Crystal manufacturing apparatus and growth method

Abstract

The present invention provides a crystal manufacturing apparatus and growth method. The crystal manufacturing apparatus includes a growth chamber for growing a crystal and a temperature control system for heating the growth chamber and preventing a radial temperature difference inside the growth chamber from exceeding a first preset range of an average temperature inside the growth chamber during crystal growth. The crystal growth method includes placing a seed crystal and a source material in the growth chamber, growing a crystal, and controlling a heating assembly based on information from a temperature sensing assembly during crystal growth so that the radial temperature difference inside the growth chamber during crystal growth does not exceed a first preset range of an average temperature inside the growth chamber.

Description

[Technical field]

[0001] <Cross-reference to related patent applications> This application claims priority to Chinese patent application No. 202010373329.8, filed on May 6, 2020, and No. 202010626511.X, filed on July 2, 2020, the entire contents of which are incorporated herein by reference. The present application relates to the field of crystal manufacturing, and in particular to a crystal manufacturing apparatus and growth method. [Background technology]

[0002] Semiconductor crystals (e.g., silicon carbide single crystals) have excellent physicochemical properties, making them important materials for manufacturing high-frequency and high-power devices. Physical vapor transport (PVT) is a method for manufacturing semiconductor crystals. Materials are decomposed and sublimated into gaseous components under high temperature, and the gaseous components are driven by the axial temperature gradient to be transported to a seed crystal in a low-temperature region, where they are deposited on the surface of the seed crystal to form a crystal. However, in the process of crystal growth, there is not only an axial temperature gradient, but also a radial temperature gradient. When growing large crystals, the large radial temperature gradient causes defects in crystal growth, reducing the quality and yield of the crystal. In addition, because the radial temperature gradient in the material-covered region is large, the molar ratio of each sublimated gaseous component is distributed unevenly along the radial direction, which is not conducive to stable crystal growth. Therefore, it is necessary to provide an improved crystal manufacturing apparatus and growth method for the same in order to manufacture large, high-quality crystals. Summary of the Invention

[0003] On the other hand, a crystal manufacturing apparatus is provided, which includes a growth chamber for growing a crystal, and a temperature control system for heating the growth chamber and preventing a radial temperature difference inside the growth chamber from exceeding a first preset range of an average temperature inside the growth chamber during crystal growth.

[0004] On the other hand, a crystal manufacturing apparatus is provided, which includes a growth chamber for placing a seed crystal and a raw material, a heating assembly for heating the growth chamber, and a temperature compensation assembly for providing temperature compensation during crystal growth, the temperature compensation assembly being disposed on an upper surface and / or a lower surface of the growth chamber, and the temperature compensation assembly including at least one heating unit.

[0005] On the other hand, a crystal manufacturing apparatus is provided, which includes a growth chamber for placing a seed crystal and a raw material, and a heating assembly for heating the growth chamber, the seed crystal being disposed at the top of the growth chamber and the raw material being disposed at the bottom of the growth chamber, the heating assembly being disposed outside the growth chamber and including a resistance heating element.

[0006] On the other hand, the present invention provides a method for growing a crystal, which includes placing a seed crystal and a source material in a growth chamber, growing a crystal, and controlling a heating assembly during the crystal growth based on information from a temperature sensing assembly so that a radial temperature difference inside the growth chamber does not exceed a first preset range of an average temperature inside the growth chamber when the crystal is grown.

[0007] On the other hand, the present invention provides a method for growing a crystal, which includes the steps of: performing a first cut on each of a plurality of hexagonal seed crystals to be expanded to obtain a plurality of regular hexagonal seed crystals whose cut surfaces are the same crystal plane family; joining the plurality of regular hexagonal seed crystals; performing a second cut on the joined plurality of regular hexagonal seed crystals to obtain a hexagonal seed crystal to be grown; performing interstitial growth on the hexagonal seed crystal to be grown under a first set condition to obtain an intermediate hexagonal seed crystal; and epitaxially growing the intermediate hexagonal seed crystal under a second set condition to obtain a target hexagonal seed crystal, the diameter of which is greater than the diameter of the hexagonal seed crystal to be expanded. [Brief description of the drawings]

[0008] The present specification will be further described by exemplary embodiments, which will be described in detail in conjunction with the accompanying drawings, which are not intended to limit the present application. In these embodiments, the same numbers indicate the same structures. [Figure 1] 1 is a schematic diagram of an exemplary crystal manufacturing apparatus as described in some embodiments. [Diagram 2] FIG. 1 is a schematic diagram of an exemplary temperature feedback regulation system as shown in some embodiments. [Diagram 3] FIG. 2 is a schematic diagram of an exemplary crystal manufacturing apparatus according to another embodiment. [Figure 4] FIG. 2 is a top view of an exemplary heating unit arrangement shown in some embodiments. [Diagram 5] FIG. 13 is a bottom view of an exemplary heating unit arrangement shown in another embodiment. [Figure 6] FIG. 2 is a schematic diagram of an exemplary first electrode and an exemplary second electrode as shown in some embodiments. [Figure 7] FIG. 2 is a top view of an exemplary electrode fixture plate shown in some embodiments. [Figure 8] FIG. 2 is a schematic diagram of an exemplary crystal manufacturing apparatus according to another embodiment. [Figure 9] FIG. 2 is a schematic diagram of an exemplary resistive heating element as shown in some embodiments. [Figure 10] FIG. 13 is a top view of an exemplary first electrode and an exemplary second electrode arrangement shown in another embodiment. [Figure 11] FIG. 13 is a top view of an exemplary first electrode and an exemplary second electrode arrangement shown in another embodiment. [Figure 12] FIG. 13 is a schematic diagram of an exemplary first electrode and / or an exemplary second electrode, as shown in another embodiment, secured to a resistive heating element. [Figure 13] FIG. 2 is a schematic diagram of an exemplary crystal manufacturing apparatus according to another embodiment. [Figure 14] 1 is a schematic diagram of at least one exemplary heating unit as shown in some embodiments. [Figure 15] FIG. 2 is a schematic diagram of an exemplary crystal manufacturing apparatus according to another embodiment. [Figure 16A] FIG. 2 illustrates a top view of an exemplary at least one heating unit shown in some embodiments. [Figure 16B] FIG. 2 is a side view of an exemplary at least one heating unit as shown in some embodiments. [Figure 17] 2 is a schematic diagram of an exemplary at least one conductive ring as shown in some embodiments. [Figure 18] 1 is a flow chart of an exemplary crystal growth method presented in some embodiments. [Figure 19] 4 is a flow chart of an exemplary crystal growth method according to another embodiment. [Figure 20] 4 is a flow chart of an exemplary crystal growth method according to another embodiment. [Figure 21] FIG. 2 is a schematic diagram of an exemplary produced crystal as shown in some embodiments. [Figure 22] 1 is a flow chart of an exemplary method for producing seed crystals as described in some embodiments. [Figure 23] FIG. 2 is a schematic diagram of an exemplary seed crystal manufacturing process as presented in some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In order to more clearly describe the technical solutions of the embodiments of the present application, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some examples or embodiments of the present application, and those skilled in the art can apply the present application to other similar situations through these drawings without creative efforts. Unless otherwise clear from the context or indicated, the same numbers in the drawings indicate the same structures or operations. It should be understood that the drawings are for illustration and description only, and are not intended to limit the scope of the present application. It should be understood that the drawings are not drawn to scale.

[0010] The orientations indicated by "center", "upper surface", "lower surface", "top", "lower", "top", "bottom", "inner", "outer", "axial", "radial", "periphery", "external", and the like are orientations shown in the drawings and are not intended to indicate that the devices, assemblies, or units must have a particular orientation, and should not be construed as a limitation of the present application.

[0011] It should be understood that the terms "system," "apparatus," "unit," and / or "module" used herein are ways of distinguishing between different assemblies, elements, parts, portions, or installations at different levels. Other terms can be substituted for said terms if they achieve the same purpose.

[0012] As used herein and in the claims, terms such as "a," "one," "a kind," and / or "the" do not refer to the singular but may include the plural unless the context clearly indicates otherwise. Generally speaking, the term "comprising" only implies the inclusion of specifically identified steps and elements, and these steps and elements do not constitute an exclusive list, and a method or device may include other steps or elements as well.

[0013] Flowcharts are used herein to describe operations performed by the system of the embodiments of the present application. It should be understood that preceding or subsequent operations are not necessarily performed in exact order. Conversely, various steps may be processed in reverse order or simultaneously. At the same time, other operations may be added to these steps or certain steps may be removed from these steps.

[0014] FIG. 1 is a schematic diagram of an exemplary crystal manufacturing apparatus according to some embodiments.

[0015] The crystal manufacturing apparatus 100 is used to manufacture crystals. In some embodiments, the crystal manufacturing apparatus 100 manufactures crystals based on physical vapor transport (PVT). A seed crystal is attached to the top of the growth chamber of the crystal manufacturing apparatus 100, a raw material is placed at the bottom of the growth chamber, and a heating assembly (e.g., an induction coil) is provided outside the growth chamber and used to heat the growth chamber. In the crystal growth process, an axial temperature gradient is formed between the raw material and the seed crystal by controlling the temperature field distribution inside the growth chamber. The raw material is decomposed and sublimated into gas phase components at high temperature, and the gas phase components are driven by the axial temperature gradient and transported to the seed crystal in the low temperature region. Since the temperature is low at the location where the seed crystal is located, the gas phase components can form crystals on the surface of the seed crystal. In some embodiments, the crystals can include, but are not limited to, silicon carbide crystals, aluminum nitride crystals, zinc oxide crystals, or zinc antimonide crystals.

[0016] 1, the crystal manufacturing apparatus 100 includes a growth chamber 110 and a heating assembly 120. The heating assembly 120 is used to heat the growth chamber 110 and provide a temperature field required for crystal growth to manufacture the crystal.

[0017] The growth chamber 110 is a place for providing crystal growth. In some embodiments, the growth chamber 110 is used to grow a seed crystal and then grow further crystals based on the seed crystal. In some embodiments, the inside of the growth chamber 110 is used to place a seed crystal and a raw material and grow a crystal based on the seed crystal and the raw material. In some embodiments, the growth chamber 110 includes a growth chamber cover 111 and a growth chamber body 112. In some embodiments, the growth chamber body 112 may be a container with a growth chamber bottom cover and no growth chamber cover. In some embodiments, the growth chamber cover 111 is disposed on the top of the growth chamber body 112 and is used to close the opening at the top of the growth chamber body 112. In some embodiments, the growth chamber 110 may be a crucible, and the crucible includes a crucible cover and a crucible body. In some embodiments, the shape of the growth chamber body 112 may include, but is not limited to, a cylinder, a rectangular parallelepiped, a cube, and the like. In some embodiments, the shape of the growth chamber cover 111 may include, but is not limited to, a circular disk, a rectangular disk, a square disk, etc. In some embodiments, the shapes of the growth chamber cover 111 and the growth chamber body 112 are compatible with each other. In some embodiments, the shape of the growth chamber body 112 may be a cylindrical barrel including a barrel bottom and a barrel sidewall, and the shape of the growth chamber cover 111 may be a disk. In some embodiments, the shape of the growth chamber body 112 may be a rectangular barrel including a barrel bottom and a barrel sidewall, and the shape of the growth chamber cover 111 may be a rectangular disk or a square disk.

[0018] In some embodiments, the material of the growth chamber 110 may include, but is not limited to, graphite. In some embodiments, the material of the growth chamber 110 may include graphite and silicon carbide. In some embodiments, the mass of the graphite may comprise 40%-90% of the mass of the growth chamber 110. In some embodiments, the mass of the graphite may comprise 45%-85% of the mass of the growth chamber 110. In some embodiments, the mass of the graphite may comprise 50%-80% of the mass of the growth chamber 110. In some embodiments, the mass of the graphite may comprise 55%-75% of the mass of the growth chamber 110. In some embodiments, the mass of the graphite may comprise 60%-70% of the mass of the growth chamber 110. In some embodiments, the mass of the graphite may comprise 64-66% of the mass of the growth chamber 110. In some embodiments, the materials of the growth chamber cover 111 and the growth chamber body 112 may be the same or different.

[0019] The heating assembly 120 is used to heat the growth chamber 110 and provide a temperature field required for crystal growth to produce crystals. In some embodiments, under the temperature field inside the growth chamber 110, the raw material can be sublimated and decomposed to generate gas phase components, which are driven by the axial temperature gradient and transported to the seed crystal, where they grow and crystallize to form crystals. In some embodiments, the heating assembly 120 is disposed outside and / or inside the growth chamber 110. In some embodiments, the heating assembly 120 can include, but is not limited to, a resistance heating device and / or an electromagnetic induction heating device, etc. As shown in FIG. 1, the heating assembly 120 includes an electromagnetic induction heating device disposed outside the growth chamber 110. In some embodiments, the electromagnetic induction heating device includes an induction coil. The induction coil can generate eddy currents on the surface of the growth chamber 110 under alternating currents of different frequencies. Under the eddy currents, the electrical energy generated on the surface of the growth chamber 110 is converted into thermal energy to heat the growth chamber 110. In some embodiments, the heating assembly 120 includes a resistance heating device. In some embodiments, the heating assembly 120 includes a graphite resistive heating device and can heat the growth chamber 110 using thermal energy generated by the Joule effect as electrical current flows through the graphite after it is energized.

[0020] As shown in FIG. 1, a seed crystal 150 is bonded to the inside of the growth chamber cover 111, and a raw material 160 is placed inside the growth chamber body 112. The dotted line a in FIG. 1 indicates the lower surface of the seed crystal 150. The dashed line b in FIG. 1 indicates the upper surface of the raw material 160. In some embodiments, the radial temperature difference represents the difference between the maximum temperature and the minimum temperature in a horizontal cross section located at the same height of the growth chamber 110. Because the growth chamber 110 has a height, the difference between the maximum temperature and the minimum temperature in the horizontal cross section at different heights may be different. In some embodiments, the radial temperature difference refers to the difference between the maximum temperature and the minimum temperature in the plane where the lower surface of the seed crystal is (the horizontal plane where the dotted line a in FIG. 1 is). In some embodiments, the radial temperature difference refers to the difference between the maximum temperature and the minimum temperature in the plane where the upper surface of the raw material is (the horizontal plane where the dotted line b in FIG. 1 is). In some embodiments, the radial temperature difference refers to the difference between the maximum temperature and the minimum temperature in any horizontal plane between the plane where the upper surface of the raw material 160 is and the plane where the lower surface of the seed crystal is.

[0021] As shown in FIG. 1 , the heating assembly 120 includes an electromagnetic induction heating device disposed outside the growth chamber 110. The electromagnetic induction heating device may be an induction coil. When the induction coil is energized to heat the growth chamber 110, thermal energy is conducted from the wall of the growth chamber to the interior of the growth chamber 110. Inside the growth chamber 110, thermal energy is conducted from the peripheral region of the growth chamber 110 to the central region of the growth chamber 110. In the process of thermal conduction, due to heat dissipation, the peripheral region inside the growth chamber 110 becomes a relatively hot region and the central region becomes a relatively cold region. In some embodiments, the peripheral region may be a region adjacent to the wall of the growth chamber 110. The central region may be a region close to the central axis of the growth chamber 110. In some embodiments, a temperature field is formed inside the growth chamber 110 with a temperature decrease from the peripheral region to the central region. The temperature field may reflect the temporal and spatial distribution of the temperature inside the growth chamber 110. The temperature field with a temperature decrease may form a radial temperature difference.

[0022] The radial temperature difference leads to the occurrence of thermal stress on the growth surface of the seed crystal, which causes the growth surface of the seed crystal to bulge toward the feedstock, resulting in defects such as micropipes and inclusions. Under certain circumstances, the radial temperature difference leads to the molar ratio of the sublimated gas phase components of the feedstock being distributed unevenly along the radial direction, thereby affecting the quality of the crystal. Therefore, in order to produce high quality crystals, it is necessary to reduce the radial temperature difference. In the embodiments of the present invention, unless otherwise specified, the terms temperature field, temperature field, and temperature distribution can be used interchangeably.

[0023] In some embodiments, the temperature control system can prevent the radial temperature difference inside the growth chamber during crystal growth from exceeding a first preset range of crystal growth temperatures. In some embodiments, the crystal growth temperature and / or the first preset range can be preset. In some embodiments, the crystal growth temperature and / or the first preset range can be dynamically determined according to a specific algorithm based on the preset conditions. In some embodiments, the preset conditions can include, but are not limited to, the size, shape and material of the growth chamber 110, the size of the seed crystal, and the type and size of the crystal to be grown. For a specific description of the temperature control system, please refer to FIG. 2 and related descriptions herein.

[0024] The radial temperature difference may cause defects such as micropipes and inclusions during crystal growth. Therefore, in order to obtain high quality crystals, it is necessary to control the radial temperature difference during crystal growth. For specific control processes, please refer to the descriptions in other parts of this specification (e.g., FIG. 2). In some embodiments, the crystal growth temperature refers to the degree Celsius required for crystal growth. Different types of crystals have different growth temperatures. In some embodiments, the growth temperature of silicon carbide crystals may be 2200°C to 2400°C. In some embodiments, the temperature control system may not allow the radial temperature difference inside the growth chamber during crystal growth to exceed 1% of the crystal growth temperature. In some embodiments, the temperature control system may not allow the radial temperature difference inside the growth chamber during crystal growth to exceed 0.8% of the crystal growth temperature. In some embodiments, the temperature control system may not allow the radial temperature difference inside the growth chamber during crystal growth to exceed 0.6% of the crystal growth temperature. In some embodiments, the temperature control system may not allow the radial temperature difference inside the growth chamber during crystal growth to exceed 0.5% of the crystal growth temperature. In some embodiments, the temperature control system can allow the radial temperature difference inside the growth chamber during crystal growth to not exceed 0.4% of the crystal growth temperature. In some embodiments, the temperature control system can allow the radial temperature difference inside the growth chamber during crystal growth to not exceed 0.3% of the crystal growth temperature. In some embodiments, the temperature control system can allow the radial temperature difference inside the growth chamber during crystal growth to not exceed 0.25% of the crystal growth temperature. In some embodiments, the temperature control system can allow the radial temperature difference inside the growth chamber during crystal growth to not exceed 0.2% of the crystal growth temperature. In some embodiments, the temperature control system can allow the radial temperature difference inside the growth chamber during crystal growth to not exceed 0.15% of the crystal growth temperature. In some embodiments, the temperature control system can allow the radial temperature difference inside the growth chamber during crystal growth to not exceed 0.1% of the crystal growth temperature.In some embodiments, the temperature control system can allow the radial temperature difference inside the growth chamber during crystal growth to not exceed 0.08% of the crystal growth temperature. In some embodiments, the temperature control system can allow the radial temperature difference inside the growth chamber during crystal growth to not exceed 0.06% of the crystal growth temperature. In some embodiments, the temperature control system can allow the radial temperature difference inside the growth chamber during crystal growth to not exceed 0.05% of the crystal growth temperature. In some embodiments, the temperature control system can allow the radial temperature difference inside the growth chamber during crystal growth to not exceed 0.02% of the crystal growth temperature.

[0025] In some embodiments, the temperature control system can prevent the radial temperature difference inside the growth chamber from exceeding a preset radial temperature difference threshold during crystal growth. In some embodiments, the preset radial temperature difference threshold can be in a range of 0.5°C to 6°C. In some embodiments, the preset radial temperature difference threshold can be in a range of 0.6°C to 5.7°C. In some embodiments, the preset radial temperature difference threshold can be in a range of 0.7°C to 5.4°C. In some embodiments, the preset radial temperature difference threshold can be in a range of 0.8°C to 5°C. In some embodiments, the preset radial temperature difference threshold can be in a range of 0.9°C to 4.7°C. In some embodiments, the preset radial temperature difference threshold can be in a range of 1°C to 4.4°C. In some embodiments, the preset radial temperature difference threshold can be in a range of 1.1°C to 4°C. In some embodiments, the preset radial temperature difference threshold can be in a range of 1.2°C to 3.5°C. In some embodiments, the preset radial temperature difference threshold can be in a range of 1.3°C to 3°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 1.4°C to 2.5°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 1.5°C to 2°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 1.6°C to 1.9°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 1.7°C to 1.8°C.

[0026] Since it takes a certain time for a crystal to grow to a certain size, it is necessary to control the radial temperature difference inside the growth chamber during the crystal growth process, so that the radial temperature difference inside the growth chamber does not exceed a first preset range of crystal growth temperature or a preset radial temperature difference threshold in a certain time zone. Since a crystal grows along a certain crystal plane, if defects occur in a crystal grown in a certain time zone, the defects will continue to accumulate and expand in the subsequent crystal growth stages, ultimately resulting in a deterioration in crystal quality and thus unusable. Therefore, it is necessary to control the radial temperature difference inside the growth chamber during crystal growth in the time preceding the crystal growth period so as not to exceed a first preset range of crystal growth temperature or a preset radial temperature difference threshold.

[0027] In some embodiments, the temperature control system maintains that the radial temperature difference inside the growth chamber during crystal growth does not exceed a first preset range of crystal growth temperatures or a preset radial temperature difference threshold, at least in the crystal growth subinterval. In some embodiments, the crystal growth subinterval may be a period of time of an interval before the crystal growth interval. In some embodiments, the crystal growth interval may be from 4:00 AM to 24:00 PM, and the crystal growth subinterval may be a period of time that is the first 90% of the crystal growth interval, and the crystal growth subinterval may be from 4:00 AM to 22:00 PM. In some embodiments, the crystal growth interval refers to the minimum time required for a crystal to grow to a predetermined size. In some embodiments, the crystal growth interval may be determined by preset conditions. In some embodiments, the preset conditions may include, but are not limited to, the size, shape, and material of the growth chamber 110, the size of the seed crystal, and the type and size of the crystal to be grown.

[0028] In some embodiments, the crystal growth subinterval may be a period that is the first 80% of the crystal growth interval. In some embodiments, the crystal growth subinterval may be a period that is the first 85% of the crystal growth interval. In some embodiments, the crystal growth subinterval may be a period that is the first 90% of the crystal growth interval. In some embodiments, the crystal growth subinterval may be a period that is the first 95% of the crystal growth interval. In some embodiments, the temperature control system may maintain a radial temperature difference within the interior of the growth chamber during crystal growth not to exceed a first preset range of crystal growth temperatures or a preset radial temperature difference threshold throughout the crystal growth interval.

[0029] In some embodiments, the radial temperature difference is related to the radius of the growth chamber. As shown in FIG. 1, the larger the radius of the growth chamber 110, the more heat energy is dissipated in the process of thermal energy being conducted from the wall of the growth chamber 110 to the inside of the growth chamber 110, which leads to a larger radial temperature difference. In some embodiments, the radial temperature difference during the growth of crystals grown in the growth chambers 110 with different radii is not greater than a first preset range of crystal growth temperatures or a preset radial temperature difference threshold.

[0030] In some embodiments, if the radius of the growth chamber does not exceed 5 cm, the temperature control system ensures that when the crystal is grown, the radial temperature difference inside the growth chamber does not exceed 0.075% of the crystal growth temperature or the preset radial temperature difference threshold. In some embodiments, the preset radial temperature difference threshold may be in the range of 0.5°C to 1.5°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 0.6°C to 1.4°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 0.7°C to 1.3°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 0.8°C to 1.2°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 0.9°C to 1.1°C.

[0031] In some embodiments, when the radius of the growth chamber is greater than 5 cm and less than or equal to 8 cm, the temperature control system can ensure that the radial temperature difference during crystal growth does not exceed 0.15% of the crystal growth temperature or the preset radial temperature difference threshold. In some embodiments, the preset radial temperature difference threshold may be in a range of 0.8°C to 2.8°C. In some embodiments, the preset radial temperature difference threshold may be in a range of 0.9°C to 2.7°C. In some embodiments, the preset radial temperature difference threshold may be in a range of 1°C to 2.6°C. In some embodiments, the preset radial temperature difference threshold may be in a range of 1.1°C to 2.5°C. In some embodiments, the preset radial temperature difference threshold may be in a range of 1.2°C to 2.4°C. In some embodiments, the preset radial temperature difference threshold may be in a range of 1.3°C to 2.3°C. In some embodiments, the preset radial temperature difference threshold may be in a range of 1.4°C to 2.2°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 1.5° C. to 2.1° C. In some embodiments, the preset radial temperature difference threshold may be in the range of 1.6° C. to 2° C. In some embodiments, the preset radial temperature difference threshold may be in the range of 1.7° C. to 1.9° C.

[0032] In some embodiments, when the radius of the growth chamber is greater than 8 cm and less than or equal to 10 cm, the temperature control system can ensure that the radial temperature difference inside the growth chamber during crystal growth does not exceed 0.2% of the crystal growth temperature or the preset radial temperature difference threshold. In some embodiments, the preset radial temperature difference threshold may be in the range of 1.5°C to 4.5°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 1.7°C to 4.3°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 1.9°C to 4.1°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 2.1°C to 3.9°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 2.3°C to 3.7°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 2.5°C to 3.5°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 2.7°C to 3.3°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 2.9° C. to 3.1° C. In some embodiments, the preset radial temperature difference threshold may be 3° C.

[0033] In some embodiments, when the radius of the growth chamber is greater than 10 cm, the temperature control system can ensure that the radial temperature difference inside the growth chamber during crystal growth does not exceed 0.3% of the crystal growth temperature or the preset radial temperature difference threshold. In some embodiments, the preset radial temperature difference threshold may be in the range of 1.5°C to 6°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 1.7°C to 5.8°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 1.9°C to 5.6°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 2.1°C to 5.4°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 2.3°C to 5.2°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 2.5°C to 5°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 2.7°C to 4.8°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 2.9°C to 4.6°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 3.1°C to 4.4°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 3.3°C to 4.2°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 3.5°C to 4°C. In some embodiments, the preset radial temperature difference threshold may be in the range of 3.7°C to 3.8°C.

[0034] In some embodiments, the radial temperature gradient includes the temperature difference per unit distance from the inner wall of the growth chamber to the central axis of the growth chamber in a horizontal cross section at the same height of the growth chamber 110. In some embodiments, the decrease in temperature creates a radial temperature gradient in the direction from the inner wall of the growth chamber to the central axis of the growth chamber. The radial temperature gradient causes thermal stresses to occur on the growth surface of the seed crystal, which causes the growth surface of the seed crystal to bulge toward the feedstock, generating defects such as micropipes and inclusions. Under certain circumstances, the radial temperature gradient causes the mole ratio of the sublimated gas phase components of the feedstock to become uniform in the radial distribution, thereby affecting the quality of the crystal. Therefore, in order to produce high quality crystals, it is necessary to reduce the radial temperature gradient.

[0035] In some embodiments, the temperature control system can prevent the radial temperature gradient inside the growth chamber from exceeding a preset radial temperature gradient threshold during crystal growth. In some embodiments, the preset radial temperature gradient threshold may be preset. In some embodiments, the preset radial temperature gradient threshold may be determined by preset conditions. In some embodiments, the preset conditions may include, but are not limited to, the size, shape, and material of the growth chamber 110, the size of the seed crystal, and the type and size of the crystal being grown.

[0036] In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.1° C. / cm to 0.5° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.11° C. / cm to 0.49° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.12° C. / cm to 0.48° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.13° C. / cm to 0.47° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.14° C. / cm to 0.46° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.15° C. / cm to 0.45° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.16° C. / cm to 0.44° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.17° C. / cm to 0.43° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.18° C. / cm to 0.42° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.19° C. / cm to 0.41° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.2° C. / cm to 0.4° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.21° C. / cm to 0.39° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.22° C. / cm to 0.38° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.23° C. / cm to 0.37° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.24° C. / cm to 0.36° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.25° C. / cm to 0.35° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.26° C. / cm to 0.34° C. / cm.In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.27° C. / cm to 0.33° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.28° C. / cm to 0.32° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.29° C. / cm to 0.31° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be 0.3° C. / cm.

[0037] In some embodiments, the radial temperature gradient is related to the radius of the growth chamber. As shown in FIG. 1, the larger the radius of the growth chamber 110, the more heat energy is dissipated in the process of conducting heat energy from the wall of the growth chamber to the inside of the growth chamber 110. Less heat energy is conducted to the central region of the growth chamber 110, and the temperature of the central region of the growth chamber 110 is lower. In some embodiments, the temperature of the central region of the growth chamber 110 is relatively low, which causes thermal stress to occur on the growth surface of the seed crystal, causing the growth surface of the seed crystal to bulge toward the feedstock, generating defects such as micropipes and inclusions. In some embodiments, the temperature of the central region of the growth chamber 110 is lower, which causes the mole ratio of the sublimated gas phase components of the feedstock to be uniformly distributed along the radial direction, thereby affecting the quality of the crystal. In some embodiments, the radial temperature gradient of the crystals grown in the growth chambers 110 with different radii does not exceed a preset radial temperature gradient threshold.

[0038] In some embodiments, if the radius of the growth chamber does not exceed 5 cm, the temperature control system can prevent the radial temperature gradient inside the growth chamber from exceeding a preset radial temperature gradient threshold during crystal growth. In some embodiments, the preset radial temperature gradient threshold may be in a range of 0.1° C. / cm to 0.3° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in a range of 0.11° C. / cm to 0.29° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in a range of 0.12° C. / cm to 0.28° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in a range of 0.13° C. / cm to 0.27° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in a range of 0.14° C. / cm to 0.26° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in a range of 0.15° C. / cm to 0.25° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.16° C. / cm to 0.24° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.17° C. / cm to 0.23° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.18° C. / cm to 0.22° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.19° C. / cm to 0.21° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be 0.2° C. / cm.

