A growth device for growing gallium oxide crystals

Abstract

The present application provides a growth device for growing gallium oxide crystals, and relates to the field of semiconductor preparation technology. The growth device includes: a heater and a crucible for placing gallium oxide crystals; the heater and the crucible are both barrel-shaped structures, and the crucible is placed in the heater; the slope of the side wall of the heater is smaller than the slope of the side wall of the crucible, and the radius of the upper end face of the heater is larger than the radius of the lower end face of the crucible; wherein the slope of the side wall of the heater is the ratio of the difference between the diameter of the upper end face of the heater and the diameter of the lower end face to the height of the heater, and the slope of the side wall of the crucible is the ratio of the difference between the diameter of the upper end face of the crucible and the diameter of the lower end face to the height of the crucible. The present application can significantly reduce the axial temperature gradient of the temperature field, effectively solve the problem of cracking of gallium oxide crystals, and thus improve the quality and efficiency of gallium oxide crystal growth.

Description

Technical Field

[0001] The present application relates to the field of semiconductor preparation technology, and in particular to a growth device for growing gallium oxide crystals. 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 growing device for growing gallium oxide crystals, so as to solve the problem that the grown gallium oxide crystals in the prior art are prone to cracking.

[0004] In a first aspect, the present application provides a growth device for growing gallium oxide crystals, the growth device comprising a heater and a crucible for placing the gallium oxide crystals;

[0005] The heater and the crucible are both barrel-shaped structures, and the crucible is placed in the heater;

[0006] The slope of the side wall of the heater is smaller than the slope of the side wall of the crucible, and the radius of the upper end surface of the heater is larger than the radius of the lower end surface of the crucible;

[0007] Among them, the slope of the side wall of the heater is the ratio of the difference between the diameter of the upper end surface of the heater and the diameter of the lower end surface to the height of the heater, and the slope of the side wall of the crucible is the ratio of the difference between the diameter of the upper end surface of the crucible and the diameter of the lower end surface to the height of the crucible.

[0008] In a possible implementation, the longitudinal section of the heater is a trapezoidal shape that is smaller at the top and larger at the bottom;

[0009] The longitudinal section of the crucible is a trapezoid that is small at the top and large at the bottom.

[0010] In a possible implementation, the radii of the multiple cross sections of the heater increase linearly from top to bottom;

[0011] The radii of the multiple cross sections of the crucible increase linearly from top to bottom.

[0012] In a possible implementation, the ratio of the diameter of the lower end surface of the heater to the diameter of the upper end surface is in the range of 1.1-4.

[0013] In a possible implementation, the diameter of the lower end surface of the heater is greater than or equal to 33 mm and less than or equal to 120 mm.

[0014] In a possible implementation, the diameter of the upper end surface of the heater is less than or equal to 30 mm.

[0015] In a possible implementation, the ratio of the diameter of the lower end surface of the crucible to the diameter of the upper end surface is in the range of 1.1-3.

[0016] In a possible implementation, the diameter of the lower end surface of the crucible is greater than or equal to 27.5 mm and less than or equal to 75 mm.

[0017] In a possible implementation, the diameter of the upper end surface of the crucible is less than or equal to 25 mm.

[0018] In a possible implementation, the height of the heater ranges from 10 to 200 mm;

[0019] The height of the crucible ranges from 10 to 120 mm.

[0020] The present application provides a growth device for growing gallium oxide crystals, the growth device comprising a heater and a crucible for placing gallium oxide crystals; the heater and the crucible are both barrel-shaped structures, and the crucible is placed in the heater; the slope of the side wall of the heater is smaller than the slope of the side wall of the crucible, and the radius of the upper end face of the heater is larger than the radius of the lower end face of the crucible; wherein the slope of the side wall of the heater is the ratio of the difference between the diameter of the upper end face of the heater and the diameter of the lower end face and the height of the heater, and the slope of the side wall of the crucible is the ratio of the difference between the diameter of the upper end face of the crucible and the diameter of the lower end face and the height of the crucible. The present application utilizes a barrel-shaped heater and a barrel-shaped crucible, and the slope of the side wall of the heater is smaller than the slope of the side wall of the crucible, so that the upper end of the heater is closer to the crucible and the lower end is farther from the crucible, which can significantly reduce the axial temperature gradient of the temperature field, effectively solve the problem of cracking of gallium oxide crystals, and thus improve the quality and efficiency of gallium oxide crystal growth. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] 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.

