CN115573041A

CN115573041A - Seed crystal bonding method and equipment

Info

Publication number: CN115573041A
Application number: CN202211103041.4A
Authority: CN
Inventors: 王宇; 官伟明
Original assignee: Meishan Boya New Material Co ltd
Current assignee: Meishan Boya New Material Co ltd
Priority date: 2022-09-09
Filing date: 2022-09-09
Publication date: 2023-01-06

Abstract

The embodiment of the specification provides a seed crystal bonding method and equipment, wherein the method comprises the following steps: coating the adhesive on the surface of the seed crystal support; placing the seed crystal holder coated with the adhesive in a bonding device; performing air extraction treatment on the bonding equipment; and adhering the seed crystal to the seed crystal support, wherein in the adhering process, air suction treatment and heating treatment are simultaneously carried out.

Description

Seed crystal bonding method and equipment

Technical Field

The specification relates to the field of crystal growth, in particular to a seed crystal bonding method and equipment.

Background

Semiconductor crystals (e.g., silicon carbide single crystals) have excellent physicochemical properties and are therefore important materials for the manufacture of high frequency and high power devices. Before the crystal is grown, the seed crystal and the seed crystal support or the crucible cover are generally required to be bonded through an adhesive (for example, glue). In the process of coating the adhesive on the seed crystal or the seed crystal holder, bubbles are easily included in the adhesive. And in the process of curing the adhesive, if the adhesive on the edge of the seed crystal is cured first, the gas discharge channel in the middle area is blocked, and bubbles appear in the middle area. In the process of crystal growth, bubbles at the bonding position of seed crystals easily cause the generation of plane hexagonal defects and the like on the crystals, and the quality of the crystals is influenced.

Therefore, it is necessary to provide a seed crystal bonding method and apparatus to improve the seed crystal bonding quality.

Disclosure of Invention

One embodiment of the present disclosure provides a method for bonding a seed crystal. The method comprises the following steps: coating the adhesive on the surface of the seed crystal support; placing the seed crystal holder coated with the adhesive in a bonding device; performing air extraction treatment on the bonding equipment; and adhering the seed crystal to the seed crystal holder, wherein in the adhering process, air suction treatment and heating treatment are carried out simultaneously.

One embodiment of the present specification provides a seed crystal bonding apparatus. The apparatus comprises: the bonding cavity is used for placing seed crystals and seed crystal holders; the vacuum assembly is used for vacuumizing the bonding cavity; the heating assembly is used for heating the bonding cavity; and the pressing assembly is used for bonding the seed crystal to the seed crystal support, and the vacuum assembly and the heating assembly are simultaneously started in the bonding process.

Drawings

The present description will be further explained by way of exemplary embodiments, which will be described in detail by way of the accompanying drawings. These embodiments are not intended to be limiting, and in these embodiments like numerals are used to indicate like structures, wherein:

FIG. 1 is a schematic view of an exemplary crystal growth system shown in accordance with some embodiments herein;

FIG. 2 is a schematic diagram of an exemplary computing device shown in accordance with some embodiments of the present description;

FIG. 3 is a flow diagram of an exemplary crystal growth method according to some embodiments herein;

FIG. 4 is a flow diagram of an exemplary feedstock preparation process shown in some examples according to the present description;

FIG. 5 is a flow diagram of an exemplary feedstock pretreatment method and seed pretreatment method according to some embodiments described herein;

FIG. 6 is a flow diagram of an exemplary seed coating method according to some embodiments described herein;

FIG. 7 is a schematic illustration of exemplary seed crystal back evaporation, according to some embodiments herein;

FIG. 8 is a flow chart of an exemplary seed coating method according to further embodiments herein;

FIG. 9 is a schematic diagram of an exemplary coating apparatus according to some embodiments of the present disclosure;

FIG. 10 is a flow diagram of an exemplary seed bonding method according to some embodiments described herein;

FIG. 11A is a schematic diagram of an exemplary seed bonding apparatus according to some embodiments of the present description;

FIG. 11B is a schematic illustration of exemplary seed crystals after bonding, according to some embodiments herein;

FIG. 12A is a schematic diagram illustrating an exemplary seed bonding apparatus, according to further embodiments of the present disclosure;

FIG. 12B is a schematic illustration of exemplary seed crystals after bonding, according to still further embodiments of the present disclosure;

FIG. 13 is a flow chart illustrating an exemplary seed bonding method according to further embodiments of the present disclosure;

FIG. 14A is a schematic diagram of an exemplary rolling operation according to some embodiments herein;

FIG. 14B is a schematic illustration of an exemplary rolling operation according to further embodiments herein;

FIG. 15 is a flow chart of an exemplary crystal growth method, according to still further embodiments of the present description;

FIG. 16A is a schematic diagram of an exemplary crystal growth apparatus, shown in accordance with some embodiments herein;

FIG. 16B is a schematic diagram illustrating an exemplary crystal growth apparatus, according to still further embodiments of the present disclosure;

FIG. 16C is a schematic diagram illustrating an exemplary crystal growth apparatus, according to still further embodiments of the present disclosure;

FIG. 17 is a schematic illustration of an exemplary crystal growth apparatus temperature profile shown in accordance with some embodiments of the present description;

FIG. 18 is a schematic diagram of an arrangement of exemplary thermometric assemblies according to some embodiments of the present description;

FIG. 19A is a schematic diagram of an exemplary monitoring assembly according to some embodiments herein;

FIG. 19B is a schematic diagram illustrating an exemplary monitoring assembly according to further embodiments of the present disclosure;

FIG. 20 is a flow chart of an exemplary crystal growth method according to further embodiments herein;

FIG. 21 is a flow chart of an exemplary crystal growth method according to further embodiments herein;

FIG. 22 is a flow chart of an exemplary crystal growth method according to further embodiments herein;

FIG. 23 is a flow diagram of an exemplary flash recycling method, shown in accordance with some embodiments of the present description;

FIG. 24 is a flow chart illustrating an exemplary slug recovery method in accordance with further embodiments of the present description.

In the figure, 100 is a crystal growth system, 101 is processing equipment, 102 is control equipment, 103 is a temperature measuring component, 103-1 is a temperature sensor, 103-2 is a heat-insulating layer, 103-3 is a cooling component, 104 is a monitoring component, 104-1 is an ultrasonic thickness gauge, 104-11 is an ultrasonic probe, 104-2 is a cooling device, 104-3 is a graphite rod, 105 is a pressure measuring component, 106 is coating equipment, 106-1 is a coating cavity, 106-11 is a pipe, 106-12 is a baffle, 106-2 is a coating frame, 106-3 is a heating component, 106-4 is an air inlet, 106-5 is an air outlet, 106-6 is a fan blade, 106-7 is heat-insulating cotton, 106-8 is a heat-insulating layer, 107 is seed crystal bonding equipment, 107-1 is a bonding cavity, 107-2 is a vacuum component, 107-3 is an upper driving component, 107-4 is a lower driving component, 107-5 is a heating component, 107-6 is a pressing component, 107-61 is a sucker, 107-62 is a support table, 107-7 is a pressure sensing component, 107-8 is a support component, 107-9 is a bonding table, 107-10 is a press roll, 108 is a crystal growing device, 108-1 is a growing cavity, 108-11 is a growing area, 108-111 is a cavity cover, 108-12 is a raw material area, 108-2 is a partition board, 108-21 is a discharge hole, 108-3 is a heating component, 108-31 is a first heating component, 108-32 is a second heating component, 108-33 is a third heating component, 108-4 is a heat preservation component, 109 is a storage device, 110 is an interaction component, 110-1 is a display device, 110-2 is an interactive device.

Detailed Description

In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings used in the description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are only examples or embodiments of the present description, and that for a person skilled in the art, the present description can also be applied to other similar scenarios on the basis of these drawings without inventive effort. Unless otherwise apparent from the context, or otherwise indicated, like reference numbers in the figures refer to the same structure or operation.

It should be understood that "system", "apparatus", "unit" and/or "module" as used herein is a method for distinguishing different components, elements, parts, portions or assemblies at different levels. However, other words may be substituted by other expressions if they accomplish the same purpose.

As used in this specification and the appended claims, the terms "a," "an," "the," and/or "the" are not to be taken in a singular sense, but rather are to be construed to include a plural sense unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" merely indicate that steps and elements are included which are explicitly identified, that the steps and elements do not form an exclusive list, and that a method or apparatus may include other steps or elements.

Flow charts are used in this description to illustrate operations performed by a system according to embodiments of the present description. It should be understood that the preceding or following operations are not necessarily performed in the exact order in which they are performed. Rather, the steps may be processed in reverse order or simultaneously. Meanwhile, other operations may be added to the processes, or a certain step or several steps of operations may be removed from the processes.

Fig. 1 is a schematic diagram of an exemplary crystal growth system, shown in accordance with some embodiments herein.

In some embodiments, the crystal growth system 100 may produce a variety of crystals (e.g., silicon carbide (SiC) crystals, aluminum nitride (AIN) crystals, zinc selenide (ZnSe) crystals, cadmium sulfide (CdS) crystals, zinc telluride (ZnTe), etc.) based on Physical Vapor Transport (PVT).

In some embodiments, as shown in FIG. 1, the crystal growth system 100 may include a processing device 101, a control device 102, a temperature measurement assembly 103, a monitoring assembly 104, a load cell assembly 105, a plating device 106, a seed bonding device 107, a crystal growth apparatus 108, a storage device 109, and an interaction assembly 110.

The processing device 101 may be used to process a variety of data and/or information involved in the crystal growth process. In some embodiments, the processing apparatus 101 may obtain temperature information within the growth chamber from the thermometry assembly 103 and adjust the position, shape, distribution, flow area, etc., or any combination thereof, of at least one of the ports (e.g., ports 108-21 for passing gas phase components as shown in fig. 16A-16C) based on the temperature information. In some embodiments, the processing tool 101 can monitor the crystal growth via the monitoring assembly 104 and adjust heating parameters of the heating assembly (e.g., the heating assembly 108-3 as shown in fig. 16A-16C) and/or the location, shape, distribution, flow area, etc., or any combination thereof, of the at least one discharge port based on the crystal growth. In some embodiments, the processing tool 101 may monitor the crystal growth by the monitoring assembly 104 and adjust the heating parameters of the heating assembly (e.g., the heating assembly 108-3 shown in fig. 16A-16C) and/or the position, shape, distribution, flow area, etc. of the at least one outlet port during the next crystal growth run or any combination thereof based on the current crystal growth. In some embodiments, the processing apparatus 101 may obtain the applied pressure of the pressing assembly (e.g., pressing assembly 107-6 as shown in fig. 11A, 12A) of the seed bonding apparatus 107 through a pressure sensing assembly (e.g., pressure sensing assembly 107-7 in fig. 11A and 12A) and adjust the applied pressure accordingly.

In some embodiments, the processing device 101 may send control instructions to the control device 102, with the control device 102 controlling the crystal growth process based on the control instructions.

In some embodiments, the processing device 101 may comprise an industrial control computer. In some embodiments, the processing device 101 may act as a superordinate control monitoring device or superordinate processing device.

The control device 102 may be used to control various operations involved in the crystal growth process (e.g., seed coating, seed bonding, crystal growth, etc.). In some embodiments, the control device 102 may receive control instructions from the processing device 101 and control the crystal growth process based on the control instructions.

In some embodiments, control device 102 may include a Programmable Logic Controller (PLC). In some embodiments, the control device 102 may act as a lower level real-time control device.

In some embodiments, the processing device 101 and/or the control device 102 may include a Central Processing Unit (CPU), an Application Specific Integrated Circuit (ASIC), an application specific instruction set processor (ASIP), an image processing unit (GPU), a physical arithmetic processing unit (PPU), a Digital Signal Processor (DSP), a Field Programmable Gate Array (FPGA), a Programmable Logic Device (PLD), a controller, a microcontroller unit, a Reduced Instruction Set Computer (RISC), a microprocessor, or the like, or any combination thereof. In some embodiments, the processing device 101 and the control device 102 may be integrated into one device. In some embodiments, the control device 102 may be part of the processing device 101. In some embodiments, the functions of the processing device 101 and the control device 102 may be shared or jointly performed with each other.

Temperature measurement component 103 may be configured to detect a temperature of a growth cavity sidewall and/or a growth cavity top and send a temperature measurement signal to processing device 101. In some embodiments, the temperature measurement component 103 may include a thermocouple sensor, a thermistor sensor, an infrared thermometer, an optical pyrometer, or a colorimetric pyrometer, among others.

The monitoring component 104 can be configured to monitor crystal growth and send a monitoring signal to the processing device 101. In some embodiments, the crystal growth condition may include at least one of a thickness, a growth rate, or a defect of the growing crystal. In some embodiments, the monitoring assembly 104 may include a contact monitoring assembly (e.g., ultrasonic thickness gauge 104-1 in fig. 19A) or a non-contact monitoring assembly (e.g., air-coupled ultrasonic non-destructive testing, electromagnetic ultrasonic (EMAT) non-destructive testing, electrostatically-coupled ultrasonic non-destructive testing, and laser ultrasonic non-destructive testing).

The load cell assembly 105 may be used to monitor the pressure of the seed bonding apparatus 107 and send the monitoring signal to the processing apparatus 101. In some embodiments, the load cell assembly 105 may include a pressure sensor. For example, a piezoelectric pressure sensor, a piezoresistive pressure sensor, a capacitive pressure sensor, an electromagnetic pressure sensor, a vibrating wire pressure sensor, and the like.

The coating apparatus 106 may be used to perform a seed coating operation. In some embodiments, the coating apparatus 106 may include a coating chamber, a coating rack, a drive assembly, a pumping assembly, a heating assembly, an air inlet, an air outlet, and the like. Further description of the coating device 106 can be found in fig. 9 and its related description, which are not repeated herein.

The seed bonding apparatus 107 may be used to perform the operation of bonding the seed. In some embodiments, the seed bonding apparatus 107 includes a bonding chamber, a vacuum assembly, an upper drive assembly, a lower drive assembly, a heating assembly, a pressing assembly, a support assembly, and the like. Further description of the seed bonding apparatus 107 can be found in fig. 11A, fig. 12A and their related descriptions, which are not repeated herein.

The crystal growing apparatus 108 may be used to perform crystal growing operations. In some embodiments, the crystal growth apparatus 108 may include a growth chamber, a heating assembly, and the like. Further description of crystal growing apparatus 108 can be found in FIGS. 16A-16C and their associated description, and will not be repeated here.

Taking a specific crystal growth process as an example, the control device 102 may control the coating device 106 to coat the back surface of the seed crystal. In some embodiments, the control device 102 may control the seed bonding device 107 to bond the seed (or coated seed) to the chamber lid or the seed holder. The pressure sensing assembly may detect the applied pressure of the pressing assembly of the seed bonding apparatus 107 and feed back to the processing apparatus 101. The processing apparatus 101 may send control instructions to the control apparatus 102, and the control apparatus 102 may control the applied pressure of the seed bonding apparatus 107 accordingly. In some embodiments, the control apparatus 102 may control the crystal growing apparatus 108 to grow a crystal. The thermometry component 103 may detect the temperature of the growth chamber sidewall and/or the growth chamber top and feed the temperature back to the processing device 101. The processing device 101 may send control instructions to the control device 102, and the control device 102 may control and adjust the position, shape, distribution, flow area, etc., or any combination thereof, of the at least one outlet. The monitoring component 104 can monitor the crystal growth and feed the crystal growth back to the processing tool 101. The processing device 101 may send control instructions to the control device 102, and the control device 102 may control adjusting the heating parameters of the heating assembly and/or the position, shape, distribution, flow area, etc. of the at least one outlet, or any combination thereof.

The memory device 109 may store a variety of data and/or information involved in the crystal growth process. In some embodiments, the storage device 109 may store parameters (e.g., temperature, crystal growth conditions), control instructions, etc. during the crystal growth process. In some embodiments, the storage device 109 may be directly connected or in communication with one or more components in the crystal growth system 100 (e.g., the processing device 101, the control device 102, the temperature measurement component 103, the monitoring component 104, the load cell component 105, the coating device 106, the seed bonding device 107, the crystal growth apparatus 108, the storage device 109, the interaction component 110, etc.). One or more components in crystal growth system 100 may access data and/or instructions stored in storage device 109 via a network or directly. In some embodiments, the storage device 109 may be part of the processing device 101 and/or the control device 102. Data relating to the crystal growth control process (e.g., pressure control parameters, discharge gate control parameters, etc.) may be recorded in real time in the memory device 109.

In some embodiments, the storage device 109 may store data and/or instructions for the processing device 101 to perform or use to perform the exemplary methods described in this specification. In some embodiments, the storage device 109 may include mass storage, removable storage, volatile read-write memory, read-only memory (ROM), the like, or any combination thereof. In some embodiments, the storage device 109 may be implemented on a cloud platform. In some embodiments, the cloud platform may include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an internal cloud, a multi-tiered cloud, and the like, or any combination thereof.

The interaction component 110 may be used to interact with a user or other components in the crystal growth system 100. In some embodiments, the interaction component 110 may include a display device 110-1 and an interaction device 110-2. Display device 110-1 may include a digital tube display, a two-dimensional display, a three-dimensional display, and the like. The interaction device 110-2 may include a mouse, keyboard, voice input device, and the like.

In some embodiments, the processing device 101 may interact with an operator (e.g., a crystal preparation engineer) via the display device 110-1 and/or the interaction device 110-2, and the operator may query the display device 110-1 for actual crystal growth, pressure control parameters, discharge outlet control parameters (e.g., location, shape, distribution, or flow area of the discharge outlet), and the like.

It should be noted that the above description of crystal growth system 100 is merely for convenience of description and is not intended to limit the scope of the present disclosure to the illustrated embodiments. It will be understood by those skilled in the art that, having the benefit of the teachings of this system, various changes may be made to the system and its components without departing from such teachings. For example, the temperature measurement assembly 103, the monitoring assembly 104, the load cell assembly 105, and the seed crystal attachment apparatus 107 may be separate components from the crystal growth apparatus 108, i.e., the components of the crystal growth apparatus 108 may not include the temperature measurement assembly 103, the monitoring assembly 104, the load cell assembly 105, and the seed crystal attachment apparatus 107.

FIG. 2 is a schematic diagram of an exemplary computing device, shown in accordance with some embodiments of the present description.

In some embodiments, the processing device 101, the control device 102, and/or the storage device 109 may be implemented on the computing device 200 and configured to implement the functionality disclosed in this specification.

Computing device 200 may include any components used to implement the systems described herein. For example, a PLC may be implemented on computing device 200 via its hardware, software programs, firmware, or a combination thereof. For convenience only one computer is depicted in the figures, but the computational functions described herein relating to charge control may be implemented in a distributed manner by a set of similar platforms to distribute the processing load of the system.

The computing device 200 may include a communication port 205 for connecting to a network for enabling data communication. Computing device 200 may include a processor 202 (e.g., CPU) that may execute program instructions in the form of one or more processors. An exemplary computer platform may include an internal bus 201, various forms of program memory and data storage such as a hard disk 207, read Only Memory (ROM) 203 or Random Access Memory (RAM) 204 for storing various data files that are processed and/or transmitted by a computer. The computing device may also include program instructions stored in read-only memory 203, random access memory 204, and/or other types of non-transitory storage media that are executed by processor 202. The methods and/or processes of the present specification can be implemented in the form of program instructions. Computing device 200 also includes input/output component 206 for supporting input/output between the computer and other components. Computing device 200 may also receive programs and data in the present disclosure via network communication.

For ease of understanding, only one processor is exemplarily depicted in fig. 2. However, it should be noted that the computing device 200 in this specification may include multiple processors, and the operations and/or methods described in this specification as being implemented by one processor may also be implemented by multiple processors, collectively or independently. For example, if the processors of computing device 200 described in this specification perform operations a and B, it should be understood that operations a and B may also be performed jointly or separately by two or more different processors in computing device 200 (e.g., a first processor performing operation a and a second processor performing operation B, or a first processor and a second processor performing operations a and B together).

FIG. 3 is a flow chart of an exemplary crystal growth method according to some embodiments of the present description. In some embodiments, flow 300 may be performed by a processing device (e.g., processing device 101) and/or a control device (e.g., control device 102). For example, the process 300 may be stored in a storage device (e.g., a storage unit of a storage device, a processing device, and/or a control device) in the form of a program or instructions, which when executed by the processor 202, may implement the process 300. In some embodiments, the process 300 may be performed manually by an operator or semi-automatically. In some embodiments, flow 300 may utilize one or more additional operations not described below, and/or be accomplished without one or more of the operations discussed below. Additionally, the order of the operations shown in FIG. 3 is not intended to be limiting.

Step 310, placing feedstock in a feedstock region of a growth chamber.

In some embodiments, the feedstock may be a raw material required to grow a crystal. In some embodiments, the feedstock may be a powder, a cake, a granule, or the like. In some embodiments, the purity of the feedstock can be greater than or equal to 90.00%. In some embodiments, the purity of the feedstock can be greater than or equal to 92.00%. In some embodiments, the purity of the feedstock can be greater than or equal to 95.00%. In some embodiments, the purity of the feedstock can be greater than or equal to 99.00%. In some embodiments, the purity of the feedstock can be greater than or equal to 99.9%. In some embodiments, the purity of the feedstock can be greater than or equal to 99.99%. In some embodiments, the purity of the feedstock can be greater than or equal to 99.999%.

The following description will be given by taking the preparation of silicon carbide crystals as an example.

In some embodiments, the feedstock may include a silicon carbide frit. For more details on the preparation of the silicon carbide powder, reference may be made to other parts of the present specification (e.g., fig. 4 and its associated description), and further description is omitted here.

In some embodiments, the growth cavity may be the site where a silicon carbide crystal is grown. For more details of the growth chamber, reference may be made to other parts of the present specification (for example, fig. 16A-16C, fig. 18 and the related description thereof), and details are not repeated herein.

In some embodiments, the feedstock region may be a location where a silicon carbide powder is placed. In some embodiments, the feedstock region may be located below the growth chamber.

In some embodiments, the feedstock can be manually placed in the feedstock region of the growth chamber. The raw materials are loaded in a manual mode, and the process is flexible to operate, simple in equipment and low in cost. In some embodiments, the robotic arm may be controlled by the processing device and/or the control device to place the feedstock into the feedstock region of the growth chamber. In some embodiments, the robotic arm may automatically pick up the feedstock in accordance with a set program and place it in the feedstock region of the growth chamber. The raw materials are loaded through the mechanical arm, so that the labor cost can be reduced, the materials are taken accurately, and the operation and the control are easy.

Step 320, a seed crystal is placed in the growth region of the growth chamber.

In some embodiments, the seed crystal may be a small silicon carbide crystal of high crystalline quality with few crystalline defects, understood as a seed for growing silicon carbide crystals.

In some embodiments, the growth zone may be a seed crystal-based location for growing a silicon carbide crystal. In some embodiments, the growth region may be located above the growth cavity.

In some embodiments, the feed zone and the growth zone may be separated by a partition. In some embodiments, the thermal insulation plate may be a high temperature resistant thermal insulation material in order to achieve less influence on the temperature of the growth region when the temperature of the raw material region is regulated during the crystal growth process so as to maintain the stability of the crystal growth environment. Such as graphite, porous graphite, and the like. In some embodiments, the baffle may include at least one spout. In some embodiments, the raw material in the raw material area is heated at high temperature to sublimate into gas-phase components, and the gas-phase components can enter the growth area through the discharge port on the partition plate, so that the silicon carbide crystal is grown on the surface of the seed crystal.

The raw material area and the growth area are separated through the partition plate, the temperatures of the raw material area, the positions near the partition plate and the growth area can be controlled respectively and independently, the crystal growth process is effectively regulated, the heat insulation plate is made of high-temperature-resistant heat insulation materials, the temperature of the growth area is slightly influenced when the temperature of the raw material area is regulated, and the stability of the crystal growth environment is guaranteed. In addition, by adjusting the position, shape, distribution, flow area and the like of at least one discharge hole on the partition plate, the carbon-silicon molar ratio, the transmission path, the transmission speed and the like of the raw material gas phase component can be regulated, the crystal growth interface can be effectively regulated, the dislocation formation probability is obviously reduced, the crystal defects are reduced, and the grown crystal quality is improved.