[0039] In some embodiments, when the radius of the growth chamber is greater than 5 cm and less than or equal to 8 cm, the temperature control system can prevent the radial temperature gradient inside the growth chamber from exceeding a preset radial temperature gradient threshold during crystal growth. In some embodiments, the preset radial temperature gradient threshold may be in a range of 0.1° C. / cm to 0.37° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in a range of 0.11° C. / cm to 0.36° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in a range of 0.12° C. / cm to 0.35° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in a range of 0.13° C. / cm to 0.34° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in a range of 0.14° C. / cm to 0.33° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in a range of 0.15° C. / cm to 0.32° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.16° C. / cm to 0.31° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.17° C. / cm to 0.3° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.18° C. / cm to 0.29° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.19° C. / cm to 0.28° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.2° C. / cm to 0.27° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.21° C. / cm to 0.26° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.22° C. / cm to 0.25° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.23° C. / cm to 0.24° C. / cm.

[0040] In some embodiments, when the radius of the growth chamber is greater than 8 cm and less than or equal to 10 cm, the temperature control system can prevent the radial temperature gradient inside the growth chamber from exceeding a preset radial temperature gradient threshold during crystal growth. In some embodiments, the preset radial temperature gradient threshold may be in a range of 0.15° C. / cm to 0.45° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in a range of 0.16° C. / cm to 0.44° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in a range of 0.17° C. / cm to 0.43° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in a range of 0.18° C. / cm to 0.42° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in a range of 0.19° C. / cm to 0.41° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in a range of 0.2° C. / cm to 0.4° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.21° C. / cm to 0.39° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.22° C. / cm to 0.38° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.23° C. / cm to 0.37° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.24° C. / cm to 0.36° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.25° C. / cm to 0.35° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.26° C. / cm to 0.34° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.27° C. / cm to 0.33° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.28° C. / cm to 0.32° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.29° C. / cm to 0.31° C. / cm.In some embodiments, the preset radial temperature gradient threshold may be 0.3° C. / cm.

[0041] In some embodiments, when the radius of the growth chamber is greater than 10 cm, the temperature control system can prevent the radial temperature gradient inside the growth chamber from exceeding a preset radial temperature gradient threshold during crystal growth. In some embodiments, the preset radial temperature gradient threshold may be in a range of 0.15° C. / cm to 0.6° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in a range of 0.17° C. / cm to 0.58° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in a range of 0.19° C. / cm to 0.56° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in a range of 0.21° C. / cm to 0.54° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in a range of 0.23° C. / cm to 0.52° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in a range of 0.25° C. / cm to 0.5° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.27° C. / cm to 0.48° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.29° C. / cm to 0.46° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.31° C. / cm to 0.44° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.33° C. / cm to 0.42° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.35° C. / cm to 0.4° C. / cm. In some embodiments, the preset radial temperature gradient threshold may be in the range of 0.37° C. / cm to 0.38° C. / cm.

[0042] As shown in FIG. 1, the distance between the lower surface of the seed crystal 150 and the upper surface of the source material 160 is expressed as H cm. In some embodiments, the axial temperature gradient refers to the temperature difference per unit distance in the direction of the central axis of the growth chamber 110. Assuming that there is no radial temperature difference or the radial temperature difference is negligible in the plane where the upper surface of the source material 160 is located, the temperature of the plane where the upper surface of the source material 160 is located can be expressed as a ° C. Assuming that there is no radial temperature difference or the radial temperature difference is negligible in the plane where the lower surface of the seed crystal 150 is located, the temperature of the plane where the lower surface of the seed crystal 150 is located can be expressed as b ° C. Wherein, a>b, the axial temperature gradient can be expressed as (ab) / H, with units of ° C / cm.

[0043] The axial temperature gradient is the driving force for transporting the gas phase components sublimated by the thermal decomposition of the raw material to the surface of the seed crystal to grow the crystal. If the axial temperature gradient is unstable, the gas phase components will not be distributed uniformly in the axial direction, and the quality of the grown crystal will be reduced. Therefore, in order to grow high quality crystals, it is necessary to maintain a stable axial temperature gradient. In some embodiments, a heating assembly is used to maintain the stability of the axial temperature gradient when the crystal is growing.

[0044] In some embodiments, the axial temperature gradient needs to be controlled in the range of the preset axial temperature gradient to ensure the quality of the crystal. If the axial temperature gradient is too small, the driving force may not be sufficient, and the deposition rate of the gas phase components on the lower surface of the seed crystal is too slow, so that the physical vapor transport (PVT) cannot meet the demand for mass transport. If the axial temperature gradient is too large, the mass transport is too fast, and the deposition rate of the gas phase components on the lower surface of the seed crystal is too fast, so that a large stress is formed on the crystal growth surface, which is easy to form defects such as inclusions, and further induce other dislocation defects, which affects the crystal quality. Therefore, the axial temperature gradient needs to be maintained in the range of a suitable preset axial temperature gradient.

[0045] In some embodiments, the temperature control system can maintain the axial temperature gradient inside the growth chamber in a preset axial temperature gradient range during crystal growth. In some embodiments, the preset axial temperature gradient range may be 0.2° C. / cm to 2.5° C. / cm. In some embodiments, the preset axial temperature gradient range may be 0.3° C. / cm to 2.4° C. / cm. In some embodiments, the preset axial temperature gradient range may be 0.4° C. / cm to 2.3° C. / cm. In some embodiments, the preset axial temperature gradient range may be 0.5° C. / cm to 2.2° C. / cm. In some embodiments, the preset axial temperature gradient range may be 0.6° C. / cm to 2.1° C. / cm. In some embodiments, the preset axial temperature gradient range may be 0.7° C. / cm to 2.0° C. / cm. In some embodiments, the preset axial temperature gradient range may be 0.8° C. / cm to 1.9° C. / cm. In some embodiments, the preset axial temperature gradient range may be 0.9° C. / cm to 1.8° C. / cm. In some embodiments, the preset axial temperature gradient may range from 1.0° C. / cm to 1.7° C. / cm. In some embodiments, the preset axial temperature gradient may range from 1.1° C. / cm to 1.6° C. / cm. In some embodiments, the preset axial temperature gradient may range from 1.2° C. / cm to 1.5° C. / cm. In some embodiments, the preset axial temperature gradient may range from 1.3° C. / cm to 1.4° C. / cm.

[0046] In some embodiments, the heating assembly includes at least one heating unit. In some embodiments, the quantity of the at least one heating unit may include one, two, three, etc. In some embodiments, the at least one heating unit is disposed outside the growth chamber. In some embodiments, a portion of the at least one heating unit is disposed around the periphery of the growth chamber. In some embodiments, at least one heating unit of the at least two heating units may be disposed around the periphery of the growth chamber, and at least one heating unit of the at least two heating units may be disposed on an outer upper and / or lower surface of the growth chamber. In some embodiments, the at least one heating unit is disposed inside the growth chamber. In some embodiments, at least one heating unit of the at least two heating units may be disposed around the periphery of the growth chamber. In some embodiments, at least one heating unit of the at least two heating units may be disposed inside the growth chamber, and at least one heating unit of the at least two heating units may be disposed around the periphery of the growth chamber. In some embodiments, at least one heating unit of the at least two heating units may be disposed inside the growth chamber, and at least one heating unit of the at least two heating units may be disposed on an outer upper and / or lower surface of the growth chamber. In some embodiments, the at least one heating unit located outside the growth chamber may include at least three first heating units, which may correspond to the locations of a crystallization region inside the growth chamber, a source zone inside the growth chamber, and a vapor transport zone between the crystallization region and the source zone, respectively.

[0047] In some embodiments, the at least one heating unit may include, but is not limited to, a resistive heating device, an electromagnetic induction heating device, and the like. In some embodiments, the at least one heating unit may include a resistive heating element and / or an electromagnetic induction coil. In some embodiments, the material of the at least one heating unit may include, but is not limited to, at least one of graphite, tungsten, platinum, molybdenum, tantalum, or iridium. In some embodiments, the at least one heating unit may include a resistive heating element. The resistive heating element may include, but is not limited to, at least one of a graphite heating element, a tungsten heating element, a platinum heating element, a molybdenum heating element, a tantalum heating element, an iridium heating element, or a composite ceramic heating element of zirconium diboride.

[0048] It should be noted that the above description of the crystal manufacturing apparatus 100 is for illustrative and explanatory purposes only, and is not intended to limit the scope of the present application. Those skilled in the art may make various modifications and variations to the crystal manufacturing apparatus 100 without departing from the spirit and scope of the technical configuration of the present invention. All such modifications and variations should be included in the scope of protection of the present invention.

[0049] FIG. 2 is a schematic diagram of an exemplary temperature feedback regulation system as shown in some embodiments.

[0050] In some embodiments, the crystal manufacturing apparatus can include a temperature feedback regulation system 200. As shown in FIG. 2, the temperature feedback regulation system 200 can include a temperature sensing assembly 210, a heating assembly 220, and a control assembly 230. In embodiments herein, unless otherwise specified, the temperature feedback regulation system and the temperature control system can be used interchangeably. In embodiments herein, the heating assembly 120 and the heating assembly 220 can refer to the same assembly.

[0051] In some embodiments, the temperature sensing assembly 210 may include at least one temperature sensing unit. In some embodiments, at least one temperature sensing unit is disposed around the growth chamber. In some embodiments, the at least one temperature sensing unit is used to measure the temperature of the growth chamber, obtain a temperature distribution during crystal growth, and send the measured temperature to the control assembly 230. In some embodiments, the temperature distribution may include, but is not limited to, a radial temperature distribution and an axial temperature distribution. In some embodiments, the radial temperature distribution may include a temperature distribution across at least one horizontal cross section of the growth chamber 110. In some embodiments, the axial temperature distribution may include a temperature distribution in a direction parallel to or at the central axis of the growth chamber 110. In some embodiments, the radial temperature distribution may include a radial temperature difference distribution and / or a radial temperature gradient distribution. In some embodiments, the axial temperature distribution may include an axial temperature gradient distribution.

[0052] In some embodiments, the quantity of the at least one temperature sensing unit may include, but is not limited to, one, two, three, etc. In some embodiments, the at least one temperature sensing unit may include, but is not limited to, at least one temperature sensor. In some embodiments, the at least one temperature sensing unit may include, but is not limited to, at least one infrared thermometer.

[0053] In some embodiments, at least one temperature sensing unit is disposed on the outer upper surface of the growth chamber and is used to measure the temperature of the lower surface of the seed crystal or the crystal growth surface. In some embodiments, at least one temperature sensing unit is disposed on the outer lower surface of the growth chamber and is used to measure the temperature of the upper surface of the source material. In some embodiments, at least one temperature sensing unit is disposed on the outer wall of the growth chamber and is used to measure the temperatures of the inner and outer peripheral regions of the growth chamber.

[0054] In some embodiments, the at least one temperature sensing unit is arranged in a ring shape around the center of the growth chamber cover or the growth chamber bottom cover, and is used to measure the temperature at the position of the same diameter of the growth chamber. In some embodiments, the at least one temperature sensing unit is arranged parallel to the central axis of the growth chamber and on the outer wall of the growth chamber, and is used to measure the axial temperature of the growth chamber. In some embodiments, the at least one temperature sensing unit may be arranged in other shapes, such as a square or a rectangle.

[0055] In some embodiments, the information of the temperature sensing assembly can include, but is not limited to, the arrangement of the at least one temperature sensing unit, the quantity of the at least one temperature sensing unit, the location of the at least one temperature sensing unit, and the temperature measured by the at least one temperature sensing unit.

[0056] In some embodiments, the control assembly 230 may include at least one control unit. In some embodiments, each of the at least one control unit may be connected to each of the at least one heating unit to independently control at least one parameter of each heating unit such that the temperature distribution during crystal growth meets a preset temperature distribution. In some embodiments, the at least one parameter may include at least one of a current or a heating power. In some embodiments, the preset temperature distribution may include, but is not limited to, a preset radial temperature difference distribution, a preset radial temperature gradient distribution, and / or a preset axial temperature gradient distribution.

[0057] In some embodiments, the control assembly 230 can generate a radial temperature difference distribution and / or a radial temperature gradient distribution based on the radial temperature measured by the temperature sensing assembly 210. In some embodiments, the control assembly 230 can generate an axial temperature gradient distribution based on the axial temperature measured by the temperature sensing assembly 210.

[0058] In some embodiments, the control assembly 230 controls at least one parameter of the at least one heating unit based on the temperature distribution during the crystal growth such that the radial temperature difference inside the growth chamber during the crystal growth does not exceed a first preset range of the average temperature inside the growth chamber or a preset radial temperature threshold. In some embodiments, the control assembly 230 controls at least one parameter of the at least one heating unit based on the temperature distribution during the crystal growth such that the radial temperature gradient inside the growth chamber during the crystal growth does not exceed a preset radial temperature gradient threshold. In some embodiments, the temperature sensing assembly 210 can measure the radial temperature of the growth chamber and send the measured radial temperature to the control assembly 230. The control assembly 230 can generate a radial temperature difference distribution and / or a radial temperature gradient distribution based on the radial temperature measured by the temperature sensing assembly 210. The control assembly 230 is used to determine the preset radial temperature difference threshold and / or radial temperature gradient threshold depending on the size, shape and material of the growth chamber 110, the size of the seed crystal, and the type and size of the crystal to be grown. The control assembly 230 can compare the radial temperature difference in the radial temperature difference distribution with a preset radial temperature difference threshold or compare the radial temperature gradient in the radial temperature gradient distribution with a preset radial temperature gradient threshold. If the radial temperature difference is greater than the preset radial temperature difference threshold or if the radial temperature gradient is greater than the preset radial temperature gradient threshold, the control assembly 230 can increase the heating power of at least one heating unit disposed in a central region of the growth chamber 110 to reduce the radial temperature difference and / or the radial temperature gradient until the radial temperature difference does not exceed the preset radial temperature difference threshold and / or the radial temperature gradient does not exceed the preset radial temperature gradient threshold.

[0059] In some embodiments, the control assembly 230 controls at least one parameter of the at least one heating unit based on the temperature distribution during the crystal growth to maintain the axial temperature gradient inside the growth chamber stable during the crystal growth. In some embodiments, the control assembly 230 further controls at least one parameter of the at least one heating unit based on the temperature distribution during the crystal growth to maintain the axial temperature gradient inside the growth chamber within a preset axial temperature gradient range. In some embodiments, the temperature sensing assembly 210 can measure the axial temperature of the growth chamber and send the measured axial temperature to the control assembly 230. The control assembly 230 can generate an axial temperature gradient distribution based on the axial temperature measured by the temperature sensing assembly 210. The control assembly 230 is used to determine the preset axial temperature gradient range according to the size, shape and material of the growth chamber 110, the size of the seed crystal, and the type and size of the crystal to be grown. The control assembly 230 can further compare the axial temperature gradient in the axial temperature gradient distribution to the preset axial temperature gradient range. If the axial temperature gradient is smaller than the preset axial temperature gradient range, the control assembly 230 decreases the heating power of at least one heating unit disposed on the periphery of the growth chamber and close to the growth chamber cover, or increases the heating power of at least one heating unit disposed on the periphery of the growth chamber and close to the bottom cover of the growth chamber, so as to increase the axial temperature gradient until the axial temperature gradient is within the preset axial temperature gradient range. If the axial temperature gradient is larger than the preset axial temperature gradient range, the control assembly 230 increases the heating power of at least one heating unit disposed on the periphery of the growth chamber and close to the growth chamber cover, or decreases the heating power of at least one heating unit disposed on the periphery of the growth chamber and close to the bottom cover of the growth chamber, so as to decrease the axial temperature gradient until the axial temperature gradient is within the preset axial temperature gradient range.

[0060] In some embodiments, the preset radial temperature difference threshold, the preset radial temperature gradient threshold, and the preset axial temperature gradient range can be determined by the size, shape, and material of the growth chamber 110, the size of the seed crystal, and the type and size of the crystal to be grown. For the relevant contents of the preset radial temperature difference threshold, the preset radial temperature gradient threshold, and the preset axial temperature gradient range, please refer to FIG. 1 and its related description and will not be repeated here.

[0061] In some embodiments, the temperature feedback adjustment system 200 further includes a storage component (not shown). The storage component can store data, instructions, and / or other information. In some embodiments, the storage component can store data and / or information related to crystal growth. In some embodiments, the storage component can store a crystal growth temperature required for crystal growth, a crystal growth period, a crystal growth interval, a preset temperature distribution, a preset radial temperature difference threshold, a preset radial temperature gradient threshold, a preset axial temperature gradient range, etc. In some embodiments, the storage component can store a crystal type, a seed crystal size, a crystal size to be grown, etc. In some embodiments, the storage component can store data and / or instructions that the crystal manufacturing apparatus 100 uses to perform or achieve the exemplary crystal growth method described in the embodiments herein. For example, the storage component can store at least one parameter of at least one heating unit that is adjusted during crystal growth.

[0062] In some embodiments, the storage component is connected to a network for communication with one or more components of temperature feedback regulation system 200 (e.g., temperature sensing assembly 210, control assembly 230, etc.). One or more components of feedback regulation system 200 (e.g., control assembly 230, etc.) can read data or instructions from the storage component over the network.

[0063] In some embodiments, the storage component includes mass storage devices, removable storage devices, volatile read-write memory, read-only memory (ROM), etc., or any combination thereof. Exemplary mass storage devices include magnetic disks, optical disks, solid state drives, removable storage devices, etc. Exemplary removable storage devices include flash drives, floppy disks, optical disks, memory cards, ZIP disks, tapes, etc. Exemplary volatile read-write memory includes random access memory (RAM). Random access memory includes dynamic random access memory (DRAM), double-date rate synchronous dynamic random access memory (DDR-SDRAM), static random access memory (SRAM), cyclic random access memory (T-RAM), zero capacitance random access memory (Z-RAM), etc. Read-only memory (ROM) includes mask read-only memory (MROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM), digital versatile disk, etc. In some embodiments, the storage component is implemented through a cloud platform as described herein, in some embodiments, the cloud platform includes one or a combination of a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, a cross cloud, a multi-cloud, and the like.

[0064] In some embodiments, the temperature feedback regulation system 200 further includes a display (not shown). In some embodiments, the display can display in real time the time of crystal growth, the size of the crystal, the temperature distribution during crystal growth, and / or at least one parameter of the at least one heating unit, etc. In some embodiments, the at least one parameter can include, but is not limited to, the current, the heating power, etc.

[0065] It should be noted that the above description of the temperature feedback regulation system 200 is for convenience of explanation only, and does not limit the scope of the present application to the exemplary embodiments. After understanding the principle of the system, a person skilled in the art can understand that each assembly may be arbitrarily combined or connected with other assemblies to form a subsystem without departing from the principle. For example, the control assembly 230 disclosed in FIG. 2 may be a single component that can realize the functions of two or more components. As an example, the control assembly 230 may include at least one control unit and at least one processing unit. All such modifications are within the scope of protection of the present application.

[0066] 3 is a schematic diagram of an exemplary crystal manufacturing apparatus shown in some examples. In some embodiments, the crystal manufacturing apparatus 100 can manufacture semiconductor crystals (e.g., silicon carbide crystals, aluminum nitride crystals, zinc oxide crystals, zinc antimonide crystals) based on physical vapor transport. As shown in FIG. 3, the crystal manufacturing apparatus 100 includes a growth chamber 110 and a heating assembly.

[0067] The growth chamber 110 is used to place the seed crystal 150 and the raw material 160. In some embodiments, the growth chamber 110 may include a growth chamber cover 111 and a growth chamber body 112, where the growth chamber cover 111 is disposed on the top of the growth chamber and is used to close an opening located on the top of the growth chamber body 112. In some embodiments, the growth chamber 110 may be a crucible, and the crucible may include a crucible cover and a crucible body. In some embodiments, the shape of the growth chamber body 112 may be a cylinder, a rectangular parallelepiped, a cube, etc. In some embodiments, the growth chamber body 112 may be a cylindrical barrel including a barrel bottom and a barrel side wall. In some embodiments, the shape of the growth chamber cover 111 may be a circular disk, a rectangular disk, a square disk, etc., corresponding to the shape of the growth chamber body 112. In some embodiments, the material of the growth chamber 110 may include graphite. In some embodiments, the material of the growth chamber 110 may be entirely or partially graphite.

[0068] In some embodiments, the seed crystal 150 may be fixedly attached to the inside (also referred to as the "lower surface") of the growth chamber cover 111 (e.g., at a central position inside), and the source material 160 may be disposed inside the chamber body 112 (e.g., at the bottom of the growth chamber 110). In some embodiments, the seed crystal 150 may be fixed to the growth chamber cover 111 by an adhesive. The adhesive may include, but is not limited to, epoxy adhesive, AB glue, phenolic resin glue, sugar glue, and the like. In some embodiments, the source material may be in the form of powder, granules, aggregates, and the like. During crystal growth, an axial temperature gradient can be formed between the source material 160 and the seed crystal 150 by controlling the heating environment of the growth chamber. When the raw material 160 is heated, it can decompose and sublime into gas phase components (for example, in the case of producing silicon carbide crystals, the gas phase components include Si2C, SiC2, and Si), and driven by the axial temperature gradient, the gas phase components are transported from the surface of the raw material 160 to the surface of the seed crystal 150, and since the temperature at the location of the seed crystal 150 is relatively low, the gas phase components crystallize on the surface of the seed crystal 150 and form crystals.

[0069] The heating assembly is used to heat the growth chamber 110. In some embodiments, the heating assembly can include an electric heating device, an electromagnetic induction heating device, etc. In some embodiments, the heating assembly can be an induction coil. In some embodiments, the heating assembly is disposed outside the growth chamber 110 to provide at least a portion of the heat required for crystal growth. Taking the induction coil as an example, the induction coil can generate eddy currents on the surface of the growth chamber 110 under an intermediate frequency alternating current, and under the eddy current, the electric energy formed on the surface of the growth chamber 110 can be converted into thermal energy to heat the surface of the growth chamber 110 and conduct heat to the inside of the growth chamber 110. In combination with the above, under the temperature field inside the growth chamber 110, the raw material 160 is sublimated and decomposed into gas phase components, and the gas phase components are driven by the axial temperature gradient to be transported to the surface of the seed crystal 150, crystallize on the surface of the seed crystal 150, and form a crystal.

[0070] In some embodiments, the heating assembly can be disposed outside the growth chamber 110. In some embodiments, the heating assembly includes at least two heating units. In some embodiments, at least one heating unit of the at least two heating units may be disposed partially around the periphery of the growth chamber 110. In some embodiments, at least one heating unit of the at least two heating units may be disposed on the upper and / or lower surface of the growth chamber 110. In some embodiments, the at least one heating unit disposed on the upper and / or lower surface of the growth chamber 110 may be referred to as a temperature compensation assembly 1210. In some embodiments, the quantity of the at least one heating unit of the temperature compensation assembly 1210 may include, but is not limited to, one, two, three, four, etc. In some embodiments, the shape of the at least one heating unit of the temperature compensation assembly 1210 may include, but is not limited to, a regular or irregular prism, such as a cylinder, a triangular prism, a square prism, a pentagonal prism, or a hexagonal prism. In some embodiments, the temperature compensation assembly 1210 may be disposed in a regular or irregular shape, such as a square, a rectangle, a circle, or a ring. In some embodiments, the temperature compensation assemblies 1210 may be arranged in a ring or a circle about the center of the upper and / or lower surface of the growth chamber 110. In some embodiments, the arrangement may be uniform or non-uniform. In some embodiments, when the temperature compensation assemblies 1210 are arranged in a ring about the center of the upper and / or lower surface of the growth chamber 110, the radius between two adjacent rings may be equal or unequal.

[0071] In some embodiments, the at least one heating unit disposed around the periphery of the growth chamber 110 is referred to as the first heating assembly 1220. In some embodiments, the quantity of the at least one heating unit of the first heating assembly 1220 can include, but is not limited to, one, two, three, four, etc. In some embodiments, the first heating assembly 1220 is disposed around the periphery of the growth chamber 110 around the central axis of the growth chamber 110. In some embodiments, the arrangement can be uniform or non-uniform. In some embodiments, the spacing between two adjacent heating units disposed around the periphery of the growth chamber 110 can be equal or unequal. In some embodiments, the heating methods of the first heating assembly 1220 and the temperature compensation assembly 1210 can be the same or different. In some embodiments, the heating method of the temperature compensation assembly 1210 can be resistive heating. In some embodiments, the heating method of the first heating assembly 1220 can be resistive heating or inductive heating.

[0072] In some embodiments, by adjusting the position of the heating assembly and / or the heating parameters (e.g., current, heating power, etc.) applied to the heating assembly (e.g., up and down along the outer surface of the growth chamber 110), the temperature field inside the growth chamber 110 can be changed to generate a suitable temperature gradient distribution to promote crystal growth. Taking an induction coil as an example, the induction coil is spirally wound on the outside of the growth chamber 110, and the distance between adjacent coils gradually increases from the bottom to the top of the growth chamber 110, to control the temperature field inside the growth chamber 110 and thereby form a suitable temperature gradient distribution. In some embodiments, the bottom of the growth chamber 110 may refer to a portion of the growth chamber 110 away from the growth chamber cover 111. In some embodiments, the top of the growth chamber 110 may refer to a portion of the growth chamber 110 close to the growth chamber cover 111. In some embodiments, the induction coil may include multiple connected sub-induction coils, and the heating parameters of each sub-induction coil may be controlled respectively to control the temperature field inside the growth chamber 110 and thereby generate a suitable temperature gradient distribution. The number and / or location of the sub-induction coils may be a system default setting or may be adjusted for various circumstances. In some embodiments, the number and / or location of the sub-induction coils may be adjusted depending on the size, shape and material of the growth chamber 110, the size of the seed crystal, and the type and size of the crystal to be grown.

[0073] The temperature compensation assembly 1210 is used to provide temperature compensation during crystal growth. In some embodiments, the temperature compensation assembly 1210 may be disposed on the upper surface and / or the lower surface of the growth chamber 110. In some embodiments, the temperature compensation assembly 1210 may be disposed near the center of the upper surface and / or near the center of the lower surface of the growth chamber 110. In conventional crystal manufacturing equipment, an induction coil is usually disposed outside the growth chamber to heat the growth chamber. Thus, heat is conducted from the peripheral region of the growth chamber to the central region of the growth chamber, resulting in the peripheral region being a relatively hotter region and the central region being a relatively colder region, with the temperature being lower closer to the central region. For the upper region of the growth chamber (e.g., the inside of the growth chamber cover where the seed crystal is placed), this radial temperature gradient can cause large thermal stresses to occur at the crystal growth surface, and even the crystal growth surface will bulge significantly toward the source material, and defects such as micropipes and inclusions will easily be generated. For the lower region of the growth chamber (e.g., the region covered with the raw material), this radial temperature gradient leads to the radial distribution of the molar ratio of the sublimated gas phase components of the raw material being non-uniform, which affects the crystal quality. Therefore, it is necessary to reduce this radial temperature gradient. Therefore, the temperature compensation assembly 1210 can provide temperature compensation to reduce the radial temperature gradient. If the temperature compensation assembly 1210 is arranged on the upper surface of the growth chamber 110, the radial temperature gradient of the inner surface (or called the "lower surface") of the growth chamber cover 111 can be reduced, thereby reducing the defects caused by the stress on the crystal growth surface, and reducing or avoiding the corrosion defects on the back surface of the crystal. If the temperature compensation assembly 1210 is arranged on the lower surface of the growth chamber 110, the radial temperature gradient of the region covered with the raw material 160 can be reduced, and the uniformity of the radial temperature distribution can be improved, which can make the radial distribution of the molar ratio of the sublimated gas phase components more uniform, thereby improving the crystal quality. FIG. 3 only shows the temperature compensation assembly 1210 located on the top surface of the growth chamber 110 .

[0074] In some embodiments, the temperature compensation assembly 1210 includes at least one heating unit 1212. In some embodiments, the at least one heating unit 1212 includes at least one high resistivity graphite unit. In some embodiments, the at least one heating unit 1212 is uniformly or non-uniformly distributed along a radial direction on the upper or lower surface of the growth chamber 110. In some embodiments, the parameters of the at least one heating unit 1212 (e.g., at least one of the number, shape, size, arrangement, current, or heating power of the at least one heating unit 1212) are adjusted according to the size of the upper or lower surface of the growth chamber 110, the type of crystal to be grown, the shape or size of the seed crystal 150, the temperature distribution of the upper or lower surface of the growth chamber 110, etc. In some embodiments, the number, shape, and / or size of the at least one heating unit 1212 can be such that the contact area between the at least one heating unit 1212 and the upper and / or lower surface of the growth chamber 110 occupies 50% or more of the area of ​​the upper and / or lower surface of the growth chamber 110. In some embodiments, the quantity and arrangement of the at least one heating unit 1212 can make the shape and area of ​​the at least one heating unit 1212 the same as the shape and area of ​​the horizontal cross section of the seed crystal 150. In some embodiments, the position of the at least one heating unit 1212 on the upper surface of the growth chamber cover 111 corresponds to the position of the seed crystal 150 on the lower surface of the growth chamber cover 111. In some embodiments, the current flowing through the at least one heating unit 1212 and / or the heating power of the at least one heating unit 1212 can make the temperature distribution inside the growth chamber 110 meet a preset temperature distribution.

[0075] In some embodiments, parameters (eg, heating power, current) of each of the at least one heating unit 1212 are independently controlled to facilitate adjustment of the radial temperature gradient distribution.

