Gallium oxide crystal growing device

Abstract

The invention provides a growth device of gallium oxide crystals, and relates to the technical field of semiconductor preparation. The growth device comprises a heater and a crucible for placing gallium oxide crystals, the heater is of a barrel-shaped structure, and the side wall of the heater is thin and thick; the crucible is placed in the heater, and the side wall of the crucible is thin and the bottom of the crucible is thick. According to the method, the axial temperature gradient of the temperature field can be obviously reduced, and the problem of cracking of the gallium oxide crystal is effectively solved, so that the growth quality and efficiency of the gallium oxide crystal are improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor manufacturing technology, and in particular to a gallium oxide crystal growth device. Background Art

[0002] β-phase gallium oxide single crystal is a transparent conductive oxide with a bandgap of 4.8eV and a high electric field strength of 8MV / cm. It has high voltage resistance and is very suitable for optoelectronic devices and high voltage devices. The melting point of gallium oxide single crystal is relatively high (about 1820℃), and it is very easy to decompose and volatilize during the high-temperature growth process, which makes the gallium oxide single crystal unstable during the growth process, and the temperature field is difficult to control, resulting in a large axial temperature gradient and the grown crystal is prone to cracking. Summary of the invention

[0003] The present application provides a gallium oxide crystal growth device to solve the problem that the gallium oxide crystals grown in the prior art are prone to cracking.

[0004] In a first aspect, the present application provides a gallium oxide crystal growth device, the growth device comprising a heater and a crucible for placing the gallium oxide crystal; The heater is a barrel-shaped structure, and the side wall of the heater is thin at the top and thick at the bottom; The crucible is placed in the heater, and a side wall of the crucible is thin at the top and thick at the bottom.

[0005] In a possible implementation, the thickness of the side wall of the heater increases linearly from top to bottom; The thickness of the side wall of the crucible increases linearly from top to bottom.

[0006] In a possible implementation, the ratio of the upper surface thickness to the lower surface thickness of the side wall of the heater is in a range of 1%-75%.

[0007] In a possible implementation, the thickness of the lower surface of the side wall of the heater is less than or equal to 3 mm.

[0008] In a possible implementation, the thickness of the upper surface of the side wall of the heater is greater than or equal to 1 mm.

[0009] In a possible implementation, the height of the heater ranges from 10 to 200 mm.

[0010] In a possible implementation, the ratio of the upper surface thickness to the lower surface thickness of the side wall of the crucible is in a range of 1%-50%.

[0011] In a possible implementation, the thickness of the lower surface of the side wall of the crucible is less than or equal to 3 mm.

[0012] In a possible implementation, the thickness of the upper surface of the side wall of the crucible is greater than or equal to 1.5 mm.

[0013] In a possible implementation, the height of the crucible ranges from 10 to 120 mm.

[0014] The present application provides a gallium oxide crystal growth device, which includes a heater and a crucible for placing the gallium oxide crystal; the heater is a barrel-shaped structure, and the side wall of the heater is thin at the top and thick at the bottom; the crucible is placed in the heater, and the side wall of the crucible is thin at the top and thick at the bottom. The present application uses a barrel-shaped heater and a crucible that are thin at the top and thick at the bottom, and have uneven thickness. According to the resistance current law, the thin-layer heater has a larger resistance and high heating efficiency, and can significantly reduce the axial temperature gradient of the temperature field, effectively solving the gallium oxide crystal cracking problem, thereby improving the quality and efficiency of gallium oxide crystal growth. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0016] Figure 1 It is a schematic diagram of the structure of a conventional heater; Figure 2 It is a schematic structural diagram of a gallium oxide crystal growth device provided in an embodiment of the present application; Figure 3 is a side sectional view of a heater provided in an embodiment of the present application; Figure 4 is a schematic diagram of a side wall of a heater provided in an embodiment of the present application; Figure 5 is a side cross-sectional view of a crucible provided in an embodiment of the present application; Figure 6 It is a schematic diagram of a side wall of a crucible provided in an embodiment of the present application. DETAILED DESCRIPTION

[0017] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0018] In order to make the purpose, technical solutions and advantages of the present application clearer, specific embodiments will be described below in conjunction with the accompanying drawings.

