Crystal growth device and method

Abstract

The embodiment of the invention provides a crystal growth device and method, the device comprises a zone melting device and a guide mold device, and the guide mold device is provided with a feed port; the zone melting device comprises a raw material placing part for placing a raw material rod, and one end of the raw material placing part is communicated with the feeding hole; the first heating device is arranged outside the raw material placing part and is used for heating one end of the raw material rod into a melt so as to form a melting zone; the guide mold device comprises a melt guide groove which is arranged in the guide mold device, is communicated with the raw material placing part through the feeding hole and is used for draining melt in the melting zone to a position corresponding to the seed crystal; and the second heating device is arranged outside the guide mold device and is used for adjusting the temperature of the melt in the melt guide groove so as to promote crystal growth of the seed crystal to obtain a target crystal.

Description

TECHNICAL FIELD

[0001] The present specification relates to the technical field of crystal growth, in particular to a crystal growth device and method combining zone melting method and guide mode method. BACKGROUND

[0002] The growth of some high-melting-point crystals depends on special crucible materials. In particular, the growth of crystals such as GAGG, YAG, Ga2O3, LYSO, and YSO usually uses iridium as a crucible. However, the iridium is often lost during the crystal growth process, resulting in increased costs. Therefore, reducing the use and consumption of precious metals is the key to expanding crystal production.

[0003] Zone melting method and guide mode method are two commonly used methods in the field of crystal growth. The advantage of zone melting method is that it does not rely on a crucible, and the process is relatively simple and easy to control. However, it is difficult to obtain large-size single crystals, and it can usually only provide single crystals for experimental testing. The advantage of guide mode method is that large-size single crystal growth is relatively simple compared to other methods, and the growth rate is fast. However, guide mode method requires using a crucible to bubble the guide mode mold in the melt, resulting in high production costs. Moreover, guide mode method relies on the melt to heat the mold, and the melt temperature is much higher than the melting point of the crystal during crystal growth. Rapid cooling is required to achieve rapid pulling crystal growth, which is not conducive to the sustained growth of the crystal.

[0004] Therefore, a crystal growth device and method are provided, which combines zone melting method and guide mode method for crystal growth. This method can produce large-size, high-purity crystals while reducing costs and making the device easy to maintain. SUMMARY

[0005] One of the embodiments of the present specification provides a crystal growth device, which includes a zone melting device and a guide mode device, and a feed inlet is formed on the guide mode device. The zone melting device includes a raw material placing part for placing a raw material rod, one end of the raw material placing part being in communication with the feed inlet, and a first heating device arranged outside the raw material placing part for heating one end of the raw material rod into a melt to form a melt zone. The guide mode device includes a melt guide groove arranged inside the guide mode device and in communication with the raw material placing part through the feed inlet for guiding the melt in the melt zone to a corresponding position of a seed crystal, and a second heating device arranged outside the guide mode device for adjusting the temperature of the melt in the melt guide groove to promote the seed crystal to grow into a target crystal.

[0006] One of the embodiments of this specification provides a crystal growth method, which is implemented using the above-mentioned crystal growth device, including: controlling a first heating device to heat one end of a raw material rod into a melt to form a melt zone; controlling a propulsion device to propel the raw material rod toward a feed port to guide the melt in the melt zone to a corresponding position of a seed crystal through the melt guide groove; controlling a second heating device to heat the melt in the melt guide groove to adjust the temperature of the melt in the melt guide groove; when the melt reaches a corresponding position of the seed crystal, using the seed crystal to guide the melt to perform crystal growth to obtain a target crystal. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] This specification will be further described in the form of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting, and in these embodiments, like numbers represent like structures, wherein:

[0008] Figure 1 is a module diagram of a crystal growth apparatus according to some embodiments of this specification;

[0009] Figure 2 is a front view of a crystal growth apparatus according to some embodiments of the present specification;

[0010] Figure 3 is a side view of a crystal growth apparatus according to some embodiments of the present specification;

[0011] Figure 4 is an exemplary flow chart of a crystal growth method according to some embodiments of this specification;

[0012] Figure 5a is an exemplary flow chart of a method for replenishing raw materials according to some embodiments of this specification;

[0013] Figure 5b This is a schematic diagram of determining the amount of raw material replenishment based on the crystal growth model shown in some embodiments of this specification. DETAILED DESCRIPTION

[0014] To more clearly illustrate the technical solutions of the embodiments of this specification, the following briefly describes the drawings required for describing the embodiments. Obviously, the drawings described below are merely examples or embodiments of this specification. Those skilled in the art can apply this specification to other similar scenarios based on these drawings without inventive effort. Unless otherwise apparent from the context or otherwise noted, the same reference numerals in the figures represent the same structure or operation.

[0015] It should be understood that the terms "system," "device," "unit," and / or "module" used herein are a method for distinguishing different components, elements, parts, portions, or assemblies at different levels. However, if other terms can achieve the same purpose, the terms may be replaced by other expressions.

[0016] Unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not refer to the singular but include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements.

[0017] Flowcharts are used throughout this specification to illustrate the operations performed by systems according to embodiments of this specification. It should be understood that preceding or following operations do not necessarily need to be performed in exact order. Instead, the steps may be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0018] Figure 1 It is a module diagram of a crystal growth device according to some embodiments of this specification.

[0019] like Figure 1 As shown, the crystal growth apparatus 100 may include a melting zone apparatus 110 , a guide mold apparatus 120 , and a control apparatus 130 .

[0020] The zone melting device 110 is a device that uses a zone melting method to heat a raw material rod to generate a melt.