In some embodiments, the seed crystal may be manually bonded to the growth region of the growth chamber. The seed crystal is bonded in a manual mode, and the process is flexible to operate, simple in equipment and low in cost. In some embodiments, the robotic arm may be controlled by the handling apparatus and/or the control apparatus to adhere the seed crystal to the growth region of the growth chamber. In some embodiments, the robot arm may automatically pick up the seed crystal according to a set program and bond it to the growth region of the growth chamber. The seed crystal is bonded through the mechanical arm, so that the labor cost can be reduced, the material taking is accurate, and the operation and the control are easy.

In some embodiments, the seed may be bonded to the cavity lid or seed holder of the growth cavity by a seed bonding apparatus 107. For more details about seed bonding, reference may be made to other parts of this specification (for example, fig. 10 to 14B and their related descriptions), and details are not repeated here.

In some embodiments, during the seed crystal bonding process and/or after the seed crystal is bonded to the cavity cover or the seed crystal holder, the bonding condition of the seed crystal can be subjected to air hole detection through the ultrasonic detection equipment. In some embodiments, the ultrasonic detection device may comprise an ultrasonic flaw detector.

In some embodiments, the air hole detection may be to detect the state of air holes in the seed crystal during and/or after the bonding of the seed crystal. In some embodiments, the results of the pore detection include at least one of pore location, pore size, pore shape, or pore density.

In some embodiments, an ultrasonic detection device (e.g., an ultrasonic flaw detector) may transmit ultrasonic waves through the seed crystal growth surface into the interior of the seed crystal to transmit the ultrasonic waves from the seed crystal growth surface into the interior of the seed crystalIn the seed crystal in the bonding process or the bonded seed crystal. Because the propagation speed, amplitude and the like of the ultrasonic wave in the bubbles (or called as 'air holes') are different from the propagation speed, amplitude and the like of the bonding part, the ultrasonic detection equipment judges the position, size, shape or density of the bubbles existing on the seed crystal during or after the seed crystal is bonded according to the receiving time, amplitude and the like of the ultrasonic wave after receiving the reflected ultrasonic wave. In some embodiments, the pressure of the seed bonding process may be adjusted based on the detection result. In some embodiments, if the density of pores detected during the seed bonding process is greater than a pore density threshold (e.g., 8 pores/cm) ² ) The pressure applied by the pressing assembly can be increased and/or the suction power of the suction assembly can be increased to reduce the pressure in the bonding apparatus to discharge air bubbles. In some embodiments, if the density of the pores detected during the seed crystal bonding process is less than the pore density threshold, the pressure of the pressing assembly and/or the pressure in the bonding equipment can be maintained, and the pressing operation can be continued. In some embodiments, if the local pore density of the seed crystal during the bonding process of the seed crystal is detected to be greater than the pore density threshold, the local pressure of the pressing assembly may be adjusted to expel the local bubbles. Through the air hole detection result, the pressure of the pressing assembly in the bonding process, the local pressure and/or the pressure in the bonding equipment are/is adjusted, and the seed crystal bonding quality can be improved. In some embodiments, if the pore density is detected to be greater than the pore density threshold after the seed crystal is bonded, the seed crystal can be taken off to be bonded again, so that the quality of the seed crystal bonding is improved.

And step 330, growing crystals by a physical vapor transport method based on the seed crystals and the raw materials.

In some embodiments, the silicon carbide feedstock in the feedstock zone is sublimated to a vapor phase component (e.g., si) via high temperature heating ₂ C、SiC ₂ And the like) the gas phase components enter a growth region with relatively low temperature through at least one discharge hole on the partition plate under the driving of the temperature gradient and/or the concentration gradient, and then are transported to the seed crystal under the driving of the temperature gradient, and the seed crystal is nucleated and grown, and crystallized to form the SiC crystal.

In some embodiments, during the growth of the crystal by physical vapor transport, the growth chamber may be heated by a heating assembly to effect sublimation of the feedstock, transport of vapor phase components, and the like. For more details on heating the growth chamber by the heating assembly, reference may be made to other parts of this specification (for example, fig. 15 and the related description thereof), and details thereof are not repeated herein.

In some embodiments, the position of the at least one discharge port may be adjusted in an axial or radial direction during the growth of the crystal by physical vapor transport. Through adjusting the position of at least one discharge gate, can make the gaseous phase component distribution of crystal growth face more even, grow out comparatively level and smooth crystal, reduce crystal growth defect, improve crystal quality. For more details on adjusting the position of the at least one outlet in the axial or radial direction, reference may be made to other parts of this specification (for example, fig. 20 and the related description thereof), and details thereof are not repeated here.

In some embodiments, temperature information within a growth chamber may be obtained during growth of a crystal by physical vapor transport; and adjusting at least one of a position, a shape, a distribution, or a flow area of the at least one discharge port based on the temperature information. In some embodiments, temperature information within a growth chamber may be obtained during growth of a crystal by physical vapor transport; and adjusting at least one of the position, shape, distribution or flow area of at least one discharge port in the next crystal growth process based on the temperature information. For more details regarding adjusting at least one of the position, shape, distribution or flow area of the at least one outlet based on the temperature information, reference may be made to other parts of this specification (e.g., fig. 20 and the related description thereof), which are not further described herein.

In some embodiments, during the process of growing the crystal by the physical vapor transport method, the distribution condition of the gas-phase components in the growth cavity can be obtained; and adjusting at least one of the position, shape, distribution or flow area of the at least one outlet based on the distribution. In some embodiments, during the process of growing the crystal by the physical vapor transport method, the distribution condition of the gas-phase components in the growth cavity can be obtained; and adjusting at least one of the position, shape, distribution or flow area of at least one discharge port in the next crystal growth process based on the distribution condition. For more details regarding adjusting at least one of the position, the shape, the distribution, or the flow area of the at least one outlet based on the distribution situation, reference may be made to other parts of this specification (for example, fig. 21 and the related description thereof), and details are not repeated herein.

In some embodiments, during the crystal growth process, the crystal growth can be monitored; and adjusting at least one of a heating parameter of the heating assembly and/or a position, a shape, a distribution, or a flow area of the at least one discharge port based on the crystal growth. In some embodiments, during the crystal growth process, the crystal growth can be monitored; and adjusting at least one of the heating parameters of the heating assembly and/or the position, shape, distribution or flow area of at least one discharge port in the next crystal growth process based on the crystal growth condition. Further details regarding adjusting at least one of a heating parameter of the heating assembly and/or a position, a shape, a distribution, or a flow area of the at least one discharge opening based on the crystal growth condition can be found in other parts of this specification (e.g., fig. 22 and the related description thereof), and will not be repeated herein.

It should be noted that the above description of the flow is for illustration and description only and does not limit the scope of the application of the present specification. Various modifications and alterations to the flow may occur to those skilled in the art, given the benefit of this description. However, such modifications and variations are intended to be within the scope of the present description. For example, process 300 may include a storage step in which a processing device and/or a control device may store information and/or data related to process 300 (e.g., a location, shape, distribution, flow area, etc. of at least one port) in a storage device (e.g., storage device 109).

In the growth process of the silicon carbide crystal, the quality and purity of the silicon carbide raw material are crucial, while the silicon carbide raw material purchased in the market at present generally has low purity, the impurity content exceeds 5ppm, and the subsequent growth of the silicon carbide crystal is influenced by too high impurity content, which is mainly represented as: (1) influencing the resistivity regulation and control of the silicon carbide crystal; (2) influencing the color and color uniformity of the silicon carbide crystal; (3) The nucleation energy and the crystal form stability which influence the growth of the silicon carbide crystal; (4) Severely corrodes the crucible and changes the component ratio in the crystal growth process. Accordingly, embodiments of the present disclosure provide a method for preparing a silicon carbide feedstock with a low impurity concentration.

FIG. 4 is a flow diagram of an exemplary feedstock preparation process, according to some embodiments herein. In some embodiments, flow 400 may utilize one or more additional operations not described below, and/or may not be accomplished by one or more of the operations discussed below. Additionally, the order of the operations shown in FIG. 4 is not intended to be limiting.

Step 410, the source material and the additive are mixed uniformly.

In some embodiments, the source material may be the starting material for the raw materials used to make the crystals. In some embodiments, the source material may include carbon powder, silicon powder, and a predetermined fraction of silicon carbide particles.

In some embodiments, the carbon powder may be a high purity carbon powder having an ash content of less than 5 ppm. In some embodiments, the carbon powder may be a high purity carbon powder having an ash content of less than 4 ppm. In some embodiments, the carbon powder may be a high purity carbon powder with less than 3ppm ash. In some embodiments, the carbon powder may be a high purity carbon powder having an ash content of less than 2ppm. In some embodiments, the carbon powder may be a high purity carbon powder with less than 1ppm ash. In some embodiments, the silicon powder can be 3N grade high purity silicon powder. In some embodiments, the silicon powder can be 4N grade high purity silicon powder. In some embodiments, the silicon powder can be 5N grade high purity silicon powder. In some embodiments, the silicon powder can be 6N grade high purity silicon powder. In some embodiments, the silicon powder can be 7N grade high-purity silicon powder.

In some embodiments, the particle size of the carbon powder, silicon powder and/or silicon carbide particles is required to achieve uniform mixing of the source materials and sufficient reaction of the raw material synthesis operation.

In some embodiments, the particle size of the carbon powder may be in the range of 0.01 μm to 2 mm. In some embodiments, the particle size of the carbon powder may be in the range of 0.03 μm to 1.8 mm. In some embodiments, the particle size of the carbon powder may be in the range of 0.05 μm to 1.5 mm. In some embodiments, the particle size of the carbon powder may be in the range of 0.08 μm to 1.0 mm. In some embodiments, the particle size of the carbon powder may be in the range of 0.1 μm to 800 μm. In some embodiments, the particle size of the carbon powder may be in the range of 0.3 μm to 500 μm. In some embodiments, the particle size of the carbon powder may be in the range of 0.5 μm to 300 μm. In some embodiments, the particle size of the carbon powder may be in the range of 1 μm to 200 μm. In some embodiments, the particle size of the carbon powder may be in the range of 5 μm to 150 μm. In some embodiments, the particle size of the carbon powder may be in the range of 10 μm to 128 μm. In some embodiments, the particle size of the carbon powder may be in the range of 30 μm to 100 μm. In some embodiments, the particle size of the carbon powder may be in the range of 50 μm to 80 mm. In some embodiments, the particle size of the carbon powder may be in the range of 60 μm to 70 μm.

In some embodiments, the particle size of the silicon powder may be in the range of 0.01mm to 5 mm. In some embodiments, the particle size of the silicon powder may be in the range of 0.1mm to 4.5 mm. In some embodiments, the particle size of the silicon powder may be in the range of 0.3mm to 4.0 mm. In some embodiments, the particle size of the silicon powder may be in the range of 0.5mm to 3.5 mm. In some embodiments, the particle size of the silicon powder may be in the range of 0.7mm to 3.0 mm. In some embodiments, the particle size of the silicon powder may be in the range of 1mm to 2.5 mm. In some embodiments, the particle size of the silicon powder may be in the range of 1.3mm to 2.0 mm. In some embodiments, the particle size of the silicon powder may be in the range of 1.5mm to 1.8 mm. In some embodiments, the particle size of the silicon powder may be in the range of 1.6mm to 1.7 mm.

In some embodiments, the particle size of the silicon carbide particles may be in the range of 10 mesh to 120 mesh. In some embodiments, the particle size of the silicon carbide particles may be in the range of 16 mesh to 100 mesh. In some embodiments, the particle size of the silicon carbide particles may be in the range of 20 mesh to 80 mesh. In some embodiments, the particle size of the silicon carbide particles can be in the range of 25 mesh to 60 mesh. In some embodiments, the particle size of the silicon carbide particles may be in the range of 30 mesh to 50 mesh. In some embodiments, the particle size of the silicon carbide particles may be in the range of 35 mesh to 45 mesh. In some embodiments, the particle size of the silicon carbide particles can be in the range of 35 mesh to 40 mesh.

In some embodiments, the predetermined ratio may be a ratio of silicon carbide particles to a total weight of the carbon and silicon powders. In some embodiments, the predetermined proportion may be in the range of 1% to 30% of the total weight of the carbon powder and the silicon powder. In some embodiments, the predetermined proportion may be in the range of 3% to 28% of the total weight of the carbon powder and the silicon powder. In some embodiments, the predetermined proportion may be in the range of 5% to 26% of the total weight of the carbon powder and the silicon powder. In some embodiments, the predetermined proportion may be in the range of 7% to 24% of the total weight of the carbon powder and the silicon powder. In some embodiments, the predetermined proportion may be in the range of 10% to 22% of the total weight of the carbon powder and the silicon powder. In some embodiments, the predetermined proportion may be in the range of 13% to 20% of the total weight of the carbon powder and the silicon powder. In some embodiments, the predetermined proportion may be in the range of 15% to 18% of the total weight of the carbon powder and the silicon powder. In some embodiments, the predetermined proportion may be in the range of 16% to 17% of the total weight of the carbon powder and the silicon powder.

In some embodiments, the additive may include polytetrafluoroethylene.

In some embodiments, the additive may be added in a proportion to the source material. In some embodiments, the carbon powder: silicon powder: the mass ratio of the polytetrafluoroethylene can be 1:2: (0.01-0.5). In some embodiments, the carbon powder: silicon powder: the mass ratio of the polytetrafluoroethylene can be 1:2: (0.03-0.4). In some embodiments, the carbon powder: silicon powder: the mass ratio of the polytetrafluoroethylene can be 1:2: (0.05-0.3). In some embodiments, the carbon powder: silicon powder: the mass ratio of the polytetrafluoroethylene can be 1:2: (0.08-0.2). In some embodiments, the carbon powder: silicon powder: the mass ratio of the polytetrafluoroethylene can be 1:2: (0.1-0.15). In some embodiments, the carbon powder: silicon powder: the mass ratio of the polytetrafluoroethylene can be 1:2: (0.12-0.14).

In some embodiments, the source material and the additive may be mixed uniformly using a powder mixing device. In some embodiments, the powder mixing apparatus may include a twin-screw conical mixer, a horizontal non-gravity mixer, a horizontal coulter mixer, a horizontal ribbon mixer, and the like, or any combination thereof. In some embodiments, the source material and the additive can be mixed uniformly using a mortar (e.g., an agate mortar).

And step 420, placing the uniformly mixed source material and the additive into a pre-synthesis device for raw material synthesis operation to obtain an initial raw material.

In some embodiments, the pre-synthesis apparatus may be a location capable of providing a temperature, pressure, and/or atmosphere to perform the synthesis of the feedstock. In some embodiments, the source material and the additive which are uniformly mixed can be placed in a crucible, and the crucible containing the source material and the additive is placed in a pre-synthesis device to perform the raw material synthesis operation. In some embodiments, the crucible may comprise a tantalum carbide crucible, a high purity graphite crucible having a tantalum carbide coating applied to the interior thereof, a high purity graphite crucible, or the like. Compared with the traditional carbon crucible, the tantalum carbide crucible or the crucible internally coated with the tantalum carbide coating can avoid the pollution of impurities such as B, al in the carbon crucible in the raw material synthesis process to the raw material and improve the purity of the raw material.

In some embodiments, the feedstock synthesis operation may include a first stage and a second stage. In some embodiments, the first stage is a reaction stage and the second stage is a sublimation recrystallization stage.

In some embodiments, the reaction temperature of the reaction stage may be in the range of 1200 ℃ to 1600 ℃. In some embodiments, the reaction temperature of the reaction stage may be in the range of 1250 ℃ to 1550 ℃. In some embodiments, the reaction temperature of the reaction stage may be in the range of 1300 ℃ to 1500 ℃. In some embodiments, the reaction temperature of the reaction stage may be in the range of 1350 ℃ to 1450 ℃. In some embodiments, the reaction temperature of the reaction stage may be in the range of 1370 ℃ to 1430 ℃. In some embodiments, the reaction temperature of the reaction stage may be in the range of 1390 ℃ to 1410 ℃.

Because the raw material gas phase transmission is favorably inhibited when the pressure is higher, the raw materials can react in situGenerating SiC crystal nucleus; while lower pressures are advantageous for removing impurities, so the reaction pressure in the reaction stage can be set within a wide range. In some embodiments, the reaction pressure of the reaction stage may be at 10 ^-5 Pa to 101 kPa. In some embodiments, the reaction pressure of the reaction stage may be at 10 ^-4 Pa to 90 kPa. In some embodiments, the reaction pressure of the reaction stage may be at 10 ^-3 Pa-80 kPa. In some embodiments, the reaction pressure of the reaction stage may be at 10 ^-2 Pa to 70 kPa. In some embodiments, the reaction pressure of the reaction stage may be in the range of 0.1Pa to 60 kPa. In some embodiments, the reaction pressure of the reaction stage may be in the range of 1Pa to 50 kPa. In some embodiments, the reaction pressure of the reaction stage may be in the range of 10Pa to 40 kPa. In some embodiments, the reaction pressure of the reaction stage may be in the range of 15Pa to 35 kPa. In some embodiments, the reaction pressure of the reaction stage may be in the range of 20Pa to 30 Pa. In some embodiments, the reaction pressure of the reaction stage may be in the range of 22Pa to 28 Pa. In some embodiments, the reaction pressure of the reaction stage may be in the range of 23Pa to 25 Pa.

In some embodiments, the reaction time of the reaction stage may be in the range of 0.5h to 10 h. In some embodiments, the reaction time of the reaction stage may be in the range of 1h to 9 h. In some embodiments, the reaction time of the reaction stage may be in the range of 2h to 8 h. In some embodiments, the reaction time of the reaction stage may be in the range of 3h to 7 h. In some embodiments, the reaction time of the reaction stage may be in the range of 4h to 6 h. In some embodiments, the reaction time of the reaction stage may be in the range of 5h to 5.5 h.

After the first stage (reaction stage), generally, the resulting silicon carbide particles are small (e.g., 40 mesh to 80 mesh). If the small-particle silicon carbide raw material is used for crystal growth, on one hand, the small-particle silicon carbide raw material has small porosity, is not beneficial to gas phase transmission after the raw material is heated, and a transmission channel is easy to block, and finally the crystal quality is influenced due to insufficient supply of the raw material; on the other hand, the fine carbon particles generated by heating and carbonizing the silicon carbide small particles at the bottom of the crucible can be transmitted to the crystal growth surface along with the gas phase, so that the defects of carbon inclusions are formed, and the crystal quality is reduced. Therefore, a second stage (i.e., a sublimation recrystallization stage) is required in which small silicon carbide particles are sublimated and then recrystallized on the surface of the silicon carbide particles to which the source material is added in step 410 to produce a starting material having larger particles (e.g., 8 mesh to 40 mesh), thereby improving the quality of subsequent crystal growth.

In some embodiments, the reaction temperature of the sublimation recrystallization stage may be in the range of 1600 ℃ to 2500 ℃. In some embodiments, the reaction temperature of the sublimation recrystallization stage may be in the range of 1650 ℃ to 2450 ℃. In some embodiments, the reaction temperature of the sublimation recrystallization stage may be in the range of 1700 ℃ to 2400 ℃. In some embodiments, the reaction temperature of the sublimation recrystallization stage may be in the range of 1750 ℃ to 2350 ℃. In some embodiments, the reaction temperature of the sublimation recrystallization stage may be in the range of 1800 ℃ to 2300 ℃. In some embodiments, the reaction temperature of the sublimation recrystallization stage may be in the range of 1850 ℃ to 2250 ℃. In some embodiments, the reaction temperature of the sublimation recrystallization stage may be in the range of 1900 ℃ to 2200 ℃. In some embodiments, the reaction temperature of the sublimation recrystallization stage may be in the range of 1950 ℃ to 2150 ℃. In some embodiments, the reaction temperature of the sublimation recrystallization stage may be in the range of 2000 ℃ to 2100 ℃. In some embodiments, the reaction temperature of the sublimation recrystallization stage may be in the range of 2030 ℃ to 2170 ℃.

In some embodiments, the reaction pressure of the sublimation recrystallization stage may be at 10 ^-3 Pa-0.1 MPa. In some embodiments, the reaction pressure of the sublimation recrystallization stage may be at 10 ^-2 Pa-0.01 MPa. In some embodiments, the reaction pressure of the sublimation recrystallization stage may be in the range of 0.1Pa to 1 kPa. In some embodiments, the reaction pressure of the sublimation recrystallization stage may be in the range of 1Pa to 100 Pa. In some embodiments, the reaction pressure of the sublimation recrystallization stage may be in the range of 3Pa to 90 Pa. In some casesIn an example, the reaction pressure in the sublimation recrystallization stage may be in the range of 5Pa to 80 Pa. In some embodiments, the reaction pressure of the sublimation recrystallization stage may be in the range of 7Pa to 70 Pa. In some embodiments, the reaction pressure of the sublimation recrystallization stage may be in the range of 10Pa to 60 Pa. In some embodiments, the reaction pressure of the sublimation recrystallization stage may be in the range of 20Pa to 50 Pa. In some embodiments, the reaction pressure of the sublimation recrystallization stage may be in the range of 30Pa to 40 Pa.

In some embodiments, the reaction time of the sublimation recrystallization stage may be in the range of 5h to 60 h. In some embodiments, the reaction time of the sublimation recrystallization stage may be in the range of 10h to 55 h. In some embodiments, the reaction time of the sublimation recrystallization stage may be in the range of 15h to 50 h. In some embodiments, the reaction time of the sublimation recrystallization stage may be in the range of 20h to 45 h. In some embodiments, the reaction time of the sublimation recrystallization stage may be in the range of 25h to 40 h. In some embodiments, the reaction time of the sublimation recrystallization stage may be in the range of 30h to 35 h.

And step 430, carrying out post-treatment on the initial raw material to obtain silicon carbide powder.

In some embodiments, post-processing the starting material may include one or more of crushing, sieving, decarbonizing, washing, drying, and packaging the starting material.

The silicon carbide raw material with uniform grain diameter and high purity can be obtained by post-processing the initial raw material.

In this specification, the silicon carbide particles added to the source material can play a role of seeding in the subsequent raw material synthesis operation, so that the small silicon carbide particles generated by the reaction are recrystallized on the surface thereof after sublimation to grow into a large-particle silicon carbide raw material, thereby reducing defects in the initial raw material and improving the quality of the initial raw material. In addition, the polytetrafluoroethylene additive is added into the source material, the polytetrafluoroethylene can be decomposed into gas by heating, and the decomposition temperature is lower than the synthesis temperature of the initial raw material, so the synthesis reaction of the initial raw material after the decomposition of the polytetrafluoroethylene is not started, and the synthesis of the initial raw material cannot be influenced. In addition, when the polytetrafluoroethylene is decomposed into gas by heating, a space is formed inside the stacked source material, and air (particularly nitrogen) inside the stacked source material can be pumped away by a vacuum pump, so that the purity of the environment during the synthesis of the initial raw material is improved, and the purity of the finally prepared initial raw material and the purity of the silicon carbide powder are improved.

FIG. 5 is a flow diagram of an exemplary feedstock pretreatment method and seed pretreatment method according to some embodiments described herein. In some embodiments, flow 500 may utilize one or more additional operations not described below, and/or be accomplished without one or more of the operations discussed below. Additionally, the order of the operations shown in FIG. 5 is not limiting.

The feedstock is subjected to acid treatment and/or cleaning, step 510.

In some embodiments, the acid solution used for acid treatment may include hydrochloric acid, sulfuric acid, aqua regia, or hydrofluoric acid. By carrying out acid treatment on the raw materials, metal impurities in the silicon carbide raw materials can be removed, and the silicon carbide and the metal impurities are prevented from reacting in the crystal growth process, so that the crystal quality is improved.

In some embodiments, the solution used for cleaning may include ultrapure water, pure water, deionized water, or distilled water. In some embodiments, to avoid secondary contamination by impurities in the water during the cleaning process, the cleaning may be performed using ultrapure water.