[0076] In some embodiments, the temperature compensation assembly 1210 further includes a stationary frame 1216, which includes at least one stationary unit for placing the at least one heating unit 1212. In some embodiments, the stationary frame 1216 may be coaxial with the growth chamber 110. In some embodiments, the stationary frame 1216 may be made of a heat-retaining material or a thermal insulating material. In some embodiments, the stationary frame 1216 may be a zirconia ceramic plate or a boron nitride ceramic plate. In some embodiments, a detachable connection may be made between the at least one stationary unit. In some embodiments, the shape of the at least one stationary unit may include a regular shape or an irregular shape, such as a hexagon, a square, a circle, a triangle, etc. Correspondingly, the shape of the at least one heating unit 1212 may also include a regular shape or an irregular shape, such as a hexagon, a square, a circle, a triangle, etc. For further description of the at least one stationary unit and the at least one heating unit 1212, please refer to other parts of this specification (e.g., FIGS. 4, 5 and description).

[0077] In some embodiments, the temperature compensation assembly 1210 further includes at least one first electrode 1213, at least one second electrode 1211, and an electrode fixing plate 1215. The electrode fixing plate 1215 is used to fix the first electrode 1213 and the second electrode 1211. In some embodiments, the materials of the first electrode 1213 and the second electrode 1211 may be the same or different. In some embodiments, the first electrode 1213 and the second electrode 1211 may both be low resistance graphite electrodes. In some embodiments, the shapes of the first electrode 1213 and the second electrode 1211 may be the same or different. In some embodiments, the first electrode 1213 and the second electrode 1211 may both be cylindrical electrodes. In some embodiments, since the outer periphery region of the growth chamber is a relatively hot region and the center region is a relatively cold region, such a radial temperature gradient can cause crystal defects. Therefore, the diameter of the first electrode 1213 is smaller than the diameter of the second electrode 1211. In some embodiments, the first electrode 1213 and the second electrode 1211 are connected to a power source (e.g., a DC power source) via lead wires (e.g., copper wires 1214). In some embodiments, the electrode fixing plate 1215 may be made of a heat-retaining material or a thermal insulating material. In some embodiments, the electrode fixing plate 1215 may be a zirconia ceramic plate. In some embodiments, the electrode fixing plate 1215 only includes at least one first hole 1215-1 and at least one second hole 1215-2 (as shown in FIG. 7), and the at least one first electrode 1213 passes through the at least one first hole 1215-1 to be fixed to the at least one heating unit 132, and the at least one second electrode 1211 passes through the at least one second hole 1215-2 to be fixed to the upper or lower surface of the growth chamber 110. Thus, the first electrode 1213, the at least one heating unit 1212, the upper or lower surface of the growth chamber 110, and the power source form a current path for heating the at least one heating unit 1212.In some embodiments, the electrode fixing plate 1215 may further include at least two temperature measurement holes 1215-3 located between radially adjacent first holes 1215-1 or at a set range of at least one second hole 1215-2. In some embodiments, the temperature of at least one heating unit 1212 or the temperature of the periphery of the upper or lower surface of the growth chamber 110 may be measured through the at least two temperature measurement holes 1215-3. For more details on the at least two temperature measurement holes 1215-3, please refer to other parts of this specification (e.g., FIG. 7 and the description thereof).

[0078] In some embodiments, the crystal manufacturing apparatus 100 may further include a control assembly for adjusting the parameters of the at least one heating unit 1212 based on at least one reference parameter (e.g., the quantity, shape, size, arrangement, current, heating power of the at least one heating unit 1212). The radial temperature gradient of the upper or lower surface of the growth chamber 110 is prevented from exceeding a preset radial temperature gradient threshold (e.g., 0.5°C / cm). In some embodiments, the preset radial temperature gradient threshold may be a system default value or may be adjusted according to different circumstances. In some embodiments, when manufacturing different crystals, the preset radial temperature gradient threshold may be correspondingly different. In some embodiments, the at least one reference parameter includes the type of crystal, the size or shape of the seed crystal, temperature information related to the growth chamber 110 during crystal growth, etc. Taking silicon carbide crystal as an example, there are three crystal types of silicon carbide crystal: close-packed hexagonal structure, cubic structure, and rhombohedral structure. Silicon carbide crystals include 3C-SiC, 4H-SiC, 6H-SiC, 15R-SiC, etc., where 3C-SiC is a cubic structure, 4H-SiC is a close-packed hexagonal structure, 6H-SiC is a close-packed hexagonal structure, and 15R-SiC is a rhombohedral structure. For different silicon carbide crystal types, by adjusting the parameters of at least one heating unit 1212, the radial temperature gradient distribution of the inner region of the growth chamber cover 111 is suitable for the growth of this silicon carbide crystal type. In some embodiments, the size or shape of the seed crystal may be different according to different crystal growth requirements. Accordingly, for different sizes or shapes of seed crystals, by adjusting the parameters of at least one heating unit 1212, the radial temperature gradient distribution of the inner region of the growth chamber cover 111 is suitable for the crystals of this size or shape to be grown into high quality crystals.

[0079] In some embodiments, the temperature information related to the growth chamber 110 during crystal growth includes a first temperature of at least one heating unit 1212 and a second temperature of the periphery of the upper or lower surface of the growth chamber 110. Take for example that the temperature compensation assembly 1210 is disposed on the upper surface of the growth chamber 110, the at least one heating unit 1212 is disposed on the outside of the growth chamber cover 111 (i.e., on the upper surface of the growth chamber 110) along a radial direction with the center of the growth chamber cover 111 as the center of the circle. Correspondingly, the first temperature includes at least one temperature (also referred to as "at least one first temperature") distributed along a radial direction on the upper surface of the growth chamber 110. When the first heating assembly 1220 heats the growth chamber 110, in the same horizontal plane, the heat gradually decreases in the direction from the periphery of the growth chamber 110 toward the central axis of the growth chamber 110 during the transfer process. Without the compensation heat, the temperature of the periphery of the growth chamber 110 is higher than the temperature inside the growth chamber 110, i.e., the second temperature is higher than the first temperature. If the difference (or radial temperature difference) between the first temperature and the second temperature is too large, the radial temperature distribution is not favorable for crystal growth. In some embodiments, the control assembly compares the difference between at least one of the first temperature and the second temperature, and adjusts the parameters of at least one heating unit 1212 to prevent the radial temperature difference of the growth chamber cover 111 from exceeding the preset radial temperature difference threshold. In some embodiments, increasing the heating power of at least one heating unit disposed in the central region of the growth chamber 110 increases the compensation heat in the central region of the growth chamber 110, raising the first temperature and decreasing the difference (or radial temperature difference) between the first temperature and the second temperature, so that the radial temperature difference of the growth chamber cover 111 is smaller than the preset radial temperature difference threshold.

[0080] In some embodiments, the control assembly includes at least one temperature sensing unit (not shown) for measuring the first temperature and the second temperature. In some embodiments, the at least one temperature sensing unit includes a thermometer (e.g., an infrared thermometer). In some embodiments, the at least one temperature sensing unit can measure the first temperature and the second temperature through at least two temperature measurement holes 1215-3 of the temperature compensation assembly. As described above, since the at least two temperature measurement holes 1215-3 are located between radially adjacent first holes, and the at least one first hole corresponds to the at least one heating unit 1212, the temperature sensing unit can measure the temperature of the at least one heating unit 1212 through the temperature measurement holes. Similarly, since the at least two temperature measurement holes are also located within a set range (e.g., 2 cm) of the at least one second hole, the temperature sensing unit can measure a second temperature of the outer periphery of the upper surface of the growth chamber through the temperature measurement holes. In some embodiments, the set range refers to the distance between the centers of the at least two temperature measurement holes and the center of the at least one second hole. In some embodiments, the set range may be 1 cm to 5 cm. In some embodiments, the set range may be 1.5 cm to 4.5 cm. In some embodiments, the setting range may be 2 cm to 4 cm. In some embodiments, the setting range may be 2.5 cm to 3.5 cm. In some embodiments, the setting range may be 2.8 cm to 3.2 cm. FIG. 4 is a top surface view of an exemplary heating unit shown in some embodiments, and FIG. 5 is a top surface view of an exemplary heating unit shown in another embodiment.

[0081] The fixing frame 1216 includes at least one fixing unit for placing at least one heating unit 1212. As shown in FIG. 4, the fixing frame 1216 is formed by connecting seven hollow regular hexagonal fixing units, and the shape of the heating unit 1212 is also a regular hexagon correspondingly. As shown in FIG. 5, the fixing frame 1216 is formed by connecting nine hollow square fixing units, and the shape of the heating unit 1212 is also a square correspondingly. In some embodiments, the number of at least one fixing unit disposed thereon is appropriately increased or decreased according to the area of ​​the upper or lower surface of the growth chamber 110.

[0082] FIG. 6 is a schematic diagram of an exemplary first electrode and an exemplary second electrode according to some embodiments, and FIG. 7 is a top surface view of an exemplary electrode fixing plate according to some embodiments.

[0083] As shown in FIG. 6 and FIG. 7, at least one first electrode 1213 is fixed to at least one heating unit 1212 through at least one first hole 1215-1, and at least one second electrode 1211 is fixed to the upper or lower surface of the growth chamber 110 through at least one second hole 1215-2. In some embodiments, the shapes of the first electrode 1213 and the second electrode 1211 may be the same or different. In some embodiments, the first electrode 1213 and the second electrode 1211 are both cylindrical electrodes, and the diameter of the first electrode 1213 may be smaller than the diameter of the second electrode 1211. In some embodiments, the first electrode 1213 and the second electrode 1211 are connected to a power source (e.g., a DC power source) through a lead wire (e.g., a copper wire 1214). After the copper wire 1214 is connected to the power source, the first electrode 1213, the at least one heating unit 1212, the upper or lower surface of the growth chamber 110, and the power source form a current path for heating the at least one heating unit 1212.

[0084] The electrode fixing plate 1215 further includes at least two temperature measurement holes 1215-3. At least one temperature sensing unit measures a first temperature of at least one heating unit 1212 and a second temperature of the outer periphery of the upper surface or the outer periphery of the lower surface of the growth chamber 110 through the at least two temperature measurement holes. As shown in FIG. 7, the at least two temperature measurement holes 1215-3 are located between adjacent first holes 1215-1 in the radial direction or within a set range of at least one second hole 1215-2. The shape of the temperature measurement holes 1215-3 is a regular shape such as a circle, a square shape, a polygon, or an irregular shape. In some embodiments, the at least one temperature sensing unit measures the first temperature of at least one heating unit 1212 and a second temperature of the outer periphery of the upper surface or the outer periphery of the lower surface of the growth chamber 110 through the at least two temperature measurement holes 1215-3, so that the temperature distribution of the upper surface or the lower surface of the growth chamber 110 can be obtained. Further, the control assembly can adjust parameters (e.g., quantity, shape, size, arrangement, current, heating power) of at least one heating unit 1212 based on at least the first temperature and the second temperature to cause a radial temperature gradient on the upper or lower surface of the growth chamber 110 to be less than a preset threshold.

[0085] In some embodiments, assuming that the quantity of the at least one heating unit 1212 is seven and the arrangement is as shown in FIG. 4, the electrodes 1213 are fixed to the at least one heating unit 1212 through the seven first holes 1215-1. Furthermore, four second electrodes 1211 are arranged on the outer periphery of the upper surface or the outer periphery of the lower surface of the growth chamber 110, and the four second electrodes 1211 are fixed to the upper surface or the lower surface of the growth chamber 110 through the four second holes 1215-2. In a clockwise direction, the infrared thermometer sequentially detects six first temperatures T1, T2, T3, T4, T5, and T6 in the at least one heating unit 1212 through the temperature measurement holes 1215-3. Also, the infrared thermometer sequentially detects four second temperatures P1, P2, P3, P4 on the outer periphery of the upper surface or the lower surface of the growth chamber 110 through the temperature measurement holes 1215-3. If at least one second temperature of the four second temperatures is lower or higher than the preset temperature P and / or if at least one first temperature of the six first temperatures is lower or higher than the preset temperature T, adjust the parameter of at least one heating unit (e.g., increase the heating power of at least one heating unit 1212 or decrease the heating power of at least one heating unit 1212) until the four second temperatures are equal to the preset temperature P and / or the six first temperatures are equal to the preset temperature T, where the preset temperature T is lower than the preset temperature P and the temperature difference between the preset temperature T and the preset temperature P is lower than a preset threshold (e.g., 10K). In some embodiments, calculate an average temperature P^ of the four second temperatures, and then compare the average temperature P^ with the six first temperatures respectively. If at least one of the six first temperatures is greater than the average temperature P^, or if at least one of the six first temperatures is smaller than the average temperature P^ and the temperature difference is greater than a preset threshold, adjust a parameter of at least one heating unit 1212 based on the average temperature P^ (e.g., increase the heating power of at least one heating unit 1212 or decrease the heating power of at least one heating unit 1212) until all six first temperatures are lower than the average temperature P^ and the temperature difference is smaller than a preset threshold (e.g., 10 K).

[0086] It should be noted that the above description of the crystal manufacturing apparatus 100 is for illustrative and explanatory purposes only and does not limit the scope of the present application. Those skilled in the art can make various modifications and changes to the crystal manufacturing apparatus 100 under the guidance of the present application. However, such modifications and changes are still within the scope of the present application.

[0087] Possible beneficial effects of these embodiments include, but are not limited to, the following: (1) By mounting a temperature compensation assembly on the upper surface of the growth chamber, the radial temperature gradient of the inner surface of the growth chamber bar caused by the heating of the induction coil can be reduced, thereby reducing defects caused by stress on the crystal growth surface, reducing or avoiding corrosion defects on the back surface of the crystal, and further improving the quality and yield of the crystal. (2) By mounting a temperature compensation assembly on the lower surface of the growth chamber, the radial temperature gradient of the source coating region caused by the heating of the induction coil can be reduced, thereby improving the uniformity of the radial temperature gradient, improving the uniformity of the radial distribution of the molar ratio of the sublimated gas phase components, and further promoting the stable growth of the crystal. (3) The parameters of the heating units of the temperature compensation assembly can be flexibly adjusted according to the size of the upper or lower surface of the growth chamber, the type of crystal to be grown, the size or shape of the seed crystal, and / or the temperature distribution inside the growth chamber, etc., and the parameters of each heating unit can be independently controlled. (4) By monitoring the temperature distribution of the upper or lower surface of the growth chamber during crystal growth, the parameters of the temperature compensation assembly can be adjusted to ensure stable, high-quality crystal growth.

[0088] 8 is a schematic diagram of an exemplary crystal manufacturing apparatus shown in some examples. In some embodiments, the crystal manufacturing apparatus 100 can manufacture semiconductor crystals (e.g., silicon carbide crystals, aluminum nitride crystals, zinc oxide crystals, zinc antimonide crystals) based on physical vapor transport. As shown in FIG. 8, the crystal manufacturing apparatus 100 includes a growth chamber 110 and a heating assembly.

[0089] The growth chamber 110 is used to place the seed crystal 150 and the raw material 160. In some embodiments, the growth chamber 110 includes a growth chamber cover 111 and a growth chamber body 112. The growth chamber cover 111 is disposed on the top of the growth chamber and is used to close an opening located on the top of the growth chamber body 112. In some embodiments, the growth chamber 110 may be a crucible. The crucible includes a crucible cover and a crucible body. In some embodiments, the shape of the growth chamber body 112 is a cylinder, a rectangular parallelepiped, a cube, etc. In some embodiments, the growth chamber body 112 is a cylindrical barrel including a barrel bottom and a barrel side wall. In some embodiments, the shape of the growth chamber cover 111 is a circular disk, a rectangular disk, a square disk, etc. corresponding to the shape of the growth chamber body 112. In some embodiments, the material of the growth chamber 110 includes graphite. In some embodiments, the material of the growth chamber 110 is entirely or partially graphite.

[0090] In some embodiments, the seed crystal 150 is placed on the top of the growth chamber 110. In some embodiments, the seed crystal 150 may be fixedly attached to the inner surface (also called the "lower surface") of the growth chamber cover 111 (e.g., at the inner central position). In some embodiments, the seed crystal 150 is fixed to the growth chamber cover 111 by an adhesive. The adhesive may include, but is not limited to, epoxy adhesive, AB glue, phenolic resin adhesive, sugar glue, and the like. In some embodiments, the raw material 160 is placed inside the chamber body 112 (e.g., at the bottom of the growth chamber 110). In some embodiments, the raw material 160 is in the form of powder, granules, aggregates, and the like. During crystal growth, an axial temperature gradient can be formed between the raw material 160 and the seed crystal 150 by controlling the heating environment of the growth chamber 110. When the raw material 160 is heated, it can decompose and sublime into gas phase components (for example, in the case of producing silicon carbide crystals, the gas phase components include Si2C, SiC2, and Si), and driven by the axial temperature gradient, the gas phase components are transported from the surface of the raw material 160 to the surface of the seed crystal 150, and since the temperature at the location of the seed crystal 150 is relatively low, the gas phase components crystallize on the surface of the seed crystal 150 and form crystals.

[0091] The heating assembly is used to heat the growth chamber 110. In some embodiments, the heating assembly is disposed outside the growth chamber 110. In some embodiments, the heating assembly is disposed surrounding the outside of the growth chamber 110. In some embodiments, the heating assembly can provide at least a portion of the heat required for crystal growth. In some embodiments, the heating assembly generates heat under an electric current, and the heat is conducted from the peripheral region of the growth chamber 110 to the central region, and transfers the heat to the growth chamber 110 by thermal radiation to form a temperature field. Under the temperature field of the growth chamber 110, the source material 160 sublimes and decomposes into gas phase components. The gas phase components are transported to the surface of the seed crystal 150 under the drive of the axial temperature gradient and crystallize to generate a crystal.

[0092] In some embodiments, the heating assembly includes a resistive heating element. In some embodiments, the resistive heating element includes a high resistance graphite heating element, a tungsten heating element, a molybdenum heating element, a zirconium diboride composite ceramic heating element, and the like. In some embodiments, the resistive heating element is in the shape of a circular ring, a square ring, a rectangular ring, and the like. In conventional crystal manufacturing equipment, an induction coil is usually placed outside the growth chamber to heat the growth chamber. At this time, heat is conducted from the peripheral region of the growth chamber to the central region of the growth chamber. Therefore, the peripheral region is a relatively high temperature region and the central region is a relatively low temperature region, and the temperature is lower closer to the central region, and the radial temperature difference or radial temperature gradient inside the growth chamber is large. In some embodiments, differences at various positions along the circumference of the growth chamber 110 (e.g., differences in surface roughness, density, or thickness, etc.) result in different heat conduction performance at various positions along the circumference of the growth chamber 110, which further results in non-uniform temperature distribution inside the growth chamber 110. For the crystal region of the growth chamber (e.g., the inner surface of the growth chamber cover where the seed crystal is placed), such a large radial temperature difference and / or radial temperature gradient will result in large thermal stress on the crystal growth surface, which will in turn cause the growth surface of the seed crystal to bulge toward the source material, and is prone to generate defects such as micropipes and inclusions. For the source region of the growth chamber (e.g., the source covering region), this large radial temperature difference and / or radial temperature gradient will cause the molar ratio of the sublimated gas phase components of the source material to be distributed unevenly along the radial direction, affecting the crystal quality. Therefore, it is necessary to reduce such radial temperature difference and / or radial temperature gradient. Compared with heating by an induction coil, heating the growth chamber 110 by a resistance heating element can effectively reduce the radial temperature difference and / or radial temperature gradient inside the growth chamber 110 and simultaneously improve the stability of the crystal growth temperature field.

[0093] In some embodiments, the resistance heating element includes three heating modules. The three heating modules are used to heat the crystallization region of the growth chamber 110, the source region of the growth chamber 110, and the vapor transport zone between the crystallization region and the source region. Here, the crystal region is located in the upper region of the growth chamber 110. In some embodiments, the crystal region refers to the region of the set range of the seed crystal 150. The source region is located in the lower region of the growth chamber 110. In some embodiments, the source region refers to the region of the set range of the source 160. The vapor transport region is located in the central region of the growth chamber 110. In some embodiments, the vapor transport region refers to the region between the crystal region and the source region. In the crystal growth process, the source 160 located in the source region is thermally decomposed and sublimated into gaseous components. The gaseous components are driven by the axial temperature gradient 150 and transported through the vapor transport region to the seed crystal 150 in the crystallization region, and crystallize on the surface of the seed crystal 150 to produce a crystal.

[0094] In some embodiments, the at least three heating modules include a first heating module 1230-1, a second heating module 1230-2, and a second heating module 1230-3. The three heating modules are used to heat the crystallization region, the raw material region, and the vapor transport region between the crystallization region and the raw material region of the growth chamber 110, respectively. In some embodiments, the number of heating modules can be flexibly increased or decreased according to actual needs. In some embodiments, at least one parameter (e.g., current, heating power) of each of the at least three heating modules can be individually controlled. In some embodiments, in order to maintain a suitable axial temperature gradient, during the crystal growth process, the heating power of the first heating module 1230-1 is smaller than that of the second heating module 1230-2, and the heating power of the second heating module 1230-2 is smaller than that of the third heating module 1230-3. In some embodiments, the axial temperature gradient distribution can be easily adjusted during crystal growth by individually controlling the heating power of each of the at least three heating modules at different axial positions. For details about the resistive heating element, please refer to FIGS. 9 to 12 and the associated explanations, and so they will not be repeated here.

[0095] In some embodiments, the crystal manufacturing apparatus 100 further includes an insulating layer. The insulating layer is used to insulate the growth chamber 110 and / or the heating assembly. In some embodiments, the insulating layer is made of any insulating material. In some embodiments, the insulating layer includes graphite felt, zirconia ceramic, etc. In some embodiments, the insulating layer is located outside the heating assembly. In some embodiments, the insulating layer is disposed around the outside of the heating assembly. In some embodiments, the quantity, thickness, and distance of the insulating layer from the heating assembly can be set according to actual needs. In some embodiments, the thickness of the graphite felt can be 10-40 mm. In some embodiments, the distance between the insulating layer and the heating assembly can be adaptively adjusted according to the size of the growth chamber 110, the type of crystal to be grown, the heating power of the resistive heating element, temperature information related to the growth chamber 110 during crystal growth, etc. In some embodiments, the distance between the insulating layer and the heating assembly can be shortened if the heating power of the resistive heating element causes the radial temperature difference of the growth chamber 110 to be larger than the preset radial temperature difference threshold. In some embodiments, the thermal insulation layer is disposed outside the heating assembly, and the parameters of the thermal insulation layer (e.g., the number, thickness, and distance between the growth chamber 110) can be flexibly adjusted to prevent the temperature of the growth chamber 110 and / or the heating assembly from dissipating easily, promoting stable growth of the crystal. If the number of layers of the thermal insulation layer is too small or the thickness is too thin, the heat is easily dissipated, the temperature field becomes unstable, and the crystal growth is not promoted. If the number of layers of the thermal insulation layer is too large or the thickness is too large, the cost of the crystal manufacturing device becomes too high. Therefore, in order to stabilize the temperature field, it is necessary to control the number and thickness of the thermal insulation layer within a set range. In some embodiments, the number of layers of the thermal insulation layer 130 includes 2 to 10 layers. In some embodiments, the number of layers of the thermal insulation layer 130 includes 3 to 9 layers. In some embodiments, the number of layers of the thermal insulation layer 130 includes 4 to 8 layers. In some embodiments, the number of layers of the thermal insulation layer 130 includes 5 to 7 layers. In some embodiments, the number of layers of the thermal insulation layer 130 includes 6 layers.In some embodiments, the thickness of the insulating layer 130 is between 1 mm and 50 mm. In some embodiments, the thickness of the insulating layer 130 is between 3 mm and 48 mm. In some embodiments, the thickness of the insulating layer 130 is between 5 mm and 45 mm. In some embodiments, the thickness of the insulating layer 130 is between 8 mm and 42 mm. In some embodiments, the thickness of the insulating layer 130 is between 10 mm and 40 mm. In some embodiments, the thickness of the insulating layer 130 is between 15 mm and 35 mm. In some embodiments, the thickness of the insulating layer 130 is between 20 mm and 30 mm. In some embodiments, the thickness of the insulating layer 130 is between 23 mm and 28 mm. In some embodiments, the distance between the insulating layer 130 and the heating assembly may be between 1 mm and 20 mm. In some embodiments, the distance between the insulating layer 130 and the heating assembly is between 2 mm and 18 mm. In some embodiments, the distance between the insulating layer 130 and the heating assembly is between 3 mm and 16 mm. In some embodiments, the distance between the insulating layer 130 and the heating assembly is between 4 mm and 14 mm. In some embodiments, the distance between the insulating layer 130 and the heating assembly is between 5 mm and 12 mm. In some embodiments, the distance between the insulating layer 130 and the heating assembly is between 6 mm and 11 mm. In some embodiments, the distance between the insulating layer 130 and the heating assembly is between 7 mm and 10 mm. In some embodiments, the distance between the insulating layer 130 and the heating assembly is between 8 mm and 9 mm.

[0096] In some embodiments, the heating assembly further includes a temperature compensation assembly 1210. The temperature compensation assembly 1210 can provide temperature compensation during crystal growth. Heating the growth chamber 110 by a resistive heating element can effectively reduce the radial temperature difference and / or the radial temperature gradient inside the growth chamber 110. Temperature compensation can also be provided by the temperature compensation assembly 1210 to further reduce the radial temperature difference and / or the radial temperature gradient to promote stable growth of the crystal.

[0097] In some embodiments, the temperature compensation assembly 1210 includes a first temperature compensation assembly 1210-1 and / or a second temperature compensation assembly 1210-2. In some embodiments, the temperature compensation assembly 1210 is disposed on an upper surface of the growth chamber 110 and / or a lower surface of the growth chamber 110. In some embodiments, the first temperature compensation assembly 1210-1 is disposed near the center of the upper surface of the growth chamber 110. The second temperature compensation assembly 1210-2 is disposed near the center of the lower surface of the growth chamber 110. In some embodiments, the material of the temperature compensation assembly 1210 is a material with high thermal conductivity. In some embodiments, the temperature compensation assembly 1210 is a graphite body with high thermal conductivity. In some embodiments, the shape of the temperature compensation assembly 1210 is a circular disk, a cubic disk, a rectangular disk, etc. In some embodiments, taking a high thermal conductivity graphite body as an example, the high thermal conductivity graphite body (e.g., first temperature compensation assembly 1210-1) is positioned at the center of the upper surface of the growth chamber 110, and the peripheral region of the lower surface of the high thermal conductivity graphite body contacts the peripheral region of the upper surface of the growth chamber 110, so that heat from the peripheral region of the upper surface of the growth chamber 110 can be conducted to the central region of the upper surface of the growth chamber 110 to reduce the radial temperature difference and / or radial temperature gradient in the crystallization region of the growth chamber 110 (e.g., the inner surface of the growth chamber cover where the seed crystal is placed). A high thermal conductivity graphite body (e.g., second temperature compensation assembly 1210-2) is disposed at the center of the lower surface of the growth chamber 110, and the peripheral region of the upper surface of the high thermal conductivity graphite body contacts the peripheral region of the lower surface of the growth chamber 110, so as to conduct heat from the peripheral region of the lower surface of the growth chamber 110 to the central region of the lower surface of the growth chamber 110, thereby reducing the radial temperature difference and / or the radial temperature gradient of the source region (e.g., the source coating region) of the growth chamber 110, and improving the heating uniformity of the source region. For details of the temperature compensation assembly 1210 (or the first temperature compensation assembly 1210-1 and the second temperature compensation assembly 1210-2), please refer to Figures 3 to 6 and related descriptions, and will not be repeated here.

[0098] In some embodiments, the crystal manufacturing apparatus 100 further includes a control assembly (not shown). The control assembly is used to adjust the heating power of the heating assembly and / or the temperature compensation assembly 1210 based on at least one crystal growth parameter to keep the temperature field between the crystal growth interface and the feedstock essentially stable. In some embodiments, the at least one crystal growth parameter includes the amount of feedstock, the size of the crystal growth, the height difference between the crystal growth interface and the feedstock, etc. In some embodiments, the axial temperature gradient distribution inside the growth chamber 110 and the radial temperature gradient distribution inside the crystal region and / or the feedstock region inside the growth chamber 110 are adjusted based on the amount of different feedstock inside the growth chamber 110 at different stages of crystal growth to suit the growth of crystals at different growth stages. At various stages of crystal growth, the heating power of the heating assembly and / or temperature compensation assembly 1210 can be adjusted based on the size of the crystal to be grown inside the growth chamber 110 to make the axial temperature gradient distribution inside the growth chamber 110, the radial temperature gradient distribution inside the crystal region and / or the raw material region inside the growth chamber 110 suitable for growing crystals of different sizes. During crystal growth, as the raw material is continuously consumed, the crystal is continuously deposited and grown on the seed crystal, and the height difference between the crystal growth interface and the raw material is continuously increased, so that by adjusting the heating power of the heating assembly and / or temperature compensation assembly 1210, the temperature gradient distribution between the crystal growth interface and the raw material can be effectively controlled without fundamentally changing. For details regarding the adjustment of the heating power of the heating assembly and / or temperature compensation assembly 1210, please refer to FIG. 9 and its related description, and will not be repeated here.

[0099] In some embodiments, each of the at least three heating units includes at least one sub-heating unit. In some embodiments, the at least one sub-heating unit is separated by at least two electrodes. In some embodiments, each of the at least two electrodes is connected to a power source via a lead wire, so that each sub-heating unit, the electrode, the lead wire, and the power source can form a current circuit, and at least one parameter (e.g., current, heating power, etc.) of each sub-heating unit can be individually controlled. In some embodiments, the resistive heating element includes multiple heating segments, the multiple heating segments are connected to each other via multiple electrodes, and are arranged around the periphery of the growth chamber 110.