[0021] In some embodiments, the zone melting device 110 may include a raw material placement portion 111 for placing raw material rods, and one end of the raw material placement portion 111 is connected to a feed port 121 provided on the guide mold device 120 .

[0022] In some embodiments, the raw material placement section 111 can be pre-configured according to the process requirements of crystal growth. For example, the material, shape, and size of the raw material placement section 111 can be determined based on the type of raw material, melting point, and target crystal size. For more information about the raw material placement section 111, see Figure 2 or Figure 3 and its description.

[0023] The first heating device 112 is disposed outside the raw material placement portion and is used to heat one end of the raw material rod into a melt to form a molten zone. In some embodiments, the first heating device 112 can be a heater of various types. For example, it can include but is not limited to an induction heater, a resistance heater, etc.

[0024] In some embodiments, the zone melting device 110 can further include a pushing device 113, which can be used to push the raw material rod towards the feeding port 121, so that the melt in the melting zone at one end of the raw material rod is extruded to the melt guide groove 122, thereby replenishing the raw material for the crystal growth of the guide die device 120.

[0025] In some embodiments, the pushing device 113 can include various types of pushing assemblies (not shown in the figure). For example, the pushing assembly can include, but is not limited to, a clamping assembly, a moving assembly, a power assembly, etc. Among them, the clamping assembly can be used to clamp the raw material rod to keep the whole raw material rod stable; the moving assembly can be used to translate the raw material rod towards the feeding port 121; and the power assembly can be used to provide power for the pushing of the raw material rod.

[0026] The guide die device 120 refers to a device for promoting the crystal growth of the seed crystal to obtain the target crystal.

[0027] The guide die device 120 can include a feeding port 121 for receiving the melt delivered by the zone melting device 110.

[0028] In some embodiments, the feeding port 121 can be provided in a circular shape (or other shape) with a preset caliber (diameter), which can be provided on one side (such as the bottom) of the guide die device 120 and oppositely arranged with the side (such as the top) where the corresponding position of the seed crystal is located.

[0029] The melt guide groove 122 is arranged inside the guide die device 120 and communicates with the raw material placing portion 111 through the feeding port 121, and is used to guide the melt in the melting zone to the corresponding position of the seed crystal.

[0030] In some embodiments, the melt guide groove 122 can include one or more guide grooves, each of which can be arranged in a cavity inside the guide die device 120, and the size (such as width, thickness, etc.) of each guide groove can be set according to the size of the guide die device 120. In some embodiments, the guide groove can be arranged in a preset structure (such as a trapezoidal structure) for connecting the corresponding end of the feeding port 121 of the guide die device 120 and the corresponding end of the corresponding position of the seed crystal. For more information about the melt guide groove 122, see Figure 2 、 Figure 3 and the description thereof.

[0031] The second heating device 123 is arranged outside the guide die device 120, and is used to adjust the temperature of the melt in the melt guide groove 122, so as to promote the crystal growth of the seed crystal 129 to obtain the target crystal. The second heating device 123 can be various types of heaters, which can be determined according to the melting point requirement of the melt. For example, the second heating device 123 can include, but is not limited to, an induction heater, a resistance heater, etc.

[0032] In some embodiments, the second heating device 123 may include multiple (e.g., 3, 6) spaced heaters that heat the melt in the melt channel 122 at different preset temperatures so that the temperature gradient of the melt in the melt channel meets the preset requirements. For more information about the second heating device 123, see Figure 2 and Figure 3 and its description.

[0033] In some embodiments, the guide mold device 120 may further include a temperature sensor 124 disposed externally of the guide mold device 120 for collecting and measuring temperature. In some embodiments, the temperature sensor 124 may be any of various temperature sensors, which may be determined based on actual requirements (e.g., temperature measurement range, thermal sensitivity, etc.), and may include, but is not limited to, a thermistor sensor, an infrared temperature sensor, etc.

[0034] In some embodiments, the temperature sensing device 124 may include multiple (e.g., 3, 6) temperature sensors, which may be determined based on the number of heaters in the second heating device 123. For example, each temperature sensor may be disposed near each heater in the second heating device 123 to collect the measured temperature of the mold guide device (e.g., the exterior / outer wall) to further determine whether the temperature gradient of the melt in the melt guide channel meets the preset requirements. For more information, see Figure 4 and its description.

[0035] Control device 130 may process data and / or information obtained from other components of crystal growth apparatus 100 or other information sources. Control device 130 may execute program instructions based on the data, information, and / or processing results to perform one or more functions described herein.

[0036] In some embodiments, the control device 130 can control the zone melting device 110 and the guide mold device 120. For example, the control device 130 controls the first heating device 112 to heat one end of the raw material rod into a melt to form a melt zone, and controls the propulsion device 113 to propel the raw material rod toward the feed port 121 to guide the melt in the melt zone to the corresponding position of the seed crystal through the melt guide groove 122. In some embodiments, the control device 130 can control the second heating device 123 to heat the melt in the melt guide groove 122 to adjust the temperature of the melt in the melt guide groove 122 so that the temperature gradient of the melt in the melt guide groove 122 meets the preset requirements. For more information about the above examples, see Figure 4 and its description.

[0037] In some embodiments, the crystal growth apparatus 100 may further include a weighing device (not shown in the figure) for collecting weight / mass change information of the seed crystal during the crystal growth process.

[0038] The above description is for illustrative purposes only, and the actual crystal growth apparatus 100 may have various variations.

[0039] It should be noted that the crystal growth apparatus 100 is provided for illustrative purposes only and is not intended to limit the scope of the present application. A person of ordinary skill in the art may make various modifications or variations based on the description of this specification. However, such modifications and variations will not depart from the scope of the present application.

