Positive pressure differential MOCVD apparatus and positive pressure differential MOCVD method

Abstract

The application provides a positive pressure difference MOCVD device, comprising: a decompression cabin (61) configured to provide an environment with a pressure lower than atmospheric pressure; a reaction cavity shell arranged in the decompression cabin (61) and used for providing an environment for chemical reaction of reaction gas; a gas inlet and a gas outlet respectively used for supplying reaction gas into the reaction cavity shell and discharging gas from the reaction cavity shell; and an inner working unit arranged in the reaction cavity shell and forming a reaction gas channel (51) with the reaction cavity shell, wherein the MOCVD device is configured to make a first pressure in the reaction cavity shell higher than a second pressure in the decompression cabin (61), and both the first pressure and the second pressure are lower than atmospheric pressure. The application also provides a positive pressure difference MOCVD method. The positive pressure difference MOCVD device and method can avoid waste of raw material gas, ensure that no foreign impurity gas enters the reaction cavity shell, improve the deposition quality of semiconductor devices and increase the production capacity.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to semiconductor epitaxial thin film vapor deposition technology, specifically, to a positive differential MOCVD apparatus and a positive differential MOCVD method. Background Technology

[0002] Metal-organic chemical vapor deposition (MOCVD) is a key technology for preparing compound semiconductor thin films and is widely used in the semiconductor and photovoltaic fields. In an MOCVD device, group III organometallic reactants and group V hydrides are introduced and heated to induce a chemical reaction. The reaction products are deposited on a heated substrate to produce the desired product, namely group III and V compound thin films.

[0003] MOCVD technology is typically implemented using MOCVD reactors. Existing typical commercial MOCVD reactors include planetary reactors, vertical spray MOCVD reactors, and high-speed rotary MOCVD reactors. The main working principle of a vertical spray MOCVD reactor is to uniformly spray reactant gases (a mixture of Group III organometallic reactants and Group V hydrides) through spray heads, causing the reactant gases to react on the heated substrate. The reactant gases that complete the chemical reaction grow the desired compound film on the substrate; unreacted reactant gases and product gases are discharged as waste gases from the MOCVD reactor. For planetary reactors, a rotating graphite base is installed in the reaction chamber. The graphite base is disk-shaped, and several substrates form a group. Multiple substrate groups are evenly arranged circumferentially on the graphite base. The graphite base can revolve around a central point, while each substrate group rotates on its own axis. Group III and Group V reactants enter from the center of the top cover and flow horizontally outwards radially through a grid along the annular space between the graphite base and the ceiling. The combination of rotation and revolution achieves a uniform growth rate on each substrate surface.

[0004] Currently, MOCVD equipment typically requires the continuous extraction of large quantities of reactant gases into the external environment to maintain a stable low-pressure environment within the reaction chamber. However, this leads to a waste of the feed gas (i.e., the MO source), and because the reaction chamber pressure is lower than the external pressure, there is a risk of external impurities entering and contaminating the reactant gases. Furthermore, low-pressure reaction chambers usually require more complex process designs and control systems to ensure their stability and safety. All these factors significantly increase the manufacturing and operating costs of MOCVD equipment.

[0005] Most current MOCVD reaction chambers employ a static design, meaning the chamber remains stationary throughout the equipment's operation. However, as the gas flows, the cross-sectional area of ​​the gas channel changes, making it impossible to guarantee the uniformity of the flow field and velocity field. This results in significant flow-through losses of the reactant gas concentration, making it difficult to ensure that the reactant gas concentration reaching the substrate remains consistent across the board. Consequently, this severely impacts the uniformity of compound film thickness and composition grown on the substrate, ultimately reducing the yield of compound film products.

[0006] Furthermore, semiconductor thin film deposition places high demands on the temperature, velocity, and concentration fields of the reactant gases, and the requirements for uniformity across these fields continue to increase as the performance requirements of semiconductor chips rise. Simultaneously, the semiconductor industry has an urgent need for large-area, high-capacity, and high-quality thin film deposition equipment. The limitation of existing reaction chamber structures lies in their difficulty in increasing throughput. This is because increasing throughput requires increasing the size of the reaction chamber, but as the chamber size increases, the uniformity of the temperature, velocity, and concentration fields decreases, making it extremely difficult to achieve high throughput.

[0007] First, the increasing size of the substrate in traditional MOCVD reaction chambers poses a challenge to temperature uniformity. A stable high-temperature environment needs to be maintained within the reaction chamber to promote epitaxial film growth. As the size of the disk-shaped substrate increases, the temperature distribution within the reaction chamber becomes increasingly non-uniform, leading to an increase in the temperature gradient during growth. Therefore, epitaxial growth uniformity is quite sensitive to substrate size. On smaller substrates, it is relatively easy to achieve uniform epitaxial film growth. However, as the substrate size increases, the distribution of the epitaxial film on the substrate surface becomes more complex, which may result in uneven deposition thickness and material composition distribution, thus affecting device performance and consistency.

[0008] Secondly, the requirements for gas composition control are extremely high during MOCVD thin film growth. The composition and flow uniformity of the gas play a crucial role in the reaction rate and mass transport during thin film growth. Increasing the substrate size leads to greater differences in the uniformity of the gas flow distribution at different diameters of the substrate, thus affecting atmosphere control during material growth. This can result in inconsistencies in the quality of the grown material, ultimately impacting device performance.

[0009] In summary, for existing MOCVD equipment, increasing the base size can improve the production capacity of the MOCVD equipment, but this comes with problems such as flow uniformity, temperature uniformity, and gas composition control. Therefore, the resulting increase in production capacity is limited. Summary of the Invention

[0010] The purpose of this invention is to at least partially overcome the deficiencies of the prior art and provide a novel MOCVD device. This invention may have multiple objectives, but it is not intended to solve all problems or achieve all objectives; solving just one technical problem achieves the objective of this invention.

[0011] The present invention also aims to provide a positive differential MOCVD device and a positive differential MOCVD method, which can avoid the waste of raw material gas.

[0012] The present invention also aims to provide a positive differential MOCVD device and a positive differential MOCVD method, which can ensure that no external impurity gas enters the reaction chamber shell, thereby improving the cleanliness of the reaction chamber shell.

[0013] The present invention also aims to provide a positive differential MOCVD apparatus and a positive differential MOCVD method, which have improved temperature uniformity, gas flow uniformity and / or gas concentration uniformity.

[0014] The present invention also aims to provide a positive differential MOCVD equipment and a positive differential MOCVD method, which can improve the deposition quality of semiconductor devices.

[0015] The present invention also aims to provide a positive differential MOCVD equipment and a positive differential MOCVD method, which can increase production capacity, or in other words, can easily increase production capacity while obtaining high-quality, high-performance deposited products.

[0016] To achieve the above-mentioned objectives or one of them, the technical solution of the present invention is as follows:

[0017] A positive differential pressure MOCVD apparatus, the MOCVD apparatus comprising:

[0018] A decompression chamber configured to provide an environment below atmospheric pressure;

[0019] The reaction chamber shell, located inside the decompression chamber, is used to provide an environment for the reaction gases to undergo a chemical reaction;

[0020] The inlet and outlet are used to supply reactant gases into and out of the reaction chamber, respectively; and

[0021] The inner working unit is located inside the reaction chamber shell, and a reaction gas channel is formed between the inner working unit and the reaction chamber shell.

[0022] The MOCVD equipment is configured to allow a first pressure inside the reaction chamber shell to be higher than a second pressure inside the decompression chamber, and both the first and second pressures are lower than atmospheric pressure.