[0019] Gallium oxide is an ultra-wide bandgap semiconductor material. It is difficult to establish a thermal field for its crystal growth, and a heater is needed to establish a thermal field for growth.

[0020] In the prior art, reference Figure 1 The heaters are all of equal thickness, that is, the side walls of the heaters are of equal thickness. Since the heat field is insulated below and there are openings and observation windows above, such a structure will form an axial temperature gradient with cold top and hot bottom. In the actual growth process, if the axial temperature gradient is too large, the grown crystals will crack, which is not conducive to improving the quality and efficiency of crystal growth.

[0021] Therefore, the embodiment of the present application provides a gallium oxide crystal growth device, which selects a barrel-shaped heater and crucible with a thin top and thick bottom and uneven thickness. According to the resistance current law, the thin layer heater has a larger resistance and high heating efficiency. This can significantly reduce the axial temperature gradient of the temperature field and effectively solve the problem of cracking of the gallium oxide crystal.

[0022] Figure 2 This is a schematic diagram of the structure of the gallium oxide crystal growth device provided in the embodiment of the present application. Figure 2 As shown, the gallium oxide crystal growth device includes a heater 1 and a crucible 2 for placing the gallium oxide crystal.

[0023] The heater 1 is a barrel-shaped structure, and the side wall of the heater 1 is thin at the top and thick at the bottom.

[0024] The crucible 2 is placed in the heater 1 , and the side wall of the crucible 2 is thin at the top and thick at the bottom.

[0025] In the embodiment of the present application, the gallium oxide crystal is a gallium oxide single crystal.

[0026] The embodiment of the present application designs the side wall of the heater to be a structure that is thin at the top and thick at the bottom, so that the temperature distribution inside the heater can be more effectively controlled. This design helps to reduce the axial temperature gradient on the side wall of the heater, making the temperature inside the heater, especially around the crucible, more uniform, thereby improving the quality of gallium oxide crystal growth. The thickened design of the lower part of the heater side wall not only enhances the structural stability, but also improves the heat conduction efficiency at the bottom of the heater. When growing crystals by the guided mold method, it is necessary to ensure that sufficient heat is transferred to the bottom of the crucible to maintain the gallium oxide in a molten state, while avoiding thermal stress or crystal defects caused by overheating. This design helps to accurately control the temperature and optimize the growth conditions.

[0027] In addition, the crucible side wall in the embodiment of the present application also adopts a design of being thin at the top and thick at the bottom, which helps to reduce heat loss during the growth process. The thickness variation of the crucible side wall can reduce unnecessary heat radiation and heat conducted to the environment, so that more heat energy can be used to maintain the molten state of gallium oxide and crystal growth, thereby improving energy utilization efficiency.

[0028] Furthermore, due to the optimization of the temperature uniformity and heat conduction efficiency, the growth device provided in the embodiment of the present application can provide a more stable growth environment, which is conducive to reducing defects such as stress, cracks and inclusions during the crystal growth process, thereby significantly improving the quality and purity of gallium oxide crystals. This is crucial for the preparation of high-performance electronic devices, optical components and semiconductor materials.

[0029] Finally, the barrel-shaped heater design is easy to install and maintain, while also providing operators with better visibility and operating space. In addition, by precisely controlling the temperature distribution of the heater, safety risks caused by overheating or temperature fluctuations can be reduced.

[0030] Based on the above discussion, it can be seen that the embodiment of the present application adopts a heater and crucible design that is thin on the top and thick on the bottom. According to the resistance current law, the thin layer heater has a larger resistance and high heating efficiency, which can significantly reduce the axial temperature gradient of the temperature field and effectively solve the problem of crystal cracking.

[0031] In a possible implementation, the thickness of the side wall of the heater increases linearly from top to bottom.

[0032] Reference Figure 3 The thickness of the side wall of the heater 1 increases uniformly from top to bottom, that is, the thickness of the side wall of the heater 1 increases linearly from top to bottom, which can ensure that the heating efficiency of the heater decreases from top to bottom, and there will be no sudden drop in heating. The embodiment of the present application reduces the axial temperature gradient on the side wall of the heater by designing a structure in which the thickness of the side wall of the heater increases linearly from top to bottom, so that the temperature inside the heater, especially the crucible period, is more uniform, thereby improving the quality of the gallium oxide crystal.