By carrying out the process steps of acid treatment and/or cleaning and the like on the silicon carbide powder, the density of the microtubules in the subsequently prepared crystal can be reduced, and the crystal quality is improved.

Step 520, the seed crystal is subjected to at least one of a polishing process, a plating process, a surface inspection, or a diameter expansion process.

In some embodiments, the polishing process may include placing the seed crystal on a polishing apparatus, and controlling the polishing apparatus to polish under polishing conditions for a polishing time to obtain the seed crystal after the polishing process.

In some embodiments, the polishing conditions may include polishing pressure and polishing rotational speed.

Too high polishing pressure may cause unstable polishing process or too thin thickness of the polished seed crystal, while too low polishing pressure may cause the roughness or flatness of the polished seed crystal surface to be unsatisfactory, and thus, a proper polishing pressure needs to be set. In some embodiments, the polishing pressure can be in the range of 0.05MPa to 1MPa. In some embodiments, the polishing pressure can be in the range of 0.5MPa to 0.95 MPa. In some embodiments, the polishing pressure can be in the range of 0.1MPa to 0.9MPa. In some embodiments, the polishing pressure can be in the range of 0.15MPa to 0.85MPa. In some embodiments, the polishing pressure can be in the range of 0.2MPa to 0.8 MPa. In some embodiments, the polishing pressure can be in the range of 0.25MPa to 0.75 MPa. In some embodiments, the polishing pressure can be in the range of 0.3MPa to 0.7 MPa. In some embodiments, the polishing pressure can be in the range of 0.35MPa to 0.65 MPa. In some embodiments, the polishing pressure can be in the range of 0.4MPa to 0.6 MPa. In some embodiments, the polishing pressure can be in the range of 0.45MPa to 0.55 MPa. In some embodiments, the polishing pressure can be in the range of 0.49MPa to 0.51 MPa.

Too high polishing speed may result in unstable polishing process, easy occurrence of splinters and scratches, or too thin thickness of the seed crystal after polishing, while too low polishing speed may result in too long polishing time and reduced polishing efficiency, and thus, it is necessary to set a suitable polishing speed. In some embodiments, the rotational speed may be in the range of 10r/min to 80 r/min. In some embodiments, the rotational speed may be in the range of 15r/min to 75 r/min. In some embodiments, the rotational speed may be in the range of 20r/min to 70 r/min. In some embodiments, the rotational speed may be in the range of 25r/min to 65 r/min. In some embodiments, the rotational speed may be in the range of 30r/min to 60 r/min. In some embodiments, the rotational speed may be in the range of 35r/min to 55 r/min. In some embodiments, the rotational speed may be in the range of 40r/min to 50r/min. In some embodiments, the rotational speed may be in the range of 43r/min to 47 r/min.

In some embodiments, the polishing time may be in the range of 5min to 480 min. In some embodiments, the polishing time may be in the range of 30min to 450 min. In some embodiments, the polishing time may be in the range of 60min to 420 min. In some embodiments, the polishing time may be in the range of 90min to 390 min. In some embodiments, the polishing time may be in the range of 120min to 360 min. In some embodiments, the polishing time may be in the range of 150min to 330 min. In some embodiments, the polishing time may be in the range of 180min to 300 min. In some embodiments, the polishing time may be in the range of 210min to 270 min. In some embodiments, the polishing time may be in the range of 230min to 250 min. In some embodiments, the polishing time may be in the range of 235min to 245 min.

In some embodiments, a polishing powder may be used during the polishing process. In some embodiments, the polishing powder may include rare earth polishing powder, diamond polishing powder (e.g., polycrystalline diamond powder, single crystal diamond powder, nano diamond powder), alumina series powder, ceria series powder, coated diamond powder.

Too large particle diameter of the polishing powder can cause scratch on the surface of the seed crystal, and too small particle diameter of the polishing powder can cause that the roughness and the flatness of the surface of the polished seed crystal cannot meet the requirements, so that the proper particle diameter of the polishing powder needs to be set. In some embodiments, the particle size of the polishing powder may be in the range of 0.01 μm to 2 μm. In some embodiments, the particle size of the polishing powder may be in the range of 0.1 μm to 1.9 μm. In some embodiments, the particle size of the polishing powder may be in the range of 0.2 μm to 1.8 μm. In some embodiments, the particle size of the polishing powder may be in the range of 0.4 μm to 1.6 μm. In some embodiments, the particle size of the polishing powder may be in the range of 0.6 μm to 1.4 μm. In some embodiments, the particle size of the polishing powder may be in the range of 0.8 μm to 1.2 μm. In some embodiments, the particle size of the polishing powder may be in the range of 1.0 μm to 1.1 μm.

In some embodiments, different types, thicknesses, and/or conditions (e.g., surface roughness) of seed crystals may correspond to different polishing conditions, different polishing times, and/or different polishing powder particle sizes.

By polishing the seed crystal, the surface defects and the surface pollution degree can be reduced, and the generation of new micropipes in the growing crystal is effectively avoided.

In some embodiments, the back surface of the growth side of the seed crystal may be coated. In some embodiments, the coating may include thermal evaporation, magnetron sputtering, physical vapor deposition, chemical vapor deposition, electron beam evaporation, reactive sintering, plasma coating, molecular beam epitaxy, liquid phase epitaxy, laser deposition, and the like. For more details of the coating process, reference may be made to other parts of this specification (for example, fig. 6 to 9 and their related descriptions), which are not described herein again.

The film coating treatment is carried out on the back of the growth surface of the seed crystal, so that the density of hexagonal cavities in the crystal can be reduced, and the increase of the number of micro-tubes in the crystal growth process is effectively avoided.

In some embodiments, the surface inspection may include inspecting the seed crystal surface for micropipes, mechanical damage to the seed crystal surface, cleanliness of the seed crystal surface, and the like.

In some embodiments, surface inspection of the seed crystal may be accomplished in a variety of ways. For example, X-ray diffraction, laser scattering, and micro-raman spectroscopy.

The surface state of the seed crystal can be strictly monitored before the crystal growth through surface inspection, and the increase of the number of micropipes in the crystal growth process is effectively avoided.

In some embodiments, because large-sized seeds of low defect density are more difficult to obtain, the diameter of the seed may be enlarged by a diameter expansion process using a smaller-sized low defect density seed to obtain a large-sized seed. In some embodiments, the seed crystal may be placed in a ring having a diameter greater than the diameter of the seed crystal such that the seed crystal first undergoes radial growth. In some embodiments, the diameter of the ring may be set according to the diameter of the crystal desired during the actual crystal growth process. For example, the crystal to be grown is 8 inches in diameter, and the setting ring is also 8 inches in diameter. In some embodiments, after the diameter of the seed crystal is increased to the diameter of the circular ring, the process parameters are controlled to perform axial growth on the surface of the seed crystal. In some embodiments, it is also possible to use a smaller size seed crystal with a low defect density, and to obtain a large size ingot by diameter expansion growth, and then slicing the ingot into a large size seed crystal of a desired crystal diameter.

By performing diameter expansion treatment on the seed crystal, the area of the low defect density region can be increased, and the number of micropipes in the prepared crystal can be reduced.

Before the crystal grows, the seed crystal is subjected to polishing treatment, film coating treatment, surface inspection or diameter expansion treatment and the like, so that the quality of the seed crystal can be improved, and the number of micro-tubes in the prepared crystal can be reduced.

Fig. 6 is a flow diagram of an exemplary seed coating method according to some embodiments described herein. In some embodiments, flow 600 may be performed by a processing device (e.g., processing device 101) and/or a control device (e.g., control device 102). For example, flow 600 may be stored in a storage device (e.g., a storage device, a processing device, and/or a storage unit of a control device) in the form of a program or instructions that, when executed by processor 202, may implement flow 600. In some embodiments, flow 600 may utilize one or more additional operations not described below, and/or be accomplished without one or more of the operations discussed below. Additionally, the order of the operations shown in FIG. 6 is not intended to be limiting.

Step 610, performing sand blasting on the back of the seed crystal.

In some embodiments, in order to make the attachment effect after the seed crystal is coated better, the back surface of the seed crystal can be subjected to sand blasting treatment before the seed crystal is subjected to coating treatment so as to obtain the seed crystal with certain roughness. In some embodiments, the seed crystal back surface may be a seed crystal face opposite the seed crystal growth face.

In some embodiments, the backside of the seed crystal may be grit blasted with a 100-200 mesh grit blast (e.g., diamond grit, quartz grit, iron grit, copper grit). In some embodiments, the backside of the seed crystal may be grit blasted with a 110-190 mesh grit blast. In some embodiments, the back side of the seed crystal may be grit blasted with 120-180 mesh grit blast. In some embodiments, the back of the seed crystal may be grit blasted with 130-170 mesh grit blast. In some embodiments, the back of the seed crystal may be grit blasted with 140-160 mesh grit blast. In some embodiments, the backside of the seed crystal may be grit blasted with a 150-155 mesh grit blast.

After sand blasting treatment, if the roughness of the back of the seed crystal is too small, the film after film coating has poor adhesive force and is easy to fall off; if the roughness is too large, the flatness of the back of the seed crystal is affected, the seed crystal is not easy to adhere to the cavity cover or the seed crystal support, and therefore the roughness of the back of the seed crystal after sand blasting needs to meet certain requirements. In some embodiments, the roughness of the seed after grit blasting is in the range of 1 μm to 80 μm. In some embodiments, the roughness of the seed after grit blasting is in the range of 5 μm to 75 μm. In some embodiments, the roughness of the seed after grit blasting is in the range of 10 μm to 70 μm. In some embodiments, the roughness of the seed after grit blasting is in the range of 15 μm to 65 μm. In some embodiments, the roughness of the seed after grit blasting is in the range of 20 μm to 60 μm. In some embodiments, the roughness of the seed after grit blasting is in the range of 25 μm to 55 μm. In some embodiments, the roughness of the seed after grit blasting is in the range of 30 μm to 50 μm. In some embodiments, the roughness of the seed after grit blasting is in the range of 35 μm to 45 μm. In some embodiments, the roughness of the seed after grit blasting is in the range of 38 μm to 42 μm.

Through carrying out sand blasting to the seed crystal back for the seed crystal back satisfies certain roughness, is convenient for follow-up carry out the coating film to the seed crystal back, and guarantees that the coating film effect is better and be difficult to drop.

And step 620, heating and pretreating the seed crystal subjected to sand blasting.

Because the temperature is higher in the coating process, the seed crystal can be heated and pretreated in advance, so that the problems that the seed crystal is broken due to overlarge thermal stress caused by overlarge temperature difference between the membrane material and the seed crystal, or the coating is not firm due to different thermal expansion between the membrane material and the seed crystal and the like are solved.

In some embodiments, the temperature of the thermal pretreatment may be in the range of 300 ℃ to 900 ℃. In some embodiments, the temperature of the thermal pretreatment may be in the range of 400 ℃ to 800 ℃. In some embodiments, the temperature of the thermal pretreatment may be in the range of 500 ℃ to 700 ℃. In some embodiments, the temperature of the thermal pretreatment may be in the range of 600 ℃ to 650 ℃.

And 630, coating the seed crystal after the heating pretreatment by using a film material.

In some embodiments, the membrane material may be a substance having high temperature stability and chemical stability. In some embodiments, the membrane material may include W, mo, N ₂ W, taC.

The coating thickness is too large, the adhesion of the film material is poor, and the film material is easy to fall off; the thickness of the coating film is too small to ensure the uniformity of the coating film and influence the coating effect, so that the proper thickness of the coating film needs to be selected. In some embodiments, the thickness of the plated film may be in the range of 1 μm to 200 μm. In some embodiments, the thickness of the plated film may be in the range of 5 μm to 175 μm. In some embodiments, the thickness of the plated film may be in the range of 10 μm to 150 μm. In some embodiments, the thickness of the plated film may be in a range of 25 μm to 125 μm. In some embodiments, the coating thickness may be in the range of 50 μm to 100 μm. In some embodiments, the coating thickness may be in the range of 60 μm to 90 μm. In some embodiments, the coating thickness may be in the range of 75 μm to 85 μm. In some embodiments, the thickness of the plated film may be in the range of 80 μm to 85 μm.

In some embodiments, the coating may include thermal evaporation, physical vapor deposition, chemical vapor deposition, electron beam evaporation, reactive sintering, plasma coating, molecular beam epitaxy, liquid phase epitaxy, laser deposition, and the like.

By coating the back of the seed crystal, the evaporation process of the back of the seed crystal in the growth process of the silicon carbide crystal can be inhibited, and the hexagonal plane defect caused by the evaporation of the back of the seed crystal is effectively eliminated, so that the crystal quality is improvedAmount and yield. Specifically, as shown in fig. 7, Z denotes a seed crystal, 108 to 111 denotes a chamber cover, and the seed crystal Z is bonded to the chamber cover 108 to 111 by an adhesive a. Due to the reasons that the machining precision of the surface of the cavity cover 108-111 is not high, the bonding of the adhesive A is not uniform, and/or the physicochemical property of the adhesive A, some air holes Q may exist in the bonding interface between the back of the seed crystal Z and the cavity cover 108-111, heat transfer is blocked due to the air holes Q, heat is condensed at the air holes, and then the back of the seed crystal is evaporated to influence the subsequent crystal growth. For example, assuming no air holes, the temperature at chamber covers 108-111 is T ₂ The temperature at the seed crystal Z is T ₁ The temperature difference between them is Δ T. This normal temperature difference does not result in sublimation of the seed crystal Z. Due to the existence of the air hole Q, heat transmission is blocked, heat is gathered at the air hole Q, and the temperature of the cavity covers 108-111 is T ₂ ', the temperature at the seed crystal Z is T ₁ ', wherein, T ₂ ’<T ₂ ，T ₁ ’＞T ₁ Accordingly, the temperature difference Δ T' therebetween is larger than that in the normal case, thereby causing the back-side evaporation of the back surface of the seed crystal Z, and the evaporated gas phase component condenses at the gas hole Q with the lapse of time. Over time, the accumulation of heat leads to an interface temperature T due to the heat transfer being impeded ₁ <T ₁ ' that is, the temperature at the growth interface where the air holes Q are located is high, the temperature gradient of crystal growth is small, and the crystal growth speed is small, so the growth rate at the growth interface where the air holes Q are located is smaller than the growth rate at the growth interface where there are no air holes Q around, and because the growth rates at various places on the same growth interface are different, crystal growth defects (such as dislocations, micropipes, or voids) are generated, and a large area of void groups (or referred to as air hole groups) can even cause macroscopic interface depression X at the crystal growth interface, which seriously affects the quality and yield of the crystal J. Therefore, through the film coating treatment on the back surface of the seed crystal, hexagonal holes caused by back surface evaporation in the crystal growth process can be eliminated, so that the quality and the yield of the silicon carbide crystal are improved. In some embodiments, the chamber covers 108-111 may also be replaced with seed holders. In some embodiments, the seed holder may be an assembly that supports the seed.

Fig. 8 is a flow chart of an exemplary seed coating method according to further embodiments described herein. In some embodiments, flow 800 may be performed by a processing device (e.g., processing device 101) and/or a control device (e.g., control device 102). For example, the process 800 may be stored in a storage device (e.g., a storage unit of a storage device, a processing device, and/or a control device) in the form of a program or instructions, which when executed by the processor 202, may implement the process 800. In some embodiments, flow 800 may utilize one or more additional operations not described below, and/or be accomplished without one or more operations discussed below. Additionally, the order of the operations shown in FIG. 8 is not limiting.

Step 810, placing a plurality of seed crystals on a plurality of coating frames of the coating equipment.

In some embodiments, a plurality of trays can be arranged on the film coating rack for placing the seed crystals. In some embodiments, the plurality of seeds may be manually placed in the plurality of trays, respectively. Seed crystals are loaded in a manual mode, and the process is flexible in operation, simple in equipment and low in cost. In some embodiments, the robotic arm may be controlled by the processing device and/or the control device to position the seed crystal on the tray. In some embodiments, the robot arm may automatically pick up the seed crystal according to a set program, placing it in the tray. Seed crystals are loaded through the mechanical arm, so that the labor cost can be reduced, the material is accurately taken, and the operation and the control are easy.

In some embodiments, a plurality of coating racks may be disposed inside the coating device. For more details of the coating device, reference may be made to other parts of this specification (for example, fig. 9 and the related description thereof), and details are not repeated here.

And 820, introducing coating gas into the coating equipment, and simultaneously growing a carbon film on the back surfaces of the plurality of seed crystals by a vapor deposition method.

In some embodiments, a polyimide film (PI) may be pre-attached to the uncoated side, and the polyimide film may be removed after coating is completed, thereby preventing the uncoated side from being coated. In some embodiments, the uncoated side can be attached to the tray by electrostatic adsorption or the like to prevent the uncoated side from being coated.

In some embodiments, the coating gas may include methane or acetylene.

In some embodiments, the silicon carbide seed crystal may be held on a tray and the chamber of the coating apparatus may be evacuated and held. In some embodiments, the pressure of the chamber of the coating apparatus after the pumping process may be in the range of 0.001Pa to 100 Pa. In some embodiments, the pressure of the chamber of the coating device after the pumping treatment can be in the range of 0.01Pa to 95 Pa. In some embodiments, the pressure of the chamber of the coating device after the pumping treatment can be in the range of 0.1Pa to 90 Pa. In some embodiments, the pressure of the chamber of the coating device after the pumping treatment can be in the range of 1Pa to 85 Pa. In some embodiments, the pressure of the chamber of the coating device after the pumping treatment can be in the range of 10Pa to 80 Pa. In some embodiments, the pressure of the chamber of the coating device after the pumping treatment can be in the range of 20Pa to 75 Pa. In some embodiments, the pressure of the chamber of the coating device after the pumping treatment can be in the range of 30Pa to 70 Pa. In some embodiments, the pressure of the chamber of the coating device after the pumping treatment can be in the range of 40Pa to 60 Pa. In some embodiments, the pressure of the chamber of the coating device after the pumping treatment can be in the range of 45Pa to 55 Pa. In some embodiments, the pressure of the chamber of the coating device after the pumping treatment can be in the range of 48Pa to 52 Pa.

In some embodiments, the chamber of the coating apparatus may be subjected to a heating process. In some embodiments, the temperature of the heat treatment may be in the range of 200 ℃ to 1000 ℃. In some embodiments, the temperature of the heat treatment may be in the range of 300 ℃ to 900 ℃. In some embodiments, the temperature of the heat treatment may be in the range of 400 ℃ to 800 ℃. In some embodiments, the temperature of the heat treatment may be in the range of 500 ℃ to 700 ℃. In some embodiments, the temperature of the heat treatment may be in the range of 550 ℃ to 650 ℃. In some embodiments, the temperature of the heat treatment may be in the range of 580 deg.C to 620 deg.C.

In some embodiments, an inert gas may be used as a carrier gas, and a reaction gas (or referred to as a coating gas) may be introduced into the chamber of the coating apparatus at the same time, and the introduction of the reaction gas may be stopped after a certain time, and the flow rate of the carrier gas may be maintained.

In some embodiments, the inert gas may be Ar or He, or the like. In some embodiments, the gas flow rate of the inert gas may be in the range of 1mL/min to 1000 mL/min. In some embodiments, the gas flow rate of the inert gas may be in the range of 50mL/min to 950 mL/min. In some embodiments, the gas flow rate of the inert gas may be in the range of 100mL/min to 900 mL/min. In some embodiments, the gas flow rate of the inert gas may be in the range of 200mL/min to 800 mL/min. In some embodiments, the gas flow rate of the inert gas may be in the range of 300mL/min to 700 mL/min. In some embodiments, the gas flow rate of the inert gas may be in the range of 400mL/min to 600 mL/min. In some embodiments, the gas flow rate of the inert gas may be in the range of 450mL/min to 550 mL/min. In some embodiments, the gas flow rate of the inert gas may be in the range of 480mL/min to 520 mL/min.

In some embodiments, the gas flow rate of the reactant gas may be in the range of 1mL/min to 1000 mL/min. In some embodiments, the gas flow rate of the reactant gas may be in the range of 50mL/min to 950 mL/min. In some embodiments, the gas flow rate of the reactant gas may be in the range of 100mL/min to 900 mL/min. In some embodiments, the gas flow rate of the reactant gas may be in the range of 200mL/min to 800 mL/min. In some embodiments, the gas flow rate of the reactant gas may be in the range of 300mL/min to 700 mL/min. In some embodiments, the gas flow rate of the reactant gas may be in the range of 400mL/min to 600 mL/min. In some embodiments, the gas flow rate of the reactant gas may be in the range of 450mL/min to 550 mL/min. In some embodiments, the gas flow rate of the reactant gas may be in the range of 480mL/min to 520 mL/min.

In some embodiments, the time for introducing the reaction gas may be in the range of 1min to 30 min. In some embodiments, the time for introducing the reaction gas may be in the range of 4min to 27 min. In some embodiments, the time for introducing the reaction gas may be in the range of 7min to 24 min. In some embodiments, the time for introducing the reaction gas may be in the range of 10min to 21 min. In some embodiments, the time for introducing the reaction gas may be in the range of 13min to 18 min. In some embodiments, the time for introducing the reaction gas may be in the range of 15min to 16 min.

In some embodiments, the inert gas carrier gas may be introduced before the reaction gas is introduced, the reaction gas is introduced again until the pressure of the chamber of the coating apparatus reaches a pressure threshold, the introduction of the reaction gas is stopped after a certain time, and the flow rate of the carrier gas is maintained unchanged.

In some embodiments, the pressure threshold may be in the range of 0.01MPa to 0.1 MPa. In some embodiments, the threshold value of pressure may be in the range of 0.02MPa to 0.09 MPa. In some embodiments, the threshold value of pressure may be in the range of 0.03MPa to 0.08 MPa. In some embodiments, the threshold value of pressure may be in the range of 0.04MPa to 0.07 MPa. In some embodiments, the threshold value of pressure may be in the range of 0.05MPa to 0.06 MPa.

In some embodiments, after the coating reaction is complete, the chamber of the coating apparatus may be cooled to room temperature. In some embodiments, to avoid defects or cracks in the grown carbon film, the cooling rate of the chamber to room temperature may be controlled within a certain rate range. In some embodiments, the cooling rate to room temperature may be in the range of 1 ℃/min to 50 ℃/min. In some embodiments, the cooling rate to room temperature may be in the range of 5 ℃/min to 45 ℃/min. In some embodiments, the cooling rate to room temperature may be in the range of 10 ℃/min to 40 ℃/min. In some embodiments, the cooling rate to room temperature may be in the range of 15 ℃/min to 35 ℃/min. In some embodiments, the cooling rate to room temperature may be in the range of 20 ℃/min to 30 ℃/min. In some embodiments, the cooling rate to room temperature may be in the range of 23 ℃/min to 27 ℃/min.

The thickness of the carbon film is affected by the reaction time, the reaction temperature, and the ratio of the reaction gas. In some embodiments, the thickness of the carbon film may be in the range of 0.1 to 100 μm by controlling the reaction time, the reaction temperature, the reaction gas ratio, and the like. In some embodiments, the thickness of the carbon film may be in the range of 10 to 90 μm. In some embodiments, the thickness of the carbon film may be in the range of 20 to 80 μm. In some embodiments, the thickness of the carbon film may be in the range of 30 to 70 μm. In some embodiments, the thickness of the carbon film may be in the range of 40 to 60 μm. In some embodiments, the thickness of the carbon film may be in the range of 45 to 55 μm.

The carbon film can be grown on the back surfaces of the seed crystals simultaneously by a vapor deposition method, the coating efficiency is high, the uniformity of the coating is good, and the consistency of the grown crystals is good.

FIG. 9 is a schematic diagram of an exemplary coating apparatus according to some embodiments of the present disclosure.

In some embodiments, as shown in FIG. 9, the coating apparatus 106 can include a coating chamber 106-1, a coating rack 106-2, a drive assembly (not shown in FIG. 9), a pumping assembly (not shown in FIG. 9), a heating assembly 106-3, an inlet port 106-4, and an outlet port 106-5.