[0023] According to a preferred embodiment of the invention, the inner working unit includes an inner cylinder, and the MOCVD apparatus is configured such that the inner cylinder and the reaction chamber shell are rotatable relative to each other.

[0024] According to a preferred embodiment of the invention, the inner cylinder is configured to rotate about its longitudinal axis, and the reaction chamber shell is configured to remain stationary during operation of the MOCVD apparatus; or

[0025] At least a portion of the reaction chamber shell is configured to rotate about the longitudinal axis of the reaction chamber shell, and the inner cylinder is configured to remain stationary during operation of the MOCVD apparatus; or

[0026] At least a portion of the reaction chamber shell and the inner cylinder are configured to rotate simultaneously, but the inner cylinder and the reaction chamber shell rotate in different directions or at different speeds.

[0027] According to a preferred embodiment of the present invention, the MOCVD apparatus further includes a first vacuum pump, which is in fluid communication with the decompression chamber for generating and maintaining a second pressure in the decompression chamber.

[0028] According to a preferred embodiment of the present invention, the MOCVD apparatus further includes a first vacuum pump and a second vacuum pump, the first vacuum pump being in fluid communication with a decompression chamber for generating and maintaining a second pressure in the decompression chamber; the second vacuum pump being in fluid communication with a reaction chamber formed by a reaction chamber shell for generating and maintaining a first pressure in the reaction chamber.

[0029] According to a preferred embodiment of the present invention, the reaction chamber shell includes a first shell and a second shell, the first shell and the second shell being capable of changing between a first state in which they are joined together to close the inner cylinder and a second state in which they are separated to expose the inner cylinder; and

[0030] A sealing assembly is provided between the first housing and the second housing.

[0031] According to another aspect of the present invention, a positive differential MOCVD method is provided, the MOCVD method using the positive differential MOCVD apparatus described in any of the foregoing embodiments, the MOCVD method comprising:

[0032] This creates a second pressure below atmospheric pressure within the decompression chamber; and

[0033] This creates a first pressure inside the reaction chamber that is lower than atmospheric pressure but higher than the second pressure.

[0034] According to a preferred embodiment of the present invention, the first pressure is at least 200 Pa higher than the second pressure.

[0035] According to a preferred embodiment of the present invention, during the operation of the MOCVD equipment, the decompression chamber is continuously evacuated to maintain a second pressure within the decompression chamber; and

[0036] By supplying reaction gas into the reaction chamber shell, a first pressure higher than the second pressure is maintained inside the reaction chamber shell.

[0037] According to a preferred embodiment of the present invention, the MOCVD method further includes: keeping the reaction chamber shell in an open state before generating a second pressure below atmospheric pressure within the decompression chamber; and sealing the reaction chamber shell after generating a second pressure below atmospheric pressure within the decompression chamber; or

[0038] The MOCVD method further includes: sealing the reaction chamber shell before generating a second pressure below atmospheric pressure in the decompression chamber, and then using an independent vacuum pump to decompress the reaction chamber shell to a pressure below atmospheric pressure.

[0039] According to the positive differential MOCVD equipment and method of the present invention, the reaction chamber shell is disposed within a depressurization chamber, and the pressure inside the reaction chamber shell is slightly higher than that inside the depressurization chamber, so that the reaction chamber shell is at the working pressure (below atmospheric pressure), but maintains a slightly positive pressure, higher than the pressure inside the depressurization chamber outside the reaction chamber shell. This eliminates the need for continuous evacuation from the reaction chamber shell to maintain a low-pressure state, as required by existing technologies. Only air needs to be evacuated from the depressurization chamber to maintain the low-pressure state of the reaction chamber shell. Therefore, the waste of raw material gas is reduced. Simultaneously, the slightly positive pressure, i.e., the pressure inside the reaction chamber shell is slightly higher than that inside the depressurization chamber, prevents external impurity gases from entering the reaction chamber shell, improves the cleanliness of the reaction chamber shell, and enables the acquisition of high-yield compound films.

[0040] Furthermore, in the MOCVD equipment and method of the present invention, an inner cylinder is provided inside the reaction chamber shell, and a reaction gas channel is formed between the inner cylinder and the reaction chamber shell. Based on the shape of the inner wall surface of the inner cylinder and the reaction chamber shell, it is easy to obtain a reaction gas channel with a constant cross-section. Therefore, the reaction gas supplied to the reaction gas channel through the gas inlet can maintain a uniform velocity field and concentration field. Moreover, the circumferential arrangement of the heating element within the cavity wall of the inner cylinder or the reaction chamber shell can also easily obtain a uniform temperature field. Therefore, the positive differential pressure MOCVD equipment and method of the present invention has improved temperature uniformity, gas flow uniformity, and / or gas concentration uniformity, thereby improving the deposition quality of semiconductor devices. More importantly, the inner cylinder and the reaction chamber shell are arranged coaxially, and the production capacity can be easily increased by increasing the axial and radial dimensions of the equipment (the area that can support the substrate is increased). Furthermore, this increase in equipment size has virtually no impact on the uniformity of the velocity field, concentration field, and temperature field of the gas inside the reaction chamber shell, which can effectively solve the problem of the current limitation on the large-scale production of epitaxial equipment in the semiconductor industry. Therefore, the positive differential MOCVD equipment and method of the present invention can increase production capacity and simultaneously ensure high quality and high performance of the deposited products.

[0041] The positive differential pressure MOCVD equipment provided by this invention can provide ultra-large-scale, expandable reaction chamber shells to achieve high-capacity, high-quality chemical reactions. The axial length and diameter of the reaction chamber shell can be expanded according to capacity requirements, while ensuring the uniformity of the velocity field, temperature field and flow field inside the reaction chamber shell. Attached Figure Description

[0042] Figure 1 This is a cross-sectional schematic diagram of a planetary reaction chamber in the prior art;

[0043] Figure 2 for Figure 1 A top view of the graphite base of the planetary reaction chamber in the image;

[0044] Figure 3 This is a cross-sectional schematic diagram of a positive differential pressure MOCVD apparatus according to an embodiment of the present invention;

[0045] Figure 4 for Figure 3 BB cross-section diagram of the positive differential pressure MOCVD equipment;

[0046] Figure 5 An MOCVD apparatus according to another embodiment of the present invention is shown, with Figure 4 Correspondingly, however, the decompression chamber was removed;

[0047] Figure 6 This is a cross-sectional schematic diagram of a positive differential pressure MOCVD apparatus according to an embodiment of the present invention;

[0048] Figure 7 This is a cross-sectional schematic diagram of an MOCVD apparatus according to an embodiment of the present invention, wherein a substrate is mounted on the outer periphery of an inner cylinder;

[0049] Figure 8 for Figure 7 CC cross-section of the MOCVD equipment in the image;

[0050] Figure 9 This is a cross-sectional schematic diagram of an MOCVD apparatus according to an embodiment of the present invention, wherein the substrate is simultaneously mounted on the outer periphery of the inner cylinder and the inner side of the reaction chamber shell;

[0051] Figure 10 for Figure 9 DD cross-sectional view of the MOCVD equipment in the image;

[0052] Figure 11 An MOCVD apparatus according to another embodiment of the present invention is shown, with Figure 10 Correspondingly, the second heating element has a different configuration;

[0053] Figure 12 This is a cross-sectional schematic diagram of an MOCVD apparatus according to an embodiment of the present invention, wherein the substrate is mounted on the inner side of the reaction chamber shell;