[0040] Figure 2 is a front view of a crystal growth apparatus according to some embodiments of this specification, Figure 3 is a side view of a crystal growth apparatus according to some embodiments of the present specification.

[0041] like Figure 2 and Figure 3 As shown, the crystal growth device 100 includes a melting zone device 110 and a guide mold device 120. The guide mold device 120 is provided with a feed port 121, and the melting zone device 110 is connected to the guide mold device 120 through the feed port 121.

[0042] In some embodiments, the feed port 121 is disposed at the first end of the guide mold device 120, and the corresponding position of the seed crystal is disposed at the second end of the guide mold device 120, and the first end and the second end are disposed opposite to each other. Figure 2 As shown, the first end may be the bottom of the guide mold device 120, and the second end may be the top opposite the first end. The bottom refers to the end of the crystal growth device 100 that is closer to the ground when placed on the ground, and the top refers to the end of the crystal growth device 100 that is farther from the ground when placed on the ground. In some other embodiments, the first end may be the top of the guide mold device 120, and the second end may be the bottom opposite the first end.

[0043] In some embodiments, the end of the raw material placement portion 111 close to the feed port 121 (i.e., the end connected to the feed port 121) is in an inverted trapezoidal shape (projected shape) or a funnel shape, wherein the narrow side is connected to the feed port 121 and the wide side is used to place the raw material rod 119.

[0044] In some embodiments of the present specification, by setting the raw material placement portion 111 to be in an inverted trapezoidal or funnel-shaped shape, it is beneficial for the zone melting device 110 and the guide mold device 120 to be stably docked and combined; in addition, it is also beneficial for the melt in the melting zone to be extruded and transported to the melt guide groove 122, thereby improving the efficiency of crystal growth.

[0045] In some embodiments, the first heating device 112 can be arranged around the outside of one end of the raw material placement portion 111 close to the feed port 121, or can be arranged on one or more surfaces of the end close to the feed port. Figure 2As shown, the first heating device 112 can include a plurality of heaters (such as induction heaters, resistance heaters) uniformly distributed at a preset first interval near one end of the raw material placement portion 111 close to the feeding port 121, so that one end of the raw material rod in the raw material placement portion 111 can be uniformly heated into a melt, thereby forming a stable melt zone. In some embodiments, as shown in Figure 2 As shown, the size of the raw material placement portion 111 is smaller than the size of the raw material rod, and the first heating device 112 can be arranged outside the entire raw material placement portion 111.

[0046] In some embodiments, the width of the guide mold device 120 is 30-180 mm, the thickness of the guide mold device 120 is 4.8-20 mm, and the size of the target crystal is 1-6 inches.

[0047] It should be noted that the width of the guide mold device 120 refers to the lateral dimension of the guide mold device 120 in the front view (i.e. Figure 2 ) and the thickness of the guide mold device 120 refers to the lateral dimension of the guide mold device 120 in the side view (i.e. Figure 3 ). The width and thickness of the melt guide groove 122 are the same below.

[0048] In some embodiments, the guide mold device 120 can be made of metal molybdenum, platinum, rhodium, iridium, or various metal alloys. In some embodiments, the corresponding material (such as a metal material) of the guide mold device 120 can be determined according to the crystal melting point and the crystal growth atmosphere. The crystal growth atmosphere can include a weak oxygen environment, an oxygen environment, an oxygen-free environment, etc.

[0049] For example only, when gallium oxide crystal needs to be grown, the melting point is 1800°C, and a weak oxygen atmosphere is required, iridium gold is used as the material of the guide mold device 120; when YAG crystal needs to be grown, the melting point is 2000°C, and an oxygen environment is required, iridium gold can be used as the material of the guide mold device 120; when aluminum oxide crystal needs to be grown, the melting point is 2050°C, and an oxygen-free environment / vacuum environment is required, molybdenum or tungsten can be used as the material of the guide mold device 120.

[0050] As shown in Figure 2 The melt guide groove 122 has a trapezoidal structure, and the first side of the trapezoidal structure is arranged at the first end, and the second side of the trapezoidal structure is arranged at the second end. The first side and the second side are parallel, and the length of the first side is less than the length of the second side. The first end is the end of the guide mold device 120 where the feeding port 121 is opened, and the second end is opposite to the first end. As shown in Figure 2Taking the crystal growth device shown as an example, the first end corresponds to the bottom of the guide mold device 120, and the second end corresponds to the top of the guide mold device 120. The top of the guide mold device 120 can be provided with a position corresponding to a seed crystal for placing the seed crystal 129. In some other embodiments, the melt guide channel 122 can be any other suitable shape, such as an irregular shape.

[0051] In some embodiments, the size (eg, width, thickness) of the melt channel 122 is related to the size of the crystal to be grown and the size (eg, width, thickness) of the guide mold device 120 .

[0052] As an example only, when a 2-inch crystal needs to be grown, the width of the guide mold device 120 can be set to 55 mm, the thickness can be set to 5.5 mm, and the thickness of the melt guide groove 122 can be set to 0.5 mm, and the width can be set to 52 mm; when a 4-inch crystal needs to be grown, the width of the guide mold device 120 can be set to 120 mm, the thickness can be set to 8.8 mm, and the thickness of the melt guide groove 122 can be set to 1 mm, and the width can be set to 146 mm; when a 6-inch crystal needs to be grown, the width of the guide mold device 120 can be set to 180 mm, the thickness can be set to 12 mm, and the thickness of the melt guide groove 122 can be set to 2 mm, and the width can be set to 170 mm.

