A multi-chamber growth system

Abstract

The utility model provides a kind of multi-chamber growth system, the multi-chamber growth system includes: processing chamber, transmission chamber and growth chamber;Processing chamber is used to carry out staged heat treatment to crucible with aluminium nitride raw material and aluminium nitride seed crystal;Wherein, in the process of staged heat treatment, temperature in processing chamber increases in ladder form;Growth chamber is used to grow aluminium nitride crystal using aluminium nitride raw material and aluminium nitride seed crystal after staged heat treatment;Transmission chamber is communicated with processing chamber and growth chamber respectively;Wherein, processing chamber, transmission chamber and growth chamber are all vacuum sealed;Transmission chamber is equipped with transmission device, and transmission device is used to transfer crucible between processing chamber and growth chamber.The multi-chamber growth system disclosed by the utility model realizes the formation of low impurity, high lattice integrity aluminium nitride crystal.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor material preparation technology, and in particular to a multi-chamber growth system. Background Technology

[0002] Aluminum nitride (Anitride) is an excellent wide-bandgap semiconductor material. Currently, the equipment used for Anitride growth in the industry generally adopts a single-chamber structure design, meaning that all core process steps in Anitride preparation, including raw material purification, crystal growth, and ingot annealing, are completed in a single growth chamber. The design concept of this type of single-chamber device is relatively simple, mainly relying on heating components within a single chamber to achieve temperature control, and maintaining a local environment within the chamber through a basic sealing structure to meet the most basic growth requirements.

[0003] However, existing single-chamber aluminum nitride growth apparatuses suffer from numerous technical defects in practical applications, severely limiting the quality and production efficiency of aluminum nitride single crystals. Existing single-chamber aluminum nitride growth apparatuses struggle to achieve complete chamber sealing, leaving gaps or risks of seal failure between the chamber and the external environment. This can easily lead to instability in the process atmosphere within the chamber and allow trace impurities from the external environment to seep into the chamber, interfering with the growth environment of the aluminum nitride single crystals and introducing potential contamination. Furthermore, because the three key processes of impurity removal, growth, and annealing are all performed in the same chamber, impurities generated during impurity removal (such as oxides removed from the raw materials and carbon-based residues) easily adhere to the inner walls of the chamber, the heating components, and the surface of the support structure. This results in residual impurities redispersing into the growth area during subsequent crystal growth and ingot annealing, directly contaminating the aluminum nitride crystals to be grown, compromising the cleanliness of the growth chamber, and consequently affecting the purity and quality of the crystals. Furthermore, existing single-chamber aluminum nitride growth apparatuses typically require opening the furnace chamber after each growth cycle to remove the finished ingot or load new growth material. During the opening process, impurities from the atmosphere (such as carbon and oxygen impurities) directly enter the chamber. When the furnace chamber is closed again for the next growth cycle, these newly introduced carbon and oxygen impurities are difficult to completely remove using conventional processes and will eventually be incorporated into the aluminum nitride crystals, leading to an increase in the impurity content of the crystals.

[0004] The aforementioned technical defects in existing single-chamber aluminum nitride growth devices collectively result in difficulties in impurity control and poor crystal quality stability during aluminum nitride single crystal growth, failing to meet the requirements for the preparation of high-purity aluminum nitride single crystals.

[0005] It should be noted that the above description of the background technology is only for the purpose of providing a clear and complete explanation of the technical solution of this utility model and facilitating understanding by those skilled in the art. It should not be assumed that the above technical solutions are known to those skilled in the art simply because they have been described in the background technology section of this utility model. Utility Model Content

[0006] The purpose of this invention is to disclose a multi-chamber growth system to solve many defects of the existing single-chamber aluminum nitride growth device, especially to achieve the formation of aluminum nitride crystals with low impurities and high lattice integrity.

[0007] To achieve the above objectives, this utility model provides a multi-chamber growth system, comprising: a processing chamber for performing staged heat treatment on a crucible containing aluminum nitride raw material and aluminum nitride seed crystal; wherein, during the staged heat treatment process, the temperature inside the processing chamber increases in a stepwise manner.

[0008] The growth chamber is used to grow aluminum nitride crystals using aluminum nitride raw materials that have undergone staged heat treatment and aluminum nitride seed crystals;

[0009] The transfer chamber is connected to both the processing chamber and the growth chamber.

[0010] The processing chamber, the transfer chamber, and the growth chamber are all vacuum-sealed; the transfer chamber is equipped with a transfer device for transferring the crucible between the processing chamber and the growth chamber.

[0011] As a further improvement of this utility model, the staged heat treatment includes a first heat treatment, a second heat treatment, and a third heat treatment; the temperature of the third heat treatment is higher than the temperature of the second heat treatment, and the temperature of the second heat treatment is higher than the temperature of the first heat treatment.

[0012] As a further improvement of this utility model, 200℃≤temperature of the first heat treatment≤400℃, 400℃<temperature of the second heat treatment≤1200℃, and 1200℃<temperature of the third heat treatment≤2300℃.

[0013] As a further improvement of this utility model, the multi-chamber growth system further includes a first monitoring device and a second monitoring device respectively provided for the processing chamber and the transmission chamber;

[0014] The first monitoring device is used to observe the cleanliness of the processing chamber and monitor the position of the crucible in the processing chamber in real time;

[0015] The second monitoring device is used to observe the cleanliness of the growth chamber and to monitor the position of the crucible in the growth chamber in real time.

[0016] As a further improvement of this utility model, the multi-chamber growth system further includes a first accommodating space and a second accommodating space respectively provided for the processing chamber and the transmission chamber;

[0017] When the temperature inside the processing chamber exceeds the first set temperature, the first monitoring device retracts into the first accommodating space.

[0018] When the temperature inside the growth chamber exceeds the second set temperature, the second monitoring device retracts into the second accommodating space.

[0019] As a further improvement of this utility model, the first monitoring device includes: a first vacuum telescopic assembly and a first camera unit controlled by the first vacuum telescopic assembly; the first vacuum telescopic assembly penetrates through the side wall of the processing chamber and is sealed to the side wall of the processing chamber to maintain the chamber vacuum; the first vacuum telescopic assembly is used to drive the first camera unit to extend or retract between the processing chamber and the first accommodating space.

[0020] The second monitoring device includes: a second vacuum telescopic assembly and a second camera unit controlled by the second vacuum telescopic assembly; the second vacuum telescopic assembly penetrates the side wall of the growth chamber and is sealed to the side wall of the growth chamber to maintain the chamber vacuum; the second vacuum telescopic assembly is used to drive the second camera unit to extend or retract between the growth chamber and the second accommodating space.

[0021] As a further improvement of this utility model, the transmission device includes: at least one transfer mechanism for performing the gripping and transferring operation of the crucible between the processing chamber and the growth chamber;

[0022] The outer peripheral wall of the crucible protrudes outward in a horizontal direction to form an annular protrusion. The transfer mechanism includes a robotic arm, and the execution end of the robotic arm is provided with a clamp that is adapted to the protrusion to grasp the crucible.

[0023] As a further improvement of this utility model, both the processing chamber and the growth chamber are provided with a first heater and a second heater distributed in a vertical direction.

[0024] The first heater is a disc heater, which is fixedly installed above the interior of the processing chamber. The second heater is a tungsten mesh heater, which is arranged in a ring below the disc heater.