[0054] Figure 13 for Figure 12 EE cross-sectional view of the MOCVD equipment in the diagram;

[0055] Figure 14 This illustrates one arrangement of mounting positions on the outer cylinder for mounting the substrate;

[0056] Figure 15 The method of fixing the fixed substrate on the inner cylinder is shown;

[0057] Figure 16 This is a cross-sectional schematic diagram of an MOCVD apparatus according to an embodiment of the present invention;

[0058] Figure 17 This is a cross-sectional schematic diagram of an MOCVD apparatus according to an embodiment of the present invention;

[0059] Figure 18 for Figure 17 GG cross-section of the MOCVD equipment in the image;

[0060] Figure 19 This is a cross-sectional schematic diagram of an MOCVD apparatus according to an embodiment of the present invention;

[0061] Figure 20 for Figure 19 HH cross-sectional view of the MOCVD equipment in the middle;

[0062] Figure 21 A schematic cross-sectional view of the shaft of an MOCVD device according to an embodiment of the present invention;

[0063] Figure 22 This is a cross-sectional schematic diagram of an MOCVD apparatus according to an embodiment of the present invention;

[0064] Figure 23 This is a cross-sectional schematic diagram of an MOCVD apparatus according to an embodiment of the present invention;

[0065] Figure 24 This is a cross-sectional schematic diagram of an MOCVD apparatus according to an embodiment of the present invention.

[0066] List of reference numerals in the attached diagram:

[0067] 11 Actuating device; 12 Drive shaft; 13 Active rotating unit; 14 Driven rotating unit; 15 Rotating shaft; 16 Bearing; 17 Supporting element; 31 First housing; 32 Second housing; 41 Inner cylinder; 42 First heat insulation material; 43 First heating element; 44 Outer cylinder; 45 Second heat insulation material; 46 Heating element support rod; 47 Annular heating belt; 48 End heat insulation material; 49 Central support ring; 50 Fixing assembly; 51 Reaction gas channel; 52 Inlet element; 53 Exhaust element; 54 Separating element; 55 Central support Shaft; 56 Insulating sheet; 57 Support cylinder; 58 Support rod; 60 Rotary seal; 61 Decompression chamber; 62 First vacuum pump; 63 Second vacuum pump; 64 Fixing groove; 65 Clamp; 66 Double-layer water-cooled pipe; 67 Outer channel; 68 Inner channel; 69 Slip ring; 70 Wire; 71 First mounting position; 72 Substrate; 73 Second heating element; 74 Heating element fixing part; 75 Second mounting position; 97 Base; 98 Support frame; 101 Lifting assembly; 102 First housing connecting element; 103 Second housing connecting element. Detailed Implementation

[0068] Exemplary embodiments of the present invention are described in detail below with reference to the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements. Furthermore, in the following detailed description, numerous specific details are set forth for ease of explanation to provide a thorough understanding of the embodiments disclosed herein. However, it will be apparent that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and apparatuses are illustrated to simplify the drawings.

[0069] Figure 3 , 4The basic structure of a positive pressure differential MOCVD apparatus according to an embodiment of the present invention is shown in the figure. The positive pressure differential MOCVD apparatus mainly includes a decompression chamber 61, a reaction chamber shell, an inlet and an outlet, an inner cylinder 41, an actuator 11, and a transmission mechanism. The decompression chamber 61 is configured to provide an environment below atmospheric pressure. The reaction chamber shell is disposed within the decompression chamber 61 to provide an environment for the chemical reaction of the reaction gases; typically, this environment is a high-temperature, low-pressure environment. The inner cylinder 41 is disposed within the reaction chamber shell, and a reaction gas channel 51 is formed between the inner cylinder 41 and the reaction chamber shell. Figure 3-4 As shown, the inner cylinder 41 is generally cylindrical, and the inner wall of the reaction chamber shell is also generally cylindrical. The inner cylinder 41 and the reaction chamber shell are arranged coaxially, so the reaction gas channel 51 is generally annular. In addition to the above parts, the complete MOCVD equipment also includes a gas transport system, a base support, and an exhaust gas treatment system.

[0070] The reaction chamber shell is hollow, allowing the inner cylinder 41 to be inserted inside. The reaction chamber shell is primarily composed of a cavity wall, which includes: an outer shell; an outer cylinder 44 disposed within the outer shell and fixed relative to it; and a second insulating material 45 disposed between the outer shell and the outer cylinder 44. The outer shell, as the outermost layer of the reaction chamber shell, includes a first shell 31 and a second shell 32. The first shell 31 and the second shell 32 can switch between a first state where they are joined together to seal the inner cylinder 41 and a second state where they are separated to expose the inner cylinder 41. The first shell 31 and the second shell 32 ensure the airtightness of the reaction chamber shell's interior from the external environment. Since the outer shell is divided into two parts, correspondingly, the outer cylinder 44 and the second insulating material 45 between the outer shell and the outer cylinder 44 should also be composed of two parts. Optionally, end caps are installed at both ends of the outer cylinder to form a cavity, ensuring the airtightness of the reaction chamber shell's interior.

[0071] The main reaction equipment of the MOCVD apparatus is entirely located within the decompression chamber 61. The decompression chamber 61 is vented externally by a vacuum pump to maintain a low internal pressure, controlling the pressure environment to the optimal level required for epitaxial processes. Specifically, the MOCVD apparatus is configured to maintain a first pressure within the reaction chamber shell higher than a second pressure within the decompression chamber 61, and both the first and second pressures are lower than atmospheric pressure. The MOCVD apparatus also includes a first vacuum pump 62, which is fluidly connected to the decompression chamber 61 and is used to generate and maintain the second pressure within the decompression chamber 61. Figure 3 As shown.

[0072] Accordingly, the present invention also provides a positive differential MOCVD method using the aforementioned positive differential MOCVD equipment. The MOCVD method includes: generating a second pressure below atmospheric pressure within a decompression chamber 61; and generating a first pressure below atmospheric pressure but above the second pressure within a reaction chamber shell. Here, the first pressure is at least 200 Pa or 300 Pa higher than the second pressure. During the operation of the MOCVD equipment, the decompression chamber 61 is continuously evacuated to maintain the second pressure within it; and a first pressure above the second pressure is maintained within the reaction chamber shell by supplying reactive gas. Using the above equipment, the MOCVD method allows the reaction chamber shell to be in an open state before generating the second pressure below atmospheric pressure within the decompression chamber 61; then, after generating the second pressure below atmospheric pressure within the decompression chamber 61, the reaction chamber shell is closed. Thus, while the decompression chamber generates operating pressure, the reaction chamber shell obtains a suitable operating pressure. When the MOCVD equipment is operating, due to the supply of reactive gas to the reaction chamber shell, a first pressure above the second pressure naturally forms within it.

[0073] Figure 6 An alternative embodiment of a positive differential pressure MOCVD apparatus is provided, wherein the MOCVD apparatus is equipped with a separate vacuum pump for the reaction chamber shell, i.e., the MOCVD apparatus includes a first vacuum pump 62 and a second vacuum pump 63. The first vacuum pump 62 is in fluid communication with a decompression chamber 61 for generating and maintaining a second pressure in the decompression chamber 61; the second vacuum pump 63 is in fluid communication with the reaction chamber shell to generate and maintain a first pressure in the reaction chamber. Figure 6 The device can seal the reaction chamber shell before generating a second pressure below atmospheric pressure inside the decompression chamber 61, and then use a separate second vacuum pump to decompress the reaction chamber shell to a pressure below atmospheric pressure.