[0053] The seed crystal corresponding position refers to the position where the seed crystal 129 is placed. In some embodiments, a seed crystal rod is provided at the seed crystal corresponding position, and the seed crystal 129 can be placed on the seed crystal rod. In some embodiments, the seed crystal corresponding position can be set at the center position of the second end. When the melt in the melt guide groove 122 is drained to the seed crystal corresponding position, the seed crystal 129 contacts the melt, thereby inducing melt crystallization and achieving seeding. For more information about crystal growth, please refer to Figure 4 and its description.

[0054] In some embodiments, the end (i.e., the second end) of the guide mold device 120 used for crystal growth is set at a preset tilt angle. Figure 3 As shown, the inclination angle a of the top of the guide mold device 120 can be set to 70-85 degrees. By setting the inclination angle, the melt directed to the top of the guide mold device 120 can be prevented from overflowing, while facilitating sufficient contact between the seed crystal and the melt, thereby improving the efficiency of crystal growth.

[0055] The second heating device 123 may include a plurality of heaters arranged at intervals, and the plurality of heaters heat the melt (outside the guide mold device 120) at different preset temperatures so that the temperature gradient of the melt in the melt guide groove meets the preset requirements. Figure 2 and Figure 3As shown, there are three heaters spaced apart on both sides of the guide mold device 120. The number and spacing of the heaters can be determined according to actual needs (such as the height of the guide mold device 120, the temperature gradient requirements, etc.). For example, the greater the height of the guide mold device 120, the greater the number and spacing of the heaters can be. For another example, the more refined the temperature gradient requirements, the greater the number of heaters can be and the smaller the spacing can be. In some embodiments, the heaters of the second heating device 123 can also be arranged around the outside of the guide mold device 120. For more information about temperature gradients, see Figure 4 and its description.

[0056] In some embodiments, the type of the second heating device 123 is related to the type of target crystal. The type of target crystal can reflect the melting point (melt temperature) requirement of the raw material required for crystal growth. When the melting point requirement is higher, the second heating device 123 needs to be able to heat to a temperature corresponding to the melting point or above. As an example only, when preparing gallium oxide (such as β-Ga2O3) crystals, the melting point of the gallium oxide material is relatively high (1790°C). The second heating device 123 can use an induction heater to heat the melt in the melt guide groove to maintain the melt state and achieve a preset temperature gradient.

[0057] In some embodiments, in order to make the temperature gradient meet the preset requirements, a temperature sensing device 124 ( Figure 2 and Figure 3 (not shown), the temperature sensing device 124 may include a plurality of (e.g., 3, 6) temperature sensors, which are respectively arranged near the second heating device 123 to collect the measured temperatures at corresponding positions of the second heating device 123, thereby detecting whether the temperature of the melt in the melt guide groove 122 meets the requirements, and then determining whether the temperature gradient meets the preset requirements.

[0058] Figure 4 is an exemplary flow chart of a crystal growth method according to some embodiments of the present specification.

[0059] In some embodiments, the process 400 can be implemented using the crystal growth apparatus 100. In some embodiments, the process 400 can be executed by a control device (such as the control device 130). Figure 4 As shown, process 400 includes the following steps.

[0060] Step 410: Control the first heating device to heat one end of the raw material rod into a melt to form a molten zone.

[0061] The raw material rods can be used to provide raw material for the crystal growth device. In some embodiments, the raw material rods can be pre-set to a specific shape and size based on actual needs (such as the size of the raw material storage area). For example, the raw material rods can be cylindrical with a diameter of 5-20 mm.

[0062] The melting zone is the area of ​​the raw material bar that is heated to form a melt (the molten state of the raw material). The size (e.g., length, width, height) of the heating area of ​​the first heating device (e.g., the area near the feed inlet end of the raw material placement unit) determines the size of the melting zone.

[0063] In some embodiments, the control device can control the first heating device to continuously heat the raw material placement portion according to the material type of the raw material bar and its corresponding melting point, so that the temperature of one end of the raw material bar reaches the melting point and becomes a melt. For more information about the first heating device and the raw material placement portion, please refer to Figure 1 and Figure 2 and its description.

[0064] Step 420: Control the propulsion device to propel the raw material rod toward the feed port, so as to guide the melt in the melting zone to the corresponding position of the seed crystal through the melt guide groove.

[0065] In some embodiments, the control device can use a propulsion device to propel the raw material rod toward the feed inlet, thereby moving the melt zone toward the feed inlet and squeezing the melt in the melt zone into the melt channel. The melt channel, which connects the feed inlet to the position corresponding to the seed crystal, further guides the melt to the position corresponding to the seed crystal, so that the melt and the seed crystal come into contact.

[0066] In some embodiments, the control device can determine the amount of raw material to be replenished based on the mass change of the target crystal; based on the amount of raw material replenished, determine the speed of the raw material rod, and then control the propulsion device to propel the raw material rod toward the feed port based on the propulsion speed, thereby replenishing raw materials for crystal growth. For more information on replenishing raw materials for crystal growth, see Figure 5a and its description.

[0067] In some embodiments of this specification, steps 410 and 420 may be referred to as a zone melting process. This process heats one end of the raw material rod to form a melt, forming a melting zone. This zone is then moved to replenish raw material for the guide mold assembly to maintain subsequent crystal growth, eliminating the need for a crucible and reducing crystal growth costs. Furthermore, raw material replenishment is controlled based on changes in the quality of the target crystal, thus avoiding material waste.

[0068] Step 430 : Control the second heating device to heat the melt in the melt channel to adjust the temperature of the melt in the melt channel.

[0069] In some embodiments, during the process of guiding the melt in the melt zone to the corresponding position of the seed crystal through the melt guide channel, the control device can control the second heating device to heat the guide mold device to the crystal melting point, so that the melt in the melt guide channel is maintained at a temperature corresponding to the crystal melting point, so that the melt remains in a molten state.