[0100] FIG. 9 is a schematic diagram of an exemplary resistive heating element as shown in some embodiments.

[0101] As shown in FIG. 9, the resistive heating element includes at least a first heating module 1230-1, a second heating module 1230-2, and a third heating module 1230-3. The first heating module 1230-1, the second heating module 1230-2, and the third heating module 1230-3 are used to heat the crystallization region of the growth chamber 110, the vapor phase transport region between the crystallization region and the raw material region, and the raw material region, respectively. In some embodiments, each heating module includes multiple sub-resistive heating elements. In some embodiments, the first heating module 1230-1 includes a first sub-resistive heating element 1230-11, a second sub-resistive heating element 1230-12, a third sub-resistive heating element 1230-13, and a fourth sub-resistive heating element. The second heating module 1230-2 includes a fifth sub-resistive heating element 1230-21, a sixth sub-resistive heating element 1230-22, and a seventh sub-resistive heating element 1230-23. The third heating module 1230-3 includes an eighth sub-resistive heating element 1230-31, a ninth sub-resistive heating element 1230-32, a tenth sub-resistive heating element 1230-33, an eleventh sub-resistive heating element 1230-34, a twelfth sub-resistive heating element 1230-35, a thirteenth sub-resistive heating element 1230-36, a fourteenth sub-resistive heating element 1230-37, a fifteenth sub-resistive heating element 1230-38, and a sixteenth sub-resistive heating element 1230-39.

[0102] In some embodiments, the heating power of the first heating module 1230-1, the second heating module 1230-2, and the third heating module 1230-3 is controlled individually. In some embodiments, the heating power of the multiple sub-resistance heating elements in each heating module is controlled individually. During crystal growth, as the raw material 160 is continuously consumed, the height difference between the crystal growth interface and the raw material 160 increases continuously, and in order to keep the temperature field between the crystal growth interface and the raw material 160 basically stable, it is necessary to adjust the heating power of the first heating module 1230-1, the heating power of the second heating module 1230-2, and the heating power of the third heating module 1230-3. In addition, it is also necessary to adjust the heating power of the first temperature compensation assembly 1210-1 and / or the second temperature compensation assembly 1210-2 to maintain the stability of the axial temperature gradient. In some embodiments, before crystal growth, the temperature of the first sub-resistance heating element 1230-11 is 2010°C, the temperature of the second sub-resistance heating element 1230-12 is 2020°C, the temperature of the third sub-resistance heating element 1230-13 is 2030°C, the temperature of the fourth sub-resistance heating element 1230-14 is 2040°C, and the temperature of the fifth sub-resistance heating element 1230-21 is 2050°C. The temperature of the sixth sub-resistance heating element 1230-22 is 2060°C, and the temperature of the seventh sub-resistance heating element 1230-23 is 2070°C. The temperatures of the eighth sub-resistance heating element 1230-31 to the sixteenth sub-resistance heating element 1230-39 are 2080°C.When the crystal growth interface reaches the horizontal surface of the fifth sub-resistance heating element 1230-21 and the upper surface of the raw material is consumed up to the horizontal surface of the ninth sub-resistance heating element 1230-32, the heating power of the first sub-resistance heating element 1230-11 to the eighth sub-resistance heating element 1230-31 is adjusted respectively to lower the temperature of the first sub-resistance heating element 1230-11 to 2000°C, the temperature of the second sub-resistance heating element 1230-12 to 2010°C, and the temperature of the third sub-resistance heating element 1230-13 to 2020°C. Then, the temperature of the fourth sub-resistance heating element 1230-14 is reduced to 2030° C., the temperature of the fifth sub-resistance heating element 1230-21 is reduced to 2040° C., the temperature of the sixth sub-resistance heating element 1230-22 is reduced to 2050° C., the temperature of the seventh sub-resistance heating element 1230-23 is reduced to 2060° C., the temperature of the eighth sub-resistance heating element 1230-31 is reduced to 2070° C., and the temperatures of the ninth sub-resistance heating element 1230-32 to the sixteenth sub-resistance heating element 1230-39 are maintained at 2080° C. The adjustment of the heating power keeps the axial temperature gradient distribution between the crystal growth interface and the raw material 160 basically stable. Furthermore, as the crystal grows, the heating power of the first temperature compensation assembly 1210-1, located on the upper surface of the growth chamber 110, needs to be reduced accordingly, and the heating power of the second temperature compensation assembly 1210-2, located on the lower surface of the growth chamber 110, needs to be kept unchanged accordingly.

[0103] 10 and 11 are top surface views of an exemplary first electrode and an exemplary second electrode arrangement as shown in some embodiments.

[0104] In some embodiments, the heating assembly further includes at least one first electrode 1213 (e.g., a positive electrode) and at least one second electrode 1211 (e.g., a negative electrode). The at least one first electrode 1213 and the at least one second electrode 1211 are distributed along the circumferential direction of the resistive heating element 1230. In some embodiments, the at least one first electrode 1213 and the at least one second electrode 1211 are connected to a power source (e.g., a DC power source) via a lead wire (e.g., a water-cooled copper wire). Accordingly, the at least one first electrode 1213, the at least one second electrode 1211, the resistive heating element 1230, the lead wire, and the power source form a current path for heating the resistive heating element 1230.

[0105] In some embodiments, as shown in FIG. 8, the resistive heating element 1230 is a circular ring, a square ring, a rectangular ring, etc. Accordingly, the at least one first electrode 1213 and the at least one second electrode 1211 are distributed along the circumferential direction of the ring. In some embodiments, the materials of the at least one first electrode 1213 and the at least one second electrode 1211 may be the same or different. For example, the at least one first electrode 1213 and the at least one second electrode 1211 are both low resistance graphite electrodes. In some embodiments, the at least one first electrode 1213 and the at least one second electrode 1211 are distributed uniformly or non-uniformly around the resistive heating element 1230. In some embodiments, the at least one first electrode 1213 and the at least one second electrode 1211 can divide the resistive heating element 1230 into multiple heating segments to control the heating power of the multiple heating segments individually. In some embodiments, the sum of the quantities of the at least one first electrode 1213 and the at least one second electrode 1211 is an even number. In some embodiments, the quantity of the at least one first electrode 1213 and the at least one second electrode 1211 can be adjusted according to actual needs. The more electrodes arranged on the resistive heating element 1230, the higher the control precision for the heating power of the resistive heating element 1230. In some embodiments, the resistive heating element 1230 includes M first electrodes 1213 and N second electrodes 1211, where M and N are both integers greater than 0. In some embodiments, M and N are equal. In some embodiments, the sum of the quantities of the first electrodes 1213 and the second electrodes 1211 is an even number.

[0106] As shown in FIG. 10, the shape of the resistive heating element 1230 is a circular ring, and two first electrodes 1213 (positive electrodes) and two second electrodes 1211 (negative electrodes) are distributed along the circumferential direction of the resistive heating element 1230. The first electrodes 1213 and the second electrodes 1211 are arranged at equal intervals, the resistive heating element 1230 is equally divided into four heating segments, and the heating power of each heating segment can be controlled independently. As shown in FIG. 11, the shape of the resistive heating element 1230 is a square ring, and two first electrodes 1213 (positive electrodes) and two second electrodes 1211 (negative electrodes) are distributed along the circumferential direction of the resistive heating element 1230. The first electrodes 1213 and the second electrodes 1211 are arranged at equal intervals, the resistive heating element 1230 is equally divided into four heating segments, and the heating power of each heating segment can be controlled independently.

[0107] In some embodiments, combining the description of FIG. 9, the resistive heating element 1230 includes at least three heating modules. Each of the at least three heating modules includes a plurality of sub-resistive heating elements. Accordingly, at least one first electrode and at least one second electrode are disposed on the plurality of sub-resistive heating elements. For the plurality of sub-resistive heating elements, the quantity of the first electrodes and the second electrodes disposed thereon may be the same or different.

[0108] FIG. 12 is a schematic diagram illustrating an example first electrode and / or an example second electrode, as shown in some embodiments, fixed to a resistive heating element via a fixing plate.

[0109] As shown in FIG. 12, the heating assembly further includes an electrode fixing plate 1215 for fixing at least one first electrode 1213 and / or at least one second electrode 1211. In some embodiments, the electrode fixing plate 1215 includes at least two holes 1215-4. In some embodiments, the at least one first electrode 1213 is fixed to the outside of the resistive heating element 1230 through one of the at least two holes, and the at least one second electrode 1211 is fixed to the outside of the resistive heating element 1230 through the other of the at least two holes. In some embodiments, the electrode fixing plate 1215 is made of a heat retaining material or a thermal insulating material. In some embodiments, the electrode fixing plate 1215 is a zirconia ceramic plate.

[0110] It should be noted that the above description of the crystal manufacturing apparatus 100 is for illustrative and explanatory purposes only and does not limit the scope of the present application. Those skilled in the art can make various modifications and changes to the crystal manufacturing apparatus 100 under the guidance of the present application. However, such modifications and changes are still within the scope of the present application.

[0111] The advantageous effects of this embodiment include, but are not limited to, the following: (1) By heating the growth chamber through the resistance heating element, the radial temperature gradient inside the growth chamber can be effectively reduced, and at the same time, the stability of the crystal growth temperature field can be improved. (2) By installing a temperature compensation assembly on the upper surface of the growth chamber, the radial temperature gradient existing on the inner surface of the growth chamber cover can be further reduced, thereby reducing the defects caused by the stress on the crystal growth surface, reducing or avoiding the corrosion defects on the back surface of the crystal, and further improving the quality and yield of the crystal. (3) By installing a temperature compensation assembly on the lower surface of the growth chamber, the radial temperature gradient in the area covered by the raw material can be further reduced, thereby improving the uniformity of the radial temperature gradient distribution, improving the uniformity of the radial distribution of the Si / C molar ratio of the sublimation gas phase components, and promoting the stable growth of the crystal. (4) The number of heating modules can be flexibly increased or decreased, and the heating power of multiple heating modules can be individually controlled, which is convenient for adjusting the axial temperature gradient during the growth process, and meeting the requirements for crystal growth. (5) The heating power of the sub-resistance heating elements included in each heating module can be individually controlled, the heating power of multiple heating segments can be individually controlled, and the axial temperature gradient can be accurately controlled.

[0112] FIG. 13 is a schematic diagram of an exemplary crystal production apparatus shown in a further embodiment.

[0113] 13, a crystal manufacturing apparatus 100 includes a growth chamber 110 and a heating assembly 120. For a description of the growth chamber 110, please refer to FIG. 1 and the related description, and it will not be repeated here.

[0114] In some embodiments, the heating assembly 120 includes at least one heating unit. The at least one heating unit is used to heat the growth chamber 110 and provide a temperature field necessary for crystal growth to produce crystals. In some embodiments, the heating assembly 120 is disposed inside the growth chamber 110. The at least one heating unit located inside the growth chamber 110 is referred to as the second heating assembly 1240. In some embodiments, the quantity of the at least one heating unit of the second heating assembly 1240 can include, but is not limited to, one, two, three, four, five, six, etc. In some embodiments, the shape of the at least one heating unit of the second heating assembly 1240 is the same as the horizontal cross-sectional shape of the growth chamber 110. In some embodiments, the growth chamber 110 is a cylinder, and the shape of the at least one heating unit of the second heating assembly 1240 is a circle. In some embodiments, the growth chamber 110 is a rectangular parallelepiped or a cube, and the shape of the at least one heating unit of the second heating assembly 1240 is a rectangle or a square.

[0115] In some embodiments, the at least one heating unit of the second heating assembly 1240 is spaced apart inside the growth chamber 110 along the axial direction of the growth chamber 110. In some embodiments, the distance between two adjacent heating units may be equal or unequal. In some embodiments, the distance refers to the axial distance. In some embodiments, the material of the at least one heating unit may include, but is not limited to, a high-resistance heating material. In some embodiments, the at least one heating unit is at least one high-resistance graphite plate. After the at least one high-resistance graphite plate is energized, the thermal energy generated by the Joule effect of the current flowing through the at least one high-resistance graphite plate can be utilized to heat the growth chamber 110.

[0116] In some embodiments, each of the at least one heating unit is removably connected to the growth chamber 110. In some embodiments, at least one first connector is provided inside the growth chamber 110, and at least one second connector is provided on each heating unit of the at least one heating unit, and the at least one first connector and the at least one second connector are removably connected. Thus, the at least one heating unit can be attached and fixed inside the growth chamber 110, and / or the at least one heating unit can be removed from inside the growth chamber 110. In some embodiments, the at least one first connector includes a bolt hole and the at least one second connector includes a bolt that mates with the bolt hole. In some embodiments, the at least one first connector includes a hook and the at least one second connector includes a hanging hole that mates with the hook.

[0117] In some embodiments, the heating unit located inside the growth chamber needs to meet a set strength so that the raw material is distributed on the upper surface of the heating unit, the heating unit does not deform, and the uniform stability of the temperature field is guaranteed. The thickness of the heating unit is adjusted according to the material of the heating unit. In some embodiments, the thickness of the graphite heating unit is not thinner than the thickness of the metal (e.g., tungsten, platinum, molybdenum, tantalum, or iridium) heating unit.

[0118] If the thickness of the heating unit is too small, the heat generation amount of the heating unit will be small, so that the temperature field formed by the heating assembly cannot satisfy the crystal growth. Since the space of the growth chamber is fixed, if the thickness of the heating unit is too large, not only the mass of the raw material placed on the upper surface of the heating unit will be reduced, but also the height of the flow channel of the heating unit will be increased. In turn, the resistance of the gas phase components generated by the sublimation of the raw material to pass through the heating unit and reach the lower surface of the seed crystal will be increased, which will affect the crystal growth rate and crystal quality. Therefore, the thickness of the heating unit needs to be controlled within a preset range. In some embodiments, the thickness of at least one heating unit of the second heating assembly 1240 is 2 mm to 30 mm. In some embodiments, the thickness of at least one heating unit of the second heating assembly 1240 is 4 mm to 28 mm. In some embodiments, the thickness of at least one heating unit of the second heating assembly 1240 is 6 mm to 26 mm. In some embodiments, the thickness of at least one heating unit of the second heating assembly 1240 is 8 mm to 24 mm. In some embodiments, the thickness of the at least one heating unit of the second heating assembly 1240 is between 10 mm and 22 mm. In some embodiments, the thickness of the at least one heating unit of the second heating assembly 1240 is between 12 mm and 20 mm. In some embodiments, the thickness of the at least one heating unit of the second heating assembly 1240 is between 14 mm and 18 mm. In some embodiments, the thickness of the at least one heating unit of the second heating assembly 1240 is between 15 mm and 17 mm. In some embodiments, the thickness of the at least one heating unit of the second heating assembly 1240 is between 15.5 mm and 16.5 mm.

[0119] In some embodiments, at least one heating unit of the second heating assembly 1240 includes at least one flow channel 1250. The at least one flow channel 1250 is opened to the upper surface of the at least one heating unit. In some embodiments, the at least one flow channel 1250 extends through the heating unit so that at least one component required for crystal growth is transported from the lower surface of the heating unit to the upper surface of the heating unit, and then transported to the lower surface of the seed crystal under the driving of the axial temperature gradient to grow the crystal. In some embodiments, the at least one component required for crystal growth is at least one gas phase component generated by pyrolysis of the raw material. Taking the growth of silicon carbide crystals as an example, the gas phase components Si, SiC2, and Si2C generated by pyrolysis of the high purity silicon carbide powder as the raw material are at least one component required for crystal growth.

[0120] In some embodiments, the quantity of the at least one flow channel 1250 is five, ten, twenty, thirty, etc. In some embodiments, the shape of the at least one flow channel 1250 is a regular or irregular shape, such as a circle, a triangle, a square, a pentagon, a hexagon, etc. In some embodiments, the shapes of the at least one flow channel 1250 of one heating unit may be the same or different. In some embodiments, the at least one flow channel 1250 may be arranged in a circle, a ring, a triangle, a square, a pentagon, a hexagon, etc.

[0121] In some embodiments, the number of at least one flow channel 1250 of different heating units may be equal or unequal. In some embodiments, in two adjacent heating units, the number of at least one flow channel 1250 of one heating unit is ten, and the number of at least one flow channel 1250 of the other heating unit is twenty. In some embodiments, the shape of at least one flow channel 1250 of different heating units may be the same or different. In some embodiments, the shape of at least one flow channel 1250 of one heating unit among two adjacent heating units is circular, and the shape of at least one flow channel 1250 of the other heating unit is hexagonal. In some embodiments, the arrangement of at least one flow channel 1250 of different heating units may be the same or different. In some embodiments, the at least one flow channel 1250 of one heating unit among two adjacent heating units is uniformly arranged, and the at least one flow channel 1250 of the other heating unit is non-uniformly arranged. In some embodiments, the at least one flow channel 1250 of two adjacent heating units is arranged in a ring shape with the center of the heating unit as the center of the circle. In some embodiments, the spacing between adjacent rings of one heating unit may be equal and the spacing between adjacent rings of the other heating unit may be unequal, hi some embodiments, the spacing between adjacent rings is expressed as the difference in radii of the adjacent rings.

[0122] If the area of ​​one flow channel is too large, the raw material 160 cannot be placed on the upper surface of at least one heating unit located in the growth chamber 110 because the raw material leaks from the flow channel to the bottom of the growth chamber 110. If the area of ​​one flow channel is too small, the raw material 160 blocks the flow channel, so that the gas phase components obtained by vaporizing the raw material 160 cannot reach the seed crystal 150 through the flow channel to grow a crystal. Therefore, it is necessary to control the cross-sectional area of ​​one flow channel within a certain range. In some embodiments, the cross-sectional area of ​​the flow channel is 1.5 times or less the particle size of the raw material. In some embodiments, the cross-sectional area of ​​the flow channel is 1.4 times or less the particle size of the raw material. In some embodiments, the cross-sectional area of ​​the flow channel is 1.3 times or less the particle size of the raw material. In some embodiments, the cross-sectional area of ​​the flow channel is 1.2 times or less the particle size of the raw material. In some embodiments, the cross-sectional area of ​​the flow channel is 1.1 times or less the particle size of the raw material. In some embodiments, the cross-sectional area of ​​one flow channel is 1.0 times or less the particle size of the raw material. In some embodiments, the cross-sectional area of ​​one flow channel may be 1.0 times or more the particle size of the raw material. In some embodiments, the cross-sectional area of ​​one flow channel is 1.1 times or more the particle size of the raw material. In some embodiments, the cross-sectional area of ​​one flow channel is 1.2 times or more the particle size of the raw material. In some embodiments, the cross-sectional area of ​​one flow channel is 1.3 times or more the particle size of the raw material. In some embodiments, the cross-sectional area of ​​one flow channel is 1.4 times or more the particle size of the raw material. In some embodiments, the cross-sectional area of ​​one flow channel is 1.5 times or more the particle size of the raw material. In some embodiments, the cross-sectional area of ​​one flow channel is 1.0 to 1.5 times the particle size of the raw material. In some embodiments, the cross-sectional area of ​​one flow channel is 1.05 to 1.45 times the particle size of the raw material. In some embodiments, the cross-sectional area of ​​one flow channel is 1.1 to 1.4 times the particle size of the raw material. In some embodiments, the cross-sectional area of ​​one flow channel is 1.15 to 1.35 times the particle size of the raw material.In some embodiments, the cross-sectional area of ​​one flow channel is 1.2 to 1.3 times the particle size of the raw material. In some embodiments, the cross-sectional area of ​​one flow channel is 1.22 to 1.28 times the particle size of the raw material. In some embodiments, the cross-sectional area of ​​one flow channel is 1.24 to 1.26 times the particle size of the raw material.

[0123] Because the total opening area of ​​at least one flow channel on the upper surface of one heating unit is too large, the mass or quantity of the raw material placed on the upper surface of one heating unit is limited, thereby affecting the crystal growth efficiency. If the total opening area of ​​at least one flow channel on the upper surface of one heating unit is too small, the flow channel cannot prevent the graphitized carbon particles from moving to the seed crystal, thereby causing crystal defects. Therefore, it is necessary to control the total opening area of ​​at least one flow channel on the upper surface of the heating unit within a certain range to prevent the graphitized carbon particles from moving to the seed crystal, which can further reduce the crystal defects and ensure the crystal growth efficiency at the same time. In some embodiments, the total opening area of ​​at least one flow channel on the upper surface of one heating unit is 20% to 60% of the area of ​​one heating unit. In some embodiments, the total opening area of ​​at least one flow channel on the upper surface of one heating unit is 25% to 55% of the area of ​​one heating unit. In some embodiments, the total opening area of ​​at least one flow channel on the upper surface of one heating unit is 30% to 50% of the area of ​​one heating unit. In some embodiments, the total open area of ​​the at least one flow channel on the upper surface of the heating unit is 35% to 45% of the area of ​​the heating unit. In some embodiments, the total open area of ​​the at least one flow channel on the upper surface of the heating unit is 38% to 42% of the area of ​​the heating unit. In some embodiments, the total open area of ​​the at least one flow channel on the upper surface of the heating unit is 40% of the area of ​​the heating unit.

[0124] As shown in FIG. 13, the heating assembly 120 is disposed inside the growth chamber 110, and when the growth chamber 110 is heated, a part of the thermal energy is conducted to the outside of the growth chamber 110 through the wall of the growth chamber 110. Thus, the temperature of the region of the heating unit close to the wall of the growth chamber 110 is lower, and the temperature of the region of the heating unit away from the wall of the growth chamber 110 is higher, forming a radial temperature difference and / or a radial temperature gradient inside the growth chamber 110. In some embodiments, the material of the at least one heating unit can include, but is not limited to, a high resistance heating material, so that the resistance of the at least one heating unit can be adjusted by adjusting the density of the at least one flow channel 1250 in the at least one heating unit. Thereby, the heating power of the at least one heating unit is adjusted. In some embodiments, the density of the at least one flow channel 1250 refers to the quantity of the at least one flow channel 1250 per unit area. In some embodiments, when the resistivity of air is greater than the resistivity of the material of the at least one heating unit, the greater the density of the at least one flow channel 1250 of the heating unit, the higher the heating resistivity and the higher the heating power of the heating unit under equal current conditions.

[0125] To reduce or eliminate radial temperature differences and / or radial temperature gradients, in some embodiments, the density of the openings of the at least one flow channel 1250 in a central region of the top surface of the at least one heating unit may be less than the density of the openings of the at least one flow channel 1250 in an edge region of the at least one heating unit. In some embodiments, the edge region of the at least one heating unit refers to a region closer to the edge of the heating unit or away from the center of the heating unit. In some embodiments, the central region of the at least one heating unit refers to a region closer to the center of the heating unit. In embodiments herein, unless otherwise specified, the density of the openings of the at least one flow channel and the density of the at least one flow channel may be used interchangeably.

[0126] As shown in FIG. 13, a raw material 160 is disposed on an upper surface of at least one heating unit inside the growth chamber 110. The raw material 160 is used to provide at least one component required for crystal growth. The raw material 160 can be decomposed under heating by the at least one heating unit to generate a gas phase component. The gas phase component is at least one component required for crystal growth. The gas phase component is driven by an axial temperature gradient and transported through at least one flow channel of the at least one heating unit to the seed crystal 150. In some embodiments, the raw material 160 is in the form of a powder, granules, aggregates, etc.

[0127] FIG. 14 is a schematic diagram of an exemplary at least one heating unit as shown in some embodiments.

[0128] As shown in FIG. 14, the shape of the at least one heating unit 1212 may be circular. The shape of the at least one flow channel 1250 may be circular. The at least one flow channel 1250 is arranged in a circumferential manner with the center O of the at least one heating unit 1212 as the center and the radius Rn. In some embodiments, the at least one flow channel 1250 is arranged in at least one circumference. As shown in FIG. 14, the at least one flow channel 1250 is arranged in four circumferences. In the radial direction from the central region of the at least one heating unit to the edge region of the at least one heating unit, the four circumferences are respectively indicated as a first flow channel circumference 1251, a second flow channel circumference 1252, a third flow channel circumference 1253, and a fourth flow channel circumference 1254. In the embodiments herein, unless otherwise specified, the circumferential arrangement and the annular arrangement can be used interchangeably.

[0129] In some embodiments, the density of the at least one flow channel 1250 may refer to the quantity of the at least one flow channel 1250 per unit arc length. In some embodiments, the density of the at least one flow channel 1250 in different flow channel circumferences may be equal or unequal. As shown in FIG. 13, the heating assembly 120 is disposed inside the growth chamber 110, and when the growth chamber 110 is heated, a portion of the thermal energy is conducted to the outside of the growth chamber 110 through the wall of the growth chamber 110. Thus, the temperature of the region of the heating unit closer to the wall of the growth chamber 110 is lower, and the temperature of the region of the heating unit farther from the wall of the growth chamber 110 is higher, thus forming a radial temperature difference and / or a radial temperature gradient inside the growth chamber 110. In some embodiments, the density of the at least one flow channel 1250 gradually increases from the central region of the at least one heating unit to the peripheral region of the at least one heating unit. In some embodiments, the opening density of the at least one flow channel in the first flow channel circumference 1251 may be less than the opening density of the at least one flow channel in the second flow channel circumference 1252. The aperture density of the at least one flow channel of the second flow channel circumference 1252 may be less than the aperture density of the at least one flow channel of the third flow channel circumference 1253. The aperture density of the at least one flow channel of the third flow channel circumference 1253 may be less than the aperture density of the at least one flow channel of the fourth flow channel circumference 1254. In some embodiments, the density of the at least one flow channel 1250 increases stepwise from a central region of the at least one heating unit to a peripheral region of the at least one heating unit. In some embodiments, the aperture density of the at least one flow channel of the first flow channel circumference 1251 and the second flow channel circumference 1252 may be equal. The aperture density of the at least one flow channel of the third flow channel circumference 1253 and the fourth flow channel circumference 1254 may be equal.The opening density of the at least one flow channel of second flow channel circumference 1252 may be less than the opening density of the at least one flow channel of third flow channel circumference 1253 .

[0130] In some embodiments, the radius of the at least one flow channel 1250 is denoted as r. In some embodiments, the radius of the at least one flow channel 1250 may be the radius of an inscribed or circumscribed circle of the at least one flow channel 1250. In some embodiments, if the shape of the at least one flow channel 1250 is circular, the radius of the at least one flow channel 1250 is the radius of the circle. In some embodiments, if the shape of the at least one flow channel 1250 is a regular shape, such as a triangle, a square, a pentagon, or a hexagon, the radius of the at least one flow channel 1250 is the radius of an inscribed or circumscribed circle of the regular shape, such as a triangle, a square, a pentagon, or a hexagon.

[0131] In order to ensure the crystal growth efficiency by allowing the gas phase components obtained by vaporizing the raw material 160 to reach the seed crystal 150 through the flow channel and grow the crystal, in some embodiments, the radius r of the at least one flow channel 1250 is 0.1 mm to 1 mm. In some embodiments, the radius r of the at least one flow channel 1250 is 0.2 mm to 0.9 mm. In some embodiments, the radius r of the at least one flow channel 1250 is 0.3 mm to 0.8 mm. In some embodiments, the radius r of the at least one flow channel 1250 is 0.4 mm to 0.7 mm. In some embodiments, the radius r of the at least one flow channel 1250 is 0.5 mm to 0.6 mm. In some embodiments, the radius r of the at least one flow channel 1250 is 0.1 mm. In some embodiments, the radius r of the at least one flow channel 1250 is 0.2 mm. In some embodiments, the radius r of the at least one flow channel 1250 is 0.3 mm. In some embodiments, the radius r of at least one flow channel 1250 is 0.4 mm. In some embodiments, the radius r of at least one flow channel 1250 is 0.5 mm. In some embodiments, the radius r of at least one flow channel 1250 is 0.6 mm. In some embodiments, the radius r of at least one flow channel 1250 is 0.7 mm. In some embodiments, the radius r of at least one flow channel 1250 is 0.8 mm. In some embodiments, the radius r of at least one flow channel 1250 is 0.9 mm. In some embodiments, the radius r of at least one flow channel 1250 is 1 mm.

[0132] As shown in FIG. 14, the distance between the centers of two adjacent flow channels on the circumference of one flow channel is denoted as d. In some embodiments, the distance between the centers is the distance between the geometric center points of two adjacent flow channels 1250 on the circumference of one flow channel. In some embodiments, when the shape of the flow channel is circular, the geometric center point of the flow channel 1250 refers to the center of the circle of the flow channel. In some embodiments, the interval between the centers of two adjacent flow channels on the circumference of the same flow channel may or may not be equal.

[0133] In some embodiments, the distance d between the centers of two adjacent flow channels on the circumference of one flow channel is expressed as 3r < d < 10r. In some embodiments, the distance d between the centers of two adjacent flow channels on the circumference of one flow channel is expressed as 4r < d < 9r. In some embodiments, the distance d between the centers of two adjacent flow channels on the circumference of one flow channel is expressed as 5r < d < 8r. In some embodiments, the distance d between the centers of two adjacent flow channels on the circumference of one flow channel is expressed as 6r < d < 7r. In some embodiments, the distance d between the centers of two adjacent flow channels on the circumference of one flow channel is expressed as 6.4r < d < 6.6r.