[0033] In a possible implementation, the ratio of the upper surface thickness to the lower surface thickness of the side wall of the heater is in a range of 1%-75%.

[0034] Reference Figure 4 , the upper surface thickness of the side wall of the heater 1 is The thickness of the lower surface is , then the upper surface thickness Thickness of lower surface The ratio calculation formula is:

[0035] in, It is the ratio of the upper surface thickness to the lower surface thickness of the side wall of the heater. The ratio is a range. In the embodiment of the present application, the ratio ranges from 1% to 75%.

[0036] In a possible implementation, the thickness of the lower surface of the side wall of the heater is less than or equal to 3 mm.

[0037] Reference Figure 4 , the thickness of the lower surface of the side wall of the heater 1 The maximum is 3mm.

[0038] In a possible implementation, the thickness of the upper surface of the side wall of the heater is greater than or equal to 1 mm.

[0039] Reference Figure 4 , the upper surface thickness of the side wall of the heater 1 Minimum 1mm, and the upper surface thickness The maximum value is no more than 2.97mm and must be smaller than the thickness of the lower surface Maximum thickness.

[0040] For example, the upper surface thickness of the side wall of a heater is 1.5 mm, and the lower surface thickness is 3 mm. Then the ratio of the upper surface thickness to the lower surface thickness of the side wall of the heater is 50%, which satisfies the ratio range of 1%-75%.

[0041] In a possible implementation, the height of the heater ranges from 10 to 200 mm.

[0042] According to the actual heating requirements, the height range of the barrel-shaped heater designed in the embodiment of the present application is between 10-200 mm. Figure 4 , the height of heater 1 It is 100mm, meeting the height range of 10-200mm.

[0043] In a possible implementation, the thickness of the side wall of the crucible increases linearly from top to bottom.

[0044] Reference Figure 5 , the thickness of the side wall of the crucible 2 increases uniformly from top to bottom, that is, the thickness of the side wall of the crucible 2 increases linearly from top to bottom, which helps to reduce the heat loss during the growth of gallium oxide crystals. The embodiment of the present application utilizes the thickness change of the crucible side wall to reduce unnecessary heat radiation and heat conducted to the environment, so that more heat energy is used to maintain the molten state of gallium oxide and crystal growth, thereby improving energy utilization efficiency.

[0045] In a possible implementation, the ratio of the upper surface thickness to the lower surface thickness of the side wall of the crucible is in a range of 1%-50%.

[0046] Reference Figure 6 The upper surface thickness of the side wall of crucible 2 is The thickness of the lower surface is , then the upper surface thickness Thickness of lower surface The ratio calculation formula is:

[0047] in, It is the ratio of the upper surface thickness to the lower surface thickness of the side wall of the crucible. The ratio is a range. In the embodiment of the present application, the ratio ranges from 1% to 50%.

[0048] In a possible implementation, the thickness of the lower surface of the side wall of the crucible is less than or equal to 3 mm.

[0049] Reference Figure 6 , the lower surface thickness of the side wall of the crucible 2 The maximum is 3mm.

[0050] In a possible implementation, the thickness of the upper surface of the side wall of the crucible is greater than or equal to 1.5 mm.

[0051] Reference Figure 6 , the upper surface thickness of the side wall of crucible 2 Minimum 1.5mm, and the upper surface thickness The maximum value is no more than 2.97mm and must be smaller than the thickness of the lower surface Maximum thickness.

[0052] For example, the upper surface thickness of the side wall of a crucible is 1.5 mm, and the lower surface thickness is 3 mm. Then the ratio of the upper surface thickness to the lower surface thickness of the side wall of the crucible is 50%, which satisfies the ratio range of 1%-50%.

[0053] In a possible implementation, the height of the crucible is in the range of 10-120 mm.

[0054] According to actual needs, and because the crucible is placed in the heater, the height of the crucible shall not be higher than the height of the heater. The height range of the crucible designed in the embodiment of the present application is between 10-120 mm. For example, referring to Figure 6 , the height of crucible 2 The crucible height is 80 mm, which satisfies the crucible height range of 10-200 mm, and the crucible will not be exposed when placed in the heater.