[0022] Figure 1 It is a schematic diagram of the structure of a conventional heater;

[0023] Figure 2It is a schematic structural diagram of a growth device for growing gallium oxide crystals provided in an embodiment of the present application;

[0024] Figure 3 is a schematic diagram of the cross-sectional radius of the heater and the crucible provided in the embodiment of the present application;

[0025] Figure 4 is a schematic structural diagram of a longitudinal section of a heater provided in an embodiment of the present application;

[0026] Figure 5 It is a schematic structural diagram of the longitudinal section of the crucible provided in an embodiment of the present application. DETAILED DESCRIPTION

[0027] 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.

[0028] 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.

[0029] 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.

[0030] In the prior art, reference Figure 1 The shape of the heaters is of equal thickness and width, that is, the side walls of the heaters are of equal thickness, and the heaters are barrel-shaped, and the distance from the crucible inside the heaters is equal. 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.

[0031] Therefore, an embodiment of the present application provides a growth device for growing gallium oxide crystals. The growth device selects a barrel-type heater and a barrel-type crucible in which the slope of the side wall of the heater is smaller than the slope of the side wall of the crucible. The upper end of such a heater is close to the crucible and the lower end is far from the crucible, which can significantly reduce the axial temperature gradient of the temperature field and effectively solve the problem of cracking of gallium oxide crystals.

[0032] Among them, the barrel-shaped heater and the barrel-shaped crucible can be a trapezoidal structure with a longitudinal section that is small at the top and large at the bottom, and the barrel-shaped crucible with such a structure can increase the loading amount, thereby growing longer crystals.

[0033] Figure 2This is a schematic diagram of the structure of a growth device for growing gallium oxide crystals provided in an embodiment of the present application. Figure 2 As shown, the growing device for growing gallium oxide crystals includes a heater 1 and a crucible 2 for placing the gallium oxide crystals.

[0034] The heater 1 and the crucible 2 are both barrel-shaped structures, and the crucible 2 is placed in the heater 1 .

[0035] The slope of the side wall of the heater 1 is smaller than the slope of the side wall of the crucible 2 .

[0036] The radius of the upper end surface of the heater 1 is greater than the radius of the lower end surface of the crucible 2. Since the crucible needs to be placed in the heater at any time, and the side walls of the heater and the crucible have slopes, it is necessary to ensure that the crucible can be placed in the heater. Figure 3 , the radius R1 of the cross section at the opening of the heater 1 is larger than the radius R2 of the cross section at the bottom of the crucible 2 .

[0037] Among them, the slope of the side wall of the heater 1 is the ratio of the difference between the diameter of the upper end face of the heater 1 and the diameter of the lower end face to the height of the heater 1, and the slope of the side wall of the crucible 2 is the ratio of the difference between the diameter of the upper end face of the crucible 2 and the diameter of the lower end face to the height of the crucible 2.

[0038] For example, Figure 4 is the longitudinal section of the heater, the diameter of the upper end face is r11, the diameter of the lower end face is r12, and the height of the heater is h1, then the slope of the side wall of the heater = (r11-r12) / h1. The calculation process of the slope of the side wall of the crucible is the same as that of the heater, and will not be repeated.

[0039] In the embodiment of the present application, the slope of the side wall of the heater is designed to be smaller than the slope of the side wall of the crucible, so that the upper end of the heater is close to the crucible and the lower end is far from the crucible. This can ensure that the transfer of heat from the heater to the crucible is smoother and more uniform, reduce the adverse effects of the temperature gradient, and is conducive to the high-quality growth of oxidized crystals.