In some embodiments, the coating chamber 106-1 may be the site where the seed is coated. In some embodiments, the coating chamber 106-1 may include a tube 106-11 and a baffle 106-12. In some embodiments, two baffles 106-12 may be sealingly connected to the left and right ends of the tube 106-11, respectively. In some embodiments, the tube 106-11 may be a quartz tube.

In some embodiments, the coating frame 106-2 may be a frame made of a high temperature resistant material. In some embodiments, the lower end of the coating frame 106-2 may be pivotally connected to a base that is fixedly attached to the bottom of the coating chamber 106-1. In some embodiments, the number of coating racks 106-2 may be one or more. In some embodiments, when there are a plurality of coating racks 106-2, the plurality of coating racks 106-2 may be alternately disposed at both sides of the air inlet direction of the air inlet 106-4, so that the coating gas can be uniformly diffused to each coating rack 106-2.

In some embodiments, multiple trays may be disposed on the coating rack 106-2. In some embodiments, the tray may be used to place the seed. In some embodiments, multiple trays may be arranged in sequence one above the other on the coating rack 106-2. In some embodiments, multiple trays may be arranged about the central axis of the coating mount 106-2 in each layer on the coating mount 106-2.

In some embodiments, a drive assembly may be used to rotate the film-coating rack 106-2 about the central axis. In some embodiments, the drive assembly may include fan blades 106-6. In some embodiments, the fan blade 106-6 may be disposed at a side of the coating frame 106-2, and when the coating gas is introduced, the fan blade 106-6 may be driven by the coating gas to rotate, so as to drive the coating frame 106-2 to rotate around the central axis.

In some embodiments, a pumping assembly may be coupled to the gas outlet 106-5 for pumping the coating chamber 106-1. In some embodiments, the pumping assembly may be a vacuum device (e.g., a vacuum pump).

In some embodiments, the heating assembly 106-3 may be disposed outside of the tube 106-11 for providing the heat required for seed coating. In some embodiments, insulation wool 106-7 may be disposed between the heating assembly 106-3 and the tube 106-11 such that heat radiated by the heating assembly 106-3 may uniformly heat the seed crystal in the tray on the coating rack 106-2. In some embodiments, the insulation wool 106-7 may comprise an insulation material such as alumina, zirconia, or the like. In some embodiments, an insulating layer 106-8 may be disposed on the outside of the heating assembly 106-3 to insulate the coating device 106.

In some embodiments, an inlet port 106-4 may be disposed on the baffle 106-12 for introducing a coating gas into the coating chamber 106-1. In some embodiments, an outlet 106-5 may be disposed on another baffle 106-12 for exhausting air or coating gas from the coating chamber 106-1. For more details of the coating gas, reference may be made to the description of fig. 8, which is not repeated herein.

In some embodiments, the plating device 160 is not limited to the structure shown in fig. 9, and structural modifications may be made on the basis of the plating device 106 shown in fig. 9.

In some embodiments, the plating chamber 106-1 may also be a closed chamber made of a metal material (e.g., stainless steel), such as a cylindrical chamber or a rectangular parallelepiped chamber.

In some embodiments, the drive assembly may include a drive motor. In some embodiments, the lower end of the coating frame 106-2 may be drivingly connected to a drive motor for rotation about its central axis.

In some embodiments, the heating assembly 106-3 may be disposed inside the coating chamber 106-1 for providing the heat required for seed coating. In some embodiments, an insulating layer 106-8 may be disposed outside the coating chamber 106-1 to insulate the coating device 106.

In some embodiments, the gas inlet 106-4 may be disposed on the coating chamber 106-1 for introducing a coating gas into the coating chamber 106-1. In some embodiments, an outlet port 106-5 may be disposed on the coating chamber 106-1 for exhausting air or coating gas from the coating chamber 106-1.

Through setting up the crisscross setting of a plurality of coating frames and rotating around its central axis under the drive assembly drives, can be when the seed crystal coating film on the tray for coating gas evenly spreads to each seed crystal department, thereby improves the homogeneity of coating film thickness on each seed crystal.

Fig. 10 is a flow diagram of an exemplary seed bonding method according to some embodiments described herein. In some embodiments, flow 1000 may be performed by a processing device (e.g., processing device 101) and/or a control device (e.g., control device 102). For example, the process 1000 may be stored in a storage device (e.g., a storage unit of a storage device, a processing device, and/or a control device) in the form of a program or instructions, which when executed by the processor 202, may implement the process 1000. In some embodiments, flow 1000 may utilize one or more additional operations not described below, and/or be accomplished without one or more of the operations discussed below. Additionally, the order of the operations shown in FIG. 10 is not limiting.

At step 1010, an adhesive (e.g., adhesive A as shown in FIG. 11A or 12A) is applied to the bottom surface of a growth chamber cover (e.g., chamber cover 108-111 as shown in FIG. 11A or 12A).

In some embodiments, an adhesive (e.g., adhesive a as shown in fig. 11A or 12A) may also be applied to the seed holder surface. In some embodiments, the adhesive may include liquid glue, AB glue, synthetic resin, synthetic rubber, and the like.

In some embodiments, the adhesive may be applied manually to the bottom surface of the growth chamber cover or the seed holder surface. The adhesive is coated in a manual mode, and the process is flexible to operate, simple in equipment and low in cost. In some embodiments, the robot may be controlled by the processing device and/or the control device to apply the adhesive to the bottom surface of the chamber lid or the seed holder surface of the growth chamber. In some embodiments, the robotic arm may automatically apply the adhesive according to a set program. Through arm coating adhesive, can reduce the cost of labor, the repeatability is high to get the material accuracy and easily control. In some embodiments, the processing equipment and/or the control equipment can control the spin coater, the glue sprayer, the glue dispenser, the glue scraper, or the like to apply the adhesive to the lower surface of the cavity cover or the surface of the seed holder of the growth cavity. The adhesive is coated by a glue spreader, a sprayer, a dispenser or a spreader, so that the complexity of coating operation can be reduced, the repeatability is high, and the material taking is accurate and easy to control.

At step 1020, the chamber lid coated with the adhesive is placed in a bonding apparatus (e.g., seed bonding apparatus 107 as shown in fig. 11A or 12A).

In some embodiments, the adhesive-coated seed holder may also be placed in a bonding apparatus (e.g., seed bonding apparatus 107 as shown in fig. 11A or 12A). In some embodiments, the adhesive coated cavity lid or seed holder may be manually held within the bonding apparatus. The cavity cover or the seed crystal support coated with the adhesive is placed in a manual mode, and the process is flexible in operation, simple in equipment and low in cost. In some embodiments, the robotic arm may be controlled by the processing device and/or the control device to hold the adhesive coated chamber lid or seed in the bonding device. In some embodiments, the robot arm may automatically place the adhesive coated chamber lid or seed holder according to a set program. The cavity cover or the seed crystal support coated with the adhesive is placed through the mechanical arm, so that the labor cost can be reduced, the automation degree is high, and the operation and the control are easy.

And step 1030, performing air exhaust treatment on the bonding equipment.

In some embodiments, the pressure of the bonding apparatus after the evacuation process is in the range of 0.1Pa to 10 Pa. In some embodiments, the pressure of the bonding apparatus after the evacuation process is in the range of 0.5Pa to 10 Pa. In some embodiments, the pressure of the bonding apparatus after the evacuation process is in the range of 1Pa to 9 Pa. In some embodiments, the pressure of the bonding apparatus after the evacuation process is in the range of 2Pa to 8 Pa. In some embodiments, the pressure of the bonding apparatus after the evacuation process is in the range of 3Pa to 7 Pa. In some embodiments, the pressure of the bonding apparatus after the evacuation process is in the range of 4Pa to 6 Pa. In some embodiments, the pressure of the bonding apparatus after the evacuation process is in the range of 4.5Pa to 5.5 Pa. In some embodiments, the pressure of the bonding apparatus after the evacuation process is in the range of 5.0Pa to 5.2 Pa.

In some embodiments, the bonding apparatus may be subjected to a suction process by a vacuum device (e.g., a vacuum pump).

Through the air exhaust treatment, a vacuum environment with almost no gas or less gas can be generated, and the desorption of the gas adsorbed in the bonding equipment, the cavity cover or the seed crystal support, the adhesive and the like is facilitated, so that bubbles in the adhesive are eliminated or reduced, the defects of micropipes, hexagonal cavities and the like generated in the subsequent crystal preparation process are avoided, and the crystal quality is improved.

At step 1040, pressure is applied by a pressing assembly (e.g., pressing assembly 107-6 shown in fig. 11A or 12A) to adhere the seed crystal to the chamber lid.

In some embodiments, the seed crystal may also be adhered to the seed holder by a pressing assembly (e.g., pressing assembly 107-6 shown in fig. 11A or 12A). In some embodiments, the seed crystal may be held to the chuck of the hold-down assembly by suction (e.g., chucks 107-61 as shown in FIG. 11A or 12A). In some embodiments, the adsorption means may include high temperature non-marking adhesive bonding, electrostatic adsorption, or the like, or any combination thereof.

In some embodiments, as shown in fig. 11A and 11B, the movement (e.g., up and down movement) of the hold-down assembly may be controlled by the processing device and/or the control device to contact the seed crystal with the chamber lid or the seed holder and further apply pressure to bond the two. In some embodiments, after contacting the seed crystal with the chamber cover or the seed holder, the ultrasonic detection device (e.g., an ultrasonic flaw detector) may be controlled by the processing device and/or the control device to detect the quality of the fit (e.g., air hole detection, i.e., the presence or absence of air bubbles, the area ratio of air bubbles) of the seed crystal and the chamber cover or the seed holder before applying pressure for bonding. In some embodiments, fit quality may qualify as no bubbles or a bubble area fraction less than a proportion threshold (e.g., less than 2%); otherwise, the lamination quality is unqualified. In some embodiments, if the quality of the fit is acceptable, the pressing assembly can be controlled by the processing device and/or the control device to move to apply pressure so as to adhere the seed crystal to the cavity cover or the seed holder. In some embodiments, if the fitting quality is not qualified, the pressing assembly can be controlled by the processing equipment and/or the control equipment to move reversely so as to fit the seed crystal with the cavity cover or the seed crystal support again, and the fitting quality is detected again until the fitting quality is qualified. For more details on the detection of the air holes, reference may be made to the description of step 320, which is not repeated herein.

In some embodiments, a buffer layer may also be disposed between the seed crystal and the chamber lid or seed holder. In some embodiments, as shown in fig. 12A and 12B, an adhesive may be applied to the upper surface of the buffer layer and/or the lower surface of the seed crystal, and the buffer layer may be snapped and placed under the seed crystal, and the adhesive-coated chamber lid or seed crystal may be held in place within the bonding apparatus. In some embodiments, the movement (e.g., up and down movement) of the hold-down assembly may be controlled by the processing and/or control apparatus to bring the seed and buffer layers (e.g., buffer layer H shown in fig. 12A and 12B) into contact with the chamber lid and further apply pressure to bond the three. In some embodiments, after contacting the seed crystal and the buffer layer with the chamber cover, the quality of the fit (e.g., presence or absence of bubbles, area ratio of bubbles) of the seed crystal to the buffer layer and the buffer layer to the chamber cover may be detected by the processing device and/or the control device controlling an ultrasonic detection device (e.g., an ultrasonic flaw detector) before applying the pressure bonding. In some embodiments, if the fitting quality is qualified, the pressing assembly can be controlled by the processing equipment and/or the control equipment to move to apply pressure so as to bond the seed crystal and the buffer layer with the cavity cover. In some embodiments, if the fitting quality is unqualified, the pressing assembly can be controlled by the processing equipment and/or the control equipment to move reversely so as to fit the seed crystal, the buffer layer and the cavity cover again, and the fitting quality is detected again until the fitting quality is qualified. In some embodiments, the chamber lid shown in fig. 12A and 12B may also be a seed holder. For more details on the detection of the air holes, reference may be made to the description of step 320, which is not repeated herein.

In some embodiments, the suction treatment and the heating treatment may be performed simultaneously during the bonding or pressing.

In some embodiments, the applied pressure of the compression assembly may be between 0.01MPa and 1.5MPa. In some embodiments, the compression assembly may apply a pressure in the range of 0.1MPa to 1.5MPa. In some embodiments, the compression assembly may apply a pressure in the range of 0.2MPa to 1.4MPa. In some embodiments, the compression assembly may apply a pressure in the range of 0.3MPa to 1.3MPa. In some embodiments, the compression assembly may apply a pressure in the range of 0.4MPa to 1.2MPa. In some embodiments, the compression assembly may apply a pressure in the range of 0.5MPa to 1.1MPa. In some embodiments, the compression assembly may apply a pressure in the range of 0.6MPa to 1.0MPa. In some embodiments, the compression assembly may apply a pressure in the range of 0.7MPa to 0.9MPa. In some embodiments, the compression assembly may apply a pressure in the range of 0.75MPa to 0.85MPa.

In some embodiments, the pressure of the bonding apparatus after the evacuation process is in the range of 0.1Pa to 10 Pa. In some embodiments, the pressure of the bonding apparatus after the evacuation process is in the range of 0.5Pa to 9.5 Pa. In some embodiments, the pressure of the bonding apparatus after the evacuation process is in the range of 1Pa to 9 Pa. In some embodiments, the pressure of the bonding apparatus after the evacuation process is in the range of 1.5Pa to 8.5 Pa. In some embodiments, the pressure of the bonding apparatus after the evacuation process is in the range of 2Pa to 8 Pa. In some embodiments, the pressure of the bonding apparatus after the evacuation process is in the range of 2.5Pa to 7.5 Pa. In some embodiments, the pressure of the bonding apparatus after the evacuation process is in the range of 3Pa to 7 Pa. In some embodiments, the pressure of the bonding apparatus after the evacuation process is in the range of 3.5Pa to 6.5 Pa. In some embodiments, the pressure of the bonding apparatus after the evacuation process is in the range of 4Pa to 6 Pa. In some embodiments, the pressure of the bonding apparatus after the evacuation process is in the range of 4.5Pa to 5.5 Pa.

In some embodiments, the temperature of the heat treatment is too low and the adhesive has not yet cured or carbonized; since the temperature of the heat treatment is too high and the viscosity of the adhesive is low, it is necessary to set an appropriate temperature range of the heat treatment. In some embodiments, the temperature of the heat treatment may be in the range of 200 ℃ to 1200 ℃. In some embodiments, the temperature of the heat treatment may be in the range of 300 ℃ to 1100 ℃. In some embodiments, the temperature of the heat treatment may be in the range of 400 ℃ to 1000 ℃. In some embodiments, the temperature of the heat treatment may be in the range of 500 ℃ to 900 ℃. In some embodiments, the temperature of the heat treatment may be in the range of 600 ℃ to 800 ℃. In some embodiments, the temperature of the heat treatment may be in the range of 650 ℃ to 750 ℃. In some embodiments, the temperature of the heat treatment may be in the range of 680 ℃ to 720 ℃.

In some embodiments, the time of the heat treatment may be in the range of 1min to 600 min. In some embodiments, the time of the heat treatment may be in the range of 50min to 600 min. In some embodiments, the time of the heat treatment may be in the range of 100min to 550 min. In some embodiments, the time of the heat treatment may be in the range of 150min to 500 min. In some embodiments, the time of the heat treatment may be in the range of 200min to 450 min. In some embodiments, the time of the heat treatment may be in the range of 250min to 400 min. In some embodiments, the time of the heat treatment may be in the range of 300min to 350 min.

The air bubbles in the adhesive are removed through air extraction treatment, so that the air bubbles in the adhesive are basically removed before bonding, pressure is further applied to compress seed crystals, air extraction treatment and heating treatment are further performed, new air bubbles can be further prevented from being generated in the bonding process, meanwhile, the heating treatment ensures the cohesiveness of the adhesive, the bonding effect is improved, the defects of micropipes, hexagonal cavities and the like generated in the subsequent crystal growth process are avoided, and the crystal quality is improved.

FIG. 11A is a schematic diagram of an exemplary seed bonding apparatus according to some embodiments of the present description; fig. 11B is a schematic illustration of exemplary seed crystals after bonding, according to some embodiments herein. Wherein A is adhesive and Z is seed crystal.

In some embodiments, as shown in FIGS. 11A and 11B, the seed bonding apparatus 107 may include a bonding chamber 107-1, a vacuum assembly 107-2, an upper drive assembly 107-3, a lower drive assembly 107-4, a heating assembly 107-5, and a pressing assembly 107-6.

Bonding chamber 107-1 may be the site of a seed bond. Vacuum assembly 107-2 may be used to evacuate bonding chamber 107-1. The upper driving assembly 107-3 may be coupled to the top end of the bonding chamber 107-1. A lower drive assembly 107-4 may be coupled to the bottom end of the bonding chamber 107-1. The heating assembly 107-5 may be used to provide the heat required for seed bonding. Pressure may be applied by pressing assembly 107-6 to bond seed crystal Z to chamber cover 108-111.

In some embodiments, the compaction assembly 107-6 can include a suction cup 107-61 and a support table 107-62. In some embodiments, the upper end of suction cup 107-61 may be connected to the top of bonding chamber 107-1 by upper actuator assembly 107-3. In some embodiments, the lower end of the support table 107-62 may be coupled to the bottom end of the bonding chamber 107-1 via a lower drive assembly 107-4. In some embodiments, the lower end of the chuck 107-61 may be used to chuck the seed crystal Z. In some embodiments, the upper ends of support tables 107-62 may be used to position chamber covers 108-111. In some embodiments, the upper surface of the chamber covers 108-111 and/or the lower surface of the seed crystal Z may be coated with the adhesive A.

In some embodiments, the pressing assembly 107-6 may bond the seed crystal Z to the chamber cover 108-111 by cooperating with the upper driving assembly 107-3, the lower driving assembly 107-4, and the heating assembly 107-5. In some embodiments, the pressure required for seed bonding may be provided by the movement of the upper drive assembly 107-3 and/or the lower drive assembly 107-4. In some embodiments, the suction cup 107-61 can drive the seed crystal Z to move downwards through the movement of the upper transmission assembly 107-3, the support table 107-62 can drive the chamber cover 108-111 to move upwards through the movement of the lower transmission assembly 107-4, and after the seed crystal Z contacts with the adhesive A on the chamber cover 108-111, the upper transmission assembly 107-3 and/or the lower transmission assembly 107-4 continue to move to provide the pressure required by the adhesion of the seed crystal, so that the seed crystal Z is adhered on the chamber cover 108-111.

In some embodiments, the seed bonding apparatus 107 may further include a pressure sensing assembly 107-7. In some embodiments, the pressure sensing assembly 107-7 may be located in the upper drive assembly 107-3 and/or the lower drive assembly 107-4. In some embodiments, the pressure sensing assembly 107-7 may be used to monitor the applied pressure of the compacting assembly 107-6 and adjust the applied pressure accordingly. In some embodiments, when the pressure of the suction cups 107-61 and the support tables 107-62 in the pressing assembly 107-6 is low, the upper driving assembly 107-3 may be lowered and/or the lower driving assembly 107-4 may be raised to increase the applied pressure; conversely, the upper drive assembly 107-3 may be raised and/or the lower drive assembly 107-4 may be lowered to reduce the applied pressure; the pressure sensing assembly 107-7 is located in the upper drive assembly 107-3 and/or the lower drive assembly 107-4 and moves therewith.

In some embodiments, the seed crystal Z may be adsorbed on the lower surface of the chuck 107-61, the chamber cover 108-111 may be placed on the support table 107-62, the seed crystal Z and the chamber cover 108-111 may be vertically concentric without contact, and the adhesive a may be coated on the lower surface of the seed crystal Z and/or the lower surface of the growth chamber cover (above the chamber cover 108-111 in fig. 11A), the seed crystal Z on the chuck 107-61 may be moved downward by the movement of the upper driving assembly 107-3, the chamber cover 108-111 on the support table 107-62 may be moved upward by the movement of the lower driving assembly 107-4, after the seed crystal Z contacts the adhesive a on the chamber cover 108-111, the upper driving assembly 107-3 and/or the lower driving assembly 107-4 may be moved further to provide the pressure required for seed crystal adhesion, the pressure applied by the pressing assembly 107-6 may be monitored by the pressure sensing assembly 107-7 during the seed crystal adhesion process, and the adhesion chamber may be kept sealed and vacuum state.

FIG. 12A is a schematic diagram illustrating an exemplary seed bonding apparatus, according to further embodiments of the present disclosure; FIG. 12B is a schematic diagram of exemplary seed bonding, wherein A is an adhesive, Z is a seed, and H is a buffer layer, in accordance with further embodiments of the present disclosure.

FIG. 12A is similar to the structure of the seed crystal bonding apparatus in FIG. 11A, and further contents of the bonding chamber 107-1, the vacuum assembly 107-2, the upper driving assembly 107-3, the lower driving assembly 107-4, the heating assembly 107-5, the pressing assembly 107-6 and the pressure sensing assembly 107-7 can be referred to in other parts of the present specification (for example, FIG. 11A and the related descriptions thereof), and will not be described herein again.

In some embodiments, as shown in FIG. 12A, the seed bonding apparatus 107 may further comprise a support assembly 107-8. In some embodiments, the support assembly 107-8 may be two L-shaped brackets symmetrically disposed on both sides of the chuck 107-61, respectively, to clamp the buffer layer H and place it under the seed crystal Z.

In some embodiments, the buffer layer H may be a material that buffers the adhesion between the seed crystal Z and the chamber covers 108 to 111. In some embodiments, buffer layer H may include a flexible carbon-based material. For example, the buffer layer H may include a flexible carbon-based material having a uniform and flat thickness, such as graphite paper, carbon fiber, or graphene.

Because the buffer layer is made of flexible materials and has a certain deformation, the buffer layer is arranged between the seed crystal and the cavity cover, and the processing errors of the plane of the cavity cover and the back of the seed crystal can be matched. Meanwhile, the compactness of the buffer layer is greater than that of the graphite cavity cover, so that the permeation of the adhesive can be avoided, and the bonding quality of the buffer layer and the seed crystal is superior to that of the seed crystal directly bonded with the graphite cavity cover.

In some embodiments, the buffer layer H may be disposed above the supporting assembly 107-8, the seed crystal Z is adsorbed on the lower surface of the chuck 107-61, and the chamber cover 108-111 is disposed on the upper surface of the supporting table 107-62, such that the seed crystal Z, the buffer layer H, and the chamber cover 108-111 are sequentially disposed concentrically in the vertical direction without contact; coating adhesive A on the lower surface of the seed crystal Z and/or the upper surface of the buffer layer H and/or the upper surface of the growth cavity cover, driving the seed crystal Z on the sucker 107-61 to move downwards through the movement of the upper transmission assembly 107-3, driving the cavity cover 108-111 on the support table 107-62 to move upwards through the movement of the lower transmission assembly 107-4, bonding through the adhesive A on the upper surface of the buffer layer H after the seed crystal Z is contacted with the buffer layer H, continuously moving downwards to bond with the cavity cover 108-111 moving upwards through the adhesive A on the upper surface of the growth cavity cover, and providing pressure required by seed crystal bonding through the continuous movement of the upper transmission assembly 107-3 and/or the lower transmission assembly 107-4. In the seed crystal bonding process, the pressure applied by the pressing component 107-6 is monitored by the pressure sensing component 107-7, and the bonding cavity is kept in a closed and vacuum state, so that the seed crystal Z, the buffer layer H and the cavity cover 108-111 are sequentially bonded in the vertical direction.

In some embodiments, the buffer layer H (e.g., graphite paper) and the adhesive a may also be processed as an integral molding to form a solid glue. In some embodiments, during the seed crystal bonding process, the integrally formed buffer layer H and the adhesive a may be disposed above the support assembly 107-8, the seed crystal Z is adsorbed on the lower surface of the chuck 107-61, and the chamber cover 108-111 is disposed on the upper surface of the support table 107-62, as described above, and the seed crystal Z is bonded to the chamber cover 108-111 by the integrally formed buffer layer H and the adhesive a through the movement of the upper and lower driving assemblies 107-3 and 107-4. In the seed crystal bonding process, the pressure applied by the compaction component 107-6 is monitored by the pressure sensing component 107-7, and the bonding cavity is kept in a closed and vacuum state, so that the seed crystal Z, the buffer layer H and the cavity cover 108-111 are sequentially bonded in the vertical direction.