[0074] The inner cylinder 41 or the reaction chamber shell, at least the portions facing each other, comprise graphite material, tungsten material, or molybdenum material with a SiC coating. To make the inner cylinder 41 and outer cylinder 44 resistant to high temperatures, they are typically graphite cylinders coated with SiC, but high-temperature resistant metal materials such as tungsten and molybdenum can also be used. The thickness of the coating can be determined based on the mechanical properties of the material.

[0075] An inlet and an outlet are disposed on the reaction chamber shell, used to supply reactant gas into the reaction chamber shell and to discharge gas from the reaction chamber shell, respectively. In this embodiment, an inlet element 52 is disposed on the inlet, and an outlet element 53 is disposed on the outlet. The inlet element 52 and the outlet element 53 extend from outside the reaction chamber shell through the cavity wall of the reaction chamber shell into the reactant gas channel 51. The inlet element 52 is configured to guide the reactant gas into the reactant gas channel 51 and flow along the reactant gas channel 51 to the outlet. Figure 4 As shown by the middle arrow, the waste gas after reaction in the reaction gas channel 51 is discharged from the exhaust element 53. In addition to the intake element 52 and the exhaust element 53, the reaction chamber shell is also provided with a partition element 54, which is located in the reaction gas channel 51, between the intake element 52 and the exhaust element 53, to prevent the exhaust gas from flowing back to the intake side.

[0076] like Figure 4 As shown, the intake element 52 and exhaust element 53 extend radially from the outside of the reaction chamber shell through the cavity wall of the reaction chamber shell into the reaction gas channel 51. The intake element 52 and exhaust element 53 are arranged adjacent to each other in the circumferential direction of the reaction chamber shell. The adjacent intake element 52, exhaust element 53, and the separating element 54 between the intake element 52 and exhaust element 53 in the circumferential direction of the reaction chamber shell form a set of ventilation elements. Figure 4 In this embodiment, the MOCVD equipment includes only one set of ventilation elements (full-circuit flow). In this set of ventilation elements, the outlet of the inlet element 52 can be a longitudinally elongated outlet, i.e., there is only one inlet element and one outlet. The outlet is located within the reaction gas channel 51 and extends along the longitudinal axis of the inner cylinder 41, preferably extending along the entire longitudinal length of the inner cylinder 41 to ensure the uniformity of the reaction gas within the reaction gas channel 51. Alternatively, in this set of ventilation elements, there can be multiple inlet elements 52, with their outlets located within the reaction gas channel 51, and these multiple inlet elements 52 are evenly distributed along the longitudinal axis of the inner cylinder 41 to ensure the uniformity of the reaction gas within the reaction gas channel 51. The exhaust element 53 can have the same form and arrangement as the inlet element 52.

[0077] Depend on Figure 4 The illustrated embodiment can be used to derive a ventilation element arrangement. Similarly, adjacent inlet elements 52, exhaust elements 53, and the separating element 54 between inlet elements 52 and exhaust elements 53 in the circumferential direction of the reaction chamber shell form a group of ventilation elements. The MOCVD equipment includes multiple groups of ventilation elements, such as two or three groups, which are evenly distributed in the circumferential direction of the reaction chamber shell. In the case of three groups, the three groups of ventilation elements are arranged on the reaction chamber shell at 120-degree angle intervals. Then, the reaction gas entering from the inlet element 52 of the first group of ventilation elements flows through the reaction gas channel 51 at a 120-degree angle and is discharged from the exhaust element 53 of the second group of ventilation elements; the reaction gas entering from the inlet element 52 of the second group of ventilation elements flows through the reaction gas channel 51 at a 120-degree angle and is discharged from the exhaust element 53 of the third group of ventilation elements; and the reaction gas entering from the inlet element 52 of the third group of ventilation elements flows through the reaction gas channel 51 at a 120-degree angle and is discharged from the exhaust element 53 of the first group of ventilation elements.

[0078] Figure 5 An embodiment of another arrangement of the intake element 52 and the exhaust element 53 (semi-circular flow) is given, as shown in the figure. The intake element 52 includes a first intake element and a second intake element. Figure 5 The left and right intake elements 52 are arranged in the middle, the first intake element and the second intake element are adjacent in the circumferential direction of the reaction chamber shell, and a separator element 54 is provided between the first intake element and the second intake element; the exhaust element 53 includes a first exhaust element and a second exhaust element. Figure 5 The left and right exhaust elements 53 of the reaction chamber shell are adjacent to each other in the circumferential direction, and a separator 54 is provided between the first and second exhaust elements; the intake element 52 and the exhaust element 53 are arranged approximately opposite each other in the radial direction of the reaction chamber shell. In this way, the reaction gas entering from the first intake element flows through the reaction gas channel 51 at a 180-degree angle and is discharged from the first exhaust element, and the reaction gas entering from the second intake element flows in the opposite direction through the reaction gas channel 51 at a 180-degree angle and is discharged from the second exhaust element.

[0079] The position of the inlet element 52 can be designed in different locations according to the working environment and specific operating conditions. In actual use, it can be set in the lower part of the outer shell of the reaction chamber shell, which is beneficial to suppressing natural convection in the channel. The reaction gas enters the reaction gas channel through the inlet element, is heated and undergoes a chemical reaction in the channel, and performs thin film deposition. Since the cross-sectional area of ​​the channel remains constant during the reaction gas flow process, the gas flow uniformity is very good. It should be noted that since the inner cylinder and the reaction chamber shell can rotate relative to each other, there should be a gap between the separator element 54 and the inner cylinder 41 when the inner cylinder 41 rotates. This gap should be a small gap to prevent affecting the rotation of the inner cylinder. The separator element 54 can be a thin-walled baffle fixed on the outer cylinder. The function of the separator element 54 is to prevent the mixing of intake and exhaust gases. In a preferred embodiment, air holes can be provided on both sides of the separator element 54, and a carrier gas (nitrogen) is injected into the air holes at a certain velocity to form a gas barrier layer. On the one hand, the vents on the intake side are used to block the flow of intake air towards exhaust air, thus avoiding the waste of organic metal source; on the other hand, the vents on the exhaust side are used to block the flow of exhaust air towards intake air, thus avoiding the source gas from being contaminated.

[0080] Advantageously, the channel at the outlet of the air inlet element 52 is curved relative to the axial direction of the air inlet element 52, such that the flow direction of the reaction gas supplied from the outlet is approximately tangent to a circle centered on a point on the longitudinal axis of the inner cylinder 41. Furthermore, the air inlet element 52 is a multi-channel air inlet element, the multi-channel existing in the form of a sleeve. The multi-channel has three or more channels because there are multiple types of reaction gases, and each layer of the sleeve carries a different gas.

[0081] Furthermore, the portion of the intake element 52 extending into the reaction gas channel 51 includes a radial section and a bent section relative to the radial section; the bent section is provided with a first outlet and a second outlet. The flow direction of the reaction gas supplied from the first outlet is approximately tangent to a circle centered on a point on the longitudinal axis of the inner cylinder 41, and the flow direction of the reaction gas supplied from the second outlet is approximately pointing towards the longitudinal axis of the inner cylinder 41, thus forming an air curtain. These vertically downward-facing nozzles (second outlets) on the intake side prevent exhaust gas from leaking into the intake section, forming an air curtain to block exhaust gas from entering the intake side through the gap of the separating element 54.