[0025] As a further improvement of this utility model, the multi-chamber growth system further includes:

[0026] The first lifting assembly includes a first lifting platform disposed in the processing chamber, a first lifting column passing through the processing chamber and the external space, and a first lifting control module disposed in the external space. The first lifting column is connected to the first lifting platform and the first lifting control module respectively. The first lifting platform is used to support the crucible, and the first lifting control module is used to drive the first lifting platform to move along the vertical direction.

[0027] The second lifting assembly includes a second lifting platform disposed within the growth chamber, a second lifting column passing through the growth chamber and the external space, and a second lifting control module disposed within the external space. The second lifting column is connected to the second lifting platform and the second lifting control module, respectively. The second lifting platform is used to support the crucible, and the second lifting control module is used to drive the second lifting platform to move along the vertical direction.

[0028] As a further improvement of this utility model, the multi-chamber growth system further includes a vacuum system, which is used to evacuate the growth chamber, the processing chamber and the transfer chamber.

[0029] Compared with existing technologies, the advantages of this invention are as follows: By vacuuming and sealing the processing chamber, transfer chamber, and growth chamber throughout the entire process, a clean process environment isolated from the outside world is formed, preventing carbon and oxygen impurities from the atmosphere from entering the chambers during the impurity removal, transfer, and growth stages. The processing chamber independently completes staged impurity removal, preventing impurities generated during removal from diffusing into the growth chamber. The transfer chamber transports the crucible under vacuum, preventing impurities from adhering to or entering the crucible during the transfer stage. Furthermore, the processing chamber, serving as a transition chamber for crystal taking and loading, only contacts the atmosphere when open, while the growth and transfer chambers remain under vacuum, thus blocking the introduction of impurities at the source and providing a pure foundation for crystal growth. Moreover, while crystal growth is occurring in the growth chamber, the processing chamber can simultaneously perform impurity removal or sintering treatment of the aluminum nitride raw material, avoiding idle chambers in a single process and eliminating the need to wait for the aluminum nitride crystal growth to complete before restarting pretreatment. This significantly shortens the total time from impurity removal to growth and substantially improves overall process efficiency. Meanwhile, the processing chamber employs a stepped heating method for staged heat treatment, which can specifically remove impurities at different desorption temperatures, avoiding impurity residue or incomplete removal caused by a single temperature. Furthermore, the stepped heating method slowly releases thermal stress, preventing agglomeration of aluminum nitride raw materials and cracking of the aluminum nitride seed crystal lattice, ensuring the integrity of the material morphology and lattice. In addition, the high purity of the pretreated raw materials and seed crystals, combined with the vacuum environment throughout the growth process, reduces the incorporation of impurities and the generation of defects during subsequent crystal growth, ultimately yielding aluminum nitride crystals with low impurity content and high lattice integrity, meeting the requirements for the preparation of high-purity aluminum nitride single crystals. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall multi-chamber growth system disclosed in this utility model. Detailed Implementation

[0031] The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings. However, it should be noted that these embodiments are not intended to limit the present invention. Equivalent transformations or substitutions in function, method, or structure made by those skilled in the art based on these embodiments are all within the protection scope of the present invention.

[0032] The accompanying drawings in this invention are not strictly drawn to scale, and the specific dimensions of each structure can be determined according to actual needs. The drawings described in this invention are merely structural schematic diagrams.

[0033] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the overall multi-chamber growth system disclosed in this utility model. In this embodiment, the multi-chamber growth system 100 includes: a processing chamber 10, a transfer chamber 20, and a growth chamber 30.

[0034] The processing chamber 10 is used to perform staged heat treatment on the crucible 40 containing aluminum nitride raw material and aluminum nitride seed crystal; wherein, during the staged heat treatment, the temperature in the processing chamber 10 increases in a stepwise manner; the growth chamber 30 is used to grow aluminum nitride crystal using the aluminum nitride raw material and aluminum nitride seed crystal after staged heat treatment; the transfer chamber 20 is connected to the processing chamber 10 and the growth chamber 30 respectively; wherein the processing chamber 10, the transfer chamber 20 and the growth chamber 30 are all vacuum sealed; the transfer chamber 20 is provided with a transfer device 21, which is used to transfer the crucible 40 between the processing chamber 10 and the growth chamber 30.

[0035] First, the crucible 40, which holds the aluminum nitride raw material and the aluminum nitride seed crystal, is placed in the processing chamber 10. The processing chamber 10, the transfer chamber 20, and the growth chamber 30 are then vacuum-evacuated to maintain a vacuum seal throughout the impurity removal, transfer, and growth processes. This creates a completely isolated clean process environment before the impurity removal process, preventing atmospheric impurities (e.g., carbon and oxygen impurities) from entering the chambers during subsequent impurity removal, transfer, and growth processes. Second, the crucible 40 undergoes staged heat treatment in the processing chamber 10 to remove various types of impurities (including oxygen, moisture, organic contaminants, metal oxides, carbon-based residues or nitrides, refractory oxides, carbide decomposition products, or metal evaporations) adhering to the crucible 40 and the aluminum nitride raw material. Meanwhile, since the impurity removal process is carried out entirely within the processing chamber 10, the impurities generated during the removal process can be prevented from diffusing into the growth chamber 30, thus avoiding contamination of the growth chamber 30 by the removal process. After the crucible 40 undergoes staged heat treatment, high-purity aluminum nitride raw materials and aluminum nitride seed crystals are obtained.

[0036] The crucible 40 is transferred to the transfer chamber 20 via a transfer device 21. The transfer device 21 moves the crucible 40 within the vacuum-sealed transfer chamber 20, allowing it to be transferred to the processing chamber 10 or the growth chamber 30, thus connecting the impurity removal process and the growth process. During the transfer of the crucible 40, the transfer chamber 20 is not connected to the atmosphere to prevent atmospheric impurities from adhering to the crucible 40 or entering its interior and contaminating the aluminum nitride raw material and aluminum nitride seed crystal. This ensures that the crucible 40 and the aluminum nitride raw material and aluminum nitride seed crystal inside it maintain a high level of cleanliness throughout the growth chamber 30. Finally, within the growth chamber 30, aluminum nitride crystals are grown using the high-cleanliness aluminum nitride raw material and aluminum nitride seed crystal to obtain aluminum nitride crystals with low impurity content and high lattice integrity.

[0037] In some examples, after the growth chamber 30 completes one round of aluminum nitride crystal growth, it is not necessary to open the growth chamber 30. Instead, the crucible 40 carrying the aluminum nitride crystal is transferred from the growth chamber 30 to the transfer chamber 20 in a vacuum environment via the transfer device 21, and then the crucible 40 is further transferred to the processing chamber 10 via the transfer chamber 20. Thus, after the crucible 40 carrying the aluminum nitride crystal is transferred to the processing chamber 10, it is only necessary to briefly open the processing chamber 10 to remove the aluminum nitride crystal. During the opening of the processing chamber 10, both the transfer chamber 20 and the growth chamber 30 remain in a vacuum-sealed state. Impurities in the atmosphere can only enter the processing chamber 10 and cannot invade the growth chamber 30 and the transfer chamber 20, thus avoiding the introduction of impurities into the existing growth chamber due to exposure to the atmosphere when the furnace is opened. When it is necessary to fill crucible 40 with new material (i.e., aluminum nitride raw material and aluminum nitride seed crystal), this is also done within processing chamber 10. After removing the aluminum nitride crystal from crucible 40, the new material is placed into crucible 40, and then processing chamber 10 is closed. Processing chamber 10 is then evacuated separately to restore its vacuum level. Processing chamber 10 serves as a transition chamber for removing aluminum nitride crystal and filling with new material. Processing chamber 10 is opened and vacuum restored independently. Growth chamber 30 and transfer chamber 20 remain vacuum-sealed throughout the replacement cycle of removing aluminum nitride crystal and filling with new material in processing chamber 10, and are not exposed to the atmosphere. This prevents carbon and oxygen impurities from being introduced into growth chamber 30 and transfer chamber 20. Furthermore, after processing chamber 10 is re-evacuated, residual atmospheric impurities inside can be further removed through subsequent staged heat treatment, preventing impurities from being transferred to growth chamber 30 with crucible 40.