[0070] In some embodiments, the second heating device comprises a plurality of heaters arranged at preset intervals along a direction from the feeding port to the corresponding position of the seed crystal. Hereinafter, the direction from the feeding port to the corresponding position of the seed crystal can be referred to as the temperature gradient direction, and the preset intervals between adjacent two heaters in the temperature gradient direction can be equal or unequal. The control device controls the plurality of heaters to heat the guide mold device at preset temperatures in the temperature gradient direction in a decreasing manner, so as to form a preset temperature gradient. The decreasing amplitudes of the preset temperatures corresponding to adjacent two heaters can be equal or unequal.

[0071] The preset temperatures corresponding to the plurality of heaters can be determined according to actual conditions (such as the crystal melting point). In some embodiments, the preset temperature corresponding to the heater closest to the feeding port (hereinafter referred to as heater H1) can be set as a first temperature, and the preset temperature corresponding to the heater closest to the corresponding position of the seed crystal (hereinafter referred to as heater H2) can be set as a second temperature. The first temperature is greater than the second temperature. The temperatures of the other heaters in the second heating device, except for the heater H1 and the heater H2, are between the first temperature and the second temperature.

[0072] In some embodiments, the second temperature can be set as a temperature corresponding to the crystal melting point, and the first temperature can be set as the second temperature plus a preset temperature threshold (such as 30-100°C).

[0073] In some embodiments of the present specification, by controlling the temperatures of the plurality of heaters in the second heating device to form a temperature gradient, it can be ensured that the raw materials in the melt zone that have not been completely melted are completely melted, and at the same time, it can be ensured that the melt guided to the corresponding position of the seed crystal is maintained within the temperature range of the crystal melting point, so as to ensure the growth efficiency of the crystal.

[0074] In some embodiments, the control device can determine a predicted temperature of the melt in the melt guide channel based on the measured temperature collected by the temperature sensing device, and adjust the temperature parameters of the second heating device based on the predicted temperature, so that the temperature gradient of the melt in the melt guide channel meets the preset requirements.

[0075] The measured temperature refers to the temperature of the guide mold device collected by the temperature sensing device, which can reflect the temperature of the outside of the guide mold device (such as the outer wall of the cavity of the guide mold device). In some embodiments, the temperature sensing device can be arranged near the second heating device, and the measured temperature collected by the temperature sensing device can reflect the temperature at the corresponding position of the second heating device.

[0076] The predicted temperature refers to the temperature of the melt in the melt channel determined based on the measured temperature. It should be noted that because the temperature of the melt is typically high, the temperature acquisition device may not be able to directly acquire the melt temperature. The control device can predict and / or provide feedback on the temperature of the melt in the melt channel based on the measured temperature to ensure that the temperature gradient of the melt in the melt channel meets preset requirements.

[0077] In some embodiments, the control device may determine a mapping relationship between the measured temperature and the predicted temperature based on the position of the temperature sensing device, the position of the second heating device, the material of the mold guide device, the material of the melt, etc., and determine the predicted temperature based on the measured temperature and the mapping relationship. The control device may adjust the temperature parameters (such as heating power, etc.) of each heater in the second heating device based on the predicted temperature, so that the temperature of the melt in the melt guide channel corresponding to the second heating device meets the preset requirements, thereby ensuring that the temperature gradient meets the preset requirements.

[0078] Step 440: When the melt reaches the position corresponding to the seed crystal, the seed crystal is used to guide the melt to grow into a target crystal.

[0079] The target crystal refers to the desired crystal product, which includes various parameters determined according to actual needs (such as type, shape, size, weight, etc.). For example, the target crystal can be a 2-inch β-Ga2O3 single crystal.

[0080] In some embodiments, after the melt reaches the second end (e.g., the top) of the guide mold device through the melt channel, the control device can further control the seed crystal to perform a crystal growth operation to obtain a target crystal. The crystal growth operation may include, but is not limited to, a seeding operation and a shoulder release operation.

[0081] In some embodiments, for the seeding operation, the control device can control the seed crystal, such as placing it at a position corresponding to the seed crystal so that the seed crystal contacts the melt, thereby inducing crystal growth. At this point, the melt begins to crystallize in an orderly manner along the crystallographic orientation (crystallographic orientation) of the seed crystal. Hereinafter, the crystal generated during the crystal growth process may be referred to as an intermediate crystal.

[0082] In some embodiments, during the shoulder release operation, the control device may perform a pulling operation on the seed crystal, thereby causing the intermediate crystal to grow into a target crystal. The control device may adjust the pulling speed of the seed crystal according to the size change of the intermediate crystal, so that the intermediate crystal grows from a small size to a target crystal of a target size (e.g., 2 inches).

[0083] It should be noted that the crystal growth operation may also include other operations. As an example only, the control device may also control the seed crystal to rotate, translate, and perform other operations so that the target crystal obtained by crystal growth meets actual requirements (such as the integrity, defect density, shape, weight, etc. of the target crystal).

[0084] In some embodiments of this specification, step 430 and step 440 can be referred to as a guided mold process, which can guide the melt through the melt guide groove, and perform crystal growth operations such as seeding operations and shoulder release operations on the seed crystal, so that the seed crystal can be grown into a target crystal of large size.

[0085] The crystal growth apparatus provided in some embodiments of this specification achieves a combination of a melting zone process and a guided mold process, eliminating the need for a crucible, reducing the cost of crystal preparation, and improving the purity of the target crystal. Furthermore, by continuously feeding the raw material for crystal growth into the melting zone formed by heating the raw material rod, the continuous growth of the crystal can be maintained, reducing raw material loss and enabling the production of large-sized crystals that meet demand. Furthermore, by controlling the melting zone process and / or the guided mold process through a control device, the smooth progress of crystal growth is ensured, thereby improving production efficiency.