[0082] Advantageously, the MOCVD apparatus is configured such that the inner cylinder 41 and the reaction chamber shell are rotatable relative to each other. This relative rotation can be achieved in several ways: the inner cylinder 41 is configured to rotate about its longitudinal axis, and the reaction chamber shell is configured to remain stationary during operation of the MOCVD apparatus; or at least a portion of the reaction chamber shell (outer cylinder or the entire reaction chamber shell) is configured to rotate about its longitudinal axis, and the inner cylinder 41 is configured to remain stationary during operation of the MOCVD apparatus; or at least a portion of the reaction chamber shell (outer cylinder or the entire reaction chamber shell) and the inner cylinder 41 are configured to rotate simultaneously, but in different directions or at different speeds. Figure 3 In the example shown, the inner cylinder 41 can rotate actively, while the reaction chamber shell remains stationary.

[0083] It should be noted that the relative rotation of the inner cylinder 41 and the reaction chamber shell is not necessary; they can also remain relatively stationary. For example, they can remain absolutely stationary during the operation of the MOCVD equipment, which can also achieve the effects of the present invention to a certain extent, as long as the reaction gas channel 51 has approximately the same cross-section along the direction of reaction gas flow. When the reaction gas channel has a constant cross-section, the flow velocity of the reaction gas in the channel remains essentially constant, thereby obtaining a uniform flow field along the flow direction. However, relative rotation can make the concentration of carrier gas / reaction gas in contact with the wafer substrate more uniform.

[0084] To achieve the operating temperature of MOCVD, the MOCVD equipment also includes heating elements, which can be disposed inside the inner cylinder 41 and / or within the cavity wall of the reaction chamber shell. Generally, the heating elements can include: a plurality of parallel heating strips, all parallel to the longitudinal axis of the inner cylinder 41 and circumferentially distributed relative to the longitudinal axis of the inner cylinder 41, such as... Figure 3-4 As shown; or multiple annular heating bands arranged in parallel, wherein the multiple annular heating bands are axially distributed relative to the longitudinal axis of the inner cylinder 41, such as... Figure 22 As shown; or multiple heating blocks, which are evenly distributed on a selected circumferential surface surrounding the longitudinal axis of the inner cylinder 41, not shown in the figure; or any combination of two of multiple heating strips, multiple annular heating belts, and multiple heating blocks, such as... Figure 17-20 The heating element can be a silicon molybdenum rod, tungsten wire, or molybdenum wire; the material can be silicon molybdenum, tungsten, or molybdenum; and the shape can be a block, strip, or bar, etc. The heating power can be uniform or non-uniform. The size of the heating element is designed according to the gas temperature in the reaction gas channel, and the heating power can be adjusted to ensure that the temperature difference on the substrate surface is less than 1°C.

[0085] Since both the reaction chamber shell and the inner cylinder 41 are approximately cylindrical, and the heating elements are arranged approximately evenly inside the inner cylinder 41 and / or within the cavity wall of the reaction chamber shell, the heat generated by the heating elements is transferred radially from the reaction chamber shell or the inner cylinder 41 to the reaction gas channel 51. The heating elements are preferably silicon molybdenum rods, tungsten wires, or molybdenum wires.

[0086] Both the interior of the inner cylinder 41 and the cavity wall of the reaction chamber are lined with heat-insulating materials, such as... Figure 3-4 As shown, the center of the inner cylinder 41 is penetrated by the rotating shaft 15, and the inner cylinder 41 and the rotating shaft 15 are relatively fixed so that the inner cylinder 41 and the rotating shaft 15 can rotate together. A heat-insulating material is provided between the outer wall of the inner cylinder 41 and the rotating shaft 15. The inner cylinder 41 is connected and fixed to the first heating element 41, the first heat-insulating material 42, and the rotating shaft 15 as a whole by a support element 17. The support element 17 should be made of a material with good rigidity and low thermal conductivity, such as zirconium oxide or other high-temperature resistant, non-decomposing ceramic materials. The first heating element 41 and the first heat-insulating material 42 are mechanically connected and fixed together with the high-temperature resistant rotating inner cylinder by the support element 17. Simultaneously, the other side of the support element 17 is mechanically connected and fixed to the rigid rotating shaft 15. The rotating shaft 15 is equipped with bearings 16, which support and fix the entire inner cylinder 41. The rotating shaft 15 can be made of stainless steel or other materials, and a cooling structure is provided inside, using liquid cooling or air cooling to efficiently cool the rigid rotating shaft.

[0087] by Figure 3-8Referring to the embodiment, it can be seen that the inner cylinder 41 is a hollow inner cylinder, and the heating element is disposed inside the inner cylinder 41; the heating element includes a plurality of heating strips arranged in parallel, the plurality of heating strips being parallel to the longitudinal axis of the inner cylinder 41 and distributed circumferentially relative to the longitudinal axis of the inner cylinder 41; and the two ends of each heating strip are fixed to the two ends of the inner cylinder 41 along the longitudinal axis. Figure 9-13 In one embodiment, a heating element is also disposed in the cavity wall of the reaction chamber shell. The heating element is a second heating element 73. The second heating element 73 also includes a plurality of heating strips arranged in parallel. The plurality of heating strips are parallel to the longitudinal axis of the reaction chamber shell and distributed circumferentially relative to the longitudinal axis of the reaction chamber shell. Each heating strip is fixed in the cavity wall of the reaction chamber shell by a heating element fixing part 74.

[0088] The heating strips in this invention can be designed in series and parallel combinations according to process requirements. This design has two advantages: first, it can minimize energy consumption by selecting the series and parallel connection scheme with the lowest energy consumption for each working condition; second, different locations within the inner cylinder have different requirements for temperature field uniformity, and this design allows for targeted adjustment of the electric heating power. The heating element of this invention is located inside the inner cylinder supporting the substrate, providing uniform heating. Simultaneously, the double thermal insulation structure on both the inner and outer cylinders ensures that the heat from the heating element is almost entirely prevented from dissipating to the external environment, minimizing energy loss. Compared to traditional MOCVD equipment, energy consumption is reduced by at least an order of magnitude, significantly reducing equipment operating costs and substrate epitaxial deposition costs from an operational perspective.

[0089] The transmission mechanism is described below. The actuator 11 is located outside the reaction chamber shell and inside the decompression chamber 61, and is directly or indirectly connected to the inner cylinder 41 or the reaction chamber shell. It is used to drive the inner cylinder 41 or the reaction chamber shell to rotate. The transmission mechanism can be a simple drive shaft or a magnetic coupler. Thus, the actuator 11 is connected to the inner cylinder 41 via the magnetic coupler. Figure 3 As shown, or the actuating device 11 is connected to the inner cylinder 41 via a drive shaft 12, such as... Figure 22 As shown, the drive shaft 12 is connected to the rotating shaft 15, and a rotating seal 60 is provided at the portion of the drive shaft 12 that passes through the reaction chamber shell. The transmission mechanism may also have other structures. The magnetic coupler includes an active rotating unit 13 disposed outside the reaction chamber shell and a driven rotating unit 14 disposed inside the reaction chamber shell. The active rotating unit 13 drives the driven rotating unit 14 in a non-contact manner. The active rotating unit 13 is connected to the actuating device 11, and the driven rotating unit 14 is connected to the inner cylinder 41.

[0090] exist Figure 3 , 6In one embodiment, the actuation device 11 is disposed inside the decompression chamber 61. As an alternative embodiment, the actuation device 1 can also be disposed outside the decompression chamber 61, using a similar transmission mechanism and sealing means.

