnace body, a accommodating space is provided in the furnace body, a crucible 30 is arranged in the furnace body, the crucible 30 can be a graphite crucible, a furnace cover 10 is provided on the furnace body, and a temperature measuring window 11 is provided on the furnace cover 10; the temperature measuring component 20 includes an infrared thermometer 21 and an isolation tube 22; the infrared thermometer 21 is installed on the temperature measuring window 11 on the furnace cover 10, and the upper end of the isolation tube 22 at least partially penetrates the hole on the temperature measuring window 11 and is aligned with the infrared thermometer; the lower end of the isolation tube 22 is arranged above the crucible 30, and the infrared thermometer 21 measures the temperature in the crystal growth furnace through the temperature measuring window 11 on the furnace cover 10 and the isolation tube 22 under the measuring window and aligned with the infrared thermometer 21.

[0036] In the utility model, the top infrared temperature measuring window 11 is connected to the top of the crucible 30 in a sealed manner by installing an isolation tube 22, so as to avoid or reduce the pollution or clogging of the temperature measuring window 11 by the high-temperature sublimation atmosphere and impurities, so that the infrared thermometer 21 can effectively and accurately measure the temperature of the top cover of the crucible 30.

[0037] In some embodiments, the temperature measuring window 11 is disposed at the center of the furnace cover 10 , thereby making the measured temperature more accurate.

[0038] In some embodiments, the isolation tube 22 includes an inner tube 222 and an outer tube 221, and the inner tube 222 can move up and down along the inner wall of the outer tube 221. Thus, the length of the isolation tube 22 can be freely selected by moving the inner tube 222, so that the temperature in different silicon carbide crystal growth furnaces can be measured.

[0039] In some specific embodiments, the outer tube 221 includes a first outer tube 2211 having a hollow cavity; the first outer tube 2211 includes a hollow cavity and an outer shell; the inner tube 222 includes a first inner tube 2221 having a hollow cavity; the first inner tube 2221 includes a hollow cavity and an outer shell; the outer diameter of the first inner tube 2221 is less than or equal to the inner diameter of the first outer tube 2211, preferably, the difference between the outer diameter of the first inner tube 2221 and the inner diameter of the first outer tube 2211 is 0-2mm, thereby enabling the first inner tube 2221 to move better inside the first outer tube 2211.

[0040] In some specific embodiments, a second outer tube 2212 is disposed below the first outer tube 2211. The second outer tube 2212 is a tube with a hollow cavity, including a hollow cavity and an outer tube 221; a second inner tube 2222 with a hollow cavity is disposed below the first inner tube 2221. The inner diameter of the second outer tube 2212 is smaller than the outer diameter of the first inner tube 2221, and the outer diameter of the second outer tube 2212 is greater than or equal to the outer diameter of the second inner tube 2222. Thus, the inner tube 222 can be prevented from falling off from the outer tube 221, so that the path of the first inner tube 2221 is limited above the second outer tube 2212, and the second inner tube 2222 moves out of the second outer tube 2212, thereby effectively realizing the control of the length of the isolation tube 22.

[0041] In an optional manner, the crucible 30 is provided with a crucible cover 31, and the lower end of the isolation tube 22 is arranged above the crucible cover 31. In a specific embodiment, the distance between the isolation tube 22 and the top of the crucible cover 31 is 2-10 mm, for example, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm or 10 mm; thereby, the infrared thermometer 21 can better measure the temperature gradient in the silicon carbide crystal growth furnace.

[0042] In some specific embodiments, the inner diameter of the second inner tube 2222 is 10-20 mm, for example, it can be 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, or 20 mm; thereby, not only will it not affect the effect of the isolation tube 22 on the insulation of the insulation cover 40, but it will also not affect the temperature measurement of the infrared thermometer 21.

[0043] In an optional manner, at least one heat-insulating cover 40 is disposed on the crucible cover 31 , and a first through hole 41 is disposed on the heat-insulating cover 40 .