By processing the buffer layer H and the adhesive A into an integral molding, the problem that the liquid adhesive is not uniformly flattened or bubbles are generated in the flattening process can be avoided, and the bonding quality of the seed crystal is improved, so that the defects of micropipes, hexagonal cavities and the like of the silicon carbide crystal caused by the bubbles in the crystal growth process are avoided.

FIG. 13 is a flow chart illustrating an exemplary seed bonding method according to further embodiments herein; FIG. 14A is a schematic view of an exemplary rolling operation, according to some embodiments herein; FIG. 14B is a schematic diagram illustrating an exemplary rolling operation according to further embodiments herein. In some embodiments, flow 1300 may be performed by a processing device (e.g., processing device 101) and/or a control device (e.g., control device 102). For example, the process 1300 may be stored in a storage device (e.g., a storage unit of a storage device, a processing device, and/or a control device) in the form of a program or instructions, which when executed by the processor 202, may implement the process 1300. In some embodiments, flow 1300 may utilize one or more additional operations not described below, and/or be accomplished without one or more of the operations discussed below. In addition, the order of the operations shown in fig. 13 is not limiting.

Step 1310, the seed crystal and the buffer are stacked on the bonding table.

In some embodiments, the interface between the buffer layer and the seed crystal is coated with an adhesive. In some embodiments, the lower surface of the buffer layer and the upper surface of the seed crystal are in contact, and accordingly, the lower surface of the buffer layer and/or the upper surface of the seed crystal may be coated with an adhesive. In some embodiments, the upper surface of the buffer layer and the lower surface of the seed crystal are in contact, and accordingly, the upper surface of the buffer layer and/or the lower surface of the seed crystal may be coated with an adhesive.

In some embodiments, the size of the buffer layer may be set according to actual needs. In some embodiments, the buffer layer may have a size greater than or equal to the size of the seed crystal. For more details of the buffer layer, reference may be made to other parts of this specification (for example, fig. 12A and 12B and their related descriptions), and details are not repeated herein. In some embodiments, the bonding stage may be any platform for placement of a seed crystal with sufficient levelness.

In some embodiments, the buffer layer and the seed crystal may be stacked on the bonding mesa by hand. The buffer layer and the seed crystal are placed in a manual mode, and the process is flexible to operate, simple in equipment and low in cost. In some embodiments, the robotic arm may be controlled by the processing device and/or the control device to place the buffer layer and the seed crystal on the bonding stage. In some embodiments, the robot arm may automatically place the buffer layer and seed according to a set program. The buffer layer or the seed crystal coated with the adhesive is placed through the mechanical arm, so that the labor cost can be reduced, the automation degree is high, and the control is easy.

In some embodiments, the adhesive may be applied to the buffer layer and/or the contact surface of the seed by hand. The adhesive is coated in a manual mode, and the process is flexible to operate, simple in equipment and low in cost. In some embodiments, the robot may be controlled by the processing apparatus and/or control apparatus to apply the adhesive to the buffer layer and/or the contact surface of the seed crystal. In some embodiments, the robotic arm may automatically apply the adhesive according to a set program. The mechanical arm is coated with the adhesive, so that the labor cost can be reduced, the repeatability is high, and the mechanical arm is accurate and easy to control.

And 1320, rolling the pressing assembly to bond the seed crystal with the buffer layer.

In some embodiments, the compaction assembly can include a pressure roller. In some embodiments, the seed crystal may be bonded to the buffer layer by a rolling operation using a roller. In some embodiments, as shown in fig. 14A, a buffer layer H and a seed crystal Z may be stacked on the bonding mesa 107-9, the seed crystal Z and the buffer layer H are concentrically arranged in the vertical direction, and the contact surface of the buffer layer H and the seed crystal Z is coated with an adhesive. The seed crystal Z may be bonded to the buffer layer H by a rolling operation of the buffer layer H by the pressing roller 107-10.

In some embodiments, during the rolling process, in order to make the seed crystal and the buffer layer adhere tightly after the rolling operation is completed, a first angle (e.g., angle θ in fig. 14A) between the buffer layer and the non-contact portion of the seed crystal, a first pressure applied by the pressing roller, and/or a first speed of movement of the pressing roller should satisfy certain requirements.

In some embodiments, the first angle may be in the range of 0.1 ° to 15 °. In some embodiments, the first angle may be in the range of 1 ° to 14 °. In some embodiments, the first angle may be in the range of 2 ° to 13 °. In some embodiments, the first angle may be in the range of 3 ° to 12 °. In some embodiments, the first angle may be in the range of 4 ° to 11 °. In some embodiments, the first angle may be in the range of 5 ° to 10 °. In some embodiments, the first angle may be in the range of 6 ° to 9 °. In some embodiments, the first angle may be in the range of 7 ° to 8 °.

In some embodiments, the first pressure may be in the range of 0.1kPa to 25 kPa. In some embodiments, the first pressure may be in the range of 2kPa to 23 kPa. In some embodiments, the first pressure may be in the range of 4kPa to 21 kPa. In some embodiments, the first pressure may be in the range of 6kPa to 19 kPa. In some embodiments, the first pressure may be in the range of 8kPa to 17 kPa. In some embodiments, the first pressure may be in the range of 10kPa to 15 kPa. In some embodiments, the first pressure may be in the range of 12kPa to 13 kPa.

In some embodiments, the first speed may be in the range of 0.1mm/s to 60 mm/s. In some embodiments, the first speed may be in the range of 5mm/s to 55 mm/s. In some embodiments, the first speed may be in the range of 10mm/s to 50 mm/s. In some embodiments, the first speed may be in the range of 15mm/s to 45 mm/s. In some embodiments, the first speed may be in the range of 20mm/s to 40 mm/s. In some embodiments, the first speed may be in the range of 25mm/s to 35 mm/s. In some embodiments, the first speed may be in a range of 27mm/s to 33 mm/s. In some embodiments, the first speed may be in the range of 29mm/s to 31 mm/s.

Step 1330, stacking the cavity cover of the growth cavity, the bonded buffer layer and the seed crystal on the bonding table, wherein the buffer layer is located between the cavity cover and the seed crystal.

In some embodiments, the interface of the buffer layer and the chamber cover is coated with an adhesive. In some embodiments, the lower surface of the buffer layer is in contact with the upper surface of the chamber cover. In some embodiments, the upper surface of the buffer layer is in contact with the lower surface of the chamber cover.

In some embodiments, the cavity cover of the growth cavity, the bonded buffer layer and the seed crystal can be manually stacked on the bonding table. The cavity cover of the growth cavity, the bonded buffer layer and the seed crystal are placed in a manual mode, and the process is flexible in operation, simple in equipment and low in cost. In some embodiments, the robot may be controlled by the processing device and/or the control device to place the chamber lid of the growth chamber, the bonded buffer layer, and the seed crystal on the bonding stage. In some embodiments, the robot arm can automatically place the chamber cover, the bonded buffer layer and the seed crystal of the growth chamber according to a set program. The cavity cover coated with the adhesive is placed through the mechanical arm, so that labor cost can be reduced, the automation degree is high, and the cavity cover is easy to control.

In some embodiments, the adhesive may be applied manually to the interface of the buffer layer and the cavity cover. The adhesive is coated in a manual mode, and the process is flexible to operate, simple in equipment and low in cost. In some embodiments, the robot arm may be controlled by the processing device and/or the control device to apply an adhesive to the interface of the buffer layer and the chamber cover. In some embodiments, the robotic arm may automatically apply the adhesive according to a set program. The mechanical arm is coated with the adhesive, so that the labor cost can be reduced, the repeatability is high, and the mechanical arm is accurate and easy to control.

And 1340, performing rolling operation through the pressing assembly to enable the seed crystal to be bonded on the cavity cover.

In some embodiments, the seed crystal may be bonded to the chamber cover by rolling the seed crystal by the pressing roller to bond the buffer layer after bonding the seed crystal to the chamber cover. In some embodiments, as shown in fig. 14B, the chamber cover 108-111 of the growth chamber, the bonded buffer layer H and the seed crystal Z are sequentially stacked on the bonding table 107-9, the chamber cover 108-111, the bonded buffer layer H and the seed crystal Z are concentrically arranged in the vertical direction, the contact surface of the buffer layer H and/or the chamber cover 108-111 is coated with an adhesive, and the seed crystal Z can be bonded on the chamber cover 108-111 by rolling the seed crystal Z by the pressing roller 107-10. In some embodiments, in the rolling process, in order to make the cavity cover and the buffer layer adhere tightly after the rolling operation is completed, the angle between the non-contact part of the buffer layer and the cavity cover is a second angle, the pressure applied by the pressing roller is a second pressure, and the moving speed of the pressing roller is a second speed until the rolling operation is completed.

In some embodiments, the second angle may be in the range of 0.01 ° to 0.2 °. In some embodiments, the second angle may be in the range of 0.03 ° to 0.18 °. In some embodiments, the second angle may be in the range of 0.05 ° to 0.16 °. In some embodiments, the second angle may be in the range of 0.07 ° to 0.14 °. In some embodiments, the second angle may be in the range of 0.09 ° to 0.12 °. In some embodiments, the second angle may be in the range of 0.11 ° to 0.10 °. In some embodiments, the second angle may be in the range of 0.7 ° to 0.9 °. Through setting up the second angle in certain extent, can guarantee the seed crystal in less safe deformation scope, the bubble in the evacuation adhesive.

In some embodiments, the second pressure may be the same as or close to the first pressure. In some embodiments, the second speed may be the same as or close to the first speed. Further details regarding the first pressure and the first speed can be found in other parts of this specification (e.g., step 1320, fig. 14A, and the related description thereof), and are not repeated herein. In some embodiments, the second pressure may be different from the first pressure. In some embodiments, the second speed may be different from the first speed.

Through the rolling operation and the control of the first angle and/or the second angle, the first pressure and/or the second pressure and the first speed and/or the second speed in the rolling process, bubbles in the adhesive can be fully extruded and eliminated, and the generation of new bubbles in the bonding process is avoided, so that the defects of micropipes, hexagonal cavities and the like in the growing silicon carbide crystal are avoided, and the quality of the silicon carbide crystal is improved.

In some embodiments, the seed crystal may be bonded directly to the chamber lid without a buffer layer between the seed crystal and the chamber lid, and

steps

1310 and 1320 may be omitted. In some embodiments, the cavity lid and the seed of the growth cavity may be stacked on the bonding stage with an adhesive applied between the cavity lid and the seed. In some embodiments, a rolling operation may also be performed by the pressing assembly to adhere the seed crystal to the cavity cover. For more details on the rolling operation, reference may be made to the foregoing description, and further details will not be described herein.

FIG. 15 is a flow chart illustrating an exemplary crystal growth method according to further embodiments herein. In some embodiments, flow 1500 may be performed by a processing device (e.g., processing device 101) and/or a control device (e.g., control device 102). For example, the flow 1500 may be stored in a storage device (e.g., a storage device, a processing device, and/or a storage unit of a control device) in the form of a program or instructions that, when executed by the processor 202, may implement the flow 1500. In some embodiments, flow 1500 may utilize one or more additional operations not described below, and/or be accomplished without one or more of the operations discussed below. In addition, the order of the operations shown in fig. 15 is not limiting.

At 1510, the feedstock region is heated by a first heating assembly (e.g., the first heating assembly 108-31 shown in FIG. 16A, the first heating assembly 108-31 shown in FIG. 16B, the first heating assembly 108-31 shown in FIG. 16C) to sublimate the feedstock into a vapor phase component required for crystal growth.

In some embodiments, the first heating assembly can provide the heat required by the feedstock zone. In some embodiments, the first heating assembly may be disposed below the feedstock region or at the periphery of the chamber where the feedstock region is located.

In some embodiments, the first heating assembly may comprise an induction heating member. In some embodiments, the induction heating component may include an electromagnetic induction coil, a medium frequency power supply, or the like. In some embodiments, the first heating assembly may comprise a resistive heating element. In some embodiments, the resistive heating elements may include high resistance graphite, silicon molybdenum rods (MoSi) ₂ ) Nickel-chromium wires (Ni-Cr), iron-chromium-aluminum wires (Fe-Cr-Al), nickel-iron wires (Ni-Fe), nickel-copper wires (Ni-Cu), silicon carbide rods (SiC) and the like.

In some embodiments, the gas phase component may include Si, for example, to produce silicon carbide crystals ₂ C、SiC ₂ In the iso-gaseous phaseAnd (4) components.

At step 1520, the vicinity of the baffle plate is heated by a second heating assembly (e.g., the second heating assembly 108-32 shown in FIG. 16A, the second heating assembly 108-32 shown in FIG. 16B, the second heating assembly 108-32 shown in FIG. 16C) to maintain a discharge rate of the gas phase component through the at least one discharge port.

In some embodiments, a second heating assembly may be disposed laterally of the baffle for heating a region proximate the baffle to maintain a discharge rate of the gas-phase component through the at least one discharge port. In some embodiments, the vicinity of the partition may refer to an area of a predetermined range (e.g., 1mm, 5mm, 10mm, etc.) up or down the position of the partition.

In some embodiments, the second heating assembly may comprise an induction heating member. In some embodiments, the induction heating component may include an electromagnetic induction coil, an intermediate frequency power supply, or the like. In some embodiments, the second heating assembly may comprise a resistive heating element. In some embodiments, the resistive heating elements may include high resistance graphite, silicon molybdenum rods (MoSi) ₂ ) Nickel-chromium wires (Ni-Cr), iron-chromium-aluminum wires (Fe-Cr-Al), nickel-iron wires (Ni-Fe), nickel-copper wires (Ni-Cu), silicon carbide rods (SiC) and the like.

In some embodiments, the types of the first and second heating assemblies may be the same or different.

In some embodiments, the discharge rate may be the total amount of gas phase component per unit time that passes through the discharge port. In some embodiments, the discharge rate may reflect how fast the gas phase component passes through the discharge port.

The second heating assembly heats the position near the partition plate, so that the discharge rate of the gas-phase components passing through the discharge hole can be maintained, the stable growth of a crystal growth surface is maintained, the dislocation formation probability is obviously reduced, the crystal defects are reduced, and the quality of the grown crystal is improved.

At 1530, the growth zone is heated by a third heating assembly (e.g., the third heating assembly 108-33 shown in FIG. 16A, the third heating assembly 108-33 shown in FIG. 16B, the third heating assembly 108-33 shown in FIG. 16C).

In some embodiments, the third heating assembly may provide the heat required for growth. In some embodiments, the third heating assembly may be a segmented or individually controlled heating assembly. In some embodiments, the third heating assembly may include a plurality of sub-heating members. In some embodiments, the plurality of sub-heating elements may be circumferentially disposed at different radial diameters at the top of the growth zone. In some embodiments, the heating parameters of the plurality of sub-heating members may be independently controlled, respectively, to achieve independent control of the temperature at different radial diameters. For example, if the local radial temperature gradient increases, the local radial temperature gradient may be reduced by individually controlling the heating parameters of the plurality of sub-heating assemblies. In some embodiments, the plurality of sub-heating elements may be a plurality of annular heating resistor elements that gradually decrease in the radial direction, and the annular heating resistor elements are connected in parallel to form the third heating assembly. In some embodiments, the plurality of annular heating resistor components can be independently controlled according to the radial temperature gradient, so that the radial temperature gradient is smaller than a preset gradient threshold, the thermal stress of the crystal is reduced, the crystal is prevented from cracking, and the high-quality crystal is grown. In some embodiments, the third heating element may be disposed above the chamber cover or at the periphery of the chamber where the chamber cover is located.

In some embodiments, the plurality of sub-heating members may be circumferentially disposed at different axial heights at the outer periphery of the growth zone. In some embodiments, the heating parameters of the plurality of sub-heating members may be independently controlled, respectively, to achieve independent control of the temperature at different axial heights. For example, if the local axial temperature gradient increases, the local axial temperature gradient may be reduced by individually controlling the heating parameters of the plurality of sub-heating members. In some embodiments, the plurality of sub-heating parts may be a plurality of annular induction coils arranged at different heights along the axial direction, and the annular induction coils are connected in parallel to form a third heating assembly. In some embodiments, the plurality of annular induction coils can be independently controlled according to the axial temperature gradient, so that the axial temperature gradient is smaller than a preset gradient threshold, the thermal stress of the crystal is reduced, the crystal is prevented from cracking, and the crystal with high quality is grown.

In some embodiments, the third heating assembly may comprise an induction heating member. In some embodiments, the inductive heating component may include an electromagnetic induction coil, a magnetically permeable object, or the like. In some embodiments, the third heating assembly may comprise a resistive heating element. In some embodiments, the resistive heating elements may include high resistance graphite, silicon molybdenum rods (MoSi 2), nickel chromium wires (Ni-Cr), iron chromium aluminum wires (Fe-Cr-Al), nickel iron wires (Ni-Fe), nickel copper wires (Ni-Cu), silicon carbide rods (SiC), and the like.

In some embodiments, the heating types of the first, second, and/or third heating assemblies may be the same or different.

In some embodiments, the temperature near the baffle is higher than the temperature of the feed zone (or "temperature at the feed") and/or the temperature of the growth zone (or "temperature at the seed"), i.e., the temperature near the baffle > the temperature of the feed zone and/or the temperature of the growth zone. Accordingly, a bidirectional temperature gradient in which the high temperature region, the raw material region, and the growth region are at low temperatures at the partition plate can be formed in the growth chamber. For example, as shown in fig. 17, the temperature distribution within the growth chamber may be two opposing temperature gradients from the outlet near the baffle to the growth surface and from the outlet near the baffle to the feedstock region, next to the feedstock region (e.g., at the feedstock upper surface), and lowest in the growth region (e.g., growth surface). In some embodiments, the temperature near the baffle plate can be adjusted by adjusting the heating parameters of the second heating assembly, thereby adjusting the temperature gradient from the discharge port to the growth surface and further maintaining the discharge rate of the gas-phase component through the at least one discharge port. By forming the bidirectional temperature gradient, the gas phase component can be driven to be transmitted through the concentration gradient under the condition of satisfying raw material sublimation, the power of the first heating component is reduced to a certain extent, and the electric energy is saved; moreover, the temperature near the separator is highest, so that the nucleation and crystal growth of gas phase components near the separator can be inhibited; furthermore, by forming a bidirectional temperature gradient, the discharge rate of the gas-phase components through the discharge port can be adjusted, the influence of temperature change on the discharge rate is reduced when the temperature of the raw material area changes, the stability of the crystal growth rate is favorably controlled, and the stable growth of the crystal growth surface is maintained.

In some embodiments, the temperature of the feed zone is higher than the temperature in the vicinity of the baffle, and the temperature in the vicinity of the baffle is higher than the temperature of the growth zone, i.e., the temperature of the feed zone > the temperature in the vicinity of the baffle > the temperature of the growth zone. Accordingly, a temperature gradient may be formed in the growth chamber in which the raw material region, the spacer, and the growth region are sequentially decreased. In some embodiments, the temperature gradient from the material region to the discharge opening and to the growth surface can be adjusted by adjusting the heating parameters of the first heating assembly and the second heating assembly to adjust the temperature in the vicinity of the material region and the partition, and the temperature gradient and the concentration gradient from the material region to the discharge opening and to the growth surface can drive the gas-phase component to move towards the growth region because the gas-phase component concentration in the material region is greater than the concentration in the vicinity of the partition and/or the concentration gradient in the growth region. Through forming the temperature gradient and the concentration gradient of raw materials district to the growth face, can be satisfying under the sublimed condition of raw materials, through temperature gradient and the transmission of concentration gradient drive gas phase component, the discharge rate of adjusting the gas phase component in the discharge gate department of baffle is favorable to controlling the stability of crystal growth rate, maintains the stable growth of crystal growth face.

The raw material zone, the vicinity of the second heating component heating partition plate and the third heating component heating growth zone are respectively heated through the first heating component, the first heating component can control the temperature of the raw material to regulate and control the sublimation rate of the raw material, and the power of the first heating component is regulated and controlled to compensate the change of heat distribution and carbon-silicon ratio caused by carbonization after the bottom of the raw material zone is carbonized; the second heating assembly can inhibit gas phase nucleation and crystallization near the partition plate, reduce the influence of temperature regulation and control of the raw material area on the discharging rate, and maintain the discharging rate of the discharging port, so that the stable growth of the crystal growth surface is maintained; the third heating assembly can regulate and control the temperature gradient between the discharge port and the growth area and the radial temperature gradient of the seed crystal, reduce the thermal stress of crystal growth, reduce the temperature influence of the first heating assembly and/or the second heating assembly on the growth area, control the stability of the temperature of the growth surface of the crystal, reduce the probability of dislocation formation, reduce crystal defects and improve the quality of the grown crystal. In addition, the raw material area and the growth area are separately arranged, and the temperature of the raw material area, the position near the partition plate and the temperature of the growth area are independently controlled, so that the temperature gradient between the discharge port and the growth area and the radial temperature gradient of the seed crystal can be regulated, the thermal stress of crystal growth can be obviously reduced, the crystal quality is improved, and the growth rate is effectively regulated.

FIG. 16A is a schematic diagram of an exemplary crystal growth apparatus, shown in accordance with some embodiments herein; FIG. 16B is a schematic diagram illustrating an exemplary crystal growth apparatus, according to still further embodiments of the present disclosure; FIG. 16C is a schematic diagram of an exemplary crystal growth apparatus, according to further embodiments herein. Wherein Z is seed crystal and Y is raw material. The crystal growth apparatus is described in detail below with reference to fig. 16A to 16C.

In some embodiments, crystal growth apparatus 108 may include growth chamber 108-1 and heating assembly 108-3.

In some embodiments, growth chamber 108-1 may include a growth region 108-11 and a feedstock region 108-12, growth region 108-11 for placing a seed crystal and feedstock region 108-12 for placing a feedstock. In some embodiments, growth zone 108-11 and feedstock zone 108-12 are separated by a partition 108-2. In some embodiments, the barrier 108-2 may include at least one outlet 108-21 through which the vapor phase components are delivered to the growth zone 108-11 via the at least one outlet 108-21. Through setting up discharge gate 108-21, can carry out reasonable distribution to the gaseous phase component that raw materials sublimation decomposition produced to further make the discharge rate of discharge gate stable even, with the high quality crystal of deposit growth obtaining suitable convexity.

In some embodiments, the heating assembly 108-3 may be used to heat the growth chamber 108-1 to achieve crystal growth based on a physical vapor transport method of the seed crystal Z and the feedstock Y. In some embodiments, the heating assembly 108-3 may include a first heating assembly 108-31, a second heating assembly 108-32, and a third heating assembly 108-33 for heating the feedstock region, the vicinity of the baffle, and the growth region, respectively.

In some embodiments, ports 108-21 may be made by mechanical drilling. In some embodiments, the partition 108-2 itself may be made of a porous material, and the gap therein may serve as the outlet 108-21. For example, as shown in FIG. 16A, the outlet port 108-21 may be formed by mechanical punching in the partition 108-2. For another example, as shown in fig. 16B and 16C, the separator 108-2 may be porous graphite with pores thereon as the outlet 108-21. The pores on the porous graphite are used as the discharge holes 108-21, so that the carbon component can be supplemented under the condition of ensuring the raw material gas phase component to pass through, and no pollution is generated. In some embodiments, the partition 108-2 may also be a multi-layer grid structure (not shown), and the size and/or shape of the through holes on the partition may be adjusted by adjusting the position relationship between different layers on the partition.

In some embodiments, at least one of the position, shape, distribution, or flow area of ports 108-21 may be adjustable. In some embodiments, the location of ports 108-21 may include an axial location of ports 108-21 and a radial location of ports 108-21. In some embodiments, the shape of ports 108-21 may be a cross-sectional shape. In some embodiments, the distribution of the outlets 108-21 is the distribution position and/or the distribution density of the outlets 108-21 on the partition 108-2. In some embodiments, the flow area of ports 108-21 is the cross-sectional area of a single port 108-21 or the sum of the cross-sectional areas of multiple ports 108-21.