[0134] In order to arrange an appropriate amount of raw material on the upper surface of the heating unit so as to ensure the efficiency of crystal growth, in some embodiments, the distance between the centers of two adjacent flow channels on the circumference of one flow channel is 1.5 mm to 2.5 mm. In some embodiments, the distance between the centers of two adjacent flow channels on the circumference of one flow channel is 1.6 mm to 2.4 mm. In some embodiments, the distance between the centers of two adjacent flow channels on the circumference of one flow channel is 1.7 mm to 2.3 mm. In some embodiments, the distance between the centers of two adjacent flow channels on the circumference of one flow channel is 1.8 mm to 2.2 mm. In some embodiments, the distance between the centers of two adjacent flow channels on the circumference of one flow channel is 1.9 mm to 2.1 mm. In some embodiments, the distance between the centers of two adjacent flow channels on the circumference of one flow channel is 1.95 mm to 2.05 mm. In some embodiments, the distance between the centers of two adjacent flow channels on the circumference of one flow channel is 1.5 mm. In some embodiments, the distance between the centers of two adjacent flow channels on the circumference of one flow channel is 1.6 mm. In some embodiments, the distance between the centers of two adjacent flow channels around the circumference of a flow channel is 1.7 mm. In some embodiments, the distance between the centers of two adjacent flow channels around the circumference of a flow channel is 1.8 mm. In some embodiments, the distance between the centers of two adjacent flow channels around the circumference of a flow channel is 1.9 mm. In some embodiments, the distance between the centers of two adjacent flow channels around the circumference of a flow channel is 2 mm. In some embodiments, the distance between the centers of two adjacent flow channels around the circumference of a flow channel is 2.1 mm. In some embodiments, the distance between the centers of two adjacent flow channels around the circumference of a flow channel is 2.2 mm. In some embodiments, the distance between the centers of two adjacent flow channels around the circumference of a flow channel is 2.3 mm.In some embodiments, the distance between the centers of two adjacent flow channels around the circumference of a flow channel is 2.4 mm. In some embodiments, the distance between the centers of two adjacent flow channels around the circumference of a flow channel is 2.5 mm.

[0135] In some embodiments, the number of flow channel circumferences in one heating unit is denoted by n, where n is an integer equal to or greater than 2. In some embodiments, n can be 2, 3, 4, 5, etc. As shown in FIG. 14, the radius of the circumference of the nth flow channel is R n Similarly, the radius of the circumference of the (n-1)th flow channel is R n-1 In some embodiments, the radius of the circumference of the nth flow channel, R, may be determined by the size of the at least one heating unit and the radius of the at least one flow channel. n In some embodiments, R n may be smaller than a radius of the at least one heating unit and larger than a radius of the at least one flow channel.

[0136] JPEG0007644779000001.jpg47170

[0137] JPEG0007644779000002.jpg77170 In some embodiments, R1 is between 7 mm and 14 mm. In some embodiments, R1 is between 8 mm and 13 mm. In some embodiments, R1 is between 9 mm and 12 mm. In some embodiments, R1 is between 10 mm and 11 mm. In some embodiments, R1 is 10 mm. In some embodiments, the radius R2 of the second flow channel circumference 1252 is between 2 mm and 30 mm. In some embodiments, R2 is between 3 mm and 29 mm. In some embodiments, R2 is between 4 mm and 28 mm. In some embodiments, R2 is between 5 mm and 27 mm. In some embodiments, R2 is between 6 mm and 26 mm. In some embodiments, R2 is between 7 mm and 25 mm. In some embodiments, R2 is between 8 mm and 24 mm. In some embodiments, R2 is between 9 mm and 23 mm. In some embodiments, R2 is between 10 mm and 22 mm. In some embodiments, R2 is between 11 mm and 21 mm. In some embodiments, R2 is between 12 mm and 20 mm. In some embodiments, R2 is between 13 mm and 19 mm. In some embodiments, R2 is between 14 mm and 18 mm. In some embodiments, R2 is between 15 mm and 17 mm. In some embodiments, R2 is 16 mm.

[0138] FIG. 15 is a schematic diagram of an exemplary crystal manufacturing apparatus according to a further embodiment.

[0139] 15, a crystal manufacturing apparatus 100 includes a growth chamber 110 and a heating assembly 120. For a description of the growth chamber 110, please refer to FIG. 1 and the related description in this specification, and it will not be repeated here.

[0140] In some embodiments, the heating assembly 120 includes at least two heating units. The at least two heating units heat the growth chamber 110 and provide a temperature field necessary for crystal growth to produce a crystal, such that the radial temperature difference during crystal growth does not exceed a preset temperature difference threshold. In some embodiments, at least one heating unit of the at least two heating units is disposed outside the growth chamber 110. In some embodiments, the at least one heating unit located outside the growth chamber 110 is referred to as a first heating assembly 1220. In some embodiments, the first heating assembly 1220 is disposed partially surrounding the periphery of the growth chamber 110. For a related description of the first heating assembly 1220 disposed surrounding the periphery of the growth chamber 110, please refer to FIG. 3 and the related description in this specification, and the details will not be repeated here. In some embodiments, the first heating assembly 1220 includes at least three first heating units. The at least three first heating units correspond to the positions of the crystallization region of the growth chamber 110, the source region of the growth chamber 110, and the vapor phase transport region between the crystallization region and the source region, respectively. For a relevant description of the at least three first heating units arranged around the periphery of the growth chamber 110, please refer to Figures 8, 9 and the relevant description herein, and the details will not be repeated here. In some embodiments, the first heating assembly 1220 is arranged on the outer upper and / or lower surface of the growth chamber 110. For a relevant description of the first heating assembly 1220 located on the outer upper and / or lower surface of the growth chamber 110, please refer to Figures 3 to 7 and the relevant description herein, and the details will not be repeated here.

[0141] In some embodiments, at least one heating unit of the at least two heating units is disposed inside the growth chamber 110. In some embodiments, the at least one heating unit disposed inside the growth chamber 110 is referred to as a second heating assembly 1240. The second heating assembly 1240 includes at least one second heating unit. For a relevant description of the second heating assembly 1240 located inside the growth chamber 110, please refer to FIG. 13 and the relevant description herein, and the details will not be repeated here.

[0142] In some embodiments, at least one heating unit of the second heating assembly 1240 includes at least one flow channel 1250. For a relevant description of the at least one flow channel 1250, please refer to FIG. 14 and the relevant description herein, and details will not be repeated here.

[0143] In some embodiments, when the growth chamber 110 is heated only by the first heating assembly 1220, in the same horizontal plane, the heat gradually decreases as it is conducted from the outer periphery of the growth chamber 110 toward the central axis of the growth chamber 110. The temperature of the outer periphery of the growth chamber 110 may be higher than the temperature inside the growth chamber 110, and a radial temperature difference or a radial temperature gradient is formed inside the growth chamber 110.

[0144] To reduce or eliminate the radial temperature difference and / or the radial temperature gradient, in some embodiments, the second heating assembly 1240 includes at least two or more flow channels. The density of the openings of the at least one flow channel 1250 in the central region of the upper surface of the at least one heating unit located inside the growth chamber 110 may be greater than the density of the openings of the at least one flow channel 1250 in the edge region of the at least one heating unit located inside the growth chamber 110. In some embodiments, the density of the openings of the at least one flow channel 1250 gradually decreases from the central region of the at least one heating unit to the edge region of the at least one heating unit. In some embodiments, the density of the openings of the at least one flow channel of the first flow channel circumference 1251 may be greater than the density of the openings of the at least one flow channel of the second flow channel circumference 1252. The density of the openings of the at least one flow channel of the second flow channel circumference 1252 may be greater than the density of the openings of the at least one flow channel of the third flow channel circumference 1253. The aperture density of the at least one flow channel on the third flow channel circumference 1253 may be greater than the aperture density of the at least one flow channel on the fourth flow channel circumference 1254. In some embodiments, the density of the at least one flow channel 1250 decreases stepwise from a central region of the at least one heating unit to a peripheral region of the at least one heating unit. In some embodiments, the aperture density of the at least one flow channel on the first flow channel circumference 1251 and the second flow channel circumference 1252 may be equal. The aperture density of the at least one flow channel on the third flow channel circumference 1253 and the fourth flow channel circumference 1254 may be equal. The aperture density of the at least one flow channel on the second flow channel circumference 1252 may be greater than the aperture density of the at least one flow channel on the third flow channel circumference 1253.

[0145] In order to ensure the crystal growth efficiency by allowing the gas phase components obtained by vaporizing the raw material 160 to reach the seed crystal 150 through the flow channel and grow the crystal, in some embodiments, the radius r of the at least one flow channel 1250 is 0.05 mm to 0.95 mm. In some embodiments, the radius r of the at least one flow channel 1250 is 0.1 mm to 0.9 mm. In some embodiments, the radius r of the at least one flow channel 1250 is 0.2 mm to 0.8 mm. In some embodiments, the radius r of the at least one flow channel 1250 is 0.3 mm to 0.7 mm. In some embodiments, the radius r of the at least one flow channel 1250 is 0.4 mm to 0.6 mm. In some embodiments, the radius r of the at least one flow channel 1250 is 0.45 mm to 0.55 mm. In some embodiments, the radius r of the at least one flow channel 1250 is 0.05 mm. In some embodiments, the radius r of the at least one flow channel 1250 is 0.1 mm. In some embodiments, the radius r of at least one flow channel 1250 is 0.2 mm. In some embodiments, the radius r of at least one flow channel 1250 is 0.3 mm. In some embodiments, the radius r of at least one flow channel 1250 is 0.4 mm. In some embodiments, the radius r of at least one flow channel 1250 is 0.5 mm. In some embodiments, the radius r of at least one flow channel 1250 is 0.6 mm. In some embodiments, the radius r of at least one flow channel 1250 is 0.7 mm. In some embodiments, the radius r of at least one flow channel 1250 is 0.8 mm. In some embodiments, the radius r of at least one flow channel 1250 is 0.9 mm. In some embodiments, the radius r of at least one flow channel 1250 is 0.95 mm.

[0146] In some embodiments, the distance d between the centers of two adjacent flow channels on the circumference of one flow channel is expressed as 4r < d < 10r. In some embodiments, the distance d between the centers of two adjacent flow channels on the circumference of one flow channel is expressed as 5r < d < 9r. In some embodiments, the distance d between the centers of two adjacent flow channels on the circumference of one flow channel is expressed as 6r < d < 8r. In some embodiments, the distance d between the centers of two adjacent flow channels on the circumference of one flow channel is expressed as 6.5r < d < 7.5r. In some embodiments, the distance d between the centers of two adjacent flow channels on the circumference of one flow channel is expressed as 6.8r < d < 7r.

[0147] In order to arrange an appropriate amount of raw material on the upper surface of the heating unit so as to ensure the efficiency of crystal growth, in some embodiments, the distance between the centers of two adjacent flow channels on the circumference of one flow channel is 1 mm to 2 mm. In some embodiments, the distance between the centers of two adjacent flow channels on the circumference of one flow channel is 1.1 mm to 1.9 mm. In some embodiments, the distance between the centers of two adjacent flow channels on the circumference of one flow channel is 1.2 mm to 1.8 mm. In some embodiments, the distance between the centers of two adjacent flow channels on the circumference of one flow channel is 1.3 mm to 1.7 mm. In some embodiments, the distance between the centers of two adjacent flow channels on the circumference of one flow channel is 1.4 mm to 1.6 mm. In some embodiments, the distance between the centers of two adjacent flow channels on the circumference of one flow channel is 1.45 mm to 1.55 mm. In some embodiments, the distance between the centers of two adjacent flow channels on the circumference of one flow channel is 1 mm. In some embodiments, the distance between the centers of two adjacent flow channels on the circumference of one flow channel is 1.1 mm. In some embodiments, the distance between the centers of two adjacent flow channels around the circumference of a flow channel is 1.2 mm. In some embodiments, the distance between the centers of two adjacent flow channels around the circumference of a flow channel is 1.3 mm. In some embodiments, the distance between the centers of two adjacent flow channels around the circumference of a flow channel is 1.4 mm. In some embodiments, the distance between the centers of two adjacent flow channels around the circumference of a flow channel is 1.5 mm. In some embodiments, the distance between the centers of two adjacent flow channels around the circumference of a flow channel is 1.6 mm. In some embodiments, the distance between the centers of two adjacent flow channels around the circumference of a flow channel is 1.7 mm. In some embodiments, the distance between the centers of two adjacent flow channels around the circumference of a flow channel is 1.8 mm.In some embodiments, the distance between the centers of two adjacent flow channels around the circumference of a flow channel is 1.9 mm. In some embodiments, the distance between the centers of two adjacent flow channels around the circumference of a flow channel is 2 mm. In some embodiments, the distance between the centers of two adjacent flow channels around the circumference of a flow channel is 2.1 mm. In some embodiments, the distance between the centers of two adjacent flow channels around the circumference of a flow channel is 2.2 mm.

[0148] JPEG0007644779000003.jpg59170

[0149] JPEG0007644779000004.jpg38170 Radius R1 of circumference 1251 is between 1 mm and 20 mm. In some embodiments, R1 is between 2 mm and 19 mm. In some embodiments, R1 is between 3 mm and 18 mm. In some embodiments, R1 is between 4 mm and 17 mm. In some embodiments, R1 is between 5 mm and 16 mm. In some embodiments, R1 is between 6 mm and 15 mm. In some embodiments, R1 is between 7 mm and 14 mm. In some embodiments, R1 is between 8 mm and 13 mm. In some embodiments, R1 is between 9 mm and 12 mm. In some embodiments, R1 is between 10 mm and 11 mm. In some embodiments, R1 is 10 mm. In some embodiments, radius R2 of second flow channel circumference 1252 is between 2 mm and 25 mm. In some embodiments, R2 is between 3 mm and 24 mm. In some embodiments, R2 is between 4 mm and 23 mm. In some embodiments, R2 is between 5 mm and 22 mm. In some embodiments, R2 is between 6 mm and 21 mm. In some embodiments, R2 is between 7 mm and 20 mm. In some embodiments, R2 is between 10 mm and 17 mm. In some embodiments, R2 is between 11 mm and 16 mm. In some embodiments, R2 is between 12 mm and 15 mm. In some embodiments, R2 is between 13 mm and 14 mm. In some embodiments, R2 is between 10.5 mm. In some embodiments, R2 is between 11 mm. In some embodiments, R2 is between 11.5 mm. In some embodiments, R2 is between 12 mm. In some embodiments, R2 is between 12.4 mm. In some embodiments, R2 is between 12.5 mm. In some embodiments, R2 is between 13 mm. In some embodiments, R2 is between 13.5 mm. In some embodiments, R2 is between 14 mm.

[0150] In some embodiments, the heating assembly 120 further includes at least one conductive electrode. In some embodiments, the at least one conductive electrode may be a low resistance graphite electrode. In some embodiments, the at least one conductive electrode may be cylindrical. In some embodiments, the cross-sectional shape of the at least one conductive electrode may be a regular or irregular shape, such as a circle, a triangle, a square, a pentagon, or a hexagon. In some embodiments, the cross-sectional shapes of the at least one conductive electrode may be the same or different. In some embodiments, the quantity of the at least one conductive electrode may be two, three, four, five, etc.

[0151] In some embodiments, the heating assembly 120 includes at least two conductive electrodes. In some embodiments, the at least two conductive electrodes are arranged along a circumferential direction at an edge region of the at least one heating unit. In some embodiments, one of the at least two conductive electrodes may be fixed at the center of the at least one heating unit, and the remaining conductive electrodes of the at least two conductive electrodes may be arranged along a circumferential direction around the conductive electrode located at the center of the at least one heating unit. In some embodiments, the at least two conductive electrodes are four. The four conductive electrodes are a first conductive electrode 1242, a second conductive electrode 1243, a third conductive electrode (not shown), and a fourth conductive electrode (not shown), respectively. In some embodiments, the first conductive electrode 1242 is located at the center of the at least one heating unit, and the second conductive electrode 1243, the third conductive electrode, and the fourth conductive electrode are uniformly arranged along a circumferential direction around the first conductive electrode.

[0152] In some embodiments, the diameter of the conductive electrode (e.g., the first conductive electrode 1242) located at the center of the at least one heating unit is larger than the diameter of the conductive electrodes located circumferentially along the edge region of the at least one heating unit. In some embodiments, the diameter of the conductive electrode located at the center of the at least one heating unit may be 13 mm to 20 mm. In some embodiments, the diameter of the conductive electrode located at the center of the at least one heating unit may be 14 mm to 19 mm. In some embodiments, the diameter of the conductive electrode located at the center of the at least one heating unit may be 15 mm to 18 mm. In some embodiments, the diameter of the conductive electrode located at the center of the at least one heating unit may be 16 mm to 17 mm.

[0153] In some embodiments, the diameters of the conductive electrodes (e.g., the second conductive electrode 1243, the third conductive electrode, and the fourth conductive electrode) arranged along the circumferential direction in the edge region of at least one heating unit may be the same or different. In some embodiments, the diameters of the conductive electrodes arranged along the circumferential direction in the edge region of at least one heating unit may be 5 mm to 13 mm. In some embodiments, the diameters of the conductive electrodes arranged along the circumferential direction in the edge region of at least one heating unit may be 6 mm to 12 mm. In some embodiments, the diameters of the conductive electrodes arranged along the circumferential direction in the edge region of at least one heating unit may be 7 mm to 11 mm. In some embodiments, the diameters of the conductive electrodes arranged along the circumferential direction in the edge region of at least one heating unit may be 8 mm to 10 mm. In some embodiments, the diameters of the conductive electrodes arranged along the circumferential direction in the edge region of at least one heating unit may be 8.5 mm to 9.5 mm.

[0154] The growth chamber 110 is provided with at least two electrode posts. In some embodiments, the at least two electrode posts are provided at the bottom of the growth chamber 110. In some embodiments, the at least two electrode posts are hollow posts and are used to attach the at least two conductive electrodes. In some embodiments, the material of the at least two electrode posts is an insulating material used to separate the at least two conductive electrodes to prevent shorting. In some embodiments, the material of the at least two electrode posts is zirconia. In some embodiments, the shape, size, and / or number of the at least two electrode posts are the same as the cross-sectional shape, cross-sectional size, and / or number of the at least two conductive electrodes. In some embodiments, the at least two electrode posts are four. The four electrode posts are a first electrode post 1244, a second electrode post 1245, a third electrode post (not shown), and a fourth electrode post (not shown), respectively.

[0155] In some embodiments, the at least one heating unit is provided with at least two first electrode holes. In some embodiments, the shape of the at least two first electrode holes is a regular or irregular shape, such as a circle, a triangle, a square, a pentagon, or a hexagon. In some embodiments, the quantity of the at least two first electrode holes is one, two, three, four, five, etc. In some embodiments, the shape, size, and / or quantity of the at least two first electrode holes is the same as the cross-sectional shape, cross-sectional size, and / or quantity of the at least two conductive electrodes.

[0156] 16A and 16B are top and side views of an exemplary at least one heating unit as shown in some embodiments and another embodiment, respectively.

[0157] As shown in Figures 16A and 16B, the quantity of the at least two first electrode holes is four, and the four first electrode holes are, respectively, one first electrode hole A1246 located at the center of the at least one heating unit and three first electrode holes B1247 arranged along the circumferential direction in the edge region of the at least one heating unit.

[0158] In some embodiments, the heating assembly 120 includes a copper wire (not shown) and a power source (not shown). The at least two conductive electrodes are respectively connected to the power source through the copper wire. Thus, the at least two conductive electrodes, the at least one heating unit, and the power source can form a current path for heating the at least one heating unit.

[0159] In some embodiments, the heating assembly 120 includes at least one conductive ring 1241. The at least one heating unit is connected to the at least one conductive ring 1241 through at least one conductive electrode. In some embodiments, the at least one conductive ring 1241 is disposed on the upper surface or / and lower surface of the at least one heating unit inside the growth chamber 110. The quantity of the at least one conductive ring 1241 and the quantity of the at least one heating unit may be equal or unequal. In some embodiments, the quantity of the at least one conductive ring 1241 is twice the quantity of the at least one heating unit. In some embodiments, the material of the at least one conductive ring 1241 is at least one of graphite, tungsten, molybdenum, tantalum, or iridium. In some embodiments, except for the surface of the at least one conductive ring 1241 that contacts the at least one heating unit, the other surfaces are coated with a carbide coating that is resistant to high temperatures. In some embodiments, the carbide coating can include, but is not limited to, tantalum carbide, tungsten carbide, niobium carbide, titanium carbide, and the like. Similarly, except for the surface (eg, edge portion) in contact with the at least one conductive ring 1241 of the at least one heating unit, other portions may also be coated with a high temperature resistant coating.

[0160] In some embodiments, the at least one conductive ring 1241 is removably connected to the growth chamber 110. The manner in which the at least one conductive ring 1241 is removably connected to the growth chamber 110 is the same as the manner in which the at least one heating unit is removably connected to the growth chamber 110, and the details will not be repeated here.

[0161] At least one second electrode hole 1248 is disposed in the at least one conductive ring 1241. In some embodiments, the shape and size of the at least one second electrode hole is the same as the cross-sectional shape and cross-sectional size of the at least one conductive electrode. In some embodiments, the number and / or arrangement of the at least one second electrode hole may be the same as or different from the number and / or arrangement of the at least one conductive electrode. In some embodiments, the number of the at least one second electrode hole is the same as the number of the at least one conductive electrode. In some embodiments, the number of the at least one second electrode hole is one less than the number of the at least one conductive electrode.

[0162] FIG. 17 is a schematic diagram of an exemplary at least one conductive ring according to some embodiments.

[0163] 17, the quantity of the at least one second electrode hole 1248 is three. The three second electrode holes 1248 are disposed along the circumferential direction in the edge region of the at least one conductive ring 1241.

[0164] In some embodiments, at least a portion of the at least two conductive electrodes pass through the at least two second electrode holes and are connected to the at least one conductive ring. The at least two conductive electrodes are respectively connected to a power source via copper wires. Thus, the at least two conductive electrodes, the at least one conductive ring 1241, the at least one heating unit and the power source form a current path. The current path heats the at least one heating unit and the at least one conductive ring 1241. Therein, the at least one conductive ring 1241 can distribute heat evenly and reduce the radial temperature difference and / or the radial temperature gradient inside the growth chamber 110.

[0165] FIG. 18 is a flow diagram of an exemplary crystal growing method presented in some embodiments.

[0166] In step 1810, the seed crystal and source material are placed in a growth chamber and the crystal is grown.

[0167] The seed crystal is a small crystal having the same crystal orientation as the crystal to be grown, and can be used as a seed for growing the crystal. In some embodiments, the seed crystal is manufactured based on physical vapor transport (PVT), chemical vapor deposition (CVD), or pulling method, etc. In some embodiments, the seed crystal is generated by at least a splicing process and interstitial growth. For the relevant description of the method for manufacturing the seed crystal, please refer to FIG. 22, FIG. 23 and the relevant description in this specification, and will not be repeated here. In some embodiments, the seed crystal is fixed to the inner surface of the growth chamber cover 111 as shown in FIG. 1.

[0168] The source material includes a material for growing the seed crystal into a crystal. In some embodiments, the composition of the source material for the silicon carbide crystal may include SiC. In some embodiments, the composition of the source material for the aluminum nitride crystal may include AlN. In some embodiments, the source material may be a powder, granular, and / or bulk material. In some embodiments, the shape of the bulk material may be a cube, a rectangular parallelepiped, an irregular block, or the like. In some embodiments, the source material is placed in the growth chamber body 112. As shown in FIG. 1 or FIG. 3 or FIG. 8, the source material is placed in the lower part of the growth chamber body 112. As shown in FIG. 13 or FIG. 15, the source material is placed on the upper surface of at least one heating unit inside the growth chamber 110.

[0169] For relevant descriptions of the growth chamber, please refer to the descriptions in other parts of this specification (eg, Figures 1 and 3) and will not be repeated here.

[0170] For relevant descriptions of placing the seed crystal and source material in the growth chamber, please refer to the descriptions in other parts of this specification (e.g., Figures 13, 15, and 19) and will not be repeated here.

[0171] For relevant descriptions of the heating assembly and temperature detection assembly, please refer to the descriptions in other parts of this specification (eg, Figures 1 to 16) and will not be repeated here.

[0172] In some embodiments, the mounting position of the temperature sensing assembly is determined by the position of the temperature distribution in the growth chamber 110 to be measured. In some embodiments, the temperature sensing assembly is disposed on the upper surface of the growth chamber 110 to measure the temperature distribution of the lower surface of the seed crystal or the crystal growth surface. In some embodiments, the temperature sensing assembly is disposed on the lower surface of the growth chamber 110 to measure the temperature distribution of the upper surface of the feedstock. In some embodiments, the temperature sensing assembly is disposed on the outer wall of the growth chamber 110 to measure the temperature distribution of the inner and outer peripheral regions of the growth chamber 110.

[0173] In step 1820, during crystal growth, the heating assembly is controlled based on information from the temperature sensing assembly to ensure that the radial temperature difference inside the growth chamber as the crystal grows does not exceed a first preset range of the average temperature inside the growth chamber.

[0174] For descriptions of the control assembly, temperature sensing assembly, temperature sensing assembly information, radial temperature difference, and preset radial temperature difference threshold, please refer to the descriptions in other parts of this specification (e.g., Figures 1 and 2) and will not be repeated here.

[0175] In some embodiments, the average temperature inside the growth chamber includes an average temperature of a lower surface of the seed crystal or growing crystal inside the growth chamber, and an average temperature of an upper surface of the feedstock inside the growth chamber. In some embodiments, the average temperature inside the growth chamber further includes a crystal growth temperature. In some embodiments, the control assembly controls at least one parameter of at least one heating unit of the heating assembly based on a temperature distribution inside the growth chamber during crystal growth. The radial temperature difference inside the growth chamber during crystal growth does not exceed a first preset range of the average temperature inside the growth chamber or a preset radial temperature difference threshold. In some embodiments, the temperature sensing assembly 210 measures temperature information inside the growth chamber and transmits the measured information to the control assembly 230. The control assembly 230 can generate a radial temperature difference distribution and / or a radial temperature gradient distribution based on the temperature information measured by the temperature sensing assembly 210. The control assembly 230 is further used to determine the first preset range, the preset radial temperature difference threshold and / or the preset radial temperature gradient threshold according to the size, shape, and material of the growth chamber 110, the size of the seed crystal, and the type and size of the crystal to be grown. The control assembly 230 can further compare the radial temperature difference in the radial temperature difference distribution with a preset radial temperature difference threshold or compare the radial temperature gradient in the radial temperature gradient distribution with a preset radial temperature gradient. If the radial temperature difference is greater than the preset radial temperature difference threshold or the radial temperature gradient is greater than the preset radial temperature gradient threshold, in some embodiments, the control assembly 230 can increase the heating power of at least one heating unit disposed in a central region of the growth chamber 110, as shown in FIG. 3 or FIG. 8. In some embodiments, if the temperature of the central region of the growth chamber is higher than the temperature of the peripheral region of the growth chamber, the control assembly 230 can reduce the current flowing through at least one conductive electrode passing through the central region of the heating unit or increase the current flowing through at least one conductive electrode passing through the edge region of the heating unit, as shown in FIG. 13.In some embodiments, when the temperature of the central region of the growth chamber is lower than the temperature of the peripheral region of the growth chamber, the control assembly 230 increases the current through at least one conductive electrode passing through the central region of the heating unit or reduces the current through at least one conductive electrode passing through the edge region of the heating unit to reduce the radial temperature difference and / or the radial temperature gradient, as shown in Fig. 15, until the radial temperature difference does not exceed a first preset range of the average temperature of the growth chamber or the preset radial temperature difference threshold, and the radial temperature gradient does not exceed the preset radial temperature gradient threshold. The control process of the temperature control system is not repeated here, and reference is made to Fig. 2 and its related description.

[0176] During crystal growth, the heating assembly is controlled based on information from the temperature sensing assembly to stabilize the axial temperature gradient inside the growth chamber as the crystal grows.

[0177] For relevant descriptions of the control assembly and the axial temperature gradient, please refer to the descriptions in other parts of this specification (eg, Figures 1 and 2) and will not be repeated here.

[0178] In some embodiments, the control assembly 230 further controls at least one parameter of at least one heating unit of the heating assembly 220 based on the temperature distribution of the growth chamber during the crystal growth to maintain the axial temperature gradient of the growth chamber stable when the crystal is grown. In some embodiments, the control assembly 230 further controls at least one parameter of at least one heating unit of the heating assembly 220 based on the temperature distribution of the growth chamber during the crystal growth to maintain the axial temperature gradient of the growth chamber within a preset axial temperature gradient range when the crystal is grown. In some embodiments, the temperature sensing assembly 210 can measure the axial temperature of the growth chamber and send the measured axial temperature to the control assembly 230. The control assembly 230 can generate an axial temperature gradient distribution based on the axial temperature measured by the temperature sensing assembly 210. The control assembly 230 can also determine a preset axial temperature gradient range depending on the size, shape, material of the growth chamber 110, the size of the seed crystal, and the type and size of the crystal to be grown. The control assembly 230 can further compare the axial temperature gradient in the axial temperature gradient distribution to the preset axial temperature gradient range. When the axial temperature gradient is smaller than the preset axial temperature gradient range, the control assembly 230 reduces the heating power of at least one heating unit arranged around the growth chamber close to the growth chamber cover to increase the axial temperature gradient, until the axial temperature gradient reaches the preset axial temperature gradient range. When the axial temperature gradient is larger than the preset axial temperature gradient range, the control assembly 230 increases the heating power of at least one heating unit arranged around the growth chamber close to the growth chamber cover to reduce the axial temperature gradient, until the axial temperature gradient reaches the preset axial temperature gradient range. The control process for the axial temperature gradient of the temperature control system is not repeated here, and is referred to FIG. 2 and its related description.