[0038] In some examples, during the aluminum nitride crystal growth process in the growth chamber 30, the processing chamber 10 can simultaneously perform staged heat treatment or sintering of the aluminum nitride raw material. This allows the processing chamber 10 and the growth chamber 30 to operate in parallel, avoiding idle periods in a single process flow (e.g., the processing chamber 10 is idle while the growth chamber 30 is performing the aluminum nitride crystal growth process). Therefore, it is not necessary to wait for the growth chamber 30 to complete the aluminum nitride crystal growth before starting the processing chamber 10 to perform staged heat treatment or sintering of the aluminum nitride raw material, shortening the process time from the impurity removal process to the growth process and improving overall process efficiency.

[0039] In some examples, the temperatures required for the desorption, decomposition, or volatilization of various types of impurities (including oxygen, moisture, or organic contaminants, metal oxides, carbon-based residues, or nitrides, refractory oxides, carbide decomposition products, or metal evaporates, etc.) adhering to the crucible 40 and the aluminum nitride raw material differ. This embodiment addresses this by increasing the temperature in the processing chamber 10 in a stepped manner during the staged heat treatment process. Specifically, this embodiment uses at least two stages of temperature progression (hereinafter referred to as "stepped heating") to specifically remove different types of impurities, avoid material damage, and prevent the incomplete removal of impurities with low thermal stability and the inability to remove impurities with high thermal stability due to a single temperature.

[0040] If a non-step heating method (e.g., direct high-temperature heating) is used, the material will experience severe thermal stress due to rapid temperature changes, which may lead to agglomeration of aluminum nitride raw materials and cracking of the aluminum nitride seed crystal lattice, damaging the original structure and properties of the material. Step heating, on the other hand, allows the aluminum nitride raw materials and aluminum nitride seed crystals to gradually adapt to temperature changes, slowly releasing thermal stress and avoiding problems such as agglomeration of aluminum nitride raw materials and damage to the aluminum nitride seed crystal lattice, ensuring the integrity of the physical morphology of the aluminum nitride raw materials and the lattice structure of the aluminum nitride seed crystals. Furthermore, the high-temperature stage of step heating not only removes stubborn impurities but also promotes the slow diffusion and fusion of atoms in the aluminum nitride raw materials, achieving initial densification of the aluminum nitride raw materials and preventing sublimation rate fluctuations caused by a loose structure of the aluminum nitride raw materials in subsequent growth stages. At the same time, the oxide layer on the surface of the aluminum nitride seed crystal is gradually removed with the progression of the temperature steps, allowing the lattice stress of the aluminum nitride seed crystal to be gradually released, forming a clean and complete lattice template.

[0041] Therefore, staged heat treatment can improve impurity removal efficiency, reduce the impurity content in aluminum nitride raw materials and aluminum nitride seed crystals, and obtain high-purity aluminum nitride raw materials and aluminum nitride seed crystals. This also reduces impurity incorporation in subsequent growth processes from the source of the aluminum nitride crystal growth process. Furthermore, it ensures the integrity of the physical morphology of the aluminum nitride raw materials and the lattice structure of the aluminum nitride seed crystals, stabilizing the sublimation rate of the aluminum nitride raw materials and enhancing the ability of the aluminum nitride seed crystals to guide atomic deposition. This results in improved lattice integrity and reduced defect density in the final grown aluminum nitride crystals. Simultaneously, because each stage of heat treatment is carried out inside the processing chamber 10, contamination of the growth chamber 30 is avoided. The vacuum sealing throughout the impurity removal, transport, and growth processes improves the stability of the aluminum nitride crystal quality, meeting the requirements for preparing high-purity aluminum nitride crystals.

[0042] In some examples, the parameter Figure 1As shown, the multi-chamber growth system 100 also includes a vacuum system 70, which is used to evacuate the growth chamber 30, processing chamber 10, and transfer chamber 20. In the initial stage, the vacuum system 70 performs vacuum evacuation of the processing chamber 10, transfer chamber 20, and growth chamber 30, ensuring that these chambers remain under vacuum throughout the impurity removal, transfer, and growth processes. During the transfer of the crucible 40 by the transfer device 21, the vacuum system 70 maintains a stable vacuum level in the processing chamber 10, transfer chamber 20, and growth chamber 30. After aluminum nitride crystals are removed from the processing chamber 10 or new materials are added, the vacuum system 70 separately evacuates the processing chamber 10 to restore its vacuum level.

[0043] In some examples, the parameter Figure 1 As shown, the multi-chamber growth system 100 further includes isolation control mechanisms 60 at the connection points between the transfer chamber 20 and the processing chamber 10, and between the transfer chamber 20 and the growth chamber 30. The isolation control mechanisms 60 are used to control the connection or isolation between the transfer chamber 20 and the processing chamber 10 and the growth chamber 30, respectively. By controlling the connection and disconnection between the transfer chamber 20 and the processing chamber 10 and the growth chamber 30 through the isolation control mechanisms 60, the independent temperature, vacuum, and other process environments of each chamber are maintained, preventing mutual interference or cross-contamination of impurities between different chambers. It should be noted that the isolation control mechanisms 60 are constructed using high-temperature resistant materials with excellent sealing performance to adapt to the high-temperature vacuum conditions of each chamber. Specific structures include, but are not limited to, sealing valve structures; this invention does not limit these specific structures.

[0044] In some examples, the staged heat treatment includes a first heat treatment, a second heat treatment, and a third heat treatment; the temperature of the third heat treatment is higher than the temperature of the second heat treatment, and the temperature of the second heat treatment is higher than the temperature of the first heat treatment.

[0045] The first heat treatment, as the initial temperature stage, has temperature conditions adapted to the removal requirements of impurities with low thermal stability (e.g., easily desorbable gaseous or light contaminants, exemplarily including oxygen, moisture, or organic contaminants) adhering to the crucible 40 and the aluminum nitride raw material. Through the first heat treatment, these easily desorbable impurities can be removed at relatively low temperatures. Simultaneously, the temperature of the first heat treatment allows the material to gradually adapt to temperature changes, reducing the impact of initial thermal stress on the material.

[0046] The second heat treatment, as an intermediate temperature stage, is higher than the first heat treatment and can specifically remove impurities with moderate thermal stability (e.g., compounds that require a certain temperature to decompose, such as metal oxides, carbon-based residues, or nitrides) adhering to the crucible 40 and the aluminum nitride raw material. By providing suitable temperature conditions to the crucible 40 through the second heat treatment, these impurities with moderate thermal stability that require a certain temperature to decompose can be removed. Thus, the treatment of impurities with moderate thermal stability that cannot be removed by the first heat treatment is completed, and the gradual increase in temperature avoids problems such as agglomeration of aluminum nitride raw material and damage to the aluminum nitride seed crystal lattice caused by a sudden increase in temperature.