[0040] Then, the present application is designed such that the radius of the upper end surface of the heater is larger than the radius of the lower end surface of the crucible, so that the heater can more effectively wrap the crucible, reduce heat loss, and improve energy efficiency. At the same time, this design also helps to maintain the stability of the temperature inside the crucible, providing favorable conditions for the continuous and stable growth of gallium oxide crystals, thereby improving the overall efficiency of gallium oxide crystal growth.

[0041] In addition, the present application is designed such that the slope of the side wall of the heater is smaller than the slope of the side wall of the crucible, which also increases the support area of ​​the heater for the crucible, further improving the overall structural stability of the growth device, which is of great significance for ensuring the safety and stability of the gallium oxide crystal growth process.

[0042] Based on the above discussion, it can be seen that the embodiment of the present application adopts a design in which the slope of the side wall of the heater is smaller than the slope of the side wall of the crucible. According to the different distances between the upper and lower ends of the heater and the crucible, the axial temperature gradient of the temperature field can be significantly reduced, thereby effectively solving the problem of cracking of gallium oxide crystals.

[0043] In a possible implementation, the longitudinal section of the heater is a trapezoid that is smaller at the top and larger at the bottom.

[0044] Optionally, refer to Figure 4 The longitudinal section of the heater 1 is a trapezoid with a small top and a large bottom, so that the upper end of the crucible placed in the heater is closer to the heater wall and the lower end is farther from the heater wall, thereby reducing the axial temperature gradient of the temperature field and making the heat applied to the crucible more uniform, thereby improving the growth quality of the gallium oxide crystal.

[0045] In a possible implementation, the radii of multiple cross sections of the heater increase linearly from top to bottom.

[0046] Optionally, since the longitudinal section of the heater is a trapezoid with a small top and a large bottom, the radii of the multiple cross sections of the heater from top to bottom increase linearly. For example, the increase coefficient of the radii of the multiple cross sections of the heater from top to bottom is x1.

[0047] In a possible implementation, the ratio of the diameter of the lower end surface of the heater to the diameter of the upper end surface is in the range of 1.1-4.

[0048] Optionally, since the radii of multiple cross sections of the heater increase linearly from top to bottom, the ratio of the lower end surface diameter to the upper end surface diameter of the heater is in the range of 1.1-4.

[0049] Correspondingly, the calculation formula of the ratio c1 of the lower end diameter to the upper end diameter of the heater is:

[0050]

[0051] in, is the ratio of the lower end diameter to the upper end diameter of the heater, is the lower end diameter of the heater, is the diameter of the upper end surface of the heater. In the embodiment of the present application, the ratio is a range.

[0052] In a possible implementation, the diameter of the lower end surface of the heater is greater than or equal to 33 mm and less than or equal to 120 mm.

[0053] Reference Figure 4 , the diameter r11 of the lower end surface of the heater 1 is greater than or equal to 33 mm and less than 120 mm.

[0054] In a possible implementation, the diameter of the upper end surface of the heater is less than or equal to 30 mm.

[0055] Reference Figure 4 , the upper end surface diameter r12 of the heater 1 is less than or equal to 30 mm.

[0056] For example, if the diameter of the upper end surface of a heater is 30 mm and the diameter of the lower end surface is 60 mm, then the ratio of the upper end surface diameter to the lower end surface diameter of the heater is 2, which satisfies the ratio range of 1.1-4.

[0057] In a possible implementation, the height of the heater ranges from 10 to 200 mm.

[0058] 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 h1 of the heater 1 is 100 mm, meeting the height range of 10-200 mm.

[0059] The embodiment of the present application utilizes a barrel-shaped heater whose longitudinal section is a trapezoid that is small at the top and large at the bottom, and whose multiple cross sections increase linearly from top to bottom. This allows the upper end of the heater to be close to the crucible and the lower end to be far from the crucible, significantly reducing the axial temperature gradient of the temperature field and effectively solving the problem of cracking of gallium oxide crystals.