[0055] The gallium oxide crystal growth device provided in the embodiment of the present application is used to grow the crystal using the temperature field structure. The specific growth method is as follows: The square mold is placed in a crucible for growing a gallium oxide single crystal, and 200 to 500 g of a gallium oxide polycrystalline raw material with a purity of 6N is weighed and placed in the crucible.

[0056] Among them, the square mold is a device for growing gallium oxide crystals.

[0057] It should be noted here that the gallium oxide polycrystalline raw material is placed in a crucible, and after the gallium oxide is melted, it is attracted into the square mold in the crucible by capillary action.

[0058] The crucible with the gallium oxide polycrystalline raw material is placed in a barrel-shaped heater structure with a thin top and a thick bottom.

[0059] Place the entire set of thermal fields into the crystal growth furnace.

[0060] The seed crystal is loaded into the single crystal growth furnace. The specific operation of the seed crystal in the single crystal growth furnace is as follows: First, after the single crystal growth furnace is evacuated, the temperature of the furnace body of the single crystal growth furnace is raised to 1950-2000°C at a temperature increase rate of 200-500°C / h, and the temperature is maintained for 2 hours.

[0061] Then, slowly place the seed crystal into the center of the square mold in the crucible until the seed crystal contacts the square mold. After the bottom of the seed crystal melts 1-10 mm, pull the seed crystal upward at a pulling speed of 15-25 mm / h. At the same time, cool the furnace body of the single crystal growth furnace at a cooling rate of 1-10°C / h.

[0062] Secondly, after the seed crystal has finished growing, the crystal is completely pulled out to above the square mold.

[0063] Finally, after the crystal is completely pulled out to above the square mold, the growth furnace is cooled at a rate of 200-500°C / h.

[0064] By using the gallium oxide crystal growth device provided in the embodiment of the present application and the above-mentioned growth process, high-quality gallium oxide crystals can be grown.

[0065] The present application provides a gallium oxide crystal growth device, which includes a heater and a crucible for placing the gallium oxide crystal; the heater is a barrel-shaped structure, and the side wall of the heater is thin at the top and thick at the bottom; the crucible is placed in the heater, and the side wall of the crucible is thin at the top and thick at the bottom. The present application uses a barrel-shaped heater and a crucible that are thin at the top and thick at the bottom, and have uneven thickness. According to the resistance current law, the thin-layer heater has a larger resistance and high heating efficiency, and can significantly reduce the axial temperature gradient of the temperature field, effectively solving the gallium oxide crystal cracking problem, thereby improving the quality and efficiency of gallium oxide crystal growth.

[0066] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0067] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A gallium oxide crystal growth device, characterized in that: The growth device includes a heater and a crucible for placing gallium oxide crystals; The heater is a barrel-shaped structure, and the side wall of the heater is thin at the top and thick at the bottom; The crucible is placed in the heater, and a side wall of the crucible is thin at the top and thick at the bottom.

2. The gallium oxide crystal growth device according to claim 1, characterized in that: The thickness of the side wall of the heater increases linearly from top to bottom; The thickness of the side wall of the crucible increases linearly from top to bottom.

3. The gallium oxide crystal growth device according to claim 1, characterized in that: The ratio of the upper surface thickness to the lower surface thickness of the side wall of the heater is in the range of 1% to 75%.

4. The gallium oxide crystal growth device according to claim 3, characterized in that: The thickness of the lower surface of the side wall of the heater is less than or equal to 3 mm.

5. The gallium oxide crystal growth device according to claim 4, characterized in that: The thickness of the upper surface of the side wall of the heater is greater than or equal to 1 mm.

6. The gallium oxide crystal growth device according to claim 1, characterized in that: The height of the heater ranges from 10 to 200 mm.

7. The gallium oxide crystal growth device according to claim 1, characterized in that: The ratio of the upper surface thickness to the lower surface thickness of the side wall of the crucible is in the range of 1%-50%.

8. The gallium oxide crystal growth device according to claim 7, characterized in that: The thickness of the lower surface of the side wall of the crucible is less than or equal to 3 mm.

9. The gallium oxide crystal growth device according to claim 7, characterized in that: The thickness of the upper surface of the side wall of the crucible is greater than or equal to 1.5 mm.

10. The gallium oxide crystal growth device according to claim 1, characterized in that: The height of the crucible ranges from 10 to 120 mm.

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