[0047] The third heat treatment, as the highest temperature stage, is higher than the second heat treatment and can meet the requirements for removing thermally stable impurities (e.g., refractory oxides, carbide decomposition products, or metal vapors) adhering to the crucible 40 and the aluminum nitride raw material. The third heat treatment provides higher temperature conditions to the crucible 40, prompting these stubborn impurities to be removed through decomposition, chemical transformation, or physical removal. Simultaneously, the temperature of the third heat treatment stage can further optimize the material structure (e.g., promote the densification of the aluminum nitride raw material and the regularization of the aluminum nitride seed crystal lattice), providing aluminum nitride raw material and aluminum nitride seed crystals with better structural compatibility for subsequent aluminum nitride crystal growth.

[0048] In summary, by employing a stepped heating process involving the first, second, and third heat treatments, impurities with low, medium, and high thermal stability adhering to the crucible 40 and the aluminum nitride raw material were effectively removed. This covered a range of impurities, from easily desorbable to stubborn ones, reducing the impurity content in the aluminum nitride raw material and aluminum nitride seed crystal, and consequently reducing the total amount of impurities in the aluminum nitride crystal growth process. Simultaneously, the stepped heating process avoided problems such as agglomeration of the aluminum nitride raw material and damage to the aluminum nitride seed crystal lattice caused by sudden temperature increases, and provided a high-quality material guarantee for the clean growth of subsequent aluminum nitride crystals (i.e., providing aluminum nitride raw material and aluminum nitride seed crystals with better structural compatibility for subsequent aluminum nitride crystal growth).

[0049] In some examples, 200℃ ≤ the temperature of the first heat treatment ≤ 400℃, 400℃ < the temperature of the second heat treatment ≤ 1200℃, and 1200℃ < the temperature of the third heat treatment ≤ 2300℃. The impurities removed by the first heat treatment include oxygen, moisture, or organic contaminants; the impurities removed by the second heat treatment include metal oxides, carbon-based residues, or nitrides; and the impurities removed by the third heat treatment include refractory oxides, decomposition products of carbides, or metal evaporations.

[0050] The first heat treatment, within a temperature range of 200°C to 400°C, is suitable for removing impurities with low thermal stability, such as oxygen, moisture, or organic contaminants (e.g., residual grease from cleaning). This temperature range provides sufficient conditions for removing these impurities, causing adsorbed oxygen to detach from the walls of the crucible 40 and the surface of the aluminum nitride material, becoming a free gas that can be discharged through the vacuum system 70. Moisture absorbs heat and converts into water vapor, detaching from the walls of the crucible 40 and the surface of the aluminum nitride material through evaporation, and is also discharged through the vacuum system 70. Organic contaminants (e.g., residual grease from cleaning) evaporate into a gaseous state within this temperature range, detaching from the walls of the crucible 40 and the surface of the aluminum nitride material, and are discharged through the vacuum system 70, thus achieving the removal of impurities with low thermal stability. Therefore, through the temperature effect of the first heat treatment, these easily detachable impurities are transformed from an attached state into a form that can be separated from the material or the crucible 40, achieving effective removal. Meanwhile, the temperature range of the first heat treatment allows the aluminum nitride raw material and aluminum nitride seed crystal to gradually adapt to temperature changes, reducing the impact of initial thermal stress on the material and avoiding problems such as agglomeration of aluminum nitride raw material and damage to the aluminum nitride seed crystal lattice.

[0051] The second heat treatment, within a temperature range of 400°C to 1200°C, can specifically remove impurities with moderate thermal stability, such as metal oxides (e.g., iron oxide Fe2O3, copper oxide CuO, etc.), carbon-based residues (e.g., carbon black C, graphite C), or nitrides (e.g., low-melting-point metal nitrides, magnesium nitride Mg3N2). The temperature range of the second heat treatment provides sufficient temperature conditions for impurities with moderate thermal stability, promoting the decomposition of metal oxides (taking iron oxide Fe2O3 as an example). Iron oxide Fe2O3 ultimately decomposes into elemental Fe and gaseous O2. The density of the elemental Fe produced is much higher than that of the aluminum nitride raw material, so it will naturally settle to the bottom of crucible 40 and will no longer migrate with the aluminum nitride raw material or participate in subsequent growth. Gaseous O2 is discharged through the vacuum system 70. Carbon-based residues are converted into easily detachable gaseous products through reaction. For example, carbon black C and graphite C will react with the O2 formed by the decomposition of metal oxides to generate gaseous carbon oxides such as CO or CO2. If N2 is present in crucible 40, some carbon-based residues will react with it. Gaseous products such as CN should be generated, which are discharged through the vacuum system 70. Nitrides (taking magnesium nitride Mg3N2 as an example) decompose, and magnesium nitride Mg3N2 eventually decomposes into metallic elemental Mg and gaseous N2. The density of the metallic elemental Mg produced by decomposition is much higher than that of aluminum nitride raw material, and it will naturally settle to the bottom of crucible 40, no longer migrating with aluminum nitride raw material or participating in subsequent growth. Gaseous N2 is discharged through the vacuum system 70. This achieves the removal of impurities with moderate thermal stability. The second heat treatment stage not only completes the treatment of impurities with moderate thermal stability that could not be removed in the first heat treatment stage, but also avoids problems such as agglomeration of aluminum nitride raw material and damage to aluminum nitride seed crystal lattice caused by a sudden increase in temperature through gradual temperature increase.

[0052] The third heat treatment, within a temperature range of 1200℃ to 2300℃, can meet the requirements for removing impurities with high thermal stability, such as refractory oxides (e.g., silicon dioxide SiO2, alumina Al2O3), decomposition products of carbides, and metal evaporation products. The temperature range of the third heat treatment provides sufficient temperature conditions for these thermally stable impurities. Refractory oxides (e.g., silicon dioxide SiO2, alumina Al2O3) melt from solid to liquid at high temperatures. Because the liquid melt does not adhere to the aluminum nitride raw material and there is a density difference, the liquid melt eventually settles to the bottom of crucible 40, physically separating from the aluminum nitride raw material, and no longer sublimates or participates in subsequent growth. The decomposition products of carbides (e.g., in the second heat treatment, carbon black C or graphite C that was not completely removed reacts with active Al atoms in the aluminum nitride raw material to form aluminum carbide Al4C3. The aluminum carbide Al4C3 is embedded in the surface of the aluminum nitride raw material or in the gaps of crucible 40 in the form of fine particles. Because the second heat treatment temperature is insufficient to completely decompose it, it remains until the third heat treatment stage) react with N2 present in crucible 40 at high temperatures to form... Aluminum nitride (AlN) and gaseous product C2N2 are formed. The main components of AlN are completely identical to those of aluminum nitride raw materials, allowing it to be directly incorporated into the aluminum nitride raw materials and become a component for subsequent aluminum nitride crystal growth. The gaseous product C2N2 is discharged through a vacuum system 70. Metal vapors (e.g., solid elemental metal Fe remaining in the second heat treatment) evaporate into gaseous Fe atoms at high temperatures and are discharged through the vacuum system 70, thereby removing impurities with high thermal stability. At the same time, the temperature range of the third heat treatment can further optimize the material structure, allowing aluminum nitride raw material atoms to slowly diffuse and fuse, achieving initial densification and avoiding sublimation rate fluctuations caused by loose structure in subsequent growth stages. The oxide layer on the surface of the aluminum nitride seed crystal is gradually removed as the temperature increases, and the lattice stress is fully released, promoting a more regular and orderly lattice arrangement and forming a clean and complete lattice template, improving its compatibility with subsequent aluminum nitride crystal growth.