[0060] In a possible implementation, the longitudinal section of the crucible is a trapezoid that is smaller at the top and larger at the bottom.

[0061] Optionally, refer to Figure 5 The longitudinal section of the crucible 2 is a trapezoid with a small top and a large bottom. Since the slope of the side wall of the heater is smaller than the slope of the side wall of the crucible, the upper end of the crucible placed in the heater is close to the heater, and the lower end is far from the heater. For details, see Figure 2 , so that the axial temperature gradient of the temperature field can be reduced, making the heat applied to the crucible more uniform, thereby improving the growth quality of gallium oxide crystals. At the same time, the crucible is set to a barrel-shaped structure with a trapezoidal longitudinal section that is small at the top and large at the bottom, which can increase the loading capacity of the crucible and thus grow longer crystals.

[0062] In a possible implementation, the radii of multiple cross sections of the crucible increase linearly from top to bottom.

[0063] Optionally, since the longitudinal section of the crucible is a trapezoid that is smaller at the top and larger at the bottom, the radii of multiple cross sections of the crucible from top to bottom increase linearly.

[0064] It should be noted that, since the slope of the side wall of the heater is smaller than the slope of the side wall of the crucible, the linear coefficient of the increase of the radius of the multiple cross sections of the crucible from top to bottom is greater than the linear coefficient of the increase of the radius of the multiple cross sections of the heater from top to bottom. For example, the radius increase coefficient of the multiple cross sections of the crucible from top to bottom is x2, and x2 is greater than x1.

[0065] In a possible implementation, the ratio of the diameter of the lower end surface of the crucible to the diameter of the upper end surface is in the range of 1.1-3.

[0066] Optionally, since the radii of multiple cross sections of the crucible increase linearly from top to bottom, the ratio of the diameter of the lower end surface of the crucible to the diameter of the upper end surface is in the range of 1.1-3.

[0067] Correspondingly, the calculation formula of the ratio c2 of the lower end diameter to the upper end diameter of the crucible is:

[0068]

[0069] in, is the ratio of the lower end diameter to the upper end diameter of the crucible, is the diameter of the lower end of the crucible, is the diameter of the upper end surface of the crucible. In the embodiment of the present application, the ratio is a range.

[0070] In a possible implementation, the diameter of the lower end surface of the crucible is greater than or equal to 27.5 mm and less than or equal to 75 mm.

[0071] Reference Figure 5 , the diameter r21 of the lower end surface of the crucible 2 is greater than or equal to 27.5 mm and less than or equal to 75 mm.

[0072] In a possible implementation, the diameter of the upper end surface of the crucible is less than or equal to 25 mm.

[0073] Reference Figure 5 , the diameter r22 of the upper end surface of the crucible 2 is less than or equal to 25 mm.

[0074] For example, if the diameter of the upper end surface of a crucible is 20 mm and the diameter of the lower end surface is 29.5 mm, then the ratio of the diameter of the lower end surface of the heater to the diameter of the lower end surface is 1.475, which satisfies the ratio range of 1.1-3.

[0075] In a possible implementation, the height of the crucible is in the range of 10-120 mm.

[0076] 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 5The height h2 of the crucible 2 is 80 mm, which meets the height range of the crucible of 10-200 mm, and the crucible will not be exposed when placed in the heater.

[0077] The embodiment of the present application uses a barrel-shaped crucible with a vertical section that is small at the top and large at the bottom, and multiple cross sections that increase linearly from top to bottom, so that the upper end of the crucible is closer to the heater and the lower end is farther from the heater, significantly reducing the axial temperature gradient of the temperature field, and effectively solving the cracking problem of gallium oxide crystals. And because the crucible adopts the above structure, the amount of material inside the crucible can be increased, thereby growing longer crystals.

[0078] The gallium oxide crystal growth device provided in the embodiment of the present application is used to grow the gallium oxide crystal using the temperature field structure. The specific growth method is as follows:

[0079] 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.