[0086] Taking the growth of gallium oxide (e.g., β-Ga2O3) crystals as an example, gallium oxide has a melting point of 1790°C and decomposes at high temperatures. Therefore, a certain oxygen partial pressure is required during the crystal growth process. Based on this, the material of the crystal growth apparatus 100 (e.g., the placement portion of the zone melting apparatus and the guide mold apparatus) can be iridium, and the first and second heating devices utilize induction heating heaters. In this example, the desired growth of a 2-inch β-Ga2O3 single crystal is desired. Therefore, the structural configuration of the crystal growth apparatus is such that the guide mold apparatus is configured to have a width of 60 mm, a thickness of 5.8 mm, and a top inclination angle of 75°. At the same time, gallium oxide powder (e.g., 300 g) of a certain purity (e.g., 99.999%) is formed into a cylindrical raw material rod with a diameter of 8 mm. After the cavity of the guide mold device is evacuated, 98% Ar (argon) and 2% O2 (oxygen) are introduced to a standard atmospheric pressure (1 atm). Then, the raw material placement portion of the zone melting device and the entire guide mold device are heated by a first heating device and a second heating device, respectively. The raw material placement portion is heated to 1850°C by the first heating device, and the second heating device heats the bottom of the guide mold device to 1870°C and the top to 1800°C. Then, a raw material rod is fed into the raw material placement portion. When one end of the raw material rod is heated to melt, a melt zone is formed. The raw material rod is then pushed toward the feed port by a pushing device. The melt in the melt zone is squeezed and transported to the melt guide groove and then drained to the top of the guide mold device. When melt appears at the corresponding position of the seed crystal at the top of the guide mold device (such as the center of the top), the seed crystal is lowered and the seeding operation is performed. The seed crystal direction is 010, the seed crystal pulling rate is controlled to 10 mm / h, and the raw material rod rising rate is controlled to 16 mm / h. During the crystal growth process, the raw material replenishment amount or raw material replenishment rate is controlled to match the pulled-out mass for constant replenishment; when the raw material is consumed, the crystal is pulled off and gradually cooled to room temperature, completing the entire crystal growth process and ultimately obtaining a 2-inch β-Ga2O3 single crystal.

[0087] Figure 5a is an exemplary flow chart of a method for replenishing raw materials according to some embodiments of this specification.

[0088] In some embodiments, process 500 may be executed by a control device (such as control device 130). Figure 5a As shown, process 500 includes the following steps.

[0089] Step 510: Determine the amount of raw material to be replenished based on the mass change of the target crystal.

[0090] The mass change of the crystal refers to the mass (or weight) increased by the seed crystal during the crystal growth process, which can reflect the mass (or weight) of the melt consumed within a preset time period during the crystal growth process. In some embodiments, the control device can collect the weight of the target crystal using a weighing device to obtain the mass change of the crystal.

[0091] The amount of raw material replenished refers to the mass (or weight) of raw material required to replenish the crystal growth. In some embodiments, the amount of raw material replenished can be equal to the mass change of the crystal within the same time period (such as 5s, 10s, etc.).

[0092] In some embodiments, the control device may determine the raw material replenishment amount based on historical mass changes and historical raw material replenishment amounts of the crystal. The historical mass changes and historical raw material replenishment amounts may be obtained based on historical production data. For example, the control device may obtain historical data for the most recent crystal growth process corresponding to the target type of crystal and determine the raw material replenishment amount based on the historical mass changes and / or historical raw material replenishment amounts corresponding to each time period of the crystal growth process.

[0093] In some embodiments, the control device can use a crystal growth model to determine the amount of raw material to be added, taking into account the different stages of crystal growth, the different crystal sizes, and the possible different growth rates of the crystals. Furthermore, the growth rate of the crystals is also affected by the growth atmosphere (e.g., vacuum, weak oxygen atmosphere, etc.) and / or the external environment (e.g., external humidity, air pressure, room temperature, etc.). For more information on crystal growth models, see Figure 5b and its description.

[0094] Step 520: Determine the advancing speed of the raw material rod based on the raw material replenishment amount.

[0095] The advancement speed refers to the distance or length that the raw material rod moves toward the feed port per unit time, which can reflect the speed of raw material replenishment.

[0096] In some embodiments, the control device can determine the density of the raw material based on the type of raw material (e.g., gallium oxide), and determine the feedstock rod advancement speed based on the feedstock replenishment amount, feedstock density, and feedstock rod shape. Taking a cylindrical feedstock rod as an example, the control device can determine the required feedstock rod volume based on the physical relationship between the feedstock replenishment amount (feedstock mass), feedstock density, and feedstock volume. The control device then determines the required feedstock rod length based on a calculation formula that uses the feedstock rod volume, its diameter (or radius), and its height (length). This length represents the distance the feedstock rod needs to move. This calculation yields the feedstock rod's movement speed per unit time, and thus the feedstock rod advancement speed.

[0097] Step 530: Control the propulsion device to propel the raw material rod toward the feed port based on the propulsion speed.

[0098] In some embodiments, the control device can adjust the propulsion parameters (such as power and transmission speed) of the propulsion device so that the propulsion device moves the raw material rod toward the feed port at the propulsion speed, thereby moving the melting zone at one end of the raw material rod, thereby providing melt for the crystal growth of the guide mold device.