[0091] like Figure 7 , 8 As shown, a first mounting position 71 for mounting the substrate 72 is provided on the outer periphery of the inner cylinder 41, such as... Figure 12 , 13 As shown, a second mounting position 75 for mounting the substrate 72 is provided on the inner side (outer cylinder 44) of the reaction chamber shell. Specifically, the mounting position is provided on the surface of the outer cylinder 44 facing the inner cylinder 41, as shown in the figure. Figure 9-11 As shown, a first mounting position 71 for mounting a substrate 72 is provided on the outer periphery of the inner cylinder 41, and a second mounting position 75 for mounting a substrate 72 is provided on the inner side of the reaction chamber shell (outer cylinder 44).

[0092] There are multiple mounting positions on the inner cylinder 41 or the reaction chamber shell, which are evenly distributed. Specifically, the multiple mounting positions can be arranged in a matrix, such as... Figure 14 As shown, multiple mounting positions can form multiple rows, with adjacent rows of mounting positions staggered. Each mounting position can be as follows: Figure 14 The fixing groove 64 shown serves to fix the substrate in place as the inner cylinder rotates around its axis. Furthermore, the inner cylinder 41 and the outer cylinder 44, which forms the inner wall of the reaction chamber shell, can be cylindrical or polygonal, such as... Figure 15 As shown, the cross-section of the inner cylinder 41 perpendicular to its longitudinal axis is a regular polygon, making the inner cylinder 41 a polygonal prism. Similarly, the cross-section of the inner wall of the reaction chamber shell perpendicular to its longitudinal axis is a regular polygon, making the inner wall of the reaction chamber shell a polygonal prism. The mounting position is located on the prism face of the polygonal prism. In addition, the mounting position is provided with a clamp 65, a slot, and a groove for fixing the substrate 72 to the mounting position. The side length of the polygon is determined by the size of the wafer substrate. The number of sides N of the polygon can be any number of 3 or more. Generally, in order to make the flow field uniform and the cross-sectional area of ​​the annular reaction gas channel not change significantly, the value of N can be slightly larger. Therefore, the diameter of the high-temperature resistant inner cylinder will also be relatively large.

[0093] The double-sided substrate mounting structure significantly improves the throughput of MOCVD equipment. Both the outer and inner surfaces of the high-temperature resistant inner cylinder are designed with grooves, slots, or clamps for placing wafer substrates. Each wafer substrate on the outer surface of the inner cylinder can be aligned with the wafer substrate on the inner surface of the outer cylinder, and the cross-section of the reaction gas channel formed between them is similar to a regular polygonal channel. When the gas passes through the annular or regular polygonal channel, epitaxial films can be deposited on both sides, minimizing reaction gas loss and achieving high epitaxial film growth efficiency. This method also simultaneously solves the problem of chemical reactants easily depositing on the reaction chamber shell walls, requiring regular cleaning.

[0094] Taking the inner cylinder rotation as an example, maintaining a uniform rotation speed during operation ensures the temperature uniformity of the large-size cylinder wall, thereby achieving uniform deposition on the wafer substrate surface. In practice, the inner cylinder rotation speed can be adjusted as needed, or the inner cylinder can be kept stationary. The cross-sectional area of ​​the annular reaction gas channel in the cylindrical reaction chamber remains constant along the flow direction, ensuring the uniformity of the gas velocity field. Simultaneously, the rotating design of the inner cylinder supporting the substrate ensures the uniformity of temperature between the inner cylinder and the substrate surface, as well as the uniformity of reactants on the substrate surface, solving the problem of uneven substrate deposition after the MOCVD equipment becomes larger. Furthermore, the increase in the axial dimension of the reaction chamber shell has almost no significant impact on the temperature field, velocity field, and reactant diffusion concentration field of the reaction gas in the MOCVD equipment. Therefore, it can greatly improve the production capacity of MOCVD epitaxial wafers while ensuring very high epitaxial deposition quality, effectively overcoming the limitations of MOCVD equipment production capacity in the semiconductor industry.

[0095] Preferably, the distribution density or power density of the heating element near the air inlet or exhaust port is greater than that at a location farther from the air inlet or exhaust port. (Refer to...) Figure 10 , 11 The distribution density of the second heating element 73 near the inlet and outlet (inlet element 52 and outlet element 53) is greater than that at other locations. This is because, in some designs, the outer cylinder 44 is stationary, and the lower inlet temperature leads to a lower temperature of the substrate 72 on the outer cylinder 44 near the inlet. Therefore, it is necessary to install or add dedicated heating elements near the inlet of the outer cylinder 44 to increase the local temperature of the outer cylinder and ensure temperature uniformity along the 360° circumference of the entire outer cylinder. Since the annular reaction gas channel is very small, the overall temperature difference between the inner and outer cylinders is not significant. Heating elements can be arranged at other locations on the outer cylinder according to temperature requirements, or no heating elements may be arranged, or heating elements may only be arranged locally (e.g., Figure 11As shown in the figure, both the inner and outer cylinders are heated by heating elements inside the inner cylinder, and heating elements are only arranged locally near the air inlet of the outer cylinder for compensation, so that the temperature difference of the entire outer cylinder is within 1°C, which meets the temperature range required for high-quality thin film deposition on the outer cylinder substrate.

[0096] Even without a substrate on the outer cylinder 44, it can still be heated to compensate for the cooling effect of the lower-temperature reaction gas on the inner cylinder. The heating power of the heating element in the outer cylinder can be uniform or non-uniform along the circumferential direction. Non-uniform heating is generally used in the lower-temperature part of the reaction gas inlet, employing a larger compensating heating power or a denser heating wire design. Along the direction of reaction gas movement within the gas channel, as the gas temperature gradually increases, the compensating heating power of the heating element in the outer cylinder gradually decreases to ensure a more uniform temperature across the entire substrate surface, creating a more uniform temperature environment for the reaction chamber. Another function of the auxiliary heating element in the outer cylinder is to accelerate the system response speed of MOCVD during temperature switching. Based on the inner cylinder surface temperature and temperature switching requirements, the power and switching of the auxiliary heating element can be controlled in advance to ensure that the system achieves the heating or cooling process more quickly.

[0097] exist Figure 16 In this configuration, a first housing 31 is located vertically above a second housing 32, which remains fixed. The first housing 31 is configured to move relative to the second housing 32. Two first housing coupling elements 102 are provided on the first housing 31, and two second housing coupling elements 103 are provided on the second housing 32. The first housing coupling elements 102 are configured to engage with the second housing coupling elements 103. The MOCVD equipment also includes two lifting assemblies 101 connected to the first housing coupling elements 102 for raising or lowering the first housing 31. The lifting assembly 101 can be a hydraulic rod. During substrate loading / unloading, the lifting assembly 101 drives the first housing 31 upwards, thereby opening the reaction chamber shell and creating space for loading / unloading the wafer substrate.

[0098] Figure 16-20Section 22 illustrates several different forms, arrangements, and support methods for the heating elements. These are several embodiments of zoned heating element placement, where the interior of the inner cylinder 41 or the interior of the reaction chamber shell is divided into different regions. The heating elements exist in at least two regions with different forms, different distribution densities, or different power densities. Specifically, the distribution density or power density of the heating elements near the air inlet or exhaust port can be greater than that at a location away from the air inlet or exhaust port. Alternatively, the heating elements may have different distribution densities or power densities at the ends of the inner cylinder 41 along its longitudinal axis and at the center of the inner cylinder 41 along its longitudinal axis. For example, the heating elements are disposed inside the inner cylinder 41, and the interior of the inner cylinder 41 includes a first region near the center of the inner cylinder 41 along its longitudinal axis and two second regions near the ends of the inner cylinder 41 along its longitudinal axis. In the first and second regions, the heating elements have different forms and arrangements.