In some embodiments, the relative position between the chamber cover and the outlet 108-21 can be adjusted by mounting the chamber cover on a slide rail. In some embodiments, a cover may be installed on the outlet 108-21, and the shape, distribution, or flow area of the outlet 108-21 may be adjusted by opening or closing the cover.

In some embodiments, as the crystal grows, the material is gradually consumed, the upper surface of the material gradually lowers, the thickness of the crystal gradually increases, and in order to maintain the distance from the crystal growth surface to the discharge opening 108-21 to stabilize the crystal growth, the axial position of the discharge opening 108-21 may be adjusted to gradually move the discharge opening 108-21 downward.

In some embodiments, as the crystal grows, the growth speed at each position on the growth surface of the seed crystal is different due to the possible radial temperature gradient on the surface of the seed crystal, and in order to ensure that the growth speed at each position on the growth surface of the seed crystal is the same or similar and the growth is a surface with a more smooth or proper convexity, the radial position of the discharge hole 108-21 can be adjusted to keep the growth speed at each position in the radial direction of the growth surface basically consistent or similar.

In some embodiments, the shape, distribution and/or flow area of the ports 108-21 may be adjusted by opening and closing the cover plate to maintain a stable discharge and growth rate of the growth surface.

In some embodiments, the relative position between the chamber cover and the discharge opening 108-21 in the next crystal growth process can be adjusted, or the shape, distribution or flow area of the discharge opening 108-21 can be adjusted, based on the crystal growth data collected in the previous crystal growth process.

In some embodiments, if the radial temperature gradient exists on the surface of the seed crystal during the previous crystal growth process, which results in different growth speeds at various positions on the growth surface of the seed crystal, in order to make the growth speeds at various positions on the growth surface of the seed crystal the same or similar and grow a surface with a smoother or proper convexity, the radial position of the discharge hole 108-21 during the next crystal growth process can be adjusted, and the growth speeds at various positions in the radial direction of the growth surface are kept basically the same or similar.

In some embodiments, if the gas-phase components are concentrated at a part of the positions in the previous crystal growth process, which results in higher concentration at the part of the positions in the growth cavity and too low concentration at the other positions, in order to make the gas-phase components at the positions below the growth surface of the seed crystal have the same or similar concentration, and grow a crystal with a relatively flat or proper convexity, the radial positions of the discharge ports 108-21 in the next crystal growth process can be adjusted, and the growth speeds at the radial positions of the growth surface are kept basically the same or similar.

In some embodiments, if the crystal thickness during the last crystal growth is less than a thickness threshold (e.g., 3mm, 5mm, or 8 mm) or the growth rate is less than a rate threshold (e.g., 0.1mm/h, 0.3mm/h, or 0.5 mm/h), the axial position of discharge ports 108-21 during the next crystal growth may be adjusted to cause the elevation of discharge ports 108-21, or the shape, distribution, or flow area of discharge ports 108-21 may be adjusted by opening the cover plate to increase the crystal growth rate.

For more details regarding adjusting at least one of the position, shape, distribution or flow area of the outlet, reference may be made to other portions of the present description (e.g., fig. 20-22 and the related descriptions thereof), which are not repeated herein.

In some embodiments, a first heating assembly 108-31 may be used to heat feedstock zone 108-12 to sublimate feedstock Y into the vapor phase components required for crystal growth. For example, as shown in FIGS. 16A and 16B, the first heating elements 108-31 may be resistive heating elements. As another example, as shown in FIG. 16C, the first heating elements 108-31 may be induction heating elements.

In some embodiments, the power of the first heating assembly 108-31 may be adjusted to compensate for the degree of carbonization of the feedstock during crystal growth to maintain the delivery rate of the gas phase component from the discharge port 108-21.

In some embodiments, a second heating assembly 108-32 may be disposed outside the baffle 108-2 for heating the vicinity of the baffle 108-2 to maintain a discharge rate of the gas-phase component through the at least one discharge port 108-21. For example, as shown in FIGS. 16A and 16B, the second heating elements 108-32 may be resistive heating elements. As another example, as shown in FIG. 16C, the second heating elements 108-32 may be induction heating elements.

In some embodiments, the power of the second heating assemblies 108-32 is maintained constant or ramped down during the crystal growth process to control the delivery rate of the gas phase constituents substantially constant.

In some embodiments, a third heating assembly 108-33 may be used to heat growth zone 108-11. For example, as shown in FIGS. 16A, 16B and 16C, the third heating elements 108-33 may be resistive heating elements.

In some embodiments, the power of third heating assemblies 108-33 is controlled during the growth of the crystal so that the radial temperature gradient of the crystal is as small as possible and so that the temperature gradient is maintained constant throughout the growth process.

In some embodiments, the third heating assembly 108-33 may include a plurality of sub-heating members disposed circumferentially at different axial heights about the periphery of the growth zone 108-11. In some embodiments, the heating parameters of the plurality of sub-heating members may be independently controlled, respectively, to achieve independent control of the temperature at different axial heights. For example, if the local axial temperature gradient increases, the local axial temperature gradient can be reduced by individually controlling the heating parameters of the plurality of sub-heating members. In some embodiments, the plurality of sub-heating parts may be a plurality of annular induction coils arranged at different heights along the axial direction, and the annular induction coils are connected in parallel to form the third heating assembly. In some embodiments, the plurality of annular induction coils can be independently controlled according to the axial temperature gradient, so that the axial temperature gradient is smaller than a preset gradient threshold, the thermal stress of the crystal is reduced, the crystal is prevented from cracking, and the crystal with high quality is grown.

In some embodiments, the third heating assembly 108-33 may include a plurality of sub-heating elements disposed around the top of the growth zone 108-11 at different radial diameters. In some embodiments, the heating parameters of the plurality of sub-heating members may be independently controlled, respectively, to achieve independent control of the temperature at different radial diameters. For example, if the local radial temperature gradient increases, the local radial temperature gradient may be reduced by individually controlling the heating parameters of the plurality of sub-heating members. In some embodiments, the plurality of sub-heating elements may be a plurality of annular heating resistor elements that gradually decrease in the radial direction, and the annular heating resistor elements are connected in parallel to form the third heating assembly. In some embodiments, the plurality of annular heating resistor components can be independently controlled according to the radial temperature gradient, so that the radial temperature gradient is smaller than a preset gradient threshold, the thermal stress of the crystal is reduced, the crystal is prevented from cracking, and the high-quality crystal is grown. In some embodiments, the third heating element may be disposed above the chamber cover or at the periphery of the chamber where the chamber cover is located.

In some embodiments, the crystal growth apparatus 108 may also include an incubation assembly 108-4. In some embodiments, a thermal insulation assembly 108-4 may be disposed between the material section 108-11 and the material section 108-12 for isolating the heat exchange between the material section 108-11 and the material section 108-12, so as to achieve the purpose of separately controlling the temperature of the material section 108-12 and the material section 108-11. In some embodiments, a plurality of apertures may be provided in the insulating assembly 108-4 to allow the vapor phase components to be transported to the growth zone 108-11 through the plurality of apertures.

In some embodiments, the crystal growth apparatus 108 may further include a thermometry assembly 103 for acquiring a plurality of temperatures associated with the growth chamber 108-1. For more reference, see fig. 18 and its associated description.

In some embodiments, the crystal growth apparatus 108 may further include a monitoring component 104 for monitoring crystal growth. For more on the monitoring component 104, reference can be made to fig. 19A and 19B and their associated description.

In some embodiments, the crystal growth apparatus 108 may also include a control component (not shown in fig. 16A-16C). In some embodiments, the control component may be implemented by the processing device 101 and/or the control device 102.

In some embodiments, the control assembly may obtain temperature information within the growth chamber 108-1; and adjusting at least one of a position, a shape, a distribution, or a flow area of the at least one discharge opening based on the temperature information. In some embodiments, the temperature information may be determined by modeling based on a plurality of temperatures. In some embodiments, the temperature information may include temperature information of the crystal growth face. In some embodiments, the control component may obtain temperature information within the growth chamber 108-1 during the last crystal growth run; and adjusting at least one of the position, shape, distribution or flow area of at least one discharge hole in the next crystal growth process based on the temperature information in the previous crystal growth process. For more contents on adjusting at least one of the position, shape, distribution or flow area of at least one discharge hole based on the temperature information or adjusting at least one of the position, shape, distribution or flow area of at least one discharge hole during the next crystal growth based on the temperature information during the previous crystal growth process, reference may be made to other parts of this specification (for example, fig. 20 and the related description thereof), and details thereof are not repeated herein.

In some embodiments, the control component may obtain a distribution of gas phase constituents within the growth chamber 108-1 that are required for crystal growth; and adjusting at least one of the position, shape, distribution or flow area of the at least one outlet based on the distribution. In some embodiments, the control component may obtain the distribution of gas phase constituents within the growth chamber 108-1 required for crystal growth during the last crystal growth; and adjusting at least one of the position, shape, distribution or flow area of at least one discharge hole in the next crystal growth process based on the distribution condition in the previous crystal growth process. For more contents of adjusting at least one of the position, the shape, the distribution, or the flow area of at least one discharge hole based on the distribution condition or adjusting at least one of the position, the shape, the distribution, or the flow area of at least one discharge hole during the next crystal growth process based on the distribution condition during the previous crystal growth process, reference may be made to other parts of this specification (for example, fig. 21 and the related description thereof), and details thereof are not repeated herein.

In some embodiments, the control assembly may also adjust at least one of a heating parameter of the heating assembly 108-3 and/or a position, shape, distribution, or flow area of the at least one discharge port 108-21 based on the crystal growth conditions. In some embodiments, the control assembly may also adjust at least one of the heating parameters of the heating assembly 108-3 and/or the position, shape, distribution, or flow area of the at least one discharge port 108-21 during the next crystal growth based on the growth of the crystal during the previous crystal growth. In some embodiments, the crystal growth condition may include at least one of a thickness, a growth rate, or a defect of the growing crystal. For more contents on adjusting the heating parameter of the heating assembly and/or the position, shape, distribution or flow area of the at least one discharge hole, or adjusting the heating parameter of the heating assembly and/or the position, shape, distribution or flow area of the at least one discharge hole in the next crystal growth process, reference may be made to other parts of this specification (for example, fig. 22 and the related description thereof), and details are not repeated here.

FIG. 18 is a schematic diagram of an arrangement of exemplary thermometric assemblies according to some embodiments of the present description.

In some embodiments, thermometry assembly 103 may include a plurality of temperature sensors 103-1. In some embodiments, as shown in FIG. 18, the side walls and/or top of growth chamber 108-1 may include insulation 103-2, and temperature sensor 103-1 may be disposed on the side walls and/or top of growth chamber 108-1 through insulation 103-2.

In some embodiments, temperature sensor 103-1 may comprise a thermocouple, an infrared pyrometer, a thermistor, or the like, or any combination thereof.

In some embodiments, the location and number of temperature sensors 103-1 may be set and adjusted according to monitoring needs. In some embodiments, multiple temperature sensors 103-1 may be arranged axially in a sidewall of growth chamber 108-1, or multiple temperature sensors 103-1 may be arranged radially in a top portion of growth chamber 108-1.

In some embodiments, temperature sensors 103-1 may be symmetrically distributed. For example, the growth chamber 108-1 has 4 temperature sensors 103-1 axially arranged on the left side wall and 4 temperature sensors 103-1 axially arranged on the right side wall. By arranging the temperature sensors 103-1 in symmetrical distribution, the temperature distribution condition of the growth cavity 108-1 can be integrally detected, and the holes are uniformly opened, so that the symmetry of a temperature field is ensured, and the influence on the crystal growth is avoided.

In some embodiments, the temperature sensors 103-1 may be asymmetrically distributed on the growth chamber 108-1. For example, the growth chamber 108-1 has 4 temperature sensors 103-1 axially arranged on the left side wall and 3 temperature sensors 103-1 axially arranged on the right side wall. By arranging the temperature sensors 103-1 in an asymmetric distribution manner, the local temperature condition in the growth cavity 108-1 can be detected with high emphasis, and the flexibility is higher.

In some embodiments, an axial temperature gradient or a radial temperature gradient within growth chamber 108-1 may be obtained by temperature sensor 103-1.

In some embodiments, to avoid deposition of volatiles in the growth chamber at the temperature measurement ports, which may lead to inaccurate temperature measurements, a cooling assembly 103-3 is disposed between the plurality of temperature sensors 103-1 and the top and/or sidewalls of the growth chamber 108-1. In some embodiments, if temperature sensor 103-1 is an infrared pyrometer, a cold trap may be disposed between temperature sensor 103-1 and the top and/or sidewalls of growth chamber 108-1. In some embodiments, the cold trap may be a hollow cylindrical structure (e.g., a hollow cylinder, a hollow cuboid, etc.), one end of the hollow cylindrical structure is connected to the chamber and is not sealed, the other end is sealed by an optical glass, and the temperature measuring point of the temperature sensor 103-1 is located on the axis of the cold trap and outside the optical glass. The side wall of the cold trap can be a hollow structure, and the temperature of the inner wall can be reduced by introducing cooling water.

In some embodiments, cooling assembly 103-3 may include one or more. In some embodiments, the cooling assembly 103-3 may be disposed in correspondence with a plurality of temperature sensors 103-1. For example, one cooling assembly 103-3 may be provided for each temperature sensor 103-1. By arranging the cooling assembly 103-3 between the temperature sensor 103-1 and the top and/or the side wall of the growth chamber 108-1, the volatile matter (e.g., gas phase components) in the growth chamber 108-1 can be cooled and attached to the side wall of the cooling assembly 103-3, and can not reach the temperature sensor 103-1, which affects the detection effect of the temperature sensor.

Be provided with cooling module between temperature sensor and growth cavity top, temperature measurement component is located the cooling module top, because cooling module department temperature is lower, volatile substance volatilizees the in-process and can attach to on the cooling module lateral wall, can not reach top temperature measurement component department to avoid volatile substance to attach to on temperature measurement component, guarantee that temperature measurement component's measurement is accurate.

FIG. 19A is a schematic structural diagram of an exemplary monitoring assembly according to some embodiments herein; FIG. 19B is a block diagram illustrating an exemplary monitoring assembly according to further embodiments of the present disclosure. Wherein Z is a seed crystal.

In some embodiments, monitoring component 104 may include a contact monitoring component or a non-contact monitoring component. For example, fig. 19A is a contact monitoring assembly, and fig. 19B is a non-contact monitoring assembly.

In some embodiments, as shown in fig. 19A, the monitoring component 104 may be a contact monitoring component. Monitoring assembly 104 may include ultrasonic thickness gauge 104-1, cooling device 104-2, and graphite rod 104-3. In some embodiments, ultrasonic thickness gauge 104-1 may include ultrasonic probe 104-11. In some embodiments, graphite rod 104-3 may be integrally formed with chamber cover 108-111. The ultrasonic probe 104-11 can emit an ultrasonic wave and reflect via the growing crystal Z, and can determine the thickness of the growing crystal Z based on the propagation time of the ultrasonic wave. Further, the crystal growth rate can also be calculated based on the thickness information at a plurality of time points.

Since the ultrasonic probe 104-11 has certain requirements on the contact temperature, damage may be caused by too high a temperature, and therefore, the temperature of the contact point of the ultrasonic probe 104-11 needs to be reduced to below 500 ℃. In some embodiments, the temperature at the contact point of the ultrasound probe 104-11 may be reduced by increasing the length of the graphite rod 104-3. In some embodiments, the temperature at the contact point of the ultrasonic probe 104-11 can be reduced by providing a cooling device 104-2 on top of the graphite rod 104-3. In some embodiments, cooling device 104-2 may be a gas-cooled device. Specifically, the cooling device 104-2 may be a sealed graphite cylinder, the ultrasonic probe 104-11 is placed inside the cooling device 104-2 from the upper part of the cooling device 104-2 and on the graphite rod 104-3, and an inert gas may be introduced into the cooling device 104-2 to cool the ultrasonic probe 104-11. It should be noted that the cooling device 104-2 and the growth chamber 108-1 are sealed devices, and the gases in the two devices do not flow through each other.

If the thickness of the graphite rod 104-3 is too thick, the conduction of ultrasonic pulses is affected, so that the measurement result of the ultrasonic thickness gauge 104-1 is affected; if the thickness of the graphite rod 104-3 is too thin, a good cooling effect cannot be achieved, and the temperature of the contact point of the ultrasonic probe 104-11 is too high, which may cause damage to the ultrasonic probe 104-11, it is necessary to set the thickness of the graphite rod 104-3 within a proper range.

In some embodiments, the thickness of the graphite rod 104-3 may be in the range of 5cm to 30 cm. In some embodiments, the thickness of the graphite rod 104-3 may be in the range of 8cm to 27 cm. In some embodiments, the thickness of the graphite rod 104-3 may be in the range of 11cm to 24 cm. In some embodiments, the thickness of the graphite rod 104-3 may be in the range of 14cm to 21 cm. In some embodiments, the thickness of the graphite rod 104-3 may be in the range of 17cm to 18 cm. In some embodiments, the thickness of the graphite rod 104-3 may be in the range of 17.3cm to 18.7 cm.

In some embodiments, a coupling agent (e.g., a polymer hydrogel) may be used at the contact point of the ultrasonic probe 104-11 and the graphite rod 104-3 of the contact monitoring assembly 104 to fill a tiny gap between the contact point of the graphite rod 104-3 and the ultrasonic probe 104-11, so as to prevent a trace of air between the gaps from affecting the measurement effect. In some embodiments, the ultrasonic probe 104-11 may take measurements at fixed positions at intervals, or may take rapid measurements while moving along a particular trajectory, to obtain data on the growth rate of the crystal at a fixed position or the thickness distribution over a certain area.

In some embodiments, as shown in fig. 19B, the monitoring component 104 may be a non-contact monitoring component. In some embodiments, the non-contact monitoring assembly 104 may include air-coupled ultrasonic non-destructive testing, electromagnetic ultrasonic (EMAT) non-destructive testing, electrostatically-coupled ultrasonic non-destructive testing, laser ultrasonic non-destructive testing, and the like.

Since no contact is required between the ultrasonic probe 104-11 of the non-contact monitoring assembly 104 and the cavity covers 108-111, the risk of damage to the ultrasonic probe 104-11 when it contacts a high temperature object to be tested can be avoided.

FIG. 20 is a flow chart of an exemplary crystal growth method according to further embodiments herein. In some embodiments, the flow 2000 may be performed by a processing device (e.g., processing device 101) and/or a control device (e.g., control device 102). For example, the process 2000 may be stored in a storage device (e.g., a storage device, a processing device, and/or a storage unit of a control device) in the form of a program or instructions, which when executed by the processor 202, may implement the process 2000. In some embodiments, flow 2000 may utilize one or more additional operations not described below, and/or be accomplished without one or more operations discussed below. In addition, the order of the operations shown in fig. 20 is not limiting.

Step 2010, acquiring temperature information in the growth cavity.

In some embodiments, the temperature information may be temperature values, temperature gradients, or temperature distributions throughout the growth cavity. In some embodiments, the temperature information may include temperature information of the crystal growth face.

In some embodiments, the processing equipment and/or the control equipment may acquire a plurality of temperatures associated with the growth chamber via a thermometry assembly. In some embodiments, the thermometric assembly may include a plurality of temperature sensors. For more details of the temperature measurement component, reference may be made to other parts of this specification (for example, fig. 18 and the related description thereof), and details are not repeated here.

In some embodiments, the processing device and/or the control device may determine temperature information within the growth chamber by modeling based on a plurality of temperatures. In some embodiments, the processing device and/or the control device can obtain positional information between a plurality of thermometric components (e.g., temperature sensor 103-1 shown in FIG. 18) and positional information of the thermometric components and the crystal growth face. In some embodiments, the processing equipment and/or the control equipment may determine positional information (e.g., distance, angle) between the plurality of thermometric components based on structural parameters of the crystal growth apparatus (e.g., dimensions of the crystal growth apparatus) and the locations of the thermometric components on the crystal growth apparatus. In some embodiments, the processing apparatus and/or the control apparatus may obtain the crystal thickness via the monitoring assembly 104 (e.g., monitoring assembly 104 of fig. 19A and 19B), and determine positional information (e.g., distance, angle) of the plurality of temperature measurement assemblies from the crystal growth surface based on the crystal thickness, structural parameters of the crystal growth apparatus (e.g., dimensions of the crystal growth apparatus), and the positions of the temperature measurement assemblies on the crystal growth apparatus. In some embodiments, the processing device and/or the control device can input the plurality of temperatures, positional information between the plurality of thermometric components, and positional information of the plurality of thermometric components and the crystal growth surface into a temperature model and output temperature information within the growth chamber via the temperature model. In some embodiments, the temperature model is trained in advance based on a plurality of historical temperatures, historical position information among the plurality of temperature measurement components, and historical position information and historical temperature information of the plurality of temperature measurement components and the crystal growth surface. The historical temperature information is training data, the historical position information among the plurality of historical temperatures and the plurality of temperature measuring assemblies and the historical position information of the crystal growth surface are training labels.

In still other embodiments, the processing device and/or the control device may acquire pressure information within the growth chamber via a pressure sensor. In some embodiments, the pressure information may include at least one pressure value. In some embodiments, the processing apparatus and/or the control apparatus may input a plurality of temperature, pressure information, and structural parameters of the crystal growth apparatus into simulation software that outputs temperature information within the growth chamber. In some embodiments, the simulation software may include virtual reactor software.

At step 2020, at least one of a position, a shape, a distribution, or a flow area of the at least one outlet is adjusted based on the temperature information.

In some embodiments, the processing apparatus and/or the control apparatus may adjust at least one of a position, a shape, a distribution, or a flow area of the at least one discharge opening during the current crystal growth run or the next crystal growth run based on the temperature information.

In some embodiments, the temperature information may be a temperature gradient, and if the temperature gradient distribution near the crystal growth surface is uneven, the temperature gradient of a part of the position near the crystal growth surface is large, and the temperature gradients of the rest positions are small, in order to make the temperature gradients at various positions below the seed crystal growth surface the same or similar, and grow a crystal with a relatively flat or proper convexity, the radial position of the discharge port 108-21 in the current crystal growth process or the next crystal growth process can be adjusted, so that the discharge port 108-21 is translated; the shape of the discharge hole 108-21 can be adjusted by opening and closing the cover plate, so that the shape of the discharge hole 108-21 is changed; the distribution of the discharge ports 108-21 can be adjusted by opening and closing the cover plate, so that part of the discharge ports 108-21 can be opened or closed; or the cover plate can be opened or closed to adjust the flow area of the discharge ports 108-21, so that part of the discharge ports 108-21 can be opened or closed. In some embodiments, the temperature gradient near the crystal growth face may be a radial temperature gradient across the crystal growth face or an axial temperature gradient in a vertical direction near the crystal growth face.

The position, the shape, the distribution or the flow area of the discharge hole in the current crystal growth process or the next crystal growth process are adjusted based on the temperature information, so that the current or next crystal growth process is stable, the crystal growth defects are reduced, and the crystal quality is improved.

FIG. 21 is a flow chart illustrating an exemplary crystal growth method according to further embodiments of the present description. In some embodiments, flow 2100 may be performed by a processing device (e.g., processing device 101) and/or a control device (e.g., control device 102). For example, the process 2100 may be stored in a storage device (e.g., a storage unit of a storage device, a processing device, and/or a control device) in the form of a program or instructions that when executed by the processor 202, may implement the process 2100. In some embodiments, flow 2100 may utilize one or more additional operations not described below, and/or be accomplished without one or more of the operations discussed below. In addition, the order of the operations shown in fig. 21 is not limiting.

Step 2110, acquiring the distribution of gas-phase components required by crystal growth in the growth cavity.

In some embodiments, the distribution of the gas phase constituents within the growth chamber may be a concentration distribution of the gas phase constituents at various locations within or within the growth chamber.

In some embodiments, the processing device and/or the control device may obtain temperature information within the growth chamber via a thermometry assembly. In some embodiments, the processing device and/or the control device may obtain a current state of the ports and determine information regarding at least one port based on the current state of the ports. In some embodiments, the information related to the ports may include at least one of a location, a shape, a distribution, or a flow area of the ports.