[0053] In some examples, during the staged heat treatment of crucible 40, the gas required for aluminum nitride crystal growth is not introduced into the treatment chamber 10; and / or, the temperature of the region where the aluminum nitride raw material is located is not higher than the temperature of the region where the aluminum nitride seed crystal is located.

[0054] It is known that the chemical conditions for aluminum nitride crystal growth require the directional bonding of Al atoms and N atoms to form an AlN lattice. This embodiment avoids introducing growth gases (e.g., nitrogen) during the staged heat treatment process. Even if a small amount of Al atoms are released through sublimation at high temperatures, the lack of a stable nitrogen source prevents the formation of an AlN crystal structure. This avoids the sublimation of the aluminum nitride raw material, the bonding of Al atoms with the nitrogen source, and the eventual deposition and growth of Al atoms on the surface of the aluminum nitride seed crystal, ensuring that the surface of the aluminum nitride seed crystal always remains a clean lattice template.

[0055] It is known that the thermodynamic condition for aluminum nitride crystal growth is that the temperature of the raw material region where the aluminum nitride raw material is located is higher than the temperature of the seed crystal region where the aluminum nitride seed crystal is located. The driving force for aluminum nitride crystal growth comes from the mass migration caused by the temperature difference between the raw material region and the seed crystal region. If the temperature of the raw material region is higher than that of the seed crystal region, the Al and N atoms sublimated from the aluminum nitride raw material will diffuse from the high-temperature raw material region to the low-temperature seed crystal region, and eventually migrate to the surface of the aluminum nitride seed crystal for deposition. However, this embodiment avoids the temperature gradient between the raw material region and the seed crystal region by controlling the temperature of the raw material region to be no higher than that of the seed crystal region. Even if the temperature of the raw material region reaches close to the sublimation threshold of the aluminum nitride raw material, the Al and N atoms generated by the sublimation of the aluminum nitride raw material cannot be directionally deposited on the surface of the aluminum nitride seed crystal due to the lack of significant temperature difference between the raw material region and the seed crystal region, thus preventing the formation of aluminum nitride crystals. This avoids the situation where the aluminum nitride raw material sublimates due to the temperature gradient and subsequently deposits and grows on the surface of the aluminum nitride seed crystal.

[0056] In some examples, the temperature of the transfer chamber 20 is controlled at 1000°C-1200°C during the process of transferring the crucible 40 from the transfer chamber 20 to the growth chamber 30.

[0057] After staged heat treatment, the crucible 40, aluminum nitride raw material, and aluminum nitride seed crystal are all at high temperatures. If they are directly transferred to the low-temperature (e.g., room temperature 20°C) transfer chamber 20, a sudden drop in temperature will cause drastic thermal expansion and contraction. The large difference in thermal expansion coefficients between the crucible 40 and the aluminum nitride seed crystal may lead to lattice cracking of the aluminum nitride seed crystal and deformation of the crucible 40. By controlling the transfer chamber 20 to maintain a temperature environment of 1000°C-1200°C, the internal temperature of the transfer chamber 20 is made close to the temperature of the heat-treated crucible 40, aluminum nitride raw material, and aluminum nitride seed crystal, a smooth transition can be achieved, reducing thermal stress and avoiding damage to the material structure. Meanwhile, during the transfer of the crucible 40, aluminum nitride raw material, and aluminum nitride seed crystal in the transfer chamber 20, the temperature environment of 1000℃-1200℃ inside the transfer chamber 20 can keep the surface of the aluminum nitride raw material and aluminum nitride seed crystal highly active, prevent impurity molecules from adhering through van der Waals forces, and ensure that the material entering the growth chamber 30 is in a high-cleanliness state.

[0058] In some examples, the transfer device 21 is a high-temperature resistant transfer device capable of operating in high-temperature environments above 1200°C, used to transfer the crucible 40 within the transfer chamber 20. It is constructed from high-temperature resistant materials to adapt to high-temperature operating conditions. The transfer device 21 includes: at least one transfer mechanism 211 for performing gripping and transferring operations of the crucible 40 between the processing chamber 10 and the growth chamber 30; the outer peripheral wall of the crucible 40 is horizontal (e.g., along the horizontal direction). Figure 1An annular protrusion 401 extends outward in the direction indicated by the X-axis. The transfer mechanism 211 includes a robotic arm (not shown), and the actuator of the robotic arm is provided with a clamp (not shown) adapted to the protrusion 401 to grasp the crucible 40. Through the cooperation between the annular protrusion 401 and the adapted clamp, the robotic arm can stably grasp the crucible 40, ensuring that the crucible 40 remains in a stable position when transferred to the processing chamber 10 or the growth chamber 30, and avoiding shaking or displacement during the transfer process.

[0059] In some examples, the temperature of the growth chamber 30 is controlled at 800°C-2500°C during the growth of aluminum nitride crystals. In this embodiment, the temperature of the growth chamber 30 is controlled within the range of 800°C-2500°C, rather than using a single constant temperature, but is adjusted according to the growth process of the aluminum nitride crystals.

[0060] For example, before formal growth, the growth chamber 30 is heated to 800℃-1200℃ to preheat the crucible 40. This temperature range not only connects to the temperature environment of the preceding transfer chamber 20, preventing cracking of the aluminum nitride seed crystal lattice and deformation of the crucible 40 due to a sudden temperature drop, but also removes impurities that may be introduced during the transfer process. After the crucible 40 is preheated, the temperature of the growth chamber 30 is gradually increased to the growth range of 1200℃-2300℃. During this stage, the temperature of the raw material region is controlled at 2000℃-2300℃, and the temperature of the seed crystal region is controlled at 1800℃-2100℃, so that the temperature of the raw material region is higher than that of the seed crystal region. This meets the stable sublimation requirements of the aluminum nitride raw material, allowing the Al and N atoms generated by the sublimation of the aluminum nitride raw material to diffuse from the high-temperature raw material region to the low-temperature seed crystal region under the influence of the temperature difference. Simultaneously, high-purity nitrogen gas is introduced into the growth chamber 30. Al atoms combine with nitrogen and eventually deposit and grow on the surface of the aluminum nitride seed crystal, thereby achieving directional and continuous growth of the aluminum nitride crystal. Finally, when the aluminum nitride crystal approaches the target size, the temperature of the growth chamber 30 is further increased to the late growth range of 2300℃-2500℃. The high temperature at this stage can repair the internal structure of the aluminum nitride crystal. For example, vacancy defects in the aluminum nitride crystal (e.g., Al atom vacancies, N atom vacancies) will be filled by atomic diffusion at high temperature, reducing lattice gaps and improving crystal density. After the aluminum nitride crystal repair is completed, the internal temperature of the growth chamber 30 is slowly reduced from 2500℃ to about 1000℃. This gradient cooling avoids severe thermal stress caused by differences in thermal expansion and contraction in the aluminum nitride crystal, preventing cracking and further stabilizing the lattice structure, ultimately obtaining an aluminum nitride crystal with high purity, high lattice integrity, and stable physical properties.

[0061] In some examples, a crucible lid 41 is disposed above the crucible 40, and an aluminum nitride seed crystal is pre-fixed on the inner surface of the crucible lid 41. In some examples, the material of the crucible 40 is tungsten with a purity ≥99.9%.