[0044] In an optional manner, the isolation tube 22 includes an inner tube 222 and an outer tube 221. Along the axial direction of the silicon carbide crystal growth furnace, a pressure ring 50 is provided on the heat preservation cover 40 closest to the furnace cover 10. The pressure ring 50 may be a graphite pressure ring 50, and a second through hole 51 is provided on the pressure ring 50. The lower end of the outer tube 221 is provided at the upper end of the pressure ring 50. The inner tube 222 passes through the heat preservation cover 40 and the pressure ring 50, and is provided below the heat preservation cover 40 and above the crucible 30 cover 31. In this way, the isolation tube 22 can be more stably provided in the silicon carbide crystal growth furnace, and the isolation tube 22 will not affect the furnace temperature of the silicon carbide crystal growth furnace.

[0045] In an optional manner, the pressure ring 50 is detachably connected to the outer tube 221. For example, the connection may be made more convenient and free by means of clamping, welding, pin connection, screw connection, bolt connection, convex-concave groove connection, etc., so that the connection between the isolation tube 22 and the pressure ring 50 can be made more convenient and free.

[0046] In a specific embodiment, the outer diameter of the first outer tube 2211 is smaller than the outer diameter of the second outer tube 2212. This can make the connection between the second outer tube 2212 and the pressure ring 50 more stable.

[0047] In an optional manner, along the axial direction of the silicon carbide crystal growth furnace, the length of the outer tube 221 is smaller than the length of the inner tube 222. The inner tube 222 has a smaller aperture, and the outer tube 221 has a larger aperture. Using the inner tube 222 with a smaller aperture can prevent the heat preservation in the silicon carbide furnace from being damaged.

[0048] In an optional manner, the isolation tube 22 is made of a material that can withstand temperatures above 2300 degrees, such as graphite, quartz ceramics, silicon nitride ceramics, etc. Thus, the isolation tube 22 can be used in a silicon carbide crystal growth furnace.

[0049] In an optional manner, the temperature measuring window 11 is arranged at the center of the furnace cover 10. This can make the measured temperature more accurate.

[0050] The method for installing and removing the isolation tube 22 of the utility model is as follows:

[0051] Installation of the isolation tube 22: After placing the crucible 30 and the insulation cover 40, ensure that the pressure ring 50 is in the center of the heat field by measuring the perimeter of the four sides, and place the second outer tube 2212 of the isolation tube 22 on the pressure ring 50 of the upper insulation cover 40. Place the inner tube 222 into the outer tube 221, and then when rotating and lowering the furnace cover 10, observe and confirm that the upper end of the first outer tube 2211 is aligned with the infrared temperature measuring hole on the furnace cover 10, indicating that the isolation tube 22 kit has been installed in place.

[0052] Disassembly of the isolation tube 22: Open the furnace cover 10, extract the isolation tube 22 and the pressure ring 50 together, then disassemble the isolation tube 22 and the pressure ring 50, decompose the outer tube 221, the pressure ring 50, the inner tube 222, and then take out the insulation cover 40 and the crucible 30 in turn.

[0053] The following describes in detail the feeding device provided by the utility model with several specific embodiments. It is worth noting that the following description is only an exemplary description and not a specific limitation of the invention. Example

[0054] like Figure 1-3 As shown, the silicon carbide crystal growth furnace includes a furnace body, a crucible 30 is arranged in the furnace body, a furnace cover 10 is arranged on the furnace body, and a temperature measuring window 11 is arranged on the furnace cover 10; the temperature measuring component 20 includes an infrared thermometer 21 and an isolation tube 22; the infrared thermometer 21 is installed on the temperature measuring window 11 on the furnace cover 10, and the upper end portion of the isolation tube 22 passes through the hole on the temperature measuring window 11 and is aligned with the infrared thermometer;

[0055] The isolation tube 22 includes an inner tube 222 and an outer tube 221; the outer tube 221 includes a first outer tube 2211 having a hollow cavity and a second outer tube 2212 having a hollow cavity; the inner tube 222 includes a first inner tube 2221 having a hollow cavity and a second inner tube 2222 having a hollow cavity; the outer diameter of the first inner tube 2221 is equal to the inner diameter of the first outer tube 2211; the inner diameter of the second outer tube 2212 is smaller than the outer diameter of the first inner tube 2221, and the outer diameter of the second outer tube 2212 is equal to the outer diameter of the second inner tube 2222; the inner diameter of the second inner tube 2222 is 10 mm;