Further, the processing device and/or the control device may simulate and determine the distribution of the gas phase component in the growth cavity based on the temperature information in the growth cavity and the information related to the at least one discharge hole. Specifically, the temperature information in the growth cavity and the related information of the at least one discharge port can be input into simulation software, and the simulation software outputs the distribution condition of the gas-phase components in the growth cavity. In some embodiments, the simulation software may include virtual reactor software.

And step 2120, adjusting at least one of the position, shape, distribution or flow area of at least one discharge hole based on the distribution situation.

In some embodiments, the processing apparatus and/or the control apparatus may adjust at least one of a position, a shape, a distribution, or a flow area of the at least one discharge opening during a current crystal growth run or a next crystal growth run based on a distribution of the gas phase components within the growth chamber.

In some embodiments, if the gas phase components are concentrated at partial positions, which results in higher concentration at partial positions and too low concentration at other positions in the growth cavity, in order to make the concentration of the gas phase components at each position below the seed crystal growth surface the same or similar, and grow a relatively flat crystal, the radial position of the discharge port 108-21 in the current crystal growth process or the next crystal growth process can be adjusted, so that the discharge port 108-21 is translated; the shape of the discharge hole 108-21 can be adjusted by opening and closing the cover plate, so that the shape of the discharge hole 108-21 is changed; the distribution of the discharge ports 108-21 can be adjusted by opening and closing the cover plate, so that part of the discharge ports 108-21 can be opened or closed; or the cover plate can be opened or closed to adjust the flow area of the discharge ports 108-21, so that part of the discharge ports 108-21 can be opened or closed.

Through adjusting the position, shape, distribution or flow area of the discharge hole in the current crystal growth process or the next crystal growth process based on the distribution condition, the gas phase components of the crystal growth surface in the current crystal growth process or the next crystal growth process can be more uniformly distributed, a smoother crystal is grown, the crystal growth defects are reduced, and the crystal quality is improved.

FIG. 22 is a flow chart illustrating an exemplary crystal growth method according to further embodiments herein. In some embodiments, flow 2200 may be performed by a processing device (e.g., processing device 101) and/or a control device (e.g., control device 102). For example, flow 2200 may be stored in a storage device (e.g., a storage unit of a storage device, a processing device, and/or a control device) in the form of a program or instructions that, when executed by processor 202, may implement flow 2200. In some embodiments, flow 2200 may utilize one or more additional operations not described below, and/or be accomplished without one or more of the operations discussed below. In addition, the order of the operations shown in fig. 22 is not limiting.

Step 2210, monitoring the crystal growth during the crystal growth process.

In some embodiments, the crystal growth condition may include at least one of a thickness of the growing crystal, a growth rate, or a defect.

In some embodiments, the processing equipment and/or control equipment may monitor crystal growth through a monitoring component (e.g., ultrasonic thickness gauge 104-1). For more details on monitoring the crystal growth by the monitoring component, reference may be made to other parts of the present specification (e.g., fig. 19A-19B and their associated descriptions), which are not repeated herein.

In some embodiments, the processing device and/or the control device may further input the acquired temperature information, pressure information, crystal thickness, and the like into the simulation software, and the simulation software outputs the crystal growth condition and/or the raw material usage condition in the growth chamber, thereby realizing online monitoring of the crystal growth process. In some embodiments, the feedstock usage may include at least one of a weight of the crystals, an amount of sublimation of the feedstock, a remaining amount of feedstock, and the like.

Step 2220, adjusting a heating parameter of the heating assembly and/or at least one of a position, a shape, a distribution, or a flow area of the at least one discharge port based on the crystal growth.

In some embodiments, the processing apparatus and/or the control apparatus may adjust the heating parameters of the heating assembly during the current crystal growth run or during the next crystal growth run based on the crystal growth conditions. In some embodiments, if the crystal thickness is less than a thickness threshold (e.g., 3mm, 5mm, or 8 mm) or the growth rate is less than the growth rateA rate threshold (e.g., 0.1mm/h, 0.3mm/h, or 0.5 mm/h) may be adjusted to increase the crystal growth rate, such that the heating power of the first heating assembly and/or the second heating assembly during the current crystal growth process or the next crystal growth process is adjusted to increase the sublimation rate of the feedstock and increase the driving force for the diffusion of the gas-phase components toward the seed crystal. In some embodiments, if the crystal defect density is greater than the density threshold, the heating power of the third heating assembly during the current crystal growth process or the next crystal growth process can be adjusted to reduce the radial temperature gradient of the seed crystal in order to improve the crystal growth quality. In some embodiments, the crystal defect density may be a pore density. In some embodiments, the density threshold may be 8/cm ² 10 pieces/cm ² Or 15/cm ² 。

In some embodiments, the processing apparatus and/or the control apparatus may adjust at least one of a position, a shape, a distribution, or a flow area of the at least one discharge opening during a current crystal growth run or a next crystal growth run based on the crystal growth conditions.

In some embodiments, if the crystal thickness is less than a thickness threshold (e.g., 3mm, 5mm, or 8 mm) or the growth rate is less than a rate threshold (e.g., 0.1mm/h, 0.3mm/h, or 0.5 mm/h), the axial position of discharge port 108-21 during the current crystal growth process or the next crystal growth process may be adjusted to raise discharge port 108-21, or the shape, distribution, or flow area of discharge port 108-21 may be adjusted by opening or closing a cover plate to increase the crystal growth rate. In some embodiments, if the crystal defect density (e.g., pore density) is greater than a density threshold (e.g., 8/cm) ² 10 pieces/cm ² Or 15/cm ² ) In order to improve the crystal growth quality, the radial position of the discharge port 108-21 in the current crystal growth process or the next crystal growth process can be adjusted, or the shape, distribution or flow area of the discharge port 108-21 can be adjusted by opening or closing a cover plate.

The heating parameters of the heating assembly and/or the position, shape, distribution or flow area of the discharge hole in the current crystal growth process or the next crystal growth process are adjusted based on the crystal growth condition, so that the crystal growth rate and the crystal growth quality can be improved.

In the process of growing silicon carbide crystals by a physical vapor transport method, silicon carbide powder is not completely utilized after the growth is finished, and the rest part which is not utilized often exists in the form of porous silicon carbide polycrystalline blocks which are agglomerated.

FIG. 23 is a flow diagram illustrating an exemplary flash recycling method according to some embodiments of the present description. In some embodiments, flow 2300 may be performed by a processing device (e.g., processing device 101) and/or a control device (e.g., control device 102). For example, the process 2300 may be stored in a storage device (e.g., a storage unit of a storage device, a processing device, and/or a control device) in the form of a program or instructions that when executed by the processor 202, may implement the process 2300. In some embodiments, flow 2300 may utilize one or more additional operations not described below and/or be accomplished without one or more operations discussed below. In addition, the order of the operations shown in fig. 23 is not limiting.

And 2310, inverting the raw material remainder after the crystal growth is finished.

In some embodiments, the feedstock surplus may be feedstock remaining after crystal growth is complete.

In the process of growing the silicon carbide crystal by the physical vapor transport method, the raw materials are not all decomposed into gas-phase components at the same time, but are decomposed at a higher temperature close to the side wall of the growth cavity and then decomposed at a lower temperature in the middle part of the growth cavity. In the sublimation decomposition process, the products of SiC material after thermal decomposition and sublimation mainly comprise gaseous Si and Si ₂ C、SiC ₂ And solid carbon particles, wherein Si is evaporated prior to C (sublimation temperature of silicon is about 1400 ℃ C. And sublimation temperature of carbon is about 2877 ℃ C.), and a part of Si moves upward from the vicinity of the side wall and the other part of Si moves to the middle of the raw material. As the reaction proceeds, carbon generated from the bottom and peripheral side walls of the raw material forms a carbon shell (carbon-rich zone) which is wrapped by the carbonThe top of the decomposed intermediate raw material is in a silicon-rich state; the carbon shell layer is fluffy and has lower heat conductivity than the original silicon carbide, which is not beneficial to heat conduction, and the carbon shell layer forms resistance to the transmission of gas phase components generated by the decomposition of the intermediate raw materials. After crystal growth is complete, the bottom and sidewall portions of the entire raw material residue are carbon rich and the middle and upper portions are silicon rich.

In some embodiments, to reduce the effect of the carbon-rich portion on the raw material residue, the carbon-rich portion (carbon residue) on the edge portion of the raw material residue may be removed first, and then the raw material residue may be inverted. In some embodiments, the feedstock remainder may be processed upside down by manual means. The inversion treatment is carried out in a manual mode, and the process is flexible in operation, simple in equipment and low in cost. In some embodiments, the robotic arm may be controlled by the processing device and/or the control device to invert the feedstock biscuit. In some embodiments, the robotic arm may automatically pick up the excess material according to a set program to invert the feedstock excess material. Invert raw materials clout through the arm, can reduce the cost of labor, and easily control.

And 2320, laying new raw materials on the inverted raw material residual materials to serve as raw materials for next crystal growth.

In some embodiments, the new feedstock may be the raw material needed for the growth of the crystal without reaction. In some embodiments, the new feedstock may include silicon carbide powder. In some embodiments, the feedstock for the next crystal growth may be the feedstock for the next silicon carbide crystal growth, i.e., the feedstock in step 310. In some embodiments, the new feedstock and feedstock excess may be laid in a ratio. In some embodiments, the ratio may be a mass ratio.

In some embodiments, the mass ratio of the virgin feedstock to the remainder of the feedstock may be in the range of 0.01 to 1. In some embodiments, the mass ratio of the virgin feedstock to the remainder of the feedstock may be in the range of 0.1 to 0.9. In some embodiments, the mass ratio of the virgin feedstock to the remainder of the feedstock may be in the range of 0.2 to 0.8. In some embodiments, the mass ratio of the virgin feedstock to the remainder of the feedstock may be in the range of 0.3 to 0.7. In some embodiments, the mass ratio of the virgin feedstock to the remainder of the feedstock may be in the range of 0.4 to 0.6. In some embodiments, the mass ratio of the virgin feedstock to the remainder of the feedstock may be in the range of 0.45 to 0.55. In some embodiments, the mass ratio of the virgin feedstock to the remainder of the feedstock may be in the range of 0.45 to 0.50.

The excess raw materials are inverted, and new raw materials are laid on the excess raw materials to serve as raw materials for next crystal growth, so that the excess raw materials can be fully utilized, and the utilization rate of the raw materials is improved. In addition, the proportion of laying new raw materials is large, so that the raw material excess can be balanced, and the silicon-rich raw material excess is beneficial to controlling the crystal form, so that the quality of next crystal growth cannot be influenced.

FIG. 24 is an exemplary flow chart of a method of crystal growth according to further embodiments of the present description. In some embodiments, flow 2400 may be performed by a processing device (e.g., processing device 101) and/or a control device (e.g., control device 102). For example, flow 2400 may be stored in a storage device (e.g., a storage unit of a storage device, a processing device, and/or a control device) in the form of a program or instructions, which when executed by processor 202, may implement flow 2400. In some embodiments, flow 2400 may utilize one or more additional operations not described below, and/or be accomplished without one or more of the operations discussed below. In addition, the order of the operations shown in fig. 24 is not limiting.

Step 2410, after the crystal growth is finished, removing the carbon-rich part of the raw material excess material to obtain a silicon-rich part.

In some embodiments, the carbon-rich portion may be a carbon residue portion of the raw material residue edge, as described in connection with fig. 23. In some embodiments, the silicon-rich portion may be a portion of the upper portion of the remainder composed of SiC and the Si solid solution structure of SiC.

The carbon-rich part is amorphous carbon slag with low hardness, so the carbon-rich part is easy to fall off from the raw material residual material, and only the middle silicon-rich part can be selected in the recovery process.

Step 2420, pre-treating the silicon-rich portion.

In some embodiments, the silicon rich fraction may be pretreated in order to mix the recovered silicon rich fraction with the newly added carbon powder. In some embodiments, the silicon-rich fraction may be ball milled pre-treated. Specifically, the silicon-rich fraction may be contained in a container (e.g., a teflon tank) of a ball mill, and a ball milling medium (e.g., a 10mm × 10mm × 10mm single crystal ingot of silicon carbide) may be added to the container, and the silicon-rich fraction may be ball-milled by the ball mill under certain ball milling conditions to obtain a ball-milled pretreated silicon-rich fraction.

In some embodiments, the ball milling conditions may include ball milling rotational speed and ball milling time.

In some embodiments, the ball milling speed may be 100r/min to 300r/min. In some embodiments, the ball milling speed may be 150r/min to 250r/min. In some embodiments, the ball milling speed may be 200r/min to 230r/min.

In some embodiments, the ball milling time may be 60min to 200min. In some embodiments, the ball milling time may be 80min to 180min. In some embodiments, the ball milling time may be from 100min to 150min. In some embodiments, the ball milling time may be 120min to 140min.

In some embodiments, the silicon-rich fraction after the ball milling pretreatment may be sieved to select silicon carbide powder with a certain particle size. In some embodiments, the particle size of the silicon carbide powder may be 8 mesh to 200 mesh. In some embodiments, the particle size of the silicon carbide powder may be 10 mesh to 180 mesh. In some embodiments, the particle size of the silicon carbide powder may be 20 mesh to 150 mesh. In some embodiments, the particle size of the silicon carbide powder may be 30 mesh to 120 mesh. In some embodiments, the particle size of the silicon carbide powder may be 40 mesh to 100 mesh. In some embodiments, the particle size of the silicon carbide powder may be 50 mesh to 90 mesh. In some embodiments, the particle size of the silicon carbide powder may be 60 mesh to 80 mesh. In some embodiments, the silicon carbide powder may have a particle size of 70 mesh to 75 mesh.

And 2430, uniformly mixing the pretreated silicon-rich part with carbon powder according to a preset mass ratio.

Since the molar ratio of carbon to silicon in the raw material is 1 or close to 1, a certain amount of carbon powder needs to be mixed in the pretreated silicon-rich part in order to ensure the quality of the raw material in the next crystal growth process.

In some embodiments, the predetermined mass ratio may be 3:1 to 6:1. In some embodiments, the preset mass ratio may be 3.5. In some embodiments, the predetermined mass ratio may be 4:1 to 5:1. In some embodiments, the preset mass ratio may be 4.2. In some embodiments, the predetermined mass ratio may be 3:1 to 6:1. In some embodiments, the preset mass ratio may be 4.4.

In some embodiments, the silicon-rich fraction and the carbon powder can be uniformly mixed using a powder mixing device (e.g., a twin-screw conical mixer, a horizontal non-gravity mixer, a horizontal coulter mixer, a horizontal ribbon mixer). In some embodiments, the silicon-rich fraction and the carbon powder can be uniformly mixed manually using a mortar (e.g., agate mortar).

And 2440, putting the uniformly mixed silicon-rich part and the carbon powder into a recovery device for recovery treatment to obtain an initial silicon carbide raw material.

In some embodiments, the recycling device may be a location where the feedstock heel is recycled.

In some embodiments, the silicon-rich part and the carbon powder which are uniformly mixed can be placed in a crucible, and the crucible is placed in a recovery device, so that the silicon-rich part and the carbon powder react under certain reaction conditions. In some embodiments, the reaction conditions may include reaction temperature, reaction atmosphere, reaction pressure, and/or reaction time.

In some embodiments, the crucible may comprise a tantalum carbide crucible or a crucible having a tantalum carbide coating applied to the interior of the crucible.

In some embodiments, the reaction temperature may be in the range of 1700 ℃ to 2500 ℃. In some embodiments, the reaction temperature may be in the range of 1800 ℃ to 2400 ℃. In some embodiments, the reaction temperature may be in the range of 1900 ℃ to 2300 ℃. In some embodiments, the reaction temperature may be in the range of 2000 ℃ to 2200 ℃. In some embodiments, the reaction temperature may be in the range of 2050 ℃ to 2150 ℃.

In some embodiments, the reaction atmosphere may include an inert gas (e.g., helium, neon, argon, etc.).

In some embodiments, the reaction pressure may be in the range of 8kPa to 14 kPa. In some embodiments, the reaction pressure may be in the range of 8.5kPa to 13.5 kPa. In some embodiments, the reaction pressure may be in the range of 9kPa to 13 kPa. In some embodiments, the reaction pressure may be in the range of 9.5kPa to 12.5 kPa. In some embodiments, the reaction pressure may be in the range of 10kPa to 12 kPa. In some embodiments, the reaction pressure may be in the range of 10.5kPa to 11.5 kPa.

In some embodiments, the reaction time may be in the range of 0.5h to 4 h. In some embodiments, the reaction time may be in the range of 0.5h to 4 h. In some embodiments, the reaction time may be in the range of 1h to 3.5 h. In some embodiments, the reaction time may be in the range of 1.5h to 3 h. In some embodiments, the reaction time may be in the range of 1.7h to 2.8 h. In some embodiments, the reaction time may be in the range of 1.9h to 2.6 h. In some embodiments, the reaction time may be in the range of 2.1h to 2.4 h.

In some embodiments, after the reaction is complete, it is cooled to a temperature (e.g., 1500 ℃ C. To 1600 ℃ C.) for a time (e.g., 30 min), and the reaction cooling process is repeated at least once more (e.g., 2, 3, 4).

In some embodiments, after the above reaction cooling process is repeated, the recovery device may be cooled to room temperature by natural cooling to obtain the initial silicon carbide raw material.

Step 2450, post-processing the initial silicon carbide raw material to obtain silicon carbide raw material as the raw material for the next crystal growth.

In some embodiments, the feedstock for the next crystal growth may be the feedstock for the next silicon carbide crystal growth, i.e., the feedstock in step 310.

In some embodiments, post-treatment may include screening, water washing, carbon removal, and the like. In some embodiments, the initial silicon carbide feedstock may be sieved to select a particle size of silicon carbide powder. In some embodiments, the silicon carbide powder may also be water washed to remove float carbon. In some embodiments, the silicon carbide powder after being washed with water may be placed in a decarbonization device, and oxygen may be introduced at a certain temperature to decarbonize the silicon carbide powder, so as to obtain the silicon carbide raw material.

In some embodiments, the particle size of the silicon carbide powder may be in the range of 8 mesh to 40 mesh. In some embodiments, the particle size of the silicon carbide powder may be in the range of 10 mesh to 35 mesh. In some embodiments, the particle size of the silicon carbide powder may be in the range of 12 mesh to 33 mesh. In some embodiments, the particle size of the silicon carbide powder may be in the range of 15 mesh to 30 mesh. In some embodiments, the particle size of the silicon carbide powder may be in the range of 18 mesh to 28 mesh. In some embodiments, the particle size of the silicon carbide powder may be in the range of 20 mesh to 25 mesh.

In some embodiments, the carbon removal device may be a carbon removal device. For example, the carbon removal device may comprise a muffle furnace.

In some embodiments, the temperature for carbon removal may be in the range of 600 ℃ to 1000 ℃. In some embodiments, the temperature for carbon removal may be in the range of 650 ℃ to 950 ℃. In some embodiments, the temperature for carbon removal may be in the range of 700 ℃ to 900 ℃. In some embodiments, the temperature for carbon removal may be in the range of 750 ℃ to 850 ℃. In some embodiments, the temperature for carbon removal may be in the range of 770 ℃ to 830 ℃. In some embodiments, the temperature for carbon removal may be in the range of 790 ℃ to 810 ℃.

By carrying out post-treatment on the initial silicon carbide raw material, the purity of the obtained silicon carbide raw material can be higher, and the quality of the crystal grown as the raw material for the next crystal growth is better.

The crystal growth method will be described in detail below by way of examples. It should be noted that the reaction conditions, the reaction materials and the amounts of the reaction materials in the examples are only for illustrating the method of preparing the crystals, and do not limit the scope of protection of the present specification.

Example 1

(1) Mixing the source material and the additive: the total weight of the required source materials calculated according to the volume of the tantalum crucible is 10000g, wherein the source materials are carbon powder with the grain diameter of 0.1 mu m, silicon powder with the grain diameter of 0.1mm and silicon carbide particles with the grain diameter of 100 meshes. Mixing carbon powder, silicon powder and additive polytetrafluoroethylene according to the weight ratio of 1:2:0.2, adding the silicon carbide particles, the carbon powder and the silicon powder into an agate mortar according to the proportion of 1 percent, and uniformly mixing in the agate mortar.

(2) Initial raw material synthesis: the mixture of the raw materials and the additives was charged into a graphite crucible (ash content less than 5 ppm) and reacted for 1 hour at a reaction temperature of 1400 ℃ and a pressure of 500 Pa. After the first stage (reaction stage), the second stage (sublimation recrystallization stage) is carried out at 2100 deg.C and 10 deg.C ^-1 Pa and the reaction time is 20h.

(3) And (3) cooling: after the reaction is finished, filling high-purity argon to 500mbar, and then cooling to 30 ℃ to obtain an initial raw material.

(4) And (3) post-treatment: and carrying out post-treatment on the obtained initial raw material, wherein the post-treatment comprises the steps of crushing, screening, decarbonizing, cleaning, drying, packaging and the like on the initial raw material to obtain the silicon carbide powder.

(5) Detecting the quality of the raw materials: the silicon carbide powder thus obtained was examined to obtain B <0.5ppm, al =0.11ppm, mg <0.05ppm, ti <0.5ppm, V <0.09ppm, cr <0.1ppm, ni <0.01ppm, cu <0.05ppm, and Na =0.02ppm.

Example 2

(1) Pretreatment of raw materials: firstly, carrying out acid treatment on a raw material by adopting 5L of aqua regia; then, the raw material was washed 4 times with each 10L of ultrapure water.

(2) Seed crystal treatment: the seed crystal is treated as follows:

a. diameter expansion treatment: the small-size seed crystal with low defect density and the diameter of 150mm is used, a large-size crystal ingot is obtained by expanding growth, and then the crystal ingot is sliced and processed into a large-size seed crystal with the diameter of 153 mm.

b. And (3) polishing treatment: polishing the seed crystal for 120min by using diamond polishing powder with the grain diameter of 0.5 mu m under the conditions that the polishing pressure is 0.08MPa and the polishing rotating speed is 30r/min.

c. Coating treatment: the seed was coated by the method of example 3.

d. Surface inspection: and (3) checking whether the surface of the seed crystal has a micropipe by an X-ray diffraction method, and observing whether the surface of the seed crystal has mechanical damage, whether the surface of the seed crystal is clean and the like by a microscope.

(3) And (3) detecting the quality of the raw materials and the seed crystals: detecting the pretreated raw material to obtain a raw material with the purity of 5 PPm; and detecting the pretreated seed crystal to obtain the seed crystal with the fineness of 2 microns, the total thickness deviation of 3.5 microns, the local thickness deviation of 1.6 microns, the curvature of 5 microns and the warping degree of 10 microns.

Example 3

The seed crystal was coated by the coating apparatus shown in FIG. 9.

(1) Non-film coating surface treatment: selecting a plurality of seed crystals to be coated, and sticking a polyimide film on the non-coating surface of the seed crystals in advance.

(2) Seed crystal placement: and placing a plurality of seed crystals with the diameter of 150mm, which are adhered with the polyimide films, on a film coating frame in the film coating equipment.

(3) Vacuumizing and heating: vacuumizing the coating equipment to 0.01Pa, and heating the chamber of the coating equipment to 500 ℃.

(4) Introducing reaction gas: and introducing inert gas serving as carrier gas into the coating equipment, wherein the flow of the inert gas is 500mL/min, introducing reaction gas methane into the chamber of the coating equipment when the pressure of the chamber of the coating equipment reaches 0.05MPa, wherein the flow of the methane is 50mL/min, stopping after continuously introducing the methane for 10min, and continuously maintaining the flow of the carrier gas unchanged.

(5) And (3) cooling: and continuing to introduce carrier gas, cooling to room temperature at the cooling rate of 30 ℃/min, stopping introducing the carrier gas, and taking out the seed crystal.

(6) Seed crystal quality detection: and detecting the seed crystal after coating to obtain the average coating thickness of 9 microns.