[0099] exist Figure 16-18 In this embodiment, the rotating shaft 15 is disposed at both ends of the inner cylinder 41 along its longitudinal axis. The rotating shaft 15 does not penetrate the center of the inner cylinder 41, and the inner cylinder 41 is fixed relative to the rotating shaft 15 so that the inner cylinder 41 and the rotating shaft 15 can rotate together. Heating elements are fixedly disposed inside the inner cylinder 41. The heating elements include a first heating element 43 and an annular heating band 47. The first heating element 43 is designed as multiple parallel heating strips in a first region, all parallel to the longitudinal axis of the inner cylinder 41 and circumferentially distributed relative to the longitudinal axis of the inner cylinder 41. The annular heating band 47 is disposed in a second region, and the axis of the annular heating band is parallel to the longitudinal axis of the inner cylinder 41. End insulation material 48 is disposed on the outside of the annular heating band 47, with two axially installed. The end insulation material 48 is vertically located at both ends of the inner cylinder and tightly fitted to the inner cylinder end caps, and can be connected together by a mechanical device. The end insulation material 48 can be composed of one or more layers of insulation material or radiant heat shield, with each layer optimized to achieve the optimal insulation thickness under the desired temperature resistance. The annular heating strip 47 is located between the end insulation material 48 and the heating strip, with a certain gap between them. This gap can be determined based on the simulation calculation results. Furthermore, in the figure, the heating strip is arranged in a single row, but it can also be arranged in multiple rows.

[0100] The multiple heating strips and annular heating band can be fixed inside the inner cylinder 41 in various ways and rotate together with the inner cylinder 41. For example, the multiple heating strips can be fixed on the inner circumferential surface of the inner cylinder 41, or the annular heating band can be fixed on the inner circumferential surface of the inner cylinder 41, or fixed on both ends of the inner cylinder 41 along the longitudinal axis, or fixed on the end insulation material 48. The design of the annular heating band is also to ensure the temperature uniformity of the reaction chamber, so that the temperature field difference between the two ends and the middle position of the inner cylinder is small, ensuring that the deposition of epitaxial wafers at both ends also has high quality.

[0101] exist Figures 19-20 In this embodiment, the form, combination, and position of the heating elements are the same as in the previous embodiment, including multiple heating bars and annular heating bands, but their support and fixing methods are different. A central support shaft 55 passes through the center of the inner cylinder 41 and extends from both ends of the inner cylinder 41 along its longitudinal axis. The central support shaft 55 is configured to be fixed relative to the reaction chamber shell, allowing the inner cylinder 41 to rotate relative to the central support shaft 55. For example, the central support shaft 55 is directly fixed to the outer shell of the reaction chamber shell, or the central support shaft 55 is supported at the center of the rotating shaft 15 by bearings, allowing the rotating shaft 15 to rotate around the central support shaft 55. The multiple heating bars and annular heating bands are fixed by the central support shaft 55, ensuring that the multiple heating bars and annular heating bands do not rotate with the inner cylinder 41 during the operation of the MOCVD equipment.

[0102] A plurality of central support rings 49 are provided on the central support shaft 55. Each central support ring 49 is provided with a plurality of heating element support rods 46 extending radially along the central support ring 49. The plurality of heating element support rods 46 are evenly distributed circumferentially along the central support ring 49. The plurality of heating strips and annular heating bands are respectively directly or indirectly fixed to the ends of the heating element support rods 46 away from the central support ring 49. A fixing plate is provided on the ends of the heating element support rods 46 away from the central support ring 49. The heating strips or annular heating bands are fixed to the fixing plate by screws. The fixing plate and screws constitute a fixing assembly 50. An insulating sheet 56 is provided between the ends of the heating strips and the heating element support rods 46 (fixing assembly 50), and an insulating sheet 56 is also provided between the annular heating bands and the ends of the heating element support rods 46. The material of the central support rings 49 can be stainless steel or other nickel-based metals.

[0103] exist Figure 22 In the embodiments, with Figure 17Unlike the illustrated embodiment, the heating elements inside the inner cylinder 41 are all composed of annular heating bands, with a certain distance between adjacent annular heating bands. The size and heating power of the annular heating bands can be adjusted according to process requirements. The annular heating bands can be partitioned according to the temperature uniformity of the inner cylinder, and can be divided into a middle zone and an edge zone in the axial direction. Since the heat loss is different between the edge and the middle, different power can be applied to each zone. By partitioning the axial direction, the surface temperature of the inner cylinder is made more uniform, and the temperature difference between the substrate surface at both ends and in the middle is less than 1°C.

[0104] Furthermore, the heating strips can also be designed in circumferential zones, allowing for independent adjustment of the electric heating power of different zones. For example, at the air inlet, due to the lower air temperature, the temperature field in this area differs significantly from that in the center of the reaction chamber. In this case, the electric heating power of the heating strip in this zone can be increased independently to ensure the uniformity of the temperature field throughout the entire reaction chamber.

[0105] Furthermore, if the inner cylinder 41 is penetrated by the rotating shaft 15 and the inner cylinder 41 is fixed relative to the rotating shaft 15 so that the inner cylinder 41 and the rotating shaft 15 can rotate together, multiple heating strips and / or annular heating bands can also be directly fixed on the rotating shaft 15.

[0106] like Figure 21 As shown, a water-cooling channel is provided inside the rotating shaft 15. The water-cooling channel is a double-layer water-cooling channel, including an outer channel 67 and an inner channel 68 that are connected. The outer channel 67 coaxially surrounds the outer periphery of the inner channel 68. The outer channel 67 is used for water supply, and the inner channel 68 is used for drainage. The rotating shaft 15 is a hollow rotating shaft, and the double-layer water-cooling channel exists in the form of double-layer water-cooling pipes 66, which are arranged inside the hollow portion of the rotating shaft 15.

[0107] like Figure 22 As shown, the cavity wall of the reaction chamber shell also includes a support cylinder 57, which is disposed between the outer shell and the outer cylinder 44; a plurality of support rods 58 are disposed between the support cylinder 57 and the outer cylinder 44, the support rods 58 extend radially along the reaction chamber shell, and the plurality of support rods 58 are evenly distributed circumferentially along the reaction chamber shell.

[0108] like Figure 23 As shown, the heating element of the MOCVD equipment is electrically heated and connected to an external power source. When the inner cylinder 41 rotates, the power supply of the first heating element 43, which is fixedly mounted on the inner cylinder 41, is achieved as follows: a collector ring 69 is provided at the end of the rotating shaft 15. The collector ring 69 is connected to an external power source through a wire 70. The first heating element 43 is connected to the collector ring 69 through a wire passing through the center of the rotating shaft 15, thereby realizing the conversion between dynamic and static states.