[0080] Among them, the square mold is a device for growing gallium oxide crystals.

[0081] It should be noted here that the gallium oxide polycrystalline raw material is placed in the crucible provided in the embodiment of the present application, and after the gallium oxide is melted, it is attracted into the square mold in the crucible through capillary action.

[0082] A crucible containing gallium oxide polycrystalline raw materials is placed in the barrel-shaped heater structure provided in the embodiment of the present application.

[0083] Place the entire set of thermal fields into the crystal growth furnace.

[0084] 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:

[0085] 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.

[0086] 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.

[0087] Secondly, after the seed crystal has finished growing, the crystal is completely pulled out to above the square mold.

[0088] 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.

[0089] By using the gallium oxide crystal growth device provided in the embodiment of the present application and the above-mentioned growth process, it is possible to grow high-quality gallium oxide crystals and also to grow longer gallium oxide crystals.

[0090] The present application provides a growth device for growing gallium oxide crystals, the growth device comprising a heater and a crucible for placing gallium oxide crystals; the heater and the crucible are both barrel-shaped structures, and the crucible is placed in the heater; the slope of the side wall of the heater is smaller than the slope of the side wall of the crucible, and the radius of the upper end face of the heater is larger than the radius of the lower end face of the crucible; wherein the slope of the side wall of the heater is the ratio of the difference between the diameter of the upper end face of the heater and the diameter of the lower end face and the height of the heater, and the slope of the side wall of the crucible is the ratio of the difference between the diameter of the upper end face of the crucible and the diameter of the lower end face and the height of the crucible. The present application utilizes a barrel-shaped heater and a barrel-shaped crucible, and the slope of the side wall of the heater is smaller than the slope of the side wall of the crucible, so that the upper end of the heater is closer to the crucible and the lower end is farther from the crucible, which can significantly reduce the axial temperature gradient of the temperature field, effectively solve the problem of cracking of gallium oxide crystals, and thus improve the quality and efficiency of gallium oxide crystal growth.

[0091] 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.

[0092] 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 growing device for growing gallium oxide crystals, characterized in that: The growth device includes a heater and a crucible for placing gallium oxide crystals; The heater and the crucible are both barrel-shaped structures, and the crucible is placed in the heater; The slope of the side wall of the heater is smaller than the slope of the side wall of the crucible, and the radius of the upper end face of the heater is larger than the radius of the lower end face of the crucible, the longitudinal section of the heater is a trapezoid with a small top and a large bottom, the radii of multiple cross sections of the heater from top to bottom increase linearly, and the ratio of the diameter of the lower end face of the heater to the diameter of the upper end face is in a range of 1.1-4; the longitudinal section of the crucible is a trapezoid with a small top and a large bottom, the radii of multiple cross sections of the crucible from top to bottom increase linearly, and the ratio of the diameter of the lower end face of the crucible to the diameter of the upper end face is in a range of 1.1-3; Among them, the slope of the side wall of the heater is the ratio of the difference between the diameter of the upper end face of the heater and the diameter of the lower end face to the height of the heater, and the slope of the side wall of the crucible is the ratio of the difference between the diameter of the upper end face of the crucible and the diameter of the lower end face to the height of the crucible.

2. The gallium oxide crystal growing device according to claim 1, characterized in that: The diameter of the lower end surface of the heater is greater than or equal to 33 mm and less than or equal to 120 mm.

3. The gallium oxide crystal growing device according to claim 1, characterized in that: The diameter of the upper end surface of the heater is less than or equal to 30 mm.

4. The gallium oxide crystal growing device according to claim 1, characterized in that: The diameter of the lower end surface of the crucible is greater than or equal to 27.5 mm and less than or equal to 75 mm.

5. The gallium oxide crystal growing device according to claim 1, characterized in that: The diameter of the upper end surface of the crucible is less than or equal to 25 mm.

6. The gallium oxide crystal growing device according to claim 1, characterized in that: The heater height range is 10-200mm; The height of the crucible ranges from 10 to 120 mm.

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