[0179] It should be noted that the above description of the process 1800 is merely illustrative and illustrative, and does not limit the scope of the present application. Those skilled in the art may, under the guidance of the present application, make various modifications and changes to the process 1800. However, such modifications and changes are still within the scope of the present application. For example, steps 1820 and 1830 may be performed simultaneously.

[0180] Some embodiments disclose a crystal growth method for producing a semiconductor crystal by the crystal production apparatus 100. The following describes the production of a silicon carbide single crystal as an example. This method includes the following steps.

[0181] Step 1: A seed crystal is glued to the inner surface of the growth chamber cover 111, raw materials are put into the growth chamber body 112, and the growth chamber cover 111 with the seed crystal glued thereto is placed on the top of the growth chamber body 112.

[0182] First, adhesive is uniformly applied to the inner surface of the growth chamber cover 111, and then the growth chamber cover 111 covered with adhesive is placed in a heating furnace, held at a temperature of 150-180°C for 5 hours, heated to 200°C and held there for 7-10 hours, cooled to room temperature, and then removed. Next, a seed crystal is placed in the center of the inner surface of the growth chamber cover 111, a silicon carbide single crystal is placed on the seed crystal, and a stainless steel block is placed on the silicon carbide single crystal. Then, it is placed in a heating furnace, held at 380-430°C for 5 hours, cooled to room temperature, and then removed.

[0183] JPEG0007644779000005.jpg10170The adhesive may include, but is not limited to, epoxy adhesive, AB adhesive, phenolic resin adhesive, sugar adhesive, and the like. In some embodiments, the adhesive is sucrose with a purity of 99.9%. A stainless steel block is used to apply a predetermined pressure to the silicon carbide single crystal, the seed crystal, and the growth chamber cover 111 to promote the attachment of the seed crystal to the inner surface of the growth chamber cover 111. In the seed crystal bonding and fixing process, air bubbles or gaps may occur between the back surface of the seed crystal and the inner surface of the growth chamber cover 111 due to uneven application of the adhesive or poor processing accuracy of the inner surface of the growth chamber cover, so that the grown crystal contains defects. Therefore, when the seed crystal is placed in the middle of the inner surface of the growth chamber cover 111, it is necessary to avoid the occurrence of air bubbles or gaps. In some embodiments, before bonding the seed crystal to the inner surface of the growth chamber cover, the seed crystal is washed to remove contaminants on the surface of the seed crystal. In some embodiments, the seed crystal is washed with deionized water, an organic solvent, or the like.

[0184] Next, the source material (e.g., silicon carbide powder) is placed in the growth chamber body 112. The distance between the top surface of the source material and the crystal growth surface is 30-50 mm. In some embodiments, the source material is in powder form. The grain size of the source material is 30-50 μm. The surface of the source material placed in the growth chamber body 112 needs to remain flat.

[0185] After the source material is placed in the growth chamber body 112, the growth chamber cover 111 with the seed crystal attached thereto is attached to the top of the growth chamber body 112 to form an enclosed space for crystal growth.

[0186] Step 2: Place a first heating assembly 1220 outside the growth chamber 110.

[0187] As shown in FIG. 3, the heating assembly includes a first heating assembly 1220 and a temperature compensation assembly 1210. The first heating assembly 1220 is an induction coil disposed on the outer periphery of the growth chamber 110 to provide at least a portion of the heat required for crystal growth. When an electric current is supplied to the induction coil, the growth chamber 110 is heated, and the raw material (e.g., silicon carbide powder) is pyrolyzed under high temperature and sublimated into gaseous components (e.g., Si2C, SiC2, Si). Driven by the axial temperature gradient, the gaseous components are transported to the surface of the seed crystal, which has a lower temperature, and crystallize to form a crystal (e.g., silicon carbide crystal). In some embodiments, the axial temperature gradient can be controlled by controlling the heating power of the induction coil at different axial positions.

[0188] If the growth chamber 110 is heated only by the induction coil arranged on the outer periphery of the growth chamber 110, the region close to the inner wall of the growth chamber 110 becomes a high temperature region and the region close to the center of the source material becomes a low temperature region, and in this case, the radial temperature gradient of the covered region of the source material is large, which does not promote sublimation of the source material and stable growth of crystals. In some embodiments, since the radial temperature gradient of the covered region of the source material is large, in the high temperature region close to the inner wall of the growth chamber 110, the Si / C molar ratio of the gas phase component generated by sublimation of the source material is large, but in the low temperature region close to the center of the source material, the Si / C molar ratio of the gas phase component generated by sublimation is small. Therefore, the radial distribution of the Si / C molar ratio of the gas phase component becomes non-uniform, which does not promote stable growth of crystals. In addition, for the growth chamber cover 111, the vicinity of the outer periphery of the growth chamber cover 111 is a high temperature area, and the vicinity of the center of the growth chamber cover 111 is a low temperature area, and the growth chamber cover 111 has a large radial temperature gradient, which brings about a large thermal stress on the crystal growth surface, causes the crystal growth surface to protrude significantly toward the raw material, and forms defects on the fixing surface of the seed crystal. Therefore, by disposing a temperature compensation device on the upper surface and / or lower surface of the growth chamber 110, the radial temperature gradient of the growth chamber cover 111 and the radial temperature gradient of the region covered by the raw material can be reduced. For the relevant description of the radial temperature gradient, please refer to the description in other parts of this specification (e.g., FIG. 1 and the related description), and will not be repeated here.

[0189] Step 3: Attach the temperature compensation assembly 1210 to the upper and / or lower surface of the growth chamber 110.

[0190] In some embodiments, a fixing frame 1216 including at least one fixing unit is fixed to the upper or lower surface of the growth chamber 110, and at least one heating unit 1212 of the temperature compensation assembly 1210 is filled and fixed to the at least one fixing unit. Then, an electrode fixing plate 1215 is attached, and at least one first electrode 1213 is passed through at least one first hole 1215-1 of the electrode fixing plate 1215 and fixed to the at least one heating unit 1212, while at the same time, at least one second electrode 1211 is passed through at least one second hole 1215-2 of the electrode fixing plate 1215 and fixed to the upper or lower surface of the growth chamber 110. Furthermore, the upper ends of the at least one first electrode 1213 and the at least one second electrode 1211 are respectively connected to copper wires 1214, and the copper wires 1214 are connected to a power source.

[0191] In some embodiments, the number, size, shape, arrangement, etc. of the at least one heating unit 1212 are determined according to the size of the upper or lower surface of the growth chamber 110, the type of crystal to be grown, the size or shape of the seed crystal, the temperature (axial temperature gradient and / or radial temperature gradient) distribution of the growth chamber 110, etc. In some embodiments, when growing a 4-10 inch silicon carbide crystal, 10-20 heating units 1212 are arranged on the upper surface of the growth chamber cover. In some embodiments, the thickness of the at least one heating unit 1212 is 5 mm to 10 mm. In some embodiments, the thickness of the at least one heating unit 1212 is 6 mm to 9 mm. In some embodiments, the thickness of the at least one heating unit 1212 is 7 mm to 8 mm. For example, the shape of the at least one heating unit 1212 is hexagonal, and the side length of the at least one heating unit 1212 is 10 to 30 mm. In some embodiments, the side length of the at least one heating unit 1212 is 12 to 28 mm. In some embodiments, the side length of the at least one heating unit 1212 is between 14 and 26 mm. In some embodiments, the side length of the at least one heating unit 1212 is between 16 and 24 mm. In some embodiments, the side length of the at least one heating unit 1212 is between 18 and 22 mm. In some embodiments, the side length of the at least one heating unit 1212 is between 20 and 21 mm.

[0192] Step 4: At least one temperature sensing unit is connected to the heating unit 132 and the outer periphery of the upper or lower surface of the growth chamber 110 through at least two temperature measurement holes 1215-3, which are located between radially adjacent first holes 1215-1 or within a set range of at least one second hole 136-3.

[0193] In some embodiments, at least one temperature sensing unit passes through at least two temperature measuring holes 1215-3 in the electrode fixing plate 1215 to measure a first temperature of the at least one heating unit 1212 and a second temperature on the periphery of the upper or lower surface of the growth chamber 110, thereby obtaining a temperature distribution on the upper or lower surface of the growth chamber 110.

[0194] Step 5: Inject an inert gas (eg, argon gas) into the growth chamber 110 , control the pressure at 5-30 Torr, and heat the growth chamber 110 by the first heating assembly 1220 and the temperature compensation assembly 1210 .

[0195] Step 6: Measure a first temperature of the at least one heating unit 1212 and a second temperature of the periphery of the upper or lower surface of the growth chamber 110 with at least one temperature sensing unit, and adjust parameters of the at least one heating unit 1212 (e.g., the quantity, shape, size, arrangement, current, heating power of the at least one heating unit 1212) based on at least the first and second temperatures to make the radial temperature gradient of the upper or lower surface of the growth chamber 110 smaller than a preset threshold value to promote uniform growth of crystals. For further description of adjusting parameters of the at least one heating unit 1212 based on the first and second temperatures, please refer to other descriptions herein (e.g., FIGS. 6 and 7 and their descriptions).

[0196] In some embodiments, during crystal growth, when the source material is sublimated, the temperature of the growth chamber 110 is maintained in the range of 2200-2400°C, and the duration of the source material being sublimated is 40-60 hours. In some embodiments, during crystal growth, the temperature of the growth chamber cover 111 is maintained in the range of 2100°C-2350°C, and a first temperature of at least one heating unit 1212 located on an upper surface of the growth chamber 110 is lower than a second temperature of an outer periphery of the growth chamber cover 111, and the temperature difference is kept within 10K.

[0197] The above manufacturing method is only an example, and the relevant process parameters may be different in different embodiments. The above steps are not inherent, and in different embodiments, the steps may be adjusted, and one or more steps may be omitted. The above examples should not be construed as limiting the scope of protection of the present application.

[0198] FIG. 19 is a flow diagram of an exemplary crystal growth method according to a further embodiment.

[0199] Some embodiments disclose a crystal growth method for producing a semiconductor crystal by the crystal production apparatus 100. In the following description, the production of a silicon carbide single crystal is taken as an example. This method includes the following steps.

[0200] Step 1910: A seed crystal is placed at the top of the growth chamber and a source material is placed at the bottom of the growth chamber.

[0201] The seed crystal is attached to the inner surface of the growth chamber cover 111 , the raw material is placed in the growth chamber body 112 , and the growth chamber cover 111 with the seed crystal attached thereto is attached to the top of the growth chamber body 112 .

[0202] First, adhesive is uniformly applied to the inner surface of the growth chamber cover 111, and then the growth chamber cover 111 covered with adhesive is placed in a heating furnace, held at a temperature of 150-180°C for 5 hours, heated to 200°C and held there for 7-10 hours, cooled to room temperature, and then removed. Next, a seed crystal is placed in the center of the inner surface of the growth chamber cover 111, a silicon carbide single crystal is placed on the seed crystal, and a stainless steel block is placed on the silicon carbide single crystal. Then, it is placed in a heating furnace, held at 380-430°C for 5 hours, cooled to room temperature, and then removed.

[0203] The adhesive may include, but is not limited to, sucrose resin adhesive, sugar adhesive, and the like. In some embodiments, the adhesive is sucrose with a purity of 99.9%. The stainless steel block is used to apply a predetermined pressure to the silicon carbide single crystal, the seed crystal, and the growth chamber cover 111 to promote the attachment of the seed crystal to the inner surface of the growth chamber cover 111. In the seed crystal bonding and fixing process, air bubbles or gaps may occur between the back surface of the seed crystal and the inner surface of the growth chamber cover 111 due to uneven application of the adhesive or poor processing accuracy of the inner surface of the growth chamber cover, so that the grown crystal contains defects. Therefore, when the seed crystal is placed in the middle of the inner surface of the growth chamber cover 111, it is necessary to avoid the occurrence of air bubbles or gaps. In some embodiments, before bonding the seed crystal to the inner surface of the growth chamber cover, the seed crystal is washed to remove contaminants on the surface of the seed crystal. In some embodiments, the seed crystal is washed with deionized water, an organic solvent, or the like.

[0204] Next, the source material (e.g., silicon carbide powder) is placed in the growth chamber body 112. The distance between the top surface of the source material and the crystal growth surface is 30-100 mm. The grain size of the source material is 30-50 μm. The surface of the source material placed in the growth chamber body 112 needs to remain flat.

[0205] After the source material is placed in the growth chamber body 112, the growth chamber cover 111 with the seed crystal attached thereto is attached to the top of the growth chamber body 112 to form an enclosed space for crystal growth and facilitate the crystal growth.

[0206] Step 1920: Attach the temperature compensation assembly 1210 to the upper and / or lower surface of the growth chamber 110. In some embodiments, the first temperature compensation assembly 1210-1 and the second temperature compensation assembly 1210-2 are attached to the upper and lower surfaces of the growth chamber 110, respectively.

[0207] First, the first temperature compensation assembly 1210-1 is fixed to the upper surface of the growth chamber 110, and the outer peripheral region of the lower surface of the first temperature compensation assembly 1210-1 is brought into contact with the outer peripheral region of the upper surface of the growth chamber 110. This allows heat in the outer peripheral region of the upper surface of the growth chamber 110 to be conducted to the central region of the upper surface of the growth chamber 110. Next, the second temperature compensation assembly 1210-2 is fixed to the lower surface of the growth chamber 110, and the outer peripheral region of the upper surface of the second temperature compensation assembly 1210-2 is brought into contact with the outer peripheral region of the lower surface of the growth chamber 110. This allows heat in the outer peripheral region of the lower surface of the growth chamber 110 to be conducted to the central region of the lower surface of the growth chamber 110. The first temperature compensation assembly 1210-1 or the second temperature compensation assembly 1210-2 is a graphite body with high thermal conductivity. The first temperature compensation assembly 1210-1 or the second temperature compensation assembly 1210-2 is disk-shaped.

[0208] Step 1930: A heating assembly is positioned outside the growth chamber 110.

[0209] First, a resistance heating element is arranged outside the growth chamber 110, and the growth chamber 110 is placed at the center of the resistance heating element. The resistance heating element includes at least a first heating module 1230-1, a second heating module 1230-2, and a third heating module 1230-3. The first heating module 1230-1 is used to heat the crystallization region of the growth chamber. The second heating module 1230-2 is used to heat the vapor phase transport region between the crystallization region and the raw material region of the growth chamber 110. The third heating module 1230-3 is used to heat the raw material region of the growth chamber 110. The heating power of each heating module can be controlled individually. The resistance heating element is a ring-shaped high-resistance graphite heating element.

[0210] Next, an electrode fixing plate 1215 is disposed on the outside of the resistance heating element, and at least one first electrode 1213 is fixed to the outside of the resistance heating element through one of at least two holes in the electrode fixing plate 1215. At the same time, at least one second electrode 1211 is fixed to the outside of the resistance heating element through another of at least two holes in the electrode fixing plate 1215. Then, the upper ends of the at least one first electrode 1213 and the at least one second electrode 1211 are respectively connected to water-cooled copper wires, and the water-cooled copper wires are connected to a power source. The first electrode 1213 and the second electrode 1211 may be low-resistance graphite electrodes. The electrode fixing plate 1215 may be a zirconia ceramic plate.

[0211] In some embodiments, the crystal growing method further comprises disposing an insulating layer around the exterior of the heating assembly.

[0212] An insulating layer is placed around the outside of the heating assembly to insulate the growth chamber 110 and / or the heating assembly. The insulating layer may include graphite felt or zirconia ceramic. The thickness of the insulating layer and the spacing between the insulating layer and the heating assembly are adjusted depending on the size of the growth chamber, the type of crystal being grown, the heating power of the resistive heating elements, temperature information about the growth chamber 110 during crystal growth, etc.

[0213] Step 1940: Heat the growth chamber by the heating assembly and temperature compensation assembly. An inert gas is introduced into the growth chamber 110, and the pressure is controlled to be 5 to 30 Torr. The growth chamber 110 is heated by the heating assembly and temperature compensation assembly 1210.

[0214] Before heating the growth chamber 110, an inert gas (e.g., argon gas) can be introduced into the growth chamber 110 to eliminate air inside the growth chamber 110. Then, the growth chamber 110 is heated by a heating assembly and a temperature compensation assembly.

[0215] Step 1950: During crystal growth, the heating power of the heating assembly and / or temperature compensation assembly 1210 is adjusted via the control assembly based on at least one crystal growth parameter (e.g., amount of raw material, crystal growth size, height difference between the crystal growth interface and the raw material material) to keep the temperature field between the crystal growth interface and the raw material 160 essentially stable.

[0216] In some embodiments, during crystal growth, the heating power (e.g., average heating power) of the first temperature compensation assembly 1210-1 is controlled to be smaller than the heating power (e.g., average heating power) of the first heating module 1230-1, the heating power (e.g., average heating power) of the first heating module 1230-1 is controlled to be smaller than the heating power (e.g., average heating power) of the second heating module 1230-2, the second heating power (e.g., average heating power) of the second heating module 1230-2 is controlled to be smaller than the heating power (e.g., average heating power) of the third heating module 1230-3, and the heating power (e.g., average heating power) of the third heating module 1230-3 is controlled to be equal to the heating power (e.g., average heating power) of the second temperature compensation assembly 1210-2. As the crystal grows, the raw material 160 is continuously consumed, and the temperature field between the crystal growth interface and the raw material 160 moves downward. In order to keep the temperature field between the crystal growth interface and the source material 160 essentially stable, the heating power of the first heating module 1230-1, the heating power of the second heating module 1230-2, and the heating power of the third heating module 1230-3 need to be adjusted so that the downward movement speed of the temperature field keeps close to the crystal growth speed (e.g., 0.8-2 mm / h). Also, as the crystal grows, the heating power of the first temperature compensation assembly 1210-1 needs to be reduced to maintain the stability of the temperature gradient. In some embodiments, the reduced heating power is 0.1%-0.5%. For further description of adjusting the heating power of the heating assembly and / or the temperature compensation assembly 1210 via the control assembly during crystal growth, see other parts of this specification (e.g., FIG. 9 and its description).

[0217] In some embodiments, when the source material is sublimated, the temperature of the growth chamber 110 is maintained in the range of 2200-2400° C., and the duration of the source material sublimation process is maintained for 40-60 hours. In some embodiments, the pressure inside the growth chamber 110 is controlled to 5-30 Torr during crystal growth.

[0218] It should be noted that the above description of the process 1900 is for illustrative and explanatory purposes only, and does not limit the scope of the present application. Those skilled in the art can make various modifications and changes to the process 1900 under the guidance of the present application. However, such modifications and changes are still within the scope of the present application. The above manufacturing process is only an example, and the related process parameters may be different in different embodiments. The order of the above steps is not specific, and in different embodiments, the order of the steps may also be adjusted, and one or more steps may even be omitted. The above examples should not be construed as limiting the scope of protection of the present application.

[0219] FIG. 20 is a flow diagram of an exemplary crystal growth method according to a further embodiment.

[0220] This embodiment also discloses a crystal growth method for manufacturing a semiconductor crystal using the crystal manufacturing apparatus 100. In the following description, the manufacturing of a silicon carbide single crystal will be taken as an example. As shown in FIG. 20, the crystal growth method includes the following steps.

[0221] Step 2010: Fabricate a heating assembly.

[0222] In some embodiments, as shown in Figure 13, the heating assembly is a second heating assembly 1240 located in the growth chamber 110. In some embodiments, as shown in Figure 15, the heating assembly includes a first heating assembly 1220 located outside the growth chamber 110 and a second heating assembly 1240 located inside the growth chamber 110. For a relevant description of the heating assembly, please refer to the relevant descriptions of Figures 13 to 16B in this specification, and details will not be repeated here.

[0223] In some embodiments, manufacturing the heating assembly includes installing at least one flow channel 1250 in a heating unit of the second heating assembly 1240. In some embodiments, information related to the at least one flow channel 1250 is determined according to the type of crystal to be grown, the size of the crystal, the size of the growth chamber 110, etc. In some embodiments, the information related to the at least one flow channel 1250 can include, but is not limited to, the density of the openings of the at least one flow channel 1250, the radius of the at least one flow channel 1250, the shape of the at least one flow channel 1250, the number of flow channel circumferences, the radius of the flow channel circumferences, the center-to-center spacing of two adjacent flow channels of different flow channel circumferences, etc. For a related description of the at least one flow channel 1250, please refer to Figures 13-15 and related descriptions and will not be repeated here.

[0224] Step 2020: Install the heating assembly and place the seed crystal and source material into the growth chamber.

[0225] In some embodiments, the seed crystal is 4H-SiC or 6H-SiC with a diameter of 70 mm to 150 mm. In some embodiments, the diameter of the seed crystal is 80 mm to 140 mm. In some embodiments, the diameter of the seed crystal is 90 mm to 130 mm. In some embodiments, the diameter of the seed crystal is 100 mm to 120 mm. In some embodiments, the diameter of the seed crystal is 105 mm to 115 mm. In some embodiments, the diameter of the seed crystal is 70 mm to 150 mm. In some embodiments, the direction of the seed crystal growth surface is <0001> It will be deflected by 4° to 8° and point in the direction of

[1120] .

[0226] In some embodiments, the purity of the raw material may be 99.99% or more. In some embodiments, the purity of the raw material may be 99.999% or more. In some embodiments, when the raw material is in powder form, the particle size of the raw material is 0.1 mm to 0.5 mm. In some embodiments, the particle size of the raw material is 0.15 mm to 0.45 mm. In some embodiments, the particle size of the raw material is 0.2 mm to 0.4 mm. In some embodiments, the particle size of the raw material is 0.25 mm to 0.35 mm.

[0227] For further description of the seed crystals, source material, and growth chamber, please refer to the descriptions elsewhere herein (eg, FIG. 19).

[0228] When the second heating assembly 1240 in the heating assembly is installed, at least two conductive electrodes are respectively passed through at least two electrode posts located at the bottom of the growth chamber 110 and fixed. In some embodiments, at least two electrode posts are provided with female threads, and at least two conductive electrodes are provided with male threads on the outside, and the at least two electrode posts fix the at least two conductive electrodes through the threads. Then, a part of the raw material is placed at the bottom of the growth chamber 110. At least two first electrode holes of one heating unit in the second heating assembly 1240 are passed through the at least two conductive electrodes, and the heating unit is fixed to the inside of the growth chamber 110 through the second connecting part of the heating unit and the first connecting part inside the growth chamber 110. Then, a part of the raw material is placed on the upper surface of the heating unit. The other heating units in the second heating assembly 1240 are installed accordingly, and the remaining raw material is placed. Then, the growth chamber cover 111 with the seed crystal attached is placed on the top of the growth chamber body 112. Then, at least two conductive electrodes are connected to copper wires, and the copper wires are connected to a power source to complete the installation of the second heating assembly 1240 and the placement of the raw material and the seed crystal. For the specific details of bonding the seed crystal to the growth chamber cover 111, please refer to the relevant descriptions in other parts of this specification (e.g., FIG. 19) and will not be repeated here.

[0229] In some embodiments, at least one conductive ring 1241 is further attached to the upper surface and / or the lower surface of the at least one heating unit of the second heating assembly 1240. In some embodiments, at least two second electrode holes of the at least one conductive ring 1241 are passed through at least two conductive electrodes, and the at least one conductive ring 1241 is fixed inside the growth chamber 110 via a third connecting part of the conductive ring and a fourth connecting part inside the growth chamber 110. In some embodiments, when the at least one conductive ring 1241 is attached, the at least one heating unit of the second heating assembly 1240 may not be fixedly connected to the growth chamber 110. The at least one heating unit of the second heating assembly 1240 may be disposed on the at least one conductive ring 1241.

[0230] In some embodiments, a high temperature resistant carbide coating is applied to the upper and lower surface portions of the at least one heating unit that are not in contact with the at least one conductive ring 1241. Thus, during crystal growth, the at least one heating unit can be prevented from contaminating the gas phase components of the raw material, resulting in the purity of the grown crystal being low and affecting its quality.

[0231] In some embodiments, the fill height of the raw material located at the bottom of the growth chamber 110 refers to the height of the raw material laid at the bottom of the growth chamber 110. In some embodiments, the fill height of the raw material located at the heating unit refers to the height of the raw material laid at the heating unit. In some embodiments, the total fill height of the raw material refers to the sum of the height of the raw material laid at the bottom of the growth chamber 110 and the height of the raw material laid at the heating unit of the second heating assembly.

[0232] In some embodiments, a first heating assembly 1220 (eg, an induction coil) is mounted to (eg, disposed around) the exterior of) the growth chamber 110.

[0233] The filling height of the source material located at the bottom of the growth chamber refers to the distance between the upper surface of the bottom cover of the growth chamber and the upper surface of the source material placed on the bottom cover of the growth chamber. If the filling height of the source material located at the bottom of the growth chamber is too high, the source material will not be heated sufficiently, and the gas phase components generated by the sublimation of the source material will not be able to effectively pass through the flow channel of the heating unit of the growth chamber, resulting in low utilization of the source material. If the filling height of the source material located at the bottom of the growth chamber is too low, the filling amount of the source material will be small, thus affecting the size of the crystal growth. Therefore, it is necessary to control the filling height of the source material located at the bottom of the growth chamber to a preset height range. In some embodiments, the filling height of the source material located at the bottom of the growth chamber 110 may be 0.1 to 0.3 of the total filling height of the source material. In some embodiments, the filling height of the source material located at the bottom of the growth chamber 110 may be 0.12 to 0.28 of the total filling height of the source material. In some embodiments, the filling height of the source material located at the bottom of the growth chamber 110 may be 0.14 to 0.26 of the total filling height of the source material. In some embodiments, the filling height of the raw material located at the bottom of the growth chamber 110 may be 0.16 to 0.24 of the total filling height of the raw material. In some embodiments, the filling height of the raw material located at the bottom of the growth chamber 110 may be 0.18 to 0.22 of the total filling height of the raw material. In some embodiments, the filling height of the raw material located at the bottom of the growth chamber 110 may be 0.19 to 0.21 of the total filling height of the raw material. In some embodiments, the filling height of the raw material located at the bottom of the growth chamber 110 may be 0.2 of the total filling height of the raw material.

[0234] The filling height of the raw material located on the upper surface of the heating unit refers to the distance between the upper surface of the heating unit and the upper surface of the raw material arranged on the upper surface of the heating unit. If the filling height of the raw material located on the upper surface of the heating unit is too high, the raw material located on the upper surface of the heating unit will be heated unevenly, and the gas phase components generated by the heating of the raw material will not be able to effectively pass through the flow channel of the heating unit of the growth chamber, so the utilization rate of the raw material will be low. If the filling height of the raw material located on the upper surface of the heating unit is too low, the filling amount of the raw material will be small, which will affect the size of the crystal growth. Therefore, it is necessary to control the filling height of the raw material located on the upper surface of the heating unit to a preset height range. In some embodiments, the filling height of the raw material located on the heating unit may be 0.2 to 0.4 of the total filling height of the raw material. In some embodiments, the filling height of the raw material located on the heating unit may be 0.22 to 0.38 of the total filling height of the raw material. In some embodiments, the filling height of the raw material located on the heating unit may be 0.24 to 0.36 of the total filling height of the raw material. In some embodiments, the filling height of the raw material located on the heating unit may be 0.26 to 0.34 of the total filling height of the raw material. In some embodiments, the filling height of the raw material located in the heating unit may be 0.28 to 0.32 of the total filling height of the raw material. In some embodiments, the filling height of the raw material located in the heating unit may be 0.29 to 0.31 of the total filling height of the raw material. In some embodiments, the filling height of the raw material located in the heating unit may be 0.3 of the total filling height of the raw material.

[0235] In some embodiments, the source material may not be placed in the top heating unit of the second heating assembly 1240 (the heating unit closest to the growth chamber cover 111). In some embodiments, the source material may be placed in the top heating unit of the second heating assembly 1240. If the distance between the top surface of the source material located in the top heating unit and the growth surface of the seed crystal is too close, a part of the source material will be dispersed on the growth surface of the seed crystal, resulting in crystal defects. If the distance between the top surface of the source material located in the top heating unit and the growth surface of the seed crystal is too far, the transport distance of the gas phase components generated by the sublimation of the source material will be too far, thus affecting the growth rate of the crystal. Therefore, it is necessary to control the distance between the top surface of the source material in the top heating unit and the seed crystal growth surface within a preset distance range. In some embodiments, the distance between the top surface of the source material located in the top heating unit and the seed crystal growth surface may be 30 mm to 50 mm. In some embodiments, the distance between the top surface of the source material located in the top heating unit and the seed crystal growth surface may be 32 mm to 48 mm. In some embodiments, the distance between the top surface of the raw material located at the top heating unit and the seed crystal growth surface may be 34 mm to 46 mm. In some embodiments, the distance between the top surface of the raw material located at the top heating unit and the seed crystal growth surface may be 36 mm to 44 mm. In some embodiments, the distance between the top surface of the raw material located at the top heating unit and the seed crystal growth surface may be 38 mm to 42 mm. In some embodiments, the distance between the top surface of the raw material located at the top heating unit and the seed crystal growth surface may be 39 mm to 41 mm. In some embodiments, the distance between the top surface of the raw material located at the top heating unit and the seed crystal growth surface may be 40 mm.

[0236] Step 2030: The crystal manufacturing equipment is started to grow the crystal.