Example 4

The seed crystal is bonded by a seed crystal bonding apparatus as shown in fig. 11A and 11B.

(1) Adhesive coating: and coating the adhesive on the lower surface of the cavity cover of the growth cavity.

(2) Placing a cavity cover: the chamber cover coated with the adhesive is placed in the bonding apparatus.

(3) Air extraction treatment: and performing air exhaust treatment on the bonding equipment through a vacuum pump, wherein the pressure of the bonding equipment after the air exhaust treatment is 0.1Pa.

(4) Seed crystal bonding: and the seed crystal is bonded and fixed on the sucking disc of the pressing assembly through high-temperature traceless glue. And controlling the compressing assembly to move up and down to contact the seed crystal with the cavity cover, and further applying pressure of 0.2MPa to bond the seed crystal and the cavity cover. And in the compaction process, vacuumizing to 0.1Pa, and heating the chamber of the seed crystal bonding equipment at 1000 ℃ for 120min.

(5) And (3) detecting the bonding quality of seed crystals: after the bonding is finished, detecting the bonded seed crystal by ultrasonic detection equipment, wherein the positions of air holes are mostly gathered at the position with the distance of 30mm from the edge of the seed crystal, and the size of the air holes is 0.01mm ² ～30mm ² In the range of (2), the shapes of the pores are different, and the density of the pores is 3 pores/cm ² . The air holes after the seed crystal bonding are mostly concentrated at the edge of the seed crystal, the size of the air holes is small, the density of the air holes is low, and the bonding effect is good.

Example 5

The seed crystal is bonded by a seed crystal bonding apparatus as shown in fig. 12A and 12B.

(3) Air exhaust treatment: and performing air exhaust treatment on the bonding equipment through a vacuum pump, wherein the pressure of the bonding equipment after the air exhaust treatment is 0.1Pa.

(4) Seed crystal bonding: and the seed crystal is bonded and fixed on the sucking disc of the pressing assembly through high-temperature traceless glue. The pressing assembly is controlled by the processing equipment to move up and down so as to contact the seed crystal and the buffer layer H with the cavity cover, and 0.5MPa pressure is further applied to bond the seed crystal, the buffer layer H and the cavity cover. And in the compaction process, vacuumizing to 0.1Pa, and heating the chamber of the seed crystal bonding equipment at 1000 ℃ for 120min.

(5) And (3) detecting the bonding quality of seed crystals: after the bonding is finished, detecting the bonded seed crystal by ultrasonic detection equipment, wherein the positions of air holes are mostly gathered at the position 15mm away from the edge of the seed crystal, and the size of the air holes is 0.01mm ² ～20mm ² In the range of (2), the shapes of the pores are different, and the density of the pores is 2/cm ² . The air holes after the seed crystal bonding are mostly concentrated at the edge of the seed crystal, the size of the air holes is small, the density of the air holes is low, and the bonding effect is good.

Example 6

The bonding of the seed crystals is performed by a rolling operation as shown in fig. 14A and 14B.

(1) Seed crystal and buffer layer placement: coating an adhesive on the lower surface of the buffer layer with the size larger than that of the seed crystal and the upper surface of the seed crystal, and stacking the buffer layer and the seed crystal on the bonding table-board.

(2) Seed crystal and buffer layer bonding: and a first angle between the compression roller and the buffer layer and a part of the seed crystal which is not contacted with the compression roller is 0.1 degrees, a first pressure applied by the compression roller is 0.5kPa, and a first speed of the compression roller is 0.5mm/s, so that the seed crystal is bonded with the buffer layer by rolling.

(3) Placing a cavity cover, bonded seed crystals and a buffer layer: coating an adhesive on the lower surface of the buffer layer and the upper surface of the cavity cover, and overlapping the bonded seed crystal, the buffer layer and the cavity cover on the bonding table board.

(4) Bonding the bonded seed crystal and buffer layer with the cavity cover: and a second angle between the compression roller and the noncontact part between the buffer layer and the cavity cover is 0.1 degrees, a second pressure applied by the compression roller is 0.5kPa, and a second speed of the compression roller movement is 0.5mm/s, so that the bonded seed crystal and the buffer layer are bonded with the cavity cover.

(5) And (3) detecting the bonding quality of seed crystals: detecting the bonded seed crystal by ultrasonic detection equipment, wherein the positions of air holes are mostly gathered at the position 5mm away from the edge of the seed crystal, and the size of the air holes is 0.01mm ² ～10mm ² In the range of (1), the pore shapes are different, and the pore density is 1

/cm ² . The air holes after the seed crystal is bonded are mostly concentrated on the seed crystalAt the edge, the size of the air holes is small, the density of the air holes is low, and the bonding effect is good.

Example 7

The crystal growth was performed by the crystal growth apparatus shown in FIG. 16A and the temperature measuring unit shown in FIG. 18.

(1) Placing raw materials: the feedstock is placed in a feedstock region of a growth chamber.

(2) Seed crystal placement: and placing the bonded seed crystal in a growth area of a growth cavity.

(3) A raw material heating area: the raw material zone was heated by a first heating means (resistance heating means) to raise the temperature to 2500 c within 5 hours to sublimate the raw material into a gas phase component required for crystal growth.

(4) Heating the vicinity of the separator: the region of 5mm upward or downward along the position of the partition wall was heated by the second heating means (resistance heating means), and the temperature was raised to 2400 ℃ within 5 hours to maintain the discharge rate of the gas-phase component through the at least one discharge port.

(5) Heating the growth area: the growth zone was heated by a third heating means (resistive heating means) and the temperature was raised to 2300 ℃ over 5 hours.

(6) And (3) crystal growth control: a plurality of temperatures associated with the growth chamber are obtained by the temperature measurement assembly. And then, according to a plurality of temperature information acquired by the temperature measuring component, the upper computer sends an adjusting instruction, the PLC receives the adjusting instruction and then outputs a control signal to control the heating power of the first heating component, the second heating component or the third heating component and/or control the opening or closing of the upper cover plates of the discharge ports 108-21, so that at least one of the position, the shape, the distribution or the flow area of at least one discharge port is controlled, the growth rate of the crystal is adjusted, and the stability of the growth rate of the crystal is realized. For example, as shown in fig. 16A, when the temperature near the chamber cover is measured to be lower than the growth temperature, the crystallization rate of the crystal is increased, and then the temperature of the growth region is increased by adjusting the power of the third heating unit, and the temperature of the raw material region is decreased by adjusting the power of the first heating unit or the second heating unit, so as to slow down the rate of the gas component passing through the partition plate, thereby decreasing the growth rate of the crystal. In some embodiments, the size or shape of the discharge port on the partition plate can be changed by adjusting the position between different layers on the partition plate or adjusting the opening or closing of the cover plate on the discharge port, so that the gas-phase components in the heating zone can pass through the partition plate at the transmission rate required by the crystal growth, and the growth rate of the crystal can be reduced. In some embodiments, the temperature adjustment range of the second heating assembly may be 2300-2600 ℃.

(7) Detecting the quality of the crystal: threading Screw Dislocation (TSD) of less than or equal to 300cm ^-2 And Threading Edge Dislocation (TED) is less than or equal to 5069cm ^-2 The Basal Plane Dislocation (BPD) is less than or equal to 1380cm ^-2 。

Example 8

The crystal growth was performed by the crystal growth apparatus shown in fig. 16A.

(3) A raw material heating area: the feedstock zone was heated by a first heating assembly (resistive heating element) to a temperature of 2350 c over a period of 5 hours to sublimate the feedstock into the vapor phase component required for crystal growth.

(4) Heating the vicinity of the separator: the area of 5mm up or down the position of the partition was heated by the second heating means (resistance heating means) to raise the temperature to 2300 ℃ within 5 hours to maintain the discharge rate of the gas-phase component through the at least one discharge port.

(5) Heating the growth area: the growth zone was heated by a third heating assembly (resistive heating element) and the temperature was raised to 2250 ℃ over 5 hours.

(6) Controlling the crystal growth: the distribution condition of gas-phase components required by crystal growth in the growth cavity is obtained through virtual reactor software. Then, based on the distribution condition of the gas-phase components in the growth cavity, the upper computer sends out an adjusting instruction, the PLC receives the adjusting instruction and then outputs a control signal to control the opening or closing of the upper cover plate of the discharge ports 108-21 or adjust the positions of different layers on the partition plate, so that at least one of the position, the shape, the distribution or the flow area of at least one discharge port is controlled, the gas-phase components in the heating zone pass through the partition plate according to the transmission rate required by the growth of the crystal, the growth rate of the crystal is adjusted, and the stability of the growth rate of the crystal is realized.

(7) And (3) crystal quality detection: TSD is less than or equal to 230cm ^-2 、TED≤4000cm ^-2 、BPD≤1207cm ^-2 。

Example 9

The crystal growth was carried out by the crystal growth apparatus shown in FIG. 16A and the monitoring unit shown in FIG. 19A.

(1) Placing the raw materials: the feedstock is placed in a feedstock region of a growth chamber.

(3) A raw material heating area: the raw material zone was heated by a first heating means (resistance heating means) to raise the temperature to 2300 ℃ within 5 hours to sublimate the raw material into a gas phase component required for crystal growth.

(4) Heating the vicinity of the separator: the area of 5mm up or down the position of the partition was heated by the second heating means (resistance heating means) and the temperature was raised to 2250 ℃ within 5 hours to maintain the discharge rate of the gas-phase component through the at least one discharge opening.

(5) Heating the growth area: the growth zone was heated by a third heating assembly (resistive heating element) and the temperature was raised to 2200 ℃ over 5 hours.

(6) Controlling the crystal growth: the growth of the crystal is monitored by the monitoring assembly. And then, based on the growth condition of the crystal, the upper computer sends an adjusting instruction, the PLC receives the adjusting instruction and then outputs a control signal to adjust the heating parameters of the first heating assembly, the second heating assembly or the third heating assembly and/or control the opening or closing of the upper cover plates of the discharge ports 108-21, so that the control of at least one of the position, the shape, the distribution or the flow area of at least one discharge port is realized, the growth rate of the crystal is adjusted, and the stability of the growth rate of the crystal is realized. In some embodiments, the temperature adjustment range of the second heating assembly may be 2200-2400 ℃.

(7) And (3) crystal quality detection: TSD is less than or equal to 100cm ^-2 、TED≤3000cm ^-2 、BPD≤900cm ^-2 。

Example 10

The crystal growth was carried out by the crystal growth apparatus shown in FIG. 16B and the temperature measuring unit shown in FIG. 18.

(3) A raw material heating area: the raw material zone was heated by a first heating means (resistance heating means) to raise the temperature to 2500 c within 4 hours to sublimate the raw material into a gas phase component required for crystal growth.

(4) Heating the vicinity of the separator: the region of 5mm upward or downward along the position of the partition wall was heated by the second heating means (resistance heating means), and the temperature was raised to 2400 ℃ over 4 hours to maintain the discharge rate of the gas-phase component through the at least one discharge port.

(5) Heating the growth area: the growth zone was heated by a third heating means (resistive heating means) and the temperature was raised to 2300 ℃ over 4 hours.

(6) Controlling the crystal growth: a plurality of temperatures associated with the growth chamber are obtained by the temperature measurement assembly. And then, according to a plurality of temperature information acquired by the temperature measuring component, the upper computer sends an adjusting instruction, the PLC receives the adjusting instruction and then outputs a control signal to control the heating power of the first heating component, the second heating component or the third heating component and/or control the opening or closing of the upper cover plates of the discharge ports 108-21, so that at least one of the position, the shape, the distribution or the flow area of at least one discharge port is controlled, the growth rate of the crystal is adjusted, and the stability of the growth rate of the crystal is realized.

In some embodiments, as shown in fig. 16B, when the temperature near the chamber lid is measured to be less than the growth temperature, the crystallization rate of the crystal is increased, and then the temperature of the growth region is increased by adjusting the power of the third heating assembly, and the temperature of the source material region is decreased by adjusting the power of the first heating assembly or the second heating assembly, so as to slow down the rate of the gas component passing through the partition plate, thereby decreasing the growth rate of the crystal. In some embodiments, the size or shape of the discharge port on the partition plate can be changed by adjusting the position between different layers on the partition plate or adjusting the opening or closing of the cover plate on the discharge port, so that the gas-phase components in the heating zone can pass through the partition plate at the transmission rate required by the crystal growth, and the growth rate of the crystal can be reduced. In some embodiments, the temperature adjustment range of the second heating assembly may be 2300-2600 ℃.

(7) And (3) crystal quality detection: TSD is less than or equal to 350cm ^-2 、TED≤6000cm ^-2 、BPD≤1540cm ^-2 。

Example 11

The crystal growth was carried out by the crystal growth apparatus shown in FIG. 16C and the temperature measuring unit shown in FIG. 18.

(3) A raw material heating area: the feedstock zone was heated by a first heating assembly (induction heating block) to a temperature of 2180 deg.C over 5 hours to sublimate the feedstock into the vapor phase components required for crystal growth.

(4) Heating the vicinity of the separator: an area 5mm up (not shown in fig. 16C) or down along the position of the partition wall was heated by the second heating unit (induction heating unit), and the temperature was raised to 2130 ℃ over 5 hours to maintain the discharge rate of the gas phase component through the at least one discharge port.

(5) Heating the growth area: the growth zone was heated by a third heating assembly (resistive heating element) and the temperature was raised to 2090 ℃ over 5 hours.

(6) Controlling the crystal growth: a plurality of temperatures associated with the growth chamber are obtained by the temperature measurement assembly. And then, according to a plurality of temperature information acquired by the temperature measuring component, the upper computer sends a temperature field adjusting instruction, the PLC receives the instruction and then outputs a control signal to control the heating power of the first heating component, the second heating component or the third heating component and/or control the opening or closing of the upper cover plate of the discharge ports 108-21, so that at least one of the position, the shape, the distribution or the flow area of at least one discharge port is controlled, the growth rate of the crystal is adjusted, and the stability of the growth rate of the crystal is realized.

(7) And (3) crystal quality detection: TSD is less than or equal to 208cm ^-2 、TED≤7000cm ^-2 、BPD≤1200cm ^-2 。

Example 12

And after the crystal growth is finished, carrying out excess material recovery on the raw material excess material.

(1) And (3) inversion treatment: after the crystal growth is completed, the carbon-rich part (carbon slag) on the edge part of the raw material residue is removed manually, and then the raw material residue is inverted.

(2) Laying new raw materials: and laying a new raw material on the inverted raw material residual material to be used as a raw material for the next crystal growth, wherein the mass ratio of the new raw material to the raw material residual material is 3:7.

(3) And (3) next crystal growth: and performing crystal growth by using the treated excess material.

(4) And after the next crystal growth is finished, carrying out crystal quality detection: the crystal has no phase change, polycrystalline positioning edge, thickness of 16mm, TSD not more than 450cm ^-2 、TED≤7500cm ^-2 、BPD≤1600cm ^-2 。

The beneficial effects that may be brought by the embodiments of the present description include, but are not limited to: (1) The raw material area and the growth area are separated by the partition plate, and the temperature of the raw material area, the vicinity of the partition plate and the growth area is independently controlled, so that the thermal stress of crystal growth can be remarkably reduced, and the growth rate can be effectively regulated and controlled; (2) The raw material sublimation rate can be regulated and controlled by heating the raw material area through the first heating assembly, heating the positions near the partition plate through the second heating assembly and heating the growth area through the third assembly, so that the stable discharge rate of the discharge port and the stable growth of the crystal growth surface are maintained, the thermal stress of crystal growth is reduced, the dislocation formation probability is reduced, the crystal defects are reduced, and the quality of the grown crystal is improved; (3) By adjusting the position, shape, distribution or flow area of at least one discharge port on the partition plate, the carbon-silicon molar ratio, the transmission path, the transmission speed and the like of the feed gas phase component can be regulated, the crystal growth interface can be effectively regulated, the dislocation formation probability is obviously reduced, the crystal defects are reduced, and the grown crystal quality is improved; (4) In the preparation process of the raw materials, the reaction is carried out in two stages, small-particle silicon carbide generated in the first stage is sublimated and recrystallized on the surface of silicon carbide particles in the second stage to generate raw materials with larger particles, so that the crystal defect caused by crystal growth by using the small-particle silicon carbide raw materials is avoided, and the quality of crystals is improved; (5) The back of the seed crystal is subjected to film coating treatment, so that the evaporation process of the back of the seed crystal in the growth process of the silicon carbide crystal can be inhibited, the planar hexagonal defect caused by the evaporation of the back of the seed crystal is effectively eliminated, and the quality and the yield of the grown silicon carbide crystal are improved; (6) The carbon film is grown on the back surfaces of the seed crystals simultaneously by a vapor deposition method, so that the coating efficiency is high, the uniformity of the coating is good, and the consistency of the grown crystals is good; (7) Bubbles in the adhesive are removed through vacuumizing, the bubbles in the adhesive are completely removed before bonding, or the buffer layer and the adhesive are processed into an integral form, so that the bubbles generated in the process of uneven flattening or flattening of the liquid adhesive are avoided, and then the seed crystal is bonded by pressurizing and heating in a vacuum state, so that the generation of new bubbles in the bonding process can be further prevented, the defects of micropipes, hexagonal cavities and the like of the silicon carbide crystal are avoided, and the quality of the silicon carbide crystal is improved; (8) The bonded seed crystals are detected by ultrasonic detection equipment, so that the seed crystals with good bonding quality (for example, few bubbles) can be screened out for crystal growth, and the quality of the subsequently grown crystals is improved; (9) The raw material excess materials are recycled in a simple and efficient mode, the excess materials can be fully utilized, and the raw material utilization rate is improved on the premise of not influencing the growth quality of the next crystal.

It is to be noted that different embodiments may produce different advantages, and in different embodiments, any one or combination of the above advantages may be produced, or any other advantages may be obtained.

Having thus described the basic concept, it will be apparent to those skilled in the art that the foregoing detailed disclosure is to be regarded as illustrative only and not as limiting the present specification. Various modifications, improvements and adaptations to the present description may occur to those skilled in the art, though not explicitly described herein. Such modifications, improvements and adaptations are proposed in the present specification and thus fall within the spirit and scope of the exemplary embodiments of the present specification.

Also, the description uses specific words to describe embodiments of the specification. Reference throughout this specification to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic described in connection with at least one embodiment of the specification is included. Therefore, it is emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, some features, structures, or characteristics of one or more embodiments of the specification may be combined as appropriate.

Additionally, the order in which the elements and sequences of the process are recited in the specification, the use of alphanumeric characters, or other designations, is not intended to limit the order in which the processes and methods of the specification occur, unless otherwise specified in the claims. While certain presently contemplated useful embodiments of the invention have been discussed in the foregoing disclosure by way of various examples, it is to be understood that such detail is solely for that purpose and that the appended claims are not limited to the disclosed embodiments, but, on the contrary, are intended to cover all modifications and equivalent arrangements that are within the spirit and scope of the embodiments herein described. For example, although the system components described above may be implemented by hardware devices, they may also be implemented by software-only solutions, such as installing the described system on an existing server or mobile device.

Similarly, it should be noted that in the preceding description of embodiments of the present specification, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the embodiments. This method of disclosure, however, is not intended to imply that more features than are expressly recited in a claim. Indeed, the embodiments may be characterized as having less than all of the features of a single embodiment disclosed above.

Numerals describing the number of components, attributes, etc. are used in some embodiments, it being understood that such numerals used in the description of the embodiments are modified in some instances by the use of the modifier "about", "approximately" or "substantially". Unless otherwise indicated, "about", "approximately" or "substantially" indicates that the number allows a variation of ± 20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximations that may vary depending upon the desired properties of the individual embodiments. In some embodiments, the numerical parameter should take into account the specified significant digits and employ a general digit preserving approach. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the range are approximations, in the specific examples, such numerical values are set forth as precisely as possible within the scope of the application.

For each patent, patent application publication, and other material, such as articles, books, specifications, publications, documents, etc., cited in this specification, the entire contents of each are hereby incorporated by reference into this specification. Except where the application history document does not conform to or conflict with the contents of the present specification, it is to be understood that the application history document, as used herein in the present specification or appended claims, is intended to define the broadest scope of the present specification (whether presently or later in the specification) rather than the broadest scope of the present specification. It is to be understood that the descriptions, definitions and/or uses of terms in the accompanying materials of this specification shall control if they are inconsistent or contrary to the descriptions and/or uses of terms in this specification.

Finally, it should be understood that the embodiments described herein are merely illustrative of the principles of the embodiments described herein. Other variations are also possible within the scope of the present description. Thus, by way of example, and not limitation, alternative configurations of the embodiments of the specification can be considered consistent with the teachings of the specification. Accordingly, the embodiments of the present description are not limited to only those embodiments explicitly described and depicted herein.

Claims

1. A method of seed crystal attachment, the method comprising:

coating the adhesive on the surface of the seed crystal support;

placing the seed crystal holder coated with the adhesive in a bonding device;

performing air extraction treatment on the bonding equipment;

and adhering the seed crystal to the seed crystal holder, wherein in the adhering process, air suction treatment and heating treatment are carried out simultaneously.

2. The method as claimed in claim 1, wherein the adhering the seed crystal to the seed tray comprises:

the seed crystal is driven to move downwards by the upper transmission component and/or the seed crystal support is driven to move upwards by the lower transmission component;

and adhering the seed crystal to the seed crystal support through a pressing assembly.

3. The method of claim 1, further comprising:

coating the adhesive on the upper surface of the buffer layer and/or the lower surface of the seed crystal;

clamping the buffer layer and placing the buffer layer below the seed crystal;

and bonding the seed crystal and the seed crystal holder through a buffer layer.

4. The method of claim 1, wherein the adhering the seed crystal to the seed holder comprises:

stacking the seed crystal and a buffer layer on an adhesion table-board, wherein the contact surface of the buffer layer and the seed crystal is coated with an adhesive;

rolling by a pressing assembly to bond the seed crystal with the buffer layer;

stacking the seed crystal support, the buffer layer and the seed crystal after being bonded on the bonding table top, wherein the buffer layer is positioned between the seed crystal support and the seed crystal, and the contact surface of the buffer layer and the seed crystal support is coated with an adhesive;

and rolling the pressing assembly to adhere the seed crystal to the seed crystal holder.

5. The method of claim 1, wherein the adhering the seed crystal to the seed holder comprises:

in the bonding process, carrying out air hole detection on the bonding condition of the seed crystal, wherein the result of the air hole detection comprises at least one of air hole position, air hole size, air hole shape or air hole density;

adjusting the pressure of the bonding process based on the detection result.

6. The method of claim 1, wherein the method further comprises:

before bonding, carrying out coating treatment on the seed crystal, wherein the coating treatment comprises the following steps:

performing sand blasting treatment on the back surface of the seed crystal to ensure that the roughness of the seed crystal after the sand blasting treatment is within the range of 10-50 mu m;

heating the seed crystal after sand blasting treatment;

and (3) coating the seed crystal subjected to heating pretreatment by using a membrane material.

7. The method of claim 1, wherein the method further comprises:

placing a plurality of seed crystals including the seed crystals on a plurality of coating frames of coating equipment; and

and introducing a coating gas into the coating equipment, and growing a carbon film on the back of the plurality of seed crystals simultaneously by a vapor deposition method.

8. A seed crystal bonding apparatus, comprising:

the bonding cavity is used for placing seed crystals and seed crystal holders;

the vacuum assembly is used for vacuumizing the bonding cavity;

the heating assembly is used for heating the bonding cavity;

and the pressing assembly is used for bonding the seed crystal to the seed crystal support, and the vacuum assembly and the heating assembly are simultaneously started in the bonding process.

9. The apparatus of claim 8, further comprising:

the upper transmission component drives the seed crystal to move downwards;

and the lower transmission assembly drives the seed crystal support to move upwards.

10. The apparatus of claim 8, further comprising:

the detection assembly is used for detecting air holes of the bonding condition of the seed crystal in the bonding process, and the air hole detection result comprises at least one of air hole position, air hole size, air hole shape or air hole density;

and the control component adjusts the pressure of the bonding process based on the detection result.