[0099] In some embodiments of this specification, raw material replenishment is performed according to the change in the mass of the crystal, which can avoid unnecessary loss of raw materials. At the same time, automatic control of the advancement of the raw material rods toward the feed port can reduce potential misjudgments or risks of manual operation, thereby ensuring smooth crystal growth.

[0100] Figure 5b This is a schematic diagram of determining the amount of raw material replenishment based on the crystal growth model shown in some embodiments of this specification.

[0101] In some embodiments, the control device can determine the model input based on the mass change and environmental information, and use the crystal growth model to process the model input to determine the raw material replenishment amount, and the crystal growth model is a machine learning model.

[0102] A crystal growth model may refer to a model used to determine the crystal growth rate. In some embodiments, the crystal growth model may be a trained machine learning model, such as a deep learning model or other customized neural network model. In some embodiments, different types of target crystals may correspond to different crystal growth models.

[0103] In some embodiments, as Figure 5b As shown, the input of the crystal growth model 517 may include the mass change 511 of the crystal and the environmental information 512 , and the output includes the crystal growth rate 518 .

[0104] The mass change 511 may be the mass increment corresponding to the current unit time period (e.g., 5 seconds, 30 seconds) at the start of crystal growth from the seed crystal. This can be determined by collecting the weight of the crystal (the weight increment during the current unit time period) using a weighing device. The mass change 511 may reflect the size change of the crystal during the current unit time period.

[0105] Environmental information 512 may include but is not limited to humidity, air pressure, room temperature, etc., which can be obtained by detecting the environment (such as indoor environment) where the crystal growth device is located through various collection devices (such as hygrometers, barometers, indoor thermometers, etc.).

[0106] In some embodiments, as Figure 5b Figure 5b As shown, the model input may further include characteristic information 513 of the target crystal and characteristic information 514 of the raw material bar.

[0107] The characteristic information 513 of the target crystal may include, but is not limited to, the type, shape, color, transparency, etc. The characteristic information 514 of the raw material bar may include, but is not limited to, the shape (e.g., cylinder), size (e.g., diameter / radius), raw material type, or density, etc.

[0108] In some embodiments, the model input may further include historical mass change 515 and historical raw material replenishment 516 of the target crystal.

[0109] The historical mass change 515 refers to the mass increment corresponding to the historical time period during the crystal growth process, wherein the historical time period can refer to one or more time periods before the current unit time period (such as the previous 5 seconds, 30 seconds). The historical mass change 515 can reflect the size change process of the crystal during the crystal growth process.

[0110] The historical raw material replenishment amount 516 refers to the raw material replenishment amount corresponding to the historical time period during the crystal growth process, which can reflect the change process of the raw material replenishment amount during the crystal growth process.

[0111] Crystal growth rate 518 may reflect the predicted growth rate of the crystal at different current growth stages (or time periods) under the influence of the environment corresponding to environmental information 512. For example, the larger the crystal, the faster its growth rate, the more melt it consumes, and the greater the amount of raw material required to be replenished.

[0112] In some embodiments, the control device may determine the melt consumption based on the current crystal growth rate 518 , and determine the raw material replenishment amount 519 based on the melt consumption.

[0113] In some embodiments, an initial crystal growth model can be iteratively trained to obtain a trained crystal growth model. Each training sample can include sample mass change and sample environment information corresponding to a sample crystal (e.g., gallium oxide). In some embodiments, each training sample can also include characteristic information of the sample crystal (e.g., type and size of the sample crystal) and characteristic information of a sample raw material rod (e.g., shape and size). In some embodiments, each training sample can also include historical mass change and historical raw material replenishment during the growth process of the sample crystal. The multiple training samples can be obtained based on historical crystal growth data corresponding to the sample crystal (e.g., historical production data). The label of each training sample can be determined by the actual crystal growth rate (i.e., the weight increase of the sample crystal per unit time) in the historical data. The training label can be manually annotated or otherwise annotated. During training, the value of a loss function can be determined based on the difference between the output of the initial crystal growth model and the training label. The parameters of the initial crystal growth model can be iteratively updated based on the value of the loss function until a training termination condition is met (e.g., loss function convergence, a specified number of iterations have been performed, etc.). The updated initial crystal growth model can serve as the trained crystal growth model.

[0114] In some embodiments of this specification, a crystal growth model can be used to learn the growth patterns of different types of crystals at different stages (or time periods) and under different environments, making the determination of crystal growth rates more accurate, and thus the determination of raw material replenishment amounts more accurate. Furthermore, the raw material replenishment amount can be automatically and in real time adjusted based on crystal growth conditions and changes in the external environment, improving the efficiency of raw material replenishment.

[0115] It should be noted that the above description of the relevant processes is for illustration and purpose only and does not limit the scope of application of this specification. For those skilled in the art, various modifications and changes can be made to the processes under the guidance of this specification. However, such modifications and changes are still within the scope of this specification.

[0116] While the basic concepts have been described above, it will be apparent to those skilled in the art that the detailed disclosure is merely illustrative and does not limit this specification. Although not explicitly stated herein, various modifications, improvements, and revisions to this specification may be made by those skilled in the art. Such modifications, improvements, and revisions are suggested in this specification and remain within the spirit and scope of the exemplary embodiments of this specification.

[0117] This specification also uses specific terms to describe the embodiments of this specification. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a feature, structure, or characteristic associated with at least one embodiment of this specification. Therefore, it should be emphasized and noted that references to "one embodiment," "an embodiment," or "an alternative embodiment" two or more times in different locations in this specification do not necessarily refer to the same embodiment. Furthermore, certain features, structures, or characteristics of one or more embodiments of this specification may be appropriately combined.