[0237] In some embodiments, starting the crystal manufacturing apparatus includes, but is not limited to, performing a vacuum treatment on the growth chamber, activating the heating assemblies (e.g., second heating assembly 1240, first heating assembly 1220, and second heating assembly 1240) to perform a heat treatment, and introducing an inert gas into the growth chamber to maintain pressure.

[0238] In some embodiments, when the heating assembly is the second heating assembly 1240 (the crystal manufacturing apparatus shown in FIG. 13), step 2030 includes the following operations: A vacuum process is performed on the growth chamber 110 to reduce the pressure inside the growth chamber 110 to 1×10 -5 Pa~1×10 -3 The pressure is then reduced to 1 Pa. Next, at least two conductive electrodes are energized and the second heating assembly 1240 is operated to heat the growth chamber 110 until the temperature detected by the growth chamber cover 111 is in the range of 900°C to 1200°C. The growth chamber 110 continues to be evacuated and is run at constant power for 20 to 120 minutes. Then, an inert gas (e.g., argon) is introduced into the growth chamber 110 up to atmospheric pressure. The heating power of the second heating assembly 1240 is further increased until the temperature detected by the growth chamber cover 111 is in the range of 1900°C to 2100°C, and is run at constant power for 20 to 80 minutes. Again, the growth chamber 110 continues to be evacuated and an inert gas (e.g., argon) is introduced into the growth chamber 110 at a rate of 2 L / min to 5 L / min until the pressure of the growth chamber 110 is in the range of 5 Torr to 30 Torr.

[0239] In some embodiments, when the heating assemblies are the first heating assembly 1220 and the second heating assembly 1240 (such as the crystal manufacturing apparatus shown in FIG. 15 ), step 2030 includes the following operations: 1. Perform a vacuum process on the growth chamber 110 to reduce the pressure inside the growth chamber 110 to 1×10 -5 Pa~1×10 -3Pa. Next, the first heating assembly 1220 is started to perform a heating process so that the temperature detected by the growth chamber cover 111 is in the range of 900°C to 1200°C. Next, the growth chamber is kept evacuated and is run at a constant power for 20 minutes to 120 minutes. Then, an inert gas (e.g., argon) is introduced into the growth chamber 110 to atmospheric pressure. Next, the first heating assembly 1220 is employed to perform a heating process so that the temperature detected by the growth chamber cover 111 is in the range of 1900°C to 2100°C and is run at a constant power for 20 minutes to 80 minutes. The first heating assembly 1220 continues to operate at a constant power, and the second heating assembly 1240 is started to perform a heating process so that the temperature detected by the growth chamber cover 111 is in the range of 2200°C to 2400°C. Again, the growth chamber 110 continues to be evacuated and an inert gas (eg, argon) is introduced into the growth chamber 110 at a rate of 2 L / min to 5 L / min until the pressure in the growth chamber 110 is in the range of 5 Torr to 30 Torr.

[0240] Step 2040: During crystal growth, based on the temperature inside the growth chamber at the time the crystal is grown obtained by the temperature sensing assembly, control the heating assembly so that the radial temperature difference inside the growth chamber at the time the crystal is grown does not exceed a first preset range of the average temperature inside the growth chamber.

[0241] Relevant descriptions of the temperature sensing assembly, control assembly, temperature distribution, radial temperature difference, first preset range, preset radial temperature difference threshold, and control process of step 2040 are referenced elsewhere in this specification (e.g., Figures 1, 2, 18) and will not be repeated here.

[0242] Step 2050: During the crystal growth, the heating assembly is controlled based on the temperature inside the growth chamber when the crystal is growing, which is obtained by the temperature sensing assembly, so as to maintain a stable axial temperature gradient inside the growth chamber when the crystal is growing.

[0243] Relevant descriptions of the temperature sensing assembly, control assembly, temperature distribution, axial temperature difference, and the control process of step 2050 are referred to elsewhere in this specification (e.g., Figures 1, 2, and 18) and will not be repeated here.

[0244] It should be noted that the above description of the process 2000 is only illustrative and explanatory, and does not limit the scope of the present application. Those skilled in the art can make various modifications and changes to the process 2000 under the guidance of the present application. However, such modifications and changes are still within the scope of the present application. For example, steps 2040 and 2050 may be performed simultaneously. The above manufacturing process is only an example, and the related process parameters may be different in different embodiments, and the order of the above steps is not specific, and in different embodiments, the order of the steps may also be adjusted, and one or more steps may even be omitted. The above examples should not be construed as limiting the scope of protection of the present application.

[0245] In this embodiment, a silicon carbide crystal is produced using silicon carbide powder with a purity of 99.999% or more as a raw material using a crystal production apparatus shown in FIG. 13. The heating assembly is a second heating assembly 1240 including at least one heating unit. In this embodiment, the heating unit is called a heating disk. The production process includes the following steps. S1, a graphite crucible with an inner diameter of 100 mm to 300 mm, a difference between the height and the inner diameter of less than 80 mm, and a bottom thickness of 40 to 100 mm is used as the growth chamber 110.

[0246] A heating disk is selected with a thickness of 5 mm to 10 mm and a diameter of 50 mm to 300 mm. A plurality of flow channels are drilled in each heating disk, and the radius of the flow channels is 0.2 mm to 1 mm. The plurality of flow channels are arranged on a circumference of 10 to 30 flow channels, with the center of the heating disk as the center of the circle. The distance between the centers of adjacent flow channels on the same circumference of the flow channel is 1 mm to 5 mm. The radius of the circumference of two adjacent flow channels is R.n , R n-1 Then, R n -R n-1 =(R2-R1)exp (-(n-1)×0.015) Here, n is an integer equal to or greater than 2, R1 is 1 mm to 20 mm, and R2-R1=1 mm to 10 mm. The radial difference between the circumference of the nth flow channel and the circumference of the (n-1)th flow channel is R n -R n-1 =Displayed as 1mm~5mm.

[0247] Each heating disk is drilled with one first electrode hole A and at least two first electrode holes B (e.g., three first electrode holes B). The first electrode hole A is located at the center of the heating disk, and the at least two first electrode holes B are arranged circumferentially in the edge region of the heating disk with the first electrode hole A as the center. The manufactured heating disk is shown in Figure 16A. The diameter of the first electrode hole A is 10mm-20mm, and the diameter of the first electrode hole B is 2mm-10mm.

[0248] Select a conductive ring with a thickness of 5 mm to 15 mm, an outer diameter of 100 mm to 300 mm, and an inner diameter of 110 mm to 280 mm. Drill a second electrode hole in the conductive ring as shown in Figure 17. The diameter of the second electrode hole in the conductive ring is adapted to the diameter of the first electrode hole B in the heating disk.

[0249] S2, a first conductive electrode 1242 is fixed to the bottom of the crucible through a first electrode post 1244, and a second conductive electrode 1243 is fixed to the bottom of the crucible through a second electrode post 1245. Similarly, a third conductive electrode and a fourth conductive electrode (not shown) are fixed to the bottom of the crucible through third electrode post and fourth electrode post (not shown), respectively.

[0250] The first layer raw material is laid on the bottom of a graphite crucible, and the filling height of the first layer raw material is 2 mm to 10 mm.

[0251] S3, sleeve the conductive ring over the second conductive electrode, the third conductive electrode, and the fourth conductive electrode, and fix the conductive ring above the silicon carbide powder. The heating disk passes through the first conductive electrode 1242, the second conductive electrode 1243, the third conductive electrode, and the fourth conductive electrode, and is placed on the conductive ring. Fix another conductive ring above the heating disk, so that the heating disk is fixed and in good contact with the first conductive electrode 1242, the second conductive electrode 1243, the third conductive electrode, and the fourth conductive electrode. Lay the second layer raw material on the upper surface of the heating disk, and the filling height of the second layer raw material is 5mm to 20mm.

[0252] S4, step S3 is repeated. The filling heights of the third layer raw material, the fourth layer raw material, and the fifth layer raw material are 10 mm to 30 mm, 10 mm to 30 mm, and 3 mm to 25 mm, respectively, and the distance between the upper surface of the fifth layer raw material and the seed crystal growth surface is 20 mm to 40 mm.

[0253] S5, a 6H-SiC seed crystal with a diameter of 100mm~200mm and a thickness of 0.4mm~2mm is glued and fixed to the crucible cover. The seed crystal growth surface direction is deflected 1°~10° to

[0001] and points in the [11-20] direction. The crucible cover with the seed crystal glued to it is sealed and attached to the crucible body, and the crucible is placed in the temperature field.

[0254] S6: Connect the water-cooled copper wires of each conductive electrode, and at the same time, pull the copper wires out of the temperature field and connect them to a DC power source. The first conductive electrode 1242 is connected to the positive electrode of the power source via a copper wire, and the second conductive electrode 1243, the third conductive electrode and the fourth conductive electrode are connected to the negative electrode of the power source via a copper wire.

[0255] S7, the growth chamber 110 is sealed and evacuated to reduce the internal pressure of the growth chamber 110 to 1×10 -5 Pa~1×10 -3The pressure in the growth chamber 110 is reduced to 100 Pa. Next, the power supply for the heating disk is started and the heating disk is allowed to increase in temperature until the temperature of the crucible cover, as measured by the temperature sensing assembly, reaches 900°C to 1400°C. The growth chamber 110 is kept under vacuum and operated at constant power for 20 minutes to 200 minutes. Next, argon is supplied to the growth chamber 110 until atmospheric pressure is reached.

[0256] S8, continue heating until the temperature of the crucible cover measured by the temperature sensing assembly reaches 2000°C to 2300°C. The control assembly adjusts the heating power of the heating disk to maintain the temperature of the crucible cover measured by the temperature sensing assembly at 2000°C to 2300°C and operate stably. Vacuum the growth chamber 110 again and introduce argon gas into the growth chamber 110 at a rate of 2L / min to 5L / min to maintain the pressure of the growth chamber 110 at 5Torr to 30Torr.

[0257] S9: The crystal starts to grow, and the growth time is 40 to 60 hours. After the growth chamber 110 is slowly cooled for 30 to 60 hours, the silicon carbide crystal and the crucible are taken out.

[0258] The silicon carbide crystal obtained had a diameter of 154 mm on the growth surface, and the height of the protrusions on the growth surface was 7.1 mm. The silicon carbide crystal obtained was cut to obtain wafers 3 mm in thickness along the growth direction from the seed crystal surface. The wafers were ground and polished, and observed under an optical microscope, revealing that the density of carbon-containing particles was 4.9 particles / cm. 2 It is.

[0259] Figure 21 is a schematic diagram of an exemplary grown-crystal as shown in some embodiments. As shown in Figure 21, the crystal growth plane is shown as the c-plane and the substrate plane is shown as the d-plane. The height of the protrusion of the growth plane represents the distance H between the highest point of the growth plane and the substrate surface.

[0260] In this embodiment, a silicon carbide crystal is manufactured using silicon carbide powder having a purity of more than 99.999% as a raw material using a crystal manufacturing apparatus shown in FIG. 15. The heating assembly includes a first heating assembly 1220 and a second heating assembly 1240. The first heating assembly 1220 employs an induction coil and is arranged around the outer periphery of the growth chamber 110. The second heating assembly 1240 is arranged inside the growth chamber 110 and includes at least one heating unit. In this embodiment, the heating unit is called a heating disk. The manufacturing process includes the following steps. S1, select a graphite crucible with an inner diameter of 100 to 300 mm, a difference between the height and the inner diameter not exceeding 50% of the inner diameter, and a thickness of the bottom not exceeding 40% of the inner diameter.

[0261] A heating disk having a thickness of 4 mm to 12 mm and a diameter of 50 mm to 300 mm is selected. A plurality of flow channels are drilled in each heating disk, and the flow channel radius is 0.2 mm to 1 mm. The plurality of flow channels are arranged on a circumference of 18 to 30 flow channels, with the center of the heating disk as the center of the circle. The distance between the centers of adjacent flow channels on the circumference of the same flow channel is 1 mm to 2 mm. If the radii of the circumferences of two adjacent flow channels are Rn and Rn-1, respectively, then Rn-Rn-1=(R2-R1)exp((n-1)×0.02+0.009), where n is an integer equal to or greater than 2, R1 is 5 mm to 20 mm, and R2-R1=1 mm to 4 mm. The radius difference between the circumference of the nth flow channel and the circumference of the (n-1)th flow channel is R 25 -R 24 =2mm~6mm.

[0262] Each heating disk is drilled with one first electrode hole A and at least two first electrode holes B (e.g., three first electrode holes B). The first electrode hole A is located at the center of the heating disk, and the three first electrode holes B are arranged circumferentially in the edge region of the heating disk with the first electrode hole A as the center. The manufactured heating disk is shown in Figure 16A. The diameter of the first electrode hole A is 10mm-20mm, and the diameter of the first electrode hole B is 4mm-15mm.

[0263] Select a conductive ring with a thickness of 2 mm to 20 mm, an outer diameter of 100 mm to 300 mm, and an inner diameter of 120 mm to 280 mm. Drill a second electrode hole in the conductive ring as shown in Figure 17. The diameter of the second electrode hole in the conductive ring is adapted to the diameter of the first electrode hole B in the heating disk.

[0264] S2, a first conductive electrode 1242 is fixed to the bottom of the crucible through a first electrode post 1244, and a second conductive electrode 1243 is fixed to the bottom of the crucible through a second electrode post 1245. Similarly, a third conductive electrode and a fourth conductive electrode (not shown) are fixed to the bottom of the crucible through third electrode post and fourth electrode post (not shown), respectively.

[0265] The first layer raw material is laid on the bottom of a graphite crucible, and the filling height of the first layer raw material is 10 mm to 20 mm.

[0266] S3, sleeve the conductive ring over the second conductive electrode, the third conductive electrode, and the fourth conductive electrode, and fix the conductive ring above the silicon carbide powder. The heating disk passes through the first conductive electrode 1242, the second conductive electrode 1243, the third conductive electrode, and the fourth conductive electrode, and is placed on the conductive ring. Fix another conductive ring above the heating disk, so that the heating disk is fixed and in good contact with the first conductive electrode 1242, the second conductive electrode 1243, the third conductive electrode, and the fourth conductive electrode. Lay the second layer raw material on the upper surface of the heating disk, and the filling height of the second layer raw material is 20mm to 30mm.

[0267] S4, step S3 is repeated. The filling heights of the third layer raw material and the fourth layer raw material are 20 mm to 30 mm and 10 mm to 20 mm, respectively, and the distance between the upper surface of the fourth layer raw material and the seed crystal growth surface is 30 mm to 60 mm.

[0268] S5, a 4H-SiC seed crystal with a diameter of 100mm~200mm and a thickness of 0.5mm~2mm is glued and fixed to the crucible cover. The direction of the seed crystal growth surface is deflected 2°~8° to [000-1] and points in the [11-20] direction. The crucible cover with the seed crystal glued to it is sealed and attached to the crucible body, and the crucible is placed in the temperature field.

[0269] S6: Connect the water-cooled copper wires of each conductive electrode, and at the same time, pull the copper wires out of the temperature field and connect them to a DC power source. The first conductive electrode 1242 is connected to the positive electrode of the power source via a copper wire, and the second conductive electrode 1243, the third conductive electrode and the fourth conductive electrode are connected to the negative electrode of the power source via a copper wire.

[0270] S7, the growth chamber 110 is sealed and evacuated to reduce the internal pressure of the growth chamber 110 to 1×10 -5 Pa~1×10 -3 The pressure in the growth chamber 110 is reduced to 100 Pa. Next, the power supply for the induction coil is started and the induction coil is allowed to heat until the temperature of the crucible cover reaches 1000°C to 1500°C as measured by the temperature sensing assembly. The growth chamber 110 is kept under vacuum and operated at constant power for 20 to 120 minutes. Next, argon is supplied to the growth chamber 110 until atmospheric pressure is reached.

[0271] S8, Adopt induction coil to keep heating until the temperature of the crucible cover reaches 1800℃~2000℃ measured by temperature sensing assembly. The control assembly controls the induction coil to keep working at constant power for 20min~80min.

[0272] At the same time, the control assembly controls the second heating assembly 1240 to heat the crucible cover until the temperature measured by the temperature sensing assembly reaches 2200° C. to 2300° C. The growth chamber 110 is again evacuated and argon gas is introduced into the growth chamber 110 at a rate of 2 L / min to 5 L / min to maintain the pressure of the growth chamber 110 at 5 Torr to 30 Torr.

[0273] S9: The crystal starts to grow, and the growth time is 40 to 60 hours. After the growth chamber 110 is slowly cooled for 40 to 60 hours, the silicon carbide crystal and the crucible are taken out.

[0274] The silicon carbide crystal obtained had a diameter of 154 mm on the growth surface, and the height of the protrusions on the growth surface was 7.5 mm. The silicon carbide crystal obtained was cut to obtain wafers 3 mm thick along the growth direction from the seed crystal surface. The wafers were ground and polished, and observed under an optical microscope, revealing that the density of carbon-containing particles was 4.1 particles / cm. 2 It is.

[0275] The above embodiments 1 to 3 can compensate the radial temperature when heating alone with the second heating assembly and when heating together with the first heating assembly and the second heating assembly. In some embodiments, the radial temperature difference and / or the radial temperature gradient can be reduced. The flow channel of the heating unit in the second heating assembly can prevent the upward movement of the graphitized carbon particles of the raw material, so as to reduce defects such as carbon encapsulated micropipes in the crystal and improve the crystal quality. At the same time, when heating with the second heating assembly, the raw material is placed on the heating units of different heights of the second heating assembly and the raw material is heated respectively, so that the raw material is heated more uniformly and sufficiently, so as to not only increase the utilization rate of the raw material, but also reduce the carbonization of the raw material and further improve the quality of the crystal. In some embodiments, the obtained crystal growth surface is flat and has a low degree of protrusion (for example, for a crystal with a diameter of the growth surface of 100 mm to 200 mm, the height of the protrusion of the growth surface is 5 mm to 7.5 mm). The density of the carbon-containing particles in the crystal is low (for example, the density of the carbon-containing particles is 3 pieces / cm 2 ~5 pieces / cm 2 (It is.)

[0276] FIG. 22 is a flow diagram of an exemplary seed crystal manufacturing method as described in some embodiments.

[0277] FIG. 23 is a schematic diagram of an exemplary seed crystal manufacturing process as described in some embodiments.

[0278] In step 2210, a first cut is performed on each of the multiple hexagonal seed crystals to be expanded, to obtain multiple regular hexagonal seed crystals whose cut surfaces are in the same crystal plane family.

[0279] A hexagonal seed crystal refers to a seed crystal having a characteristic symmetry element of 6-fold or 6-fold anti-axis in the direction of the main axis with a high-order axis. In some embodiments, a hexagonal seed crystal to be expanded refers to a hexagonal seed crystal to be systematically expanded. As shown in FIG. 23, a hexagonal seed crystal to be expanded is indicated at 2310. In some embodiments, the diameter of the hexagonal seed crystal to be expanded is less than 8 inches. In some embodiments, the thickness of the hexagonal seed crystal to be expanded is 100 μm to 500 μm. In some embodiments, the hexagonal seed crystal to be expanded is manufactured based on physical vapor transport (PVT), chemical vapor deposition (CVD), or pulling method. In some embodiments, the hexagonal seed crystal may be 4H-SiC or 6H-SiC.

[0280] In some embodiments, the first cut refers to cutting the hexagonal seed crystal to be expanded along a set cutting direction into a seed crystal having a first predetermined size (e.g., 4 inches or 6 inches) and a first predetermined shape (e.g., regular hexagon). In some embodiments, the set cutting direction may be a direction perpendicular to the (0001) plane of the seed crystal. In some embodiments, the cut surface refers to a new surface formed after the seed crystal is first cut. In some embodiments, the crystal plane family refers to all crystal planes in which the arrangement of atoms, ions, or molecules of the crystal is the same. In some embodiments, the hexagonal seed crystal to be expanded is cut perpendicular to the (0001) plane to obtain a plurality of regular hexagonal seed crystals whose cut surfaces are the same crystal plane family. In some embodiments, the crystal plane family is {1120} or {1100}. As shown in FIG. 23, after the first cut, a regular hexagonal seed crystal 2321 with a crystal face family {1100} and / or a regular hexagonal seed crystal 2322 with a crystal face family {11-20} is obtained.

[0281] In some embodiments, before the first cutting is performed on each of the multiple hexagonal seed crystals to be expanded, each of the multiple hexagonal seed crystals to be expanded may be polished (for example, double-sided polishing). The polishing process removes scratches on the surface of the multiple hexagonal seed crystals to be expanded and makes the surface flat, which facilitates subsequent processing. In some embodiments, the (0001) face of the hexagonal seed crystal to be expanded is polished, and then the (0001) face is polished. In some embodiments, the thickness of the polished hexagonal seed crystal to be expanded is 100 μm to 500 μm. In some embodiments, the thickness of the polished hexagonal seed crystal to be expanded is 150 μm to 450 μm. In some embodiments, the thickness of the polished hexagonal seed crystal to be expanded is 200 μm to 400 μm. In some embodiments, the thickness of the polished hexagonal seed crystal to be expanded is in the range of 250 μm to 350 μm. In some embodiments, the polished hexagonal seed crystal to be expanded has a thickness of 280 μm to 320 μm.

[0282] In step 2220, a plurality of regular hexagonal seed crystals are joined.

[0283] The term "closely bonded" refers to bonding the cut surfaces of a plurality of regular hexagonal seed crystals, bonding each cut surface to the maximum extent, and making the bonding gap between the bonded plurality of regular hexagonal seed crystals as small as possible. In some embodiments, bonding a plurality of regular hexagonal seed crystals includes bonding one regular hexagonal seed crystal as a center with six sides of the centered regular hexagonal seed crystal closely to one side of six different regular hexagonal seed crystals. In some embodiments, bonding seven regular hexagonal seed crystals closely includes bonding six regular hexagonal seed crystals closely to the periphery of the centered regular hexagonal seed crystal with one regular hexagonal seed crystal as a center. In some embodiments, the closely bonded plurality of regular hexagonal seed crystals may all have (0001) or (0001) faces facing up. As shown in FIG. 23, a plurality of closely joined regular hexagonal seed crystals are indicated at 2330.

[0284] In step 2230, a second cut is made on the bonded plurality of regular hexagonal seed crystals to obtain hexagonal seed crystals to be grown.

[0285] In some embodiments, the second cutting includes grinding the tightly bonded multiple regular hexagonal hexagonal seed crystals to have a second set size (e.g., 8 inches or 10 inches) and a second set shape (e.g., circular). In some embodiments, the tightly bonded multiple regular hexagonal hexagonal seed crystals are cut into 8 inch or larger bonded circular seed crystals. In some embodiments, the second set size is larger than the first set size. In some embodiments, the grinding process may include off-axis grinding. In some embodiments, the direction of the off-axis grinding is deflected 3°-6° to the

[0001] and points in the

[1120] direction to further improve the crystal quality so that step flow growth is performed during the crystal growth.

[0286] In some embodiments, the second cut performed on the multiple closely joined regular hexagonal hexagonal seed crystals includes making a circular cut with a center point of the central regular hexagonal hexagonal seed crystal as the center of the circle and a preset radius as the radius. In some embodiments, the preset radius is determined by the radius of the target hexagonal seed crystal. In some embodiments, a circular track is drawn on the surface of the multiple closely joined regular hexagonal hexagonal seed crystals with a radius of 100 mm to 130 mm, and then grinding is performed on the circular track to obtain a grown hexagonal seed crystal. As shown in FIG. 23, after making the second cut, the resulting grown hexagonal seed crystal is shown at 2340.

[0287] During crystal growth, a radial temperature gradient exists, so that a large thermal stress is generated on the growth surface of the seed crystal, the growth surface of the seed crystal bulges significantly toward the raw material, and defects such as micropipes and inclusions are generated. In order to prevent the joining gap from generating more defects during growth due to the radial temperature gradient, the surface area of ​​the centered regular hexagonal hexagonal seed crystal is made larger than the surface area of ​​the regular hexagonal hexagonal seed crystals located at other positions. In some embodiments, the larger the ratio of the surface area of ​​the centered regular hexagonal hexagonal seed crystal, the fewer defects in the joining gap. In some embodiments, the surface area of ​​the centered regular hexagonal hexagonal seed crystal is 25% to 55% of the surface area of ​​the target hexagonal seed crystal or the surface area of ​​the hexagonal seed crystal to be grown. In some embodiments, the surface area of ​​the centered regular hexagonal hexagonal seed crystal is 28% to 52% of the surface area of ​​the target hexagonal seed crystal or the surface area of ​​the hexagonal seed crystal to be grown. In some embodiments, the surface area of ​​the centered regular hexagonal seed crystal is 30% to 50% of the surface area of ​​the target hexagonal seed crystal or the surface area of ​​the hexagonal seed crystal to be grown. In some embodiments, the surface area of ​​the centered regular hexagonal seed crystal is 32% to 48% of the surface area of ​​the target hexagonal seed crystal or the surface area of ​​the hexagonal seed crystal to be grown. In some embodiments, the surface area of ​​the centered regular hexagonal seed crystal is 35% to 45% of the surface area of ​​the target hexagonal seed crystal or the surface area of ​​the hexagonal seed crystal to be grown. In some embodiments, the surface area of ​​the centered regular hexagonal seed crystal is 38% to 42% of the surface area of ​​the target hexagonal seed crystal or the surface area of ​​the hexagonal seed crystal to be grown. In some embodiments, the surface area of ​​the centered regular hexagonal seed crystal is 40% of the surface area of ​​the target hexagonal seed crystal or the surface area of ​​the hexagonal seed crystal to be grown.

[0288] In some embodiments, the hexagonal seed crystal grown refers to a bonded seed crystal that is tightly bonded from a plurality of regular hexagonal seed crystals and is equal or approximately equal to the shape and diameter of the target hexagonal seed crystal. In some embodiments, the target hexagonal seed crystal is circular in shape and 8 inches in diameter. The hexagonal seed crystal grown is an 8 inch bonded circular seed crystal that is tightly bonded from seven regular hexagonal seed crystals.

[0289] In step 2240, interstitial growth is performed on the hexagonal seed crystal to be grown under a first set of conditions to obtain an intermediate hexagonal seed crystal.

[0290] In some embodiments, the gap growth refers to growing the joint gaps 2341 of the growing hexagonal seed crystal, thereby growing the tightly joined growing hexagonal seed crystal without gaps or with gaps filled. In some embodiments, the gap growth needs to be performed under a first set of conditions to promote the growth of {1120} or {1100} crystal plane family and suppress the growth of (0001) or (000 1) crystal planes. The growth of the joint gaps of the growing hexagonal seed crystal can be realized. In some embodiments, the first set of conditions refers to the conditions under which the growing hexagonal seed crystal performs gap growth. In some embodiments, the first set of conditions can include, but are not limited to, a first set of temperature, a first set of pressure, a first set of carbon to silicon ratio, a set of gap growth time, etc.

[0291] Each growth condition in the first set of conditions is mutually exclusive, and one or some of the growth conditions can control the other growth conditions. In some embodiments, under different first set temperatures and first set carbon to silicon ratios, the growth rates of the {1120} or {1100} crystal plane family are different. In some embodiments, when the first set temperature is in the range of 1600°C to 1700°C, controlling the first set carbon to silicon ratio in the range of 1.1 to 1.6 increases the growth rate of the {1120} or {1100} crystal plane family, promoting the growth of gaps.

[0292] If the gap growth temperature is too high, the gap growth rate will be slowed down, and at the same time, the grown hexagonal seed crystal will grow epitaxially to form a part of the thin film, so that the intermediate of the hexagonal seed crystal and the internal defects of the target hexagonal seed crystal will increase. Therefore, the grown crystal will have poor quality. If the gap growth temperature is too low, the source gas required for gap growth will not react sufficiently, the gap growth rate will be slowed down, and the gaps will not be filled, so that the quality of the intermediate of the hexagonal seed crystal will be reduced. Therefore, it is necessary to control the first set temperature within a set temperature range. In some embodiments, the first set temperature may be 1000°C to 2000°C. In some embodiments, the first set temperature may be 1050°C to 1950°C. In some embodiments, the first set temperature may be 1100°C to 1900°C. In some embodiments, the first set temperature may be 1150°C to 1850°C. In some embodiments, the first set temperature may be 1200°C to 1800°C. In some embodiments, the first set temperature may be 1300°C to 1750°C. In some embodiments, the first set temperature may be 1400°C to 1700°C. In some embodiments, the first set temperature may be 1420°C to 1680°C. In some embodiments, the first set temperature may be 1440°C to 1660°C. In some embodiments, the first set temperature may be 1460°C to 1640°C. In some embodiments, the first set temperature may be 1480°C to 1620°C. In some embodiments, the first set temperature may be 1500°C to 1600°C. In some embodiments, the first set temperature may be 1520°C to 1580°C. In some embodiments, the first set temperature may be 1540°C to 1560°C.

[0293] If the first set pressure is too high, the mean free path of the source gas required for gap growth is reduced, the joining gap cannot be filled, and even some gaps remain, resulting in a decrease in the quality of the intermediate of the hexagonal seed crystal. If the first set pressure is too low, the gap growth rate is slowed down, and the surface of the hexagonal seed crystal being grown is partially etched, further increasing the defects of the intermediate of the hexagonal seed crystal--and decreasing the quality of the intermediate of the hexagonal seed crystal. Therefore, it is necessary to control the first set pressure within a set pressure range. In some embodiments, the first set pressure may be 10 Pa to 1000 Pa. In some embodiments, the first set pressure may be 15 Pa to 800 Pa. In some embodiments, the first set pressure may be 20 Pa to 600 Pa. In some embodiments, the first set pressure may be 25 Pa to 400 Pa. In some embodiments, the first set pressure may be 30 Pa to 200 Pa. In some embodiments, the first set pressure may be 40 Pa to 170 Pa. In some embodiments, the first set pressure may be 50 Pa to 150 Pa. In some embodiments, the first set pressure may be 60 Pa to 120 Pa. In some embodiments, the first set pressure may be 70 Pa to 100 Pa. In some embodiments, the first set pressure may be 80 Pa to 90 Pa.