[0109] In the embodiments described above, the longitudinal axes of the inner cylinder 41 are all arranged in the horizontal direction, and the longitudinal axes of the reaction chamber shell are all arranged in the horizontal direction. The actuation device 11 is arranged on one side of the reaction chamber shell, and the resulting MOCVD equipment is a horizontal MOCVD equipment. However, alternatively, the longitudinal axis of the inner cylinder 41 can also be arranged in the vertical direction, and the longitudinal axis of the reaction chamber shell can also be arranged in the vertical direction. The actuation device 11 is arranged on the lower (or upper) side of the reaction chamber shell, thereby forming a vertical MOCVD equipment. Figure 24 This is an embodiment of a vertical MOCVD apparatus. In this embodiment, a decompression chamber 61 is also shown. The decompression chamber 61 is configured to provide an environment below atmospheric pressure. A reaction chamber shell is disposed within the decompression chamber 61. During the operation of the MOCVD apparatus, a first pressure within the reaction chamber shell is higher than a second pressure within the decompression chamber 61, and both the first and second pressures are lower than atmospheric pressure. The MOCVD apparatus also includes a first vacuum pump 62 and a second vacuum pump 63. The first vacuum pump 62 is in fluid communication with the decompression chamber 61 and is used to generate and maintain the second pressure in the decompression chamber 61. The second vacuum pump 63 is in fluid communication with the reaction chamber formed by the reaction chamber shell and is used to generate and maintain the first pressure in the reaction chamber. Furthermore, the decompression chamber 61 is fixed to a base 97, and a support frame 98 with a U-shaped groove is also provided in the decompression chamber 61. The reaction chamber shell is fixed to the support frame 98, and the actuator 11 and the active rotation unit 13 of the magnetic coupler are located within the U-shaped groove. In addition, Figure 24 The other settings of the upright MOCVD equipment are the same as in the previous embodiments.

[0110] The depressurization chamber in this invention is a crucial component for controlling the pressure environment required for epitaxial processes, ensuring that the chemical reactions occurring within the reaction chamber are within an ideal pressure range. The advantages of this design are twofold: First, during operation, only continuous evacuation from the external depressurization chamber is needed to effectively maintain a low-pressure environment; there are no reactive gases inside the depressurization chamber, eliminating waste. The reaction chamber shell, through the first and second shells, forms a small sealed environment. Normal process flow can easily maintain a slightly positive pressure environment, eliminating the need for continuous gas extraction from the reaction chamber shell. Therefore, less reactive gas is wasted, reducing the operating costs of the MOCVD equipment. Second, the slightly positive pressure environment of the reaction chamber shell prevents any external gases from entering, creating the cleanest possible space for the epitaxial deposition process within the reaction chamber shell. This significantly reduces the risk of contamination of the epitaxial quality, resulting in higher-quality epitaxial deposition.

[0111] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that variations may be made to these embodiments without departing from the principles and spirit of the invention. The scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A positive differential pressure MOCVD device, characterized in that, The MOCVD equipment includes: Decompression chamber (61), the decompression chamber (61) being configured to provide an environment below atmospheric pressure; The reaction chamber shell is located inside the decompression chamber (61) and is used to provide an environment for the reaction gases to undergo chemical reactions. The inlet and outlet are used to supply reactant gases into and out of the reaction chamber, respectively; and An inner working unit is disposed inside the reaction chamber shell, and a reaction gas channel (51) is formed between the inner working unit and the reaction chamber shell. The inner working unit includes an inner cylinder (41). An air inlet and an exhaust outlet are provided on the reaction chamber shell. An air inlet element (52) is provided on the air inlet, and an exhaust element (53) is provided on the exhaust outlet. A partition element (54) is also provided on the reaction chamber shell. The partition element (54) is located in the reaction gas channel (51) and between the air inlet element (52) and the exhaust element (53). Air holes are provided on both sides of the partition element (54). Carrier gas is injected into the air holes to form a gas barrier layer. There is a gap between the partition element (54) and the inner cylinder (41); The intake element (52) and the exhaust element (53) are arranged adjacent to each other in the circumferential direction of the reaction chamber shell; The portion of the air intake element (52) extending into the reaction gas channel (51) includes a radial section and a bent section that bends relative to the radial section; the bent section is provided with a first air outlet and a second air outlet, the flow direction of the reaction gas supplied from the first air outlet is approximately tangent to a circle centered on a point on the longitudinal axis of the inner cylinder (41), and the flow direction of the reaction gas supplied from the second air outlet is approximately directed toward the longitudinal axis of the inner cylinder (41) to form an air curtain; The MOCVD equipment is configured to make a first pressure inside the reaction chamber shell higher than a second pressure inside the decompression chamber (61), and both the first and second pressures are lower than atmospheric pressure.

2. The positive differential pressure MOCVD equipment according to claim 1, characterized in that: The MOCVD equipment is configured such that the inner cylinder (41) and the reaction chamber shell can rotate relative to each other.

3. The positive differential pressure MOCVD equipment according to claim 2, characterized in that: The inner cylinder (41) is configured to rotate about the longitudinal axis of the inner cylinder (41), and the reaction chamber shell is configured to remain stationary during the operation of the MOCVD equipment; or The reaction chamber shell is configured to rotate about its longitudinal axis, and the inner cylinder (41) is configured to remain stationary during operation of the MOCVD equipment; or The reaction chamber shell and the inner cylinder (41) are configured to rotate simultaneously, but the inner cylinder (41) and the reaction chamber shell have different rotation directions or rotation speeds.

4. The positive differential pressure MOCVD equipment according to claim 2, characterized in that: The MOCVD equipment also includes a first vacuum pump (62) which is in fluid communication with the decompression chamber (61) and is used to generate and maintain a second pressure in the decompression chamber (61).

5. The positive differential pressure MOCVD equipment according to claim 2, characterized in that: The MOCVD equipment also includes a first vacuum pump (62) and a second vacuum pump (63). The first vacuum pump (62) is in fluid communication with the decompression chamber (61) and is used to generate and maintain a second pressure in the decompression chamber (61). The second vacuum pump (63) is in fluid communication with the reaction chamber formed by the reaction chamber shell and is used to generate and maintain a first pressure in the reaction chamber.

6. The positive differential pressure MOCVD apparatus according to any one of claims 2-5, characterized in that: The reaction chamber shell includes a first shell (31) and a second shell (32), which are capable of changing between a first state in which they are joined together to close the inner cylinder (41) and a second state in which they are separated to expose the inner cylinder (41); and A sealing assembly is provided between the first housing (31) and the second housing (32).

7. A positive differential pressure MOCVD method, characterized in that, The MOCVD method uses the positive differential MOCVD apparatus according to any one of claims 1-6, and the MOCVD method comprises: To create a second pressure below atmospheric pressure within the decompression chamber (61); and This creates a first pressure inside the reaction chamber that is lower than atmospheric pressure but higher than the second pressure.

8. The positive differential pressure MOCVD method according to claim 7, characterized in that: The first pressure is at least 200 Pa higher than the second pressure.

9. The positive differential pressure MOCVD method according to claim 7, characterized in that: During the operation of the MOCVD equipment, the decompression chamber (61) is continuously evacuated to maintain a second pressure within the decompression chamber (61); and By supplying reaction gas into the reaction chamber shell, a first pressure higher than the second pressure is maintained inside the reaction chamber shell.

10. The positive differential pressure MOCVD method according to claim 7, characterized in that: The MOCVD method further includes: keeping the reaction chamber shell in an open state before generating a second pressure below atmospheric pressure inside the decompression chamber (61); and closing the reaction chamber shell after generating a second pressure below atmospheric pressure inside the decompression chamber (61); or The MOCVD method further includes: sealing the reaction chamber shell before generating a second pressure below atmospheric pressure in the decompression chamber (61), and then using an independent vacuum pump to decompress the reaction chamber shell to a pressure below atmospheric pressure.

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