[0118] In addition, unless expressly stated in the claims, the order of the processing elements and sequences, the use of alphanumeric characters, or the use of other names described in this specification are not intended to limit the order of the processes and methods of this specification. Although the above disclosure discusses some of the invention embodiments currently considered useful through various examples, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that are consistent with the spirit and scope of the embodiments of this specification. For example, although the system components described above can be implemented by hardware devices, they can also be implemented only by software solutions, such as installing the described system on an existing server or mobile device.

[0119] Similarly, it should be noted that, in order to simplify the presentation of this specification and thus facilitate understanding of one or more embodiments of the invention, the foregoing descriptions of the embodiments of this specification sometimes combine multiple features into a single embodiment, figure, or description thereof. However, this disclosure method does not imply that the subject matter of this specification requires more features than those recited in the claims. In fact, an embodiment may have fewer features than all of the features of a single disclosed embodiment.

[0120] In some embodiments, numbers are used to describe the quantity of components and attributes. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise stated, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the description and claims are approximate values, which may change according to the required characteristics of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of this specification are approximate values, in specific embodiments, the settings of such numerical values ​​are as accurate as possible within the feasible range.

[0121] Each patent, patent application, patent application publication, and other materials, such as articles, books, specifications, publications, and documents, cited in this specification is hereby incorporated by reference in its entirety. This includes application history documents that are inconsistent with or conflict with the content of this specification, as well as documents (currently or subsequently attached to this specification) that limit the broadest scope of the claims of this specification. It should be noted that if the descriptions, definitions, and / or terminology used in the accompanying materials are inconsistent or conflicting with the content of this specification, the descriptions, definitions, and / or terminology used in this specification will control.

[0122] Finally, it should be understood that the embodiments described in this specification are intended only to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, by way of example and not limitation, alternative configurations of the embodiments of this specification may be considered consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly described and illustrated in this specification.

Claims

1. A crystal growth device, characterized in that: It includes a zone melting device and a guide mold device, wherein the guide mold device is provided with a feed port, wherein: The zone melting device comprises: a raw material placement portion, for placing raw material bars, one end of the raw material placement portion being connected to the feed port; and a first heating device, disposed outside the raw material placement portion, for heating one end of the raw material rod into a melt to form a molten zone; The guide mold device comprises: The melt guide groove is arranged inside the guide mold device and is connected to the original material through the feed port. The material placement part is connected to the seed crystal, and is used to guide the melt in the melting zone to the corresponding position of the seed crystal; and The second heating device is arranged outside the guide mold device and is used to adjust the temperature of the melt in the melt guide groove to promote the seed crystal to grow into a target crystal.

2. The crystal growth apparatus according to claim 1, wherein: Also includes: A propulsion device, used to propel the raw material rod toward the feed port; Control device for: Determining a raw material replenishment amount based on a mass change of the target crystal; determining a speed of advancing the raw material bar based on the raw material replenishment amount; The propulsion device is controlled to propel the raw material rod toward the feed port based on the propulsion speed.

3. The crystal growth apparatus according to claim 2, wherein: The determining of the amount of raw material replenishment based on the mass change of the target crystal comprises: determining a model input based on the mass change and environmental information; The model input is processed using a crystal growth model to determine the raw material replenishment amount, and the crystal growth model is a machine learning model.

4. The crystal growth apparatus according to claim 1, wherein: The second heating device includes a plurality of heaters arranged at intervals, and the plurality of heaters heat the melt at different preset temperatures so that the temperature gradient of the melt in the melt channel meets preset requirements.

5. The crystal growth apparatus according to claim 4, wherein: Also includes: A temperature sensing device, installed on the outside of the guide mold device, for collecting and measuring temperature; Controls are used to: determining a predicted temperature of the melt in the melt channel based on the measured temperature; Based on the predicted temperature, the temperature parameters of the second heating device are adjusted so that the temperature gradient meets the preset requirement.

6. The crystal growth apparatus according to claim 1, wherein: The feed port is provided at the first end of the guide mold device, the corresponding position of the seed crystal is provided at the second end of the guide mold device, and the first end and the second end are provided opposite to each other; The melt guide groove has a trapezoidal structure, a first side of the trapezoidal structure is arranged at the first end, a second side of the trapezoidal structure is arranged at the second end, and the first side and the second side are parallel.

7. The crystal growth apparatus according to claim 6, wherein: The width of the guide mold device is 30-180 mm, the thickness of the guide mold device is 4.8-20 mm, and the size of the target crystal is 1-6 inches.

8. A crystal growth method, implemented using the crystal growth apparatus according to claim 1, comprising: controlling the first heating device to heat one end of the raw material rod into a melt to form a molten zone; Controlling the propulsion device to propel the raw material rod toward the feed port, so as to guide the melt in the melting zone to a position corresponding to the seed crystal through the melt guide groove; controlling a second heating device to heat the melt in the melt channel to adjust the temperature of the melt in the melt channel; When the melt reaches the position corresponding to the seed crystal, the seed crystal is used to guide the melt to perform crystal growth to obtain a target crystal.

9. The method according to claim 8, characterized in that The step of pushing the raw material rod toward the feed port comprises: Determining a raw material replenishment amount based on a mass change of the target crystal; determining a speed of advancing the raw material bar based on the raw material replenishment amount; The propulsion device is controlled to propel the raw material rod toward the feed port based on the propulsion speed.

10. The method according to claim 8, characterized in that Further including: determining a predicted temperature of the melt in the melt channel based on a measured temperature collected by a temperature sensing device; Based on the predicted temperature, the temperature parameters of the second heating device are adjusted so that the temperature gradient of the melt in the melt channel meets a preset requirement.

Images