[0062] In this invention, the aluminum nitride raw material is high-purity aluminum nitride with a purity of ≥99.9%, and the aluminum nitride raw material can be in powder, granular or aggregate form.

[0063] In some examples, the aluminum nitride raw material is in granular form and placed at the bottom of crucible 40.

[0064] In some examples, after the crucible 40 undergoes staged heat treatment, the heat-treated aluminum nitride raw material can be sintered in the processing chamber 10. Although most impurities have been removed from the staged heat-treated aluminum nitride raw material, it is still in a loose granular form with numerous pores and gaps between the particles. By sintering the staged heat-treated aluminum nitride raw material, a certain temperature (e.g., 2000℃~2300℃) needs to be used to connect the third high-temperature heat treatment stage to avoid temperature discontinuity and save energy. This allows the aluminum nitride raw material particles to undergo viscous flow and atomic diffusion under thermal action, gradually merging the particle boundaries and filling the pores, ultimately forming a denser aluminum nitride raw material. This densification structure avoids fluctuations in the sublimation rate of the loose aluminum nitride raw material due to excessively large particle gaps during the sublimation stage, ensuring that the dense aluminum nitride raw material can stably and uniformly release Al and N atoms.

[0065] In some examples, the parameter Figure 1 As shown, both the processing chamber 10 and the growth chamber 30 have vertically oriented (e.g., Figure 1 The first heater 81 and the second heater 82 are distributed in the direction shown by the Y-axis; wherein, the first heater 81 is a disc heater, which is fixedly installed above the interior of the processing chamber 10, and the second heater 82 is a tungsten mesh heater, which is arranged in a ring below the disc heater.

[0066] The first heater 81 can generate comprehensive and uniform thermal radiation on the upper surface of the crucible 40, avoiding insufficient heating of the top of the material; the second heater 82 surrounds the outer periphery of the crucible 40 to achieve lateral heating, eliminate the temperature gradient between the side wall and the center of the crucible 40, achieve uniform heating of the crucible 40, ensure that the aluminum nitride raw material is heated evenly during the impurity removal or sintering stage, avoid local agglomeration of the aluminum nitride raw material or incomplete sintering, and ensure a stable lattice growth environment during the aluminum nitride crystal growth stage.

[0067] In some examples, the parameter Figure 1As shown, the multi-chamber growth system 100 further includes a first lifting assembly 51 and a second lifting assembly 52. ​​The first lifting assembly 51 includes a first lifting platform 511 disposed within the processing chamber 10, a first lifting column 512 passing through the processing chamber 10 and the external space, and a first lifting control module 513 disposed in the external space. The first lifting column 512 is connected to the first lifting platform 511 and the first lifting control module 513 respectively. The first lifting platform 511 is used to support the crucible 40, and the first lifting control module 513 is used to drive the first lifting platform 511 to move in the vertical direction.

[0068] The first lifting platform 511 stably supports the crucible 40 containing the aluminum nitride raw material and aluminum nitride seed crystal. The first lifting control module 513 externally controls the first lifting column 512 to drive the first lifting platform 511 to move precisely vertically. When the transfer mechanism 211 needs to send the crucible 40 from the outside or the transfer chamber 20 into the processing chamber 10, the first lifting control module 513 drives the first lifting platform 511 vertically to a preset receiving position. This ensures that the height of the first lifting platform 511 matches the transfer path of the transfer mechanism 211, allowing the robotic arm's gripper to smoothly place the crucible 40 on the first lifting platform 511. When the crucible 40 needs to be moved out of the processing chamber 10, the first lifting platform 511 supporting the crucible 40 is adjusted vertically to a preset transfer position, ensuring accurate alignment between the crucible 40 and the gripper, preventing gripper failure due to crucible 40 positional deviation. The first lifting assembly 51 stably supports the crucible 40 and achieves precise vertical movement. By controlling the first lifting platform 511 to precisely adjust to the preset receiving and transfer positions, it ensures that the crucible 40 is precisely aligned with the gripper on the robotic arm when entering and exiting the processing chamber 10, so as to smoothly complete the receiving and transfer, avoid gripping failure or damage to the crucible 40 due to position deviation, and ensure the reliability and stability of material transfer.

[0069] In some examples, such as Figure 1 As shown, the second lifting assembly 52 includes a second lifting platform 521 disposed in the growth chamber 30, a second lifting column 522 passing through the growth chamber 30 and the external space, and a second lifting control module 523 disposed in the external space. The second lifting column 522 is connected to the second lifting platform 521 and the second lifting control module 523 respectively. The second lifting platform 521 is used to support the crucible 40, and the second lifting control module 523 is used to drive the second lifting platform 521 to move in the vertical direction.

[0070] The second lifting platform 521 stably supports the crucible 40 containing the aluminum nitride raw material and aluminum nitride seed crystal. An external second lifting control module 523 controls the second lifting column 522 to drive the second lifting platform 521 to move precisely vertically. When the transfer mechanism 211 needs to send the crucible 40 from the transfer chamber 20 into the growth chamber 30, the second lifting control module 523 drives the second lifting platform 521 vertically to a preset receiving position. This ensures that the height of the second lifting platform 521 matches the transfer path of the transfer mechanism 211, allowing the robotic arm's gripper to smoothly place the crucible 40 on the second lifting platform 521. When the crucible 40 needs to be moved out of the growth chamber 30, the second lifting platform 521 supporting the crucible 40 is adjusted vertically to a preset transfer position, ensuring accurate alignment between the crucible 40 and the gripper, preventing gripper failure due to crucible 40 positional deviation. The second lifting assembly 52 stably supports the crucible 40 and achieves precise vertical movement. By controlling the second lifting platform 521 to precisely adjust to the preset receiving and transfer positions, it ensures that the crucible 40 is precisely aligned with the gripper on the robotic arm when entering and exiting the growth chamber 30, so as to smoothly complete the receiving and transfer, avoid gripping failure or damage to the crucible 40 due to position deviation, and ensure the reliability and stability of material transfer.

[0071] In some examples, the first lifting column 512 is sealed to the processing chamber 10 to ensure the airtightness of the processing chamber 10 while achieving the lifting function. The second lifting column 522 is sealed to the growth chamber 30 to ensure the airtightness of the growth chamber 30 while achieving the lifting function. During the reciprocating movement of the first lifting column 512 and the second lifting column 522 in the vertical direction, impurities in the external air are prevented from seeping into the processing chamber 10 or the growth chamber 30, while preventing the leakage of special gases (e.g., high-purity nitrogen introduced into the growth chamber 30) from the processing chamber 10 and the growth chamber 30. This ensures that the processing chamber 10 and the growth chamber 30 always maintain the high vacuum and inert atmosphere purity required by the process, thereby ensuring the cleanliness of the material removal process or sintering treatment and the stability of aluminum nitride crystal growth.

[0072] In some examples, the parameter Figure 1 As shown, the multi-chamber growth system 100 also includes a first monitoring device 91 and a second monitoring device 92 respectively provided for the processing chamber 10 and the transfer chamber 20.