[0056] A crucible 30 cover 31 is arranged above the crucible 30, and two insulation covers 40 are arranged on the crucible 30 cover 31, wherein a pressure ring 50 is arranged on the insulation cover 40 away from the crucible 30, and through holes are arranged on the insulation cover 40 and the pressure ring 50, and the second outer tube 2212 of the isolation tube 22 is connected to the pressure ring 50 by screws, and the inner tube 222 passes through the insulation cover 40 and the pressure ring 50, and its lower end is arranged 5 mm above the crucible 30 cover 31, and the isolation tube 22 is made of quartz ceramic.

[0057] Other structures and operations of the silicon carbide crystal growth furnace according to the embodiment of the utility model are known to ordinary technicians in the field and will not be described in detail here.

[0058] In the description of the present utility model, it is necessary to understand that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, "multiple" means two or more.

[0059] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0060] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0061] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A silicon carbide crystal growth furnace, characterized in that: include: Furnace body; A temperature measuring window is provided on the furnace cover of the furnace body; A crucible is arranged in the furnace body; Temperature measuring components; The temperature measuring component comprises: Infrared thermometer; the infrared thermometer is arranged on the temperature measuring window of the furnace cover; An isolation tube; the isolation tube is arranged in the furnace body, the upper end of the isolation tube at least partially penetrates the hole on the temperature measuring window and is aligned with the infrared thermometer; the lower end of the isolation tube is arranged above the crucible.

2. The silicon carbide crystal growth furnace according to claim 1, characterized in that: The isolation tube comprises an inner tube and an outer tube, and the inner tube can move up and down along the inner wall of the outer tube.

3. The silicon carbide crystal growth furnace according to claim 2, characterized in that: The outer tube includes a first outer tube having a hollow cavity; the inner tube includes a first inner tube having a hollow cavity, and the inner diameter of the first outer tube is greater than or equal to the outer diameter of the first inner tube.

4. The silicon carbide crystal growth furnace according to claim 3, characterized in that: The outer tube also includes a second outer tube having a hollow cavity arranged below the first outer tube, and the inner tube also includes a second inner tube having a hollow cavity arranged below the first inner tube, the inner diameter of the second outer tube is smaller than the outer diameter of the first inner tube, and the inner diameter of the second outer tube is greater than or equal to the outer diameter of the second inner tube.

5. The silicon carbide crystal growth furnace according to claim 4, characterized in that: The outer diameter of the first outer tube is smaller than the outer diameter of the second outer tube.

6. The silicon carbide crystal growth furnace according to claim 1 or 2, characterized in that: The crucible is provided with a crucible cover, and the lower end of the isolation tube is arranged above the crucible cover.

7. The silicon carbide crystal growth furnace according to claim 6, characterized in that: At least one heat-insulating cover is arranged on the crucible cover, and a first through hole is arranged on the heat-insulating cover.

8. The silicon carbide crystal growth furnace according to claim 7, characterized in that: The isolation tube includes an inner tube and an outer tube. Along the axial direction of the silicon carbide crystal growth furnace, a pressure ring is arranged on the insulation cover closest to the furnace cover, and a second through hole is arranged on the pressure ring; the lower end of the outer tube is arranged on the upper end of the pressure ring; the inner tube passes through the insulation cover and the pressure ring, and is arranged below the insulation cover and above the crucible cover.

9. The silicon carbide crystal growth furnace according to claim 8, characterized in that: The pressure ring is detachably connected to the outer tube; and / or, along the axial direction of the silicon carbide crystal growth furnace, the length of the outer tube is smaller than the length of the inner tube.

10. The silicon carbide crystal growth furnace according to claim 1, characterized in that: The temperature measuring window is arranged at the center of the furnace cover.

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