[0294] In some embodiments, the ratio of carbon to silicon in the first set is determined by a first set source gas whose flow rate is set. In some embodiments, the first set source gas includes components necessary for interstitial growth. In some embodiments, the first set source gas can include, but is not limited to, silane and a carbon source (e.g., an alkane).

[0295] If the first set ratio of carbon to silicon is too high or too low, the source gas cannot react sufficiently. Therefore, it is necessary to control the first set ratio of carbon to silicon to a preset range. In some embodiments, the first set ratio of carbon to silicon may be 1.0 to 10.0. In some embodiments, the first set ratio of carbon to silicon may be 1.0 to 9.0. In some embodiments, the first set ratio of carbon to silicon may be 1.0 to 8.0. In some embodiments, the first set ratio of carbon to silicon may be 1.0 to 7.0. In some embodiments, the first set ratio of carbon to silicon may be 1.0 to 6.0. In some embodiments, the first set ratio of carbon to silicon may be 1.0 to 5.0. In some embodiments, the first set ratio of carbon to silicon may be 1.0 to 4.0. In some embodiments, the first set ratio of carbon to silicon may be 1.0 to 3.0. In some embodiments, the first set ratio of carbon to silicon may be 1.2 to 2.8. In some embodiments, the first set ratio of carbon to silicon may be between 1.4 and 2.6. In some embodiments, the first set ratio of carbon to silicon may be between 1.6 and 2.4. In some embodiments, the first set ratio of carbon to silicon may be between 1.8 and 2.2. In some embodiments, the first set ratio of carbon to silicon may be between 1.9 and 2.0.

[0296] In some embodiments, the first set source gas can include, but is not limited to, SiH4, C3H8, or H2, etc.

[0297] In some embodiments, the set flow rate of SiH4 may be 50 to 300 mL / min. In some embodiments, the set flow rate of SiH4 may be 60 to 280 mL / min. In some embodiments, the set flow rate of SiH4 may be 70 to 260 mL / min. In some embodiments, the set flow rate of SiH4 may be 80 to 240 mL / min. In some embodiments, the set flow rate of SiH4 may be 90 to 220 mL / min. In some embodiments, the set flow rate of SiH4 may be 100 to 200 mL / min. In some embodiments, the set flow rate of SiH4 may be 110 to 190 mL / min. In some embodiments, the set flow rate of SiH4 may be 120 to 180 mL / min. In some embodiments, the set flow rate of SiH4 may be 130 to 170 mL / min. In some embodiments, the set flow rate of SiH4 may be 140 to 160 mL / min. In some embodiments, the set flow rate of SiH4 may be 150 mL / min.

[0298] In some embodiments, the set flow rate of C3H8 may be 10 to 200 mL / min. In some embodiments, the set flow rate of C3H8 may be 20 to 180 mL / min. In some embodiments, the set flow rate of C3H8 may be 30 to 160 mL / min. In some embodiments, the set flow rate of C3H8 may be 40 to 140 mL / min. In some embodiments, the set flow rate of C3H8 may be 50 to 120 mL / min. In some embodiments, the set flow rate of C3H8 may be 60 to 100 mL / min. In some embodiments, the set flow rate of C3H8 may be 70 to 90 mL / min. In some embodiments, the set flow rate of C3H8 may be 75 to 85 mL / min.

[0299] In some embodiments, the set flow rate of H2 may be 10 to 200 mL / min. In some embodiments, the set flow rate of H2 may be 20 to 180 mL / min. In some embodiments, the set flow rate of H2 may be 30 to 160 mL / min. In some embodiments, the set flow rate of H2 may be 40 to 140 mL / min. In some embodiments, the set flow rate of H2 may be 50 to 120 mL / min. In some embodiments, the set flow rate of H2 may be 60 to 100 mL / min. In some embodiments, the set flow rate of H2 may be 70 to 90 mL / min. In some embodiments, the set flow rate of H2 may be 75 to 85 mL / min.

[0300] In some embodiments, the gap growth time is determined according to the gap size (e.g., gap depth) and gap growth rate of the hexagonal seed crystal to be grown. If the gap growth time is too long, the hexagonal seed crystal to be grown epitaxially to form a part of the thin film, so that the internal defects of the intermediate of the hexagonal seed crystal and the target hexagonal seed crystal increase. Therefore, the grown crystal has poor quality. If the gap growth time is too short, the joining gap cannot be filled, and thus some gaps remain, so that the quality of the intermediate of the hexagonal seed crystal is further reduced. Therefore, it is necessary to control the gap growth time to a preset time range. In some embodiments, the set gap growth time may be 3 hours to 7 hours. In some embodiments, the set gap growth time may be 3.5 hours to 6.5 hours. In some embodiments, the set gap growth time may be 4 hours to 6 hours. In some embodiments, the set gap growth time may be 4.5h to 5.5h. In some embodiments, the set gap growth time may be 5 hours.

[0301] In some embodiments, Chemical Vapor Deposition (CVD) is utilized to perform the interstitial growth. Accordingly, the interstitial growth is performed in a Chemical Vapor Deposition (CVD) apparatus.

[0302] The hexagonal seed intermediate refers to the seed after the junction gap of the hexagonal seed to be grown has been grown.

[0303] In step 2250, the hexagonal seed intermediate is epitaxially grown under a second set of conditions to obtain a target hexagonal seed.

[0304] In some embodiments, epitaxial growth refers to growing a hexagonal seed intermediate in a direction perpendicular to the (0001) or (000-1) crystal plane to grow the hexagonal seed intermediate into a target hexagonal seed crystal having a set thickness. In some embodiments, the set thickness may be in the range of 400 μm to 700 μm. In some embodiments, the set thickness may be in the range of 450 μm to 650 μm. In some embodiments, the set thickness may be in the range of 500 μm to 600 μm. In some embodiments, the set thickness may be in the range of 540 μm to 560 μm.

[0305] In some embodiments, epitaxial growth should be performed under a second set of conditions to promote the growth of (0001) or (0001) crystal planes and suppress the growth of {1120} or {1100} crystal planes. In some embodiments, the second set of conditions refers to conditions under which the intermediate hexagonal seed crystals are epitaxially grown. In some embodiments, the second set of conditions can include, but are not limited to, a second set of temperature, a second set of pressure, a second set of carbon to silicon ratio, a set epitaxial growth time, etc.

[0306] If the epitaxial growth temperature is too high, the epitaxial growth rate will be slowed down, and at the same time, the outer surface of the intermediate hexagonal seed crystal will be partially etched, the target hexagonal seed crystal will have many defects, and the quality of the grown crystal will be poor. If the epitaxial growth temperature is too low, the source gas required for epitaxial growth will not react sufficiently, the epitaxial growth rate will be slowed down, and the quality of the target hexagonal seed crystal will be reduced. Therefore, it is necessary to control the second set temperature within the set temperature range. In some embodiments, the second set temperature may be 1100°C to 2000°C. In some embodiments, the second set temperature may be 1200°C to 1900°C. In some embodiments, the second set temperature may be 1300°C to 1800°C. In some embodiments, the second set temperature may be 1400°C to 1700°C. In some embodiments, the second set temperature may be 1420°C to 1680°C. In some embodiments, the second set temperature may be 1440°C to 1660°C. In some embodiments, the second set temperature may be between 1460°C and 1640°C. In some embodiments, the second set temperature may be between 1480°C and 1620°C. In some embodiments, the second set temperature may be between 1500°C and 1600°C. In some embodiments, the second set temperature may be between 1520°C and 1580°C. In some embodiments, the second set temperature may be between 1540°C and 1560°C.

[0307] If the second set pressure is too high, the mean free path of the source gas required for epitaxial growth is reduced, and the epitaxial growth rate is slowed. If the second set pressure is too low, the outer surface of the intermediate body of the hexagonal seed crystal is partially etched, and the target hexagonal seed crystal has many defects. Therefore, it is necessary to control the second set pressure within the set pressure range. In some embodiments, the second set pressure may be 10 Pa to 1000 Pa. In some embodiments, the second set pressure may be 15 Pa to 800 Pa. In some embodiments, the second set pressure may be 20 Pa to 600 Pa. In some embodiments, the second set pressure may be 25 Pa to 400 Pa. In some embodiments, the second set pressure may be 30 Pa to 200 Pa. In some embodiments, the second set pressure may be 40 Pa to 170 Pa. In some embodiments, the second set pressure may be 50 Pa to 150 Pa. In some embodiments, the second set pressure may be 60 Pa to 120 Pa. In some embodiments, the second set pressure may be 70 Pa to 100 Pa. In some embodiments, the second set pressure may be 80 Pa to 90 Pa.

[0308] In some embodiments, the proportion of carbon and silicon in the second set is determined by the second set of source gases whose flow rates are set. In some embodiments, the second set of source gases includes components required for epitaxial growth. In some embodiments, the second set of source gases can include, but are not limited to, silane and a carbon source (e.g., an alkane). In some embodiments, the compositions of the second set of source gases and the first set of source gases can be the same or different. In some embodiments, the first set of source gases can include, but are not limited to, SiH4, C3H8, or H2, etc.

[0309] If the ratio of carbon to silicon in the second setting is too high or too low, the source gases cannot react sufficiently to perform epitaxial growth, so the ratio of carbon to silicon in the second setting needs to be controlled within a preset range.

[0310] In some embodiments, the second set ratio between carbon and silicon may be 0.1 to 2. In some embodiments, the second set ratio between carbon and silicon may be 0.3 to 1.7. In some embodiments, the second set ratio between carbon and silicon may be 0.5 to 1.5. In some embodiments, the second set ratio between carbon and silicon may be 0.8 to 1.2. In some embodiments, the second set ratio between carbon and silicon may be 0.9 to 1.1. In some embodiments, the second set ratio between carbon and silicon may be 0.92 to 1.08. In some embodiments, the second set ratio between carbon and silicon may be 0.95 to 1.05. In some embodiments, the second set ratio between carbon and silicon may be 0.96 to 1.04. In some embodiments, the second set ratio between carbon and silicon may be 0.97 to 1.03. In some embodiments, the second set ratio between carbon and silicon may be 0.98 to 1.02. In some embodiments, the second set carbon to silicon ratio may be between 0.99 and 1.01 In some embodiments, the second set carbon to silicon ratio may be 1.

[0311] The epitaxial growth time is determined by the thickness of the target hexagonal seed crystal to be deposited. In some embodiments, the epitaxial growth is performed in a chemical vapor deposition (CVD) apparatus.

[0312] In some embodiments, the target hexagonal seed crystal refers to a seed crystal after the diameter expansion process is performed on the hexagonal seed crystal to be expanded. In some embodiments, the diameter of the target hexagonal seed crystal is more than twice the diameter of the hexagonal seed crystal to be expanded. In some embodiments, the diameter of the target hexagonal seed crystal is more than 2.5 times the diameter of the hexagonal seed crystal to be expanded. In some embodiments, the diameter of the target hexagonal seed crystal is more than 3 times the diameter of the hexagonal seed crystal to be expanded. In some embodiments, the diameter of the target hexagonal seed crystal is more than 8 inches. In some embodiments, the diameter of the target hexagonal seed crystal is 8 inches, 9 inches, 10 inches, etc. In some embodiments, the target hexagonal seed crystal is used as the hexagonal seed crystal to be expanded, and the operations of process 2200 are repeated to grow a hexagonal seed crystal having a larger diameter.

[0313] In some embodiments, the epitaxial growth includes growing a crystal layer having a size and the same crystal orientation as the seed crystal. The seed crystal has various defects, which are usually inherited during epitaxial growth, so the seed crystal needs to be in-situ etched to remove these defects. In some embodiments, the grown hexagonal seed crystal may be in-situ etched under a third set of conditions to improve the flatness of the surface of the grown hexagonal seed crystal before the gap growth is performed. In some embodiments, the in-situ etching is performed in a chemical vapor deposition (CVD) device.

[0314] In some embodiments, the CVD apparatus needs to be pre-treated before performing the in-situ etching. The pre-treatment includes, but is not limited to, vacuum treatment and thermal treatment. In some embodiments, the vacuum treatment is performed by increasing the pressure of the CVD apparatus to 1000 to remove most of the air inside the CVD apparatus. -5In some embodiments, the heat treatment includes heating the CVD apparatus to 400° C. to 800° C. In some embodiments, the heat treatment further includes maintaining the CVD apparatus at a temperature in the range of 400° C. to 800° C. for about 1 hour.

[0315] In some embodiments, the third set conditions may include, but are not limited to, introducing a set gas at a set flow rate, a third set temperature, a third set pressure, and a set etching time. In some embodiments, the set gas refers to a gas that can react with carbon. In some embodiments, the set gas is hydrogen gas. The hydrogen gas reacts with the carbon in the hexagonal silicon carbide seed crystals being grown to produce a hydrocarbon gas that performs the in-situ etching.

[0316] If the flow rate is set too high, the introduced setting gas (e.g., hydrogen gas) will be excessive, and the setting gas will be wasted. Also, if the flow rate is set too high, the temperature field will become unstable, affecting the etching uniformity of the hexagonal silicon carbide seed crystals being grown. If the flow rate is set too low, the etching efficiency will decrease. Therefore, it is necessary to control the set flow rate within the set flow rate range. In some embodiments, the set flow rate may be 5 L / min to 200 L / min. In some embodiments, the set flow rate may be 10 L / min to 150 L / min. In some embodiments, the set flow rate may be 15 L / min to 100 L / min. In some embodiments, the set flow rate may be 20 L / min to 80 L / min. In some embodiments, the set flow rate may be 25 L / min to 75 L / min. In some embodiments, the set flow rate may be 30 L / min to 70 L / min. In some embodiments, the set flow rate may be 35 L / min to 65 L / min. In some embodiments, the set flow rate may be between 40 L / min and 60 L / min. In some embodiments, the set flow rate may be between 44 L / min and 46 L / min.

[0317] If the third set temperature is too high, the etching efficiency will be too fast or uncontrollable, which will affect the quality of the hexagonal seed crystal grown. If the third set temperature is too low, etching will not be possible because the set gas and the third set temperature are too high to react. Therefore, it is necessary to control the third set temperature within the set temperature range. In some embodiments, the third set temperature may be 1200°C to 1500°C. In some embodiments, the third set temperature may be 1250°C to 1450°C. In some embodiments, the third set temperature may be 1300°C to 1400°C. In some embodiments, the third set temperature may be 1340°C to 1360°C.

[0318] If the third set pressure is too high, the gas phase material generated by the reaction between the set gas and the hexagonal seed crystal being grown cannot be effectively removed immediately, so that the quality of the etched hexagonal seed crystal being grown is reduced. If the third set pressure is too low, the etching efficiency becomes too fast or uncontrollable, so that it affects the quality of the hexagonal seed crystal being grown. Therefore, it is necessary to control the third set pressure within a set pressure range. In some embodiments, the third set pressure may be 1 kPa to 12 kPa. In some embodiments, the third set pressure may be 2 kPa to 11 kPa. In some embodiments, the third set pressure may be 3 kPa to 10 kPa. In some embodiments, the third set pressure may be 4 kPa to 9 kPa. In some embodiments, the third set pressure may be 5 kPa to 8 kPa. In some embodiments, the third set pressure may be 6 kPa to 7 kPa.

[0319] The set etching time is determined according to the flatness and surface morphology of the surface of the hexagonal seed crystal to be grown. If the set etching time is too long, the uniformity of the etched hexagonal seed crystal to be grown cannot be guaranteed. If the set etching time is too short, the surface of the hexagonal seed crystal to be grown will have many defects, which will affect the quality. Therefore, it is necessary to control the set etching time within a set time range. In some embodiments, the set etching time may be 10 min to 30 min. In some embodiments, the set etching time may be 12 min to 28 min. In some embodiments, the set etching time may be 15 min to 25 min. In some embodiments, the set etching time may be in the range of 18 min to 22 min. In some embodiments, the set etching time may be 19 min to 20 min.

[0320] In some embodiments, the inherent properties of the hexagonal seed crystal allow it to be cut into a regular hexagonal seed crystal with all six sides being {1120} or {1100} crystal face family. Crystallographically, the physicochemical properties of the six sides with {1120} or {1100} crystal face family are the same, so the quality of interstitial growth between the same crystal face family is higher or there are fewer dislocations. Therefore, the obtained target hexagonal seed crystal is of better quality.

[0321] It should be noted that the above description of the process 2200 is only illustrative and explanatory, and does not limit the scope of the present application. Those skilled in the art can make various modifications and changes to the process 2200 under the guidance of the present application. However, such modifications and changes are still within the scope of the present application. The above manufacturing process is only an example, and the relevant process parameters may be different in different embodiments, and the order of the above steps is not specific, and in different embodiments, the order of the steps may also be adjusted, or even one or more steps may be omitted. The above examples should not be construed as limiting the scope of protection of the present application.

[0322] This embodiment provides a method for producing a seed crystal. The steps are as follows: S1, produce seven 6H-SiC with a diameter of 110 mm to 160 mm, and polish the seven 6H-SiC respectively to flatten the surface of the 6H-SiC. For example, first polish the (0001) plane of the 6H-SiC, and then polish the (0001) plane. The thickness of the polished 6H-SiC is about 100 μm to 150 μm.

[0323] S2: A first cut is made on the polished 6H-SiC perpendicular to the (0001) plane to obtain a regular hexagonal 6H-SiC whose cut surface is in the {1100} crystal plane family, which is a regular hexagonal seed crystal 2321 in the {1100} crystal plane family, as shown in FIG. 23 .

[0324] S3: Seven regular hexagonal 6H-SiC are tightly bonded together. With one regular hexagonal 6H-SiC at the center, six regular hexagonal 6H-SiC are tightly bonded to the periphery of the central regular hexagonal 6H-SiC, resulting in a plurality of regular hexagonal seed crystals 2330 after tight bonding, as shown in Fig. 23. With the (0001) faces of the seven regular hexagonal 6H-SiC all facing upwards, the tightly bonded seven regular hexagonal 6H-SiC are firmly attached to a platform (such as a stainless steel disk) with a horizontal surface using an adhesive (e.g., paraffin) so that the bonding surfaces fit together tightly.

[0325] S4, a second cut is made on the seven regular hexagonal 6H-SiC pieces tightly bonded and bonded to the platform. A circular track is drawn on the surface of the seven regular hexagonal 6H-SiC pieces tightly bonded and bonded to the platform, with the center point of the centrally arranged regular hexagonal 6H-SiC as the center and a radius of 100 mm to 120 mm. Off-axis grinding is performed on the circular track, and the off-axis grinding direction is deflected 3.8° to

[0001] and points to the

[1120] direction, to obtain a circular 6H-SiC. As shown in FIG. 23, after the second cut, the grown hexagonal seed crystal 2340 is obtained.

[0326] S5, remove the circular 6H-SiC that is attached to the platform. The circular 6H-SiC is placed in an acetone solution and ultrasonically cleaned, then washed with deionized water to remove paraffin and particulate matter from the circular 6H-SiC. Next, the outer circumference of the circular 6H-SiC is ground and finely polished to remove scratches on the surface of the circular 6H-SiC.

[0327] The circular 6H-SiC after grinding and fine polishing is placed in an isopropanol solution and ultrasonically cleaned at 30°C to 100°C for 10 to 100 minutes. Next, ultrasonic cleaning is performed using deionized water for 5 to 30 minutes to further remove impurities and organic matter on the surface of the circular 6H-SiC, resulting in a clean circular 6H-SiC. The adhesive (e.g., paraffin) of the circular 6H-SiC bonded to the platform is washed away, so that the clean circular 6H-SiC is essentially the seven small circular seeds in the hexagonal seed crystal 2340 to be grown, as shown in FIG. 23.

[0328] According to the grinding sequence of S6 and S4, the clean circular 6H-SiC is arranged and glued to a graphite tray with a flat surface using adhesive (such as sucrose). The tray with the circular 6H-SiC glued to it is placed in a CVD device. First, the CVD device is heated to 1×10 -5 Pa~1×10 -3 After evacuating to 10 Pa, the CVD apparatus is slowly heated to 600°C-1000°C at a heating rate of 1°C / min-20°C / min and kept at the same temperature for 0.5-2 hours to remove the air inside the CVD apparatus. Next, the CVD apparatus is heated to 1200°C-1600°C, hydrogen gas is introduced at a rate of 20L / min-80L / min, the pressure inside the CVD apparatus is kept at 2000Pa-10000Pa, and the temperature is kept at the same temperature for 10-30 minutes, and the circular 6H-SiC is in-situ etched to remove scratches on the surface of the circular 6H-SiC and improve the surface flatness and surface appearance of the circular 6H-SiC.

[0329] S7, perform interstitial growth of {1 100} crystal plane family on circular 6H-SiC. Hydrogen gas is introduced into the CVD apparatus until the pressure of the CVD apparatus becomes atmospheric pressure, and the CVD apparatus is heated to 1500℃-2000℃. 100-200mL / min of SiH4, 40-100mL / min of C3H8, and 40-100L / min of H2 are introduced into the CVD apparatus, so that the ratio of carbon to silicon inside the CVD apparatus is maintained at 1.0-5.0. After that, the pressure inside the CVD apparatus is reduced to 30Pa-200Pa, and interstitial growth of {1100} crystal plane family is performed. The interstitial growth time is 2 hours-5 hours.

[0330] The circular 6H-SiC in S8 and S7 is epitaxially grown. The temperature of the CVD apparatus is adjusted to 1500°C to 1700°C, and 100 to 300mL / min of SiH4, 40 to 100mL / min of C3H8, and 40 to 100L / min of H2 are introduced into the CVD apparatus, and the ratio of carbon to silicon is controlled to 0.5 to 1.5 to perform epitaxial growth of the (0001) plane. When the epitaxial growth reaches a set thickness of 500μm to 900μm, helium gas is introduced into the CVD apparatus until the pressure inside the CVD apparatus reaches atmospheric pressure, and the epitaxial growth is stopped. Next, after 60 to 120 hours, it is gradually cooled to room temperature, and then removed to obtain a seed crystal of 6H-SiC with a diameter exceeding 250mm.

[0331] This embodiment provides another method for manufacturing a seed crystal. This method includes the following steps: S1, manufacture seven 6H-SiC crystals with diameters of 110 mm to 160 mm, and polish the seven 6H-SiC crystals respectively to flatten the surfaces of the 6H-SiC crystals. For example, first polish the (0001) plane of the 6H-SiC crystals, and then polish the (0001) plane of the 6H-SiC crystals. The thickness of the polished 6H-SiC crystals is about 100 μm to 150 μm.

[0332] S2: A first cut is made on the polished 6H-SiC perpendicular to the (0001) plane to obtain a regular hexagonal 6H-SiC whose cut surface is in the {1120} crystal plane family, which is a regular hexagonal seed crystal 2322 in the {1120} crystal plane family, as shown in FIG. 23 .

[0333] S3: Seven regular hexagonal 6H-SiC are tightly bonded together. With one regular hexagonal 6H-SiC at the center, six regular hexagonal 6H-SiC are tightly bonded to the periphery of the central regular hexagonal 6H-SiC, resulting in a plurality of regular hexagonal seed crystals 2330 after tight bonding, as shown in Fig. 23. The (0001) faces of the seven regular hexagonal 6H-SiC are all facing upwards, and the tightly bonded seven regular hexagonal 6H-SiC are attached to a platform (such as a stainless steel disk) with a flat surface using an adhesive (e.g., paraffin) so that the bonding surfaces fit together perfectly.

[0334] S4, a second cut is made on the seven regular hexagonal 6H-SiC pieces tightly bonded and bonded to the platform. A circular track is drawn on the surface of the seven regular hexagonal 6H-SiC pieces tightly bonded and bonded to the platform, with the center point of the centrally placed regular hexagonal 6H-SiC as the center and a radius of 100 mm to 130 mm. Off-axis grinding is performed on the circular track, and the off-axis grinding direction is deflected 2° to 8° to

[0001] and points to the

[1120] direction, to obtain a circular 6H-SiC. As shown in FIG. 23, after the second cut, the grown hexagonal seed crystal 2340 is obtained.

[0335] S5, remove the circular 6H-SiC that is attached to the platform. The circular 6H-SiC is placed in an acetone solution and ultrasonically cleaned, then washed with deionized water to remove paraffin and particulate matter from the circular 6H-SiC. Next, the outer circumference of the circular 6H-SiC is ground and finely polished to remove scratches on the surface of the circular 6H-SiC.

[0336] The circular 6H-SiC after grinding and fine polishing is placed in an isopropanol solution and ultrasonically cleaned at 30°C to 100°C for 10 to 70 minutes. Next, ultrasonic cleaning is performed using deionized water for 5 to 20 minutes to further remove impurities and organic matter on the surface of the circular 6H-SiC, resulting in a clean circular 6H-SiC. The adhesive (e.g., paraffin) of the circular 6H-SiC bonded to the platform is washed away, so that the clean circular 6H-SiC is essentially the seven small circular seeds in the hexagonal seed crystal 2340 to be grown, as shown in FIG. 23.

[0337] According to the grinding sequence of S6 and S4, the clean circular 6H-SiC is arranged and glued to a graphite tray with a flat surface using adhesive (such as sucrose). The tray with the circular 6H-SiC glued to it is placed in a CVD device. First, the CVD device is heated to 1×10 -5 Pa~1×10 -3 After evacuating to 10 Pa, the CVD apparatus is slowly heated to 600°C-1000°C at a heating rate of 1°C / min-20°C / min and kept at the same temperature for 0.5-3 hours ...

Claims

1. a growth chamber for growing the crystal; a temperature control system for heating the growth chamber such that a radial temperature difference within the growth chamber during crystal growth does not exceed a first preset range of an average temperature within the growth chamber; The temperature control system includes a heating assembly, the heating assembly including a heating unit located within the at least one growth chamber, the heating unit located within the at least one growth chamber including at least one flow channel; The at least one flow channel is opened on an upper surface of a heating unit located inside the at least one growth chamber, and when a crystal is grown, a raw material is placed on the upper surface of the heating unit located inside the at least one growth chamber, and the total opening area of ​​the at least one flow channel on the upper surface of the heating unit located inside one growth chamber is 20% to 60% of the area of ​​one heating unit; The temperature control system includes a temperature sensing assembly and a control assembly for controlling at least one parameter of at least one of the heating units based on information of the temperature sensing assembly so that when a crystal is grown, a radial temperature difference inside the growth chamber does not exceed a first preset range of an average temperature inside the growth chamber; a heating unit located inside the at least one growth chamber, the heating unit including at least two conductive electrodes and at least one conductive ring, the at least one conductive ring having at least two electrode holes; A crystal manufacturing apparatus characterized in that at least a portion of the at least two conductive electrodes pass through the at least two electrode holes and are connected to the at least one conductive ring, and the at least one conductive ring is located on an upper and / or lower surface of a heating unit located inside the at least one growth chamber.

2. 2. The crystal manufacturing apparatus of claim 1, wherein the temperature control system prevents a radial temperature difference inside the growth chamber during crystal growth from exceeding a first preset range of an average temperature inside the growth chamber, at least during a crystal growth subinterval, the crystal growth subinterval being a period that is the first 80% of the crystal growth interval.

3. 2. The crystal manufacturing apparatus of claim 1, wherein the temperature control system prevents a radial temperature gradient inside the growth chamber during crystal growth from exceeding a preset radial temperature gradient threshold.

4. 2. The apparatus of claim 1, wherein the temperature control system stabilizes an axial temperature gradient inside the growth chamber as the crystal grows.

5. The crystal manufacturing apparatus of claim 1, characterized in that the heating unit located inside the growth chamber includes at least two or more flow channels, and the opening density of at least one of the flow channels in the central region of the upper surface of at least one of the heating units located inside the growth chamber is smaller than the opening density of at least one of the flow channels in the edge region of at least one of the heating units.

6. 2. The crystal manufacturing apparatus of claim 1, wherein the heating assembly further comprises the heating unit located within at least one growth chamber.

7. The crystal manufacturing apparatus of claim 6, characterized in that the heating unit located inside the growth chamber includes at least two or more flow channels, and the opening density of at least one of the flow channels in the central region of the upper surface of the heating unit located inside the at least one growth chamber is greater than the opening density of at least one of the flow channels in the edge region of the heating unit located inside the at least one growth chamber.

8. 7. The crystal manufacturing apparatus according to claim 6, wherein the cross-sectional area of ​​one of the flow channels is 1.5 times or less the particle size of the raw material.

9. The crystal manufacturing apparatus of claim 8, characterized in that the heating unit located outside the at least one growth chamber includes at least three first heating units, the at least three first heating units being arranged surrounding the outside of the growth chamber and corresponding respectively to a crystallization region inside the growth chamber, a source zone inside the growth chamber, and a vapor phase transport zone between the crystallization region and the source zone.

10. The heating assembly includes at least two heating units located external to the growth chamber; A portion of at least one of the heating units located outside the at least two growth chambers is disposed around an outer periphery of the growth chamber; The crystal manufacturing apparatus according to claim 1 , characterized in that at least one of the heating units located outside the at least two growth chambers is arranged on an upper surface and / or a lower surface outside the growth chamber.

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