[0073] The first monitoring device 91 is used to observe the cleanliness of the processing chamber 10 and monitor the position of the crucible 40 within the processing chamber 10 in real time. After the crucible 40 undergoes staged heat treatment, the cleanliness of the processing chamber 10 will affect the purity of the aluminum nitride raw material generated from the subsequent aluminum nitride sintering process. If impurities remain in the processing chamber 10, they may re-adhere to the surface of the aluminum nitride raw material during sintering, negating the impurity removal effect of the previous staged heat treatment. By setting the first monitoring device 91 (e.g., a high-temperature endoscope or an infrared imager), the cleanliness of the inner wall of the processing chamber 10 and the periphery of the crucible 40 can be directly observed. If residual impurities are found, the processing chamber 10 can be cleaned a second time in a timely manner (e.g., extending the vacuum pumping time of the vacuum system 70 in the processing chamber 10, controlling the high-temperature heating of the first heater 81 and the second heater 82) to prevent impurities from contaminating the aluminum nitride raw material. Once the cleanliness of the processing chamber 10 is confirmed to meet the standards, a clean environment is provided for the subsequent sintering of aluminum nitride raw materials, ensuring that the purity of the aluminum nitride raw materials is not affected by the environment of the processing chamber 10.

[0074] The second monitoring device 92 is used to observe the cleanliness of the growth chamber 30 and monitor the position of the crucible 40 within the growth chamber 30 in real time. The second monitoring device 92 (e.g., a high-temperature resistant in-situ camera or a laser scattering sensor) can observe the cleanliness of the growth chamber 30 in real time, and can promptly detect whether there are residual impurities in the growth chamber 30, such as carbides or oxides that were not thoroughly cleaned after the previous growth. If residual impurities are found, the growth chamber 30 can be cleaned a second time (e.g., extending the vacuum pumping time of the vacuum system 70 in the growth chamber 30, controlling the high-temperature heating of the first heater 81 and the second heater 82) to avoid contamination of subsequent aluminum nitride crystal growth, ultimately stabilizing and improving the purity and lattice integrity of the aluminum nitride crystal.

[0075] In some examples, during the process of transferring the crucible 40 from the transfer chamber 20 to the second lifting platform 521 in the growth chamber 30 using the transfer device 21, the position of the crucible 40 is monitored in real time by the second monitoring device 92; during the process of transferring the crucible 40 from the transfer chamber 20 to the first lifting platform 511 in the processing chamber 10 using the transfer device 21, the position of the crucible 40 is monitored in real time by the first monitoring device 91.

[0076] When the crucible 40 is transferred to the processing chamber 10, the first monitoring device 91 monitors and confirms the position of the crucible 40 in the processing chamber 10. If the position of the crucible 40 is detected to deviate from the preset position, the transmission device 21 can be controlled to adjust the position of the crucible 40 to avoid collision with the first lifting platform 511, reduce the alignment error between the crucible 40 and the first lifting platform 511, and ensure that subsequent processes (e.g., uniform heating during the annealing stage of the processing chamber 10) can proceed normally, avoiding local temperature abnormalities or uneven heating of aluminum nitride crystals caused by the position deviation of the crucible 40.

[0077] When the crucible 40 is transferred to the growth chamber 30, the position of the crucible 40 in the growth chamber 30 is monitored and confirmed by the second monitoring device 92. If the position of the crucible 40 is detected to deviate from the preset position, the transmission device 21 can be controlled to adjust the position of the crucible 40 to avoid collision with the second lifting platform 521, reduce the alignment error between the crucible 40 and the second lifting platform 521, and ensure that subsequent processes (e.g., the temperature gradient during the growth stage in the growth chamber 30) can proceed normally, avoiding local temperature abnormalities or uneven heating of aluminum nitride crystals caused by the position deviation of the crucible 40.

[0078] In some examples, the multi-chamber growth system 100 further includes a first accommodating space (not shown) and a second accommodating space (not shown) respectively corresponding to the processing chamber 10 and the transfer chamber 20; when the temperature in the processing chamber 10 is greater than a first set temperature, the first monitoring device 91 retracts to the first accommodating space; when the temperature in the growth chamber 30 is greater than a second set temperature, the second monitoring device 92 retracts to the second accommodating space.

[0079] In the process stages where the temperature of the processing chamber 10 exceeds the first set temperature and the temperature of the growth chamber 30 exceeds the second set temperature, it is unnecessary for the first monitoring device 91 and the second monitoring device 92 to monitor the processing chamber 10 and the growth chamber 30 respectively. For example, when the temperature of the processing chamber 10 exceeds 1200℃, the main purpose of this process stage is for the high-temperature decomposition and volatilization of impurities. At this time, there are no complex dynamic changes in the processing chamber 10 (only impurities are gasified and discharged), so it is not necessary for the first monitoring device 91 to observe in real time. It is only necessary to observe the cleanliness of the inner wall of the processing chamber 10 and the area around the crucible 40 before sintering. When the temperature of the growth chamber 30 reaches 2300℃-2500℃, the aluminum nitride crystal is close to being formed in this process stage. The growth of the aluminum nitride crystal is mainly controlled by stabilizing the temperature parameters, rather than by visual monitoring and adjustment, so it is not necessary for the second monitoring device 92 to observe in real time. The first monitoring device 91 and the second monitoring device 92 are respectively withdrawn to their corresponding accommodating spaces in the above process stages, which can avoid damage to themselves and will not affect the continuity of the process.

[0080] In some examples, when the processing chamber 10 cools down to below the first set temperature (e.g., 800°C) and the growth chamber 30 cools down to below the second set temperature (e.g., 1500°C), the first monitoring device 91 and the second monitoring device 92 can be extended to continue monitoring subsequent stages (e.g., the cleanliness of the processing chamber 10 before sintering and the cleanliness of the growth chamber 30) to ensure that the monitoring function is aligned with the process requirements.

[0081] Furthermore, both the first and second accommodating spaces are equipped with heat insulation layers (not shown), which can maintain the internal temperature within the tolerance range of the first monitoring device 91 and the second monitoring device 92. By physically isolating and blocking high temperature conduction and heat radiation, the first monitoring device 91 and the second monitoring device 92 are prevented from aging or failing due to long-term exposure to the overheated environment, thus extending the service life of the first monitoring device 91 and the second monitoring device 92.

[0082] In some examples, the first monitoring device 91 and the second monitoring device 92 are each equipped with a water-cooled protective cover (not shown). The water-cooled protective cover protects the first monitoring device 91 and the second monitoring device 92 from overheating and affecting their performance.

[0083] In some examples, a high-temperature resistant glass window (not shown) is provided on the side of the first accommodating space near the processing chamber 10 to observe the situation inside the processing chamber 10; a high-temperature resistant glass window (not shown) is also provided on the side of the second accommodating space near the growth chamber 30 to observe the situation inside the growth chamber 30.

[0084] In some examples, the parameter Figure 1 As shown, the first monitoring device 91 includes: a first vacuum telescopic assembly 911 and a first camera unit 912 controlled by the first vacuum telescopic assembly 911; the first vacuum telescopic assembly 911 penetrates the side wall of the processing chamber 10 and is sealed to the side wall of the processing chamber 10 to maintain the chamber vacuum; the first vacuum telescopic assembly 911 is used to drive the first camera unit 912 to extend or retract between the processing chamber 10 and the first accommodating space. The second monitoring device 92 includes: a second vacuum telescopic assembly 921 and a second camera unit 922 controlled by the second vacuum telescopic assembly 921; the second vacuum telescopic assembly 921 penetrates the side wall of the growth chamber 30 and is sealed to the side wall of the growth chamber 30 to maintain the chamber vacuum; the second vacuum telescopic assembly 921 is used to drive the second camera unit 922 to extend or retract between the growth chamber 30 and the second accommodating space.

[0085] After the temperature of the processing chamber 10 exceeds the first set temperature, the first vacuum telescopic component 911 drives the first camera unit 912 to retract into the first accommodating space; after the temperature of the growth chamber 30 exceeds the second set temperature, the second vacuum telescopic component 921 drives the second camera unit 922 to retract into the second accommodating space.

[0086] It should be noted that both the first vacuum telescopic component 911 and the second vacuum telescopic component 921 are high-temperature resistant vacuum telescopic devices that can operate stably in a high-temperature vacuum environment. They are used to drive the corresponding camera unit to perform telescopic movements inside and outside the cavity. They are constructed with high-temperature resistant sealing materials and corrosion-resistant metal structures to adapt to the high-temperature vacuum working conditions of the cavity. The specific structure is not limited in this utility model.

[0087] In some examples, after growing aluminum nitride crystals using aluminum nitride raw materials and aluminum nitride seed crystals in growth chamber 30, the process further includes: transferring the crucible 40 carrying the aluminum nitride crystals from growth chamber 30 to transfer chamber 20 using transfer device 21; transferring the crucible 40 from transfer chamber 20 to processing chamber 10 using transfer device 21; and annealing the aluminum nitride crystals in processing chamber 10.

[0088] After the aluminum nitride crystal growth is completed, the transfer chamber 20 can maintain a temperature environment close to the tail temperature (e.g., 1000°C) of the growth chamber 30, allowing the aluminum nitride crystal to cool down slowly during transfer, reducing thermal stress and avoiding damage to the material structure. Subsequently, when transferring from the transfer chamber 20 to the processing chamber 10, the processing chamber 10 can be preheated to the initial temperature required for annealing, further reducing the temperature difference between the aluminum nitride crystal and the target annealing temperature. This ensures that the annealing process can be initiated without introducing additional thermal stress, avoiding secondary damage to the aluminum nitride crystal structure during the transfer process. During the aluminum nitride crystal growth process, due to factors such as temperature gradient fluctuations and uneven atomic deposition rates, lattice defects such as dislocations, vacancies, and stacking faults are easily retained inside the aluminum nitride crystal, thus affecting its thermal conductivity, electrical insulation, and other properties. Annealing, through constant temperature holding and slow cooling within a specific temperature range (usually below the sublimation temperature of aluminum nitride crystal to avoid crystal loss, for example, 1200℃-2000℃), provides sufficient diffusion energy to the atoms of aluminum nitride crystal. The vacancies and defects inside the aluminum nitride crystal are filled by surrounding atoms, dislocations are gradually eliminated through lattice rearrangement, and the stacking fault structure is smoothed out, significantly improving the lattice integrity of aluminum nitride crystal.

[0089] The detailed descriptions listed above are merely specific descriptions of feasible implementations of this utility model, and are not intended to limit the scope of protection of this utility model. All equivalent implementations or modifications made without departing from the spirit of this utility model should be included within the scope of protection of this utility model.

[0090] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0091] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A multi-chamber growth system, characterized in that, include: A processing chamber is used to perform staged heat treatment on a crucible containing aluminum nitride raw materials and aluminum nitride seed crystals; wherein, during the staged heat treatment process, the temperature in the processing chamber increases in a stepwise manner. The growth chamber is used to grow aluminum nitride crystals using aluminum nitride raw materials that have undergone staged heat treatment and aluminum nitride seed crystals; The transfer chamber is connected to both the processing chamber and the growth chamber. The processing chamber, the transfer chamber, and the growth chamber are all vacuum-sealed; the transfer chamber is equipped with a transfer device for transferring the crucible between the processing chamber and the growth chamber.

2. The multi-chamber growth system according to claim 1, characterized in that, The phased heat treatment includes a first heat treatment, a second heat treatment, and a third heat treatment; the temperature of the third heat treatment is higher than the temperature of the second heat treatment, and the temperature of the second heat treatment is higher than the temperature of the first heat treatment.

3. The multi-chamber growth system according to claim 2, characterized in that, 200℃≤Temperature of the first heat treatment≤400℃, 400℃<Temperature of the second heat treatment≤1200℃, 1200℃<Temperature of the third heat treatment≤2300℃.

4. The multi-chamber growth system according to claim 1, characterized in that, The multi-chamber growth system also includes a first monitoring device and a second monitoring device respectively provided for the processing chamber and the transmission chamber; The first monitoring device is used to observe the cleanliness of the processing chamber and monitor the position of the crucible in the processing chamber in real time; The second monitoring device is used to observe the cleanliness of the growth chamber and to monitor the position of the crucible in the growth chamber in real time.

5. The multi-chamber growth system according to claim 4, characterized in that, The multi-chamber growth system further includes a first accommodating space and a second accommodating space respectively corresponding to the processing chamber and the transmission chamber; When the temperature inside the processing chamber exceeds the first set temperature, the first monitoring device retracts into the first accommodating space. When the temperature inside the growth chamber exceeds the second set temperature, the second monitoring device retracts into the second accommodating space.

6. The multi-chamber growth system according to claim 5, characterized in that, The first monitoring device includes: a first vacuum telescopic assembly and a first camera unit controlled by the first vacuum telescopic assembly; the first vacuum telescopic assembly penetrates through the side wall of the processing chamber and is sealed to the side wall of the processing chamber to maintain the chamber vacuum; the first vacuum telescopic assembly is used to drive the first camera unit to extend or retract between the processing chamber and the first accommodating space; The second monitoring device includes: a second vacuum telescopic assembly and a second camera unit controlled by the second vacuum telescopic assembly; the second vacuum telescopic assembly penetrates the side wall of the growth chamber and is sealed to the side wall of the growth chamber to maintain the chamber vacuum; the second vacuum telescopic assembly is used to drive the second camera unit to extend or retract between the growth chamber and the second accommodating space.

7. The multi-chamber growth system according to claim 1, characterized in that, The transmission device includes at least one transfer mechanism for performing the gripping and transferring operation of the crucible between the processing chamber and the growth chamber; The outer peripheral wall of the crucible protrudes outward in a horizontal direction to form an annular protrusion. The transfer mechanism includes a robotic arm, and the execution end of the robotic arm is provided with a clamp that is adapted to the protrusion to grasp the crucible.

8. The multi-chamber growth system according to claim 1, characterized in that, Both the processing chamber and the growth chamber are equipped with a first heater and a second heater distributed vertically. The first heater is a disc heater, which is fixedly installed above the interior of the processing chamber. The second heater is a tungsten mesh heater, which is arranged in a ring below the disc heater.

9. The multi-chamber growth system according to claim 1, characterized in that, The multi-chamber growth system also includes: The first lifting assembly includes a first lifting platform disposed in the processing chamber, a first lifting column passing through the processing chamber and the external space, and a first lifting control module disposed in the external space. The first lifting column is connected to the first lifting platform and the first lifting control module respectively. The first lifting platform is used to support the crucible, and the first lifting control module is used to drive the first lifting platform to move along the vertical direction. The second lifting assembly includes a second lifting platform disposed within the growth chamber, a second lifting column passing through the growth chamber and the external space, and a second lifting control module disposed within the external space. The second lifting column is connected to the second lifting platform and the second lifting control module, respectively. The second lifting platform is used to support the crucible, and the second lifting control module is used to drive the second lifting platform to move along the vertical direction.

10. The multi-chamber growth system according to claim 1, characterized in that, The multi-chamber growth system also includes a vacuum system for evacuating the growth chamber, the processing chamber, and the transfer chamber.

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