MOCVD apparatus

Abstract

The present application provides a MOCVD device, which comprises a reaction cavity shell for providing an environment for chemical reaction of reaction gas, a gas inlet and a gas outlet for supplying and discharging the reaction gas into and out of the reaction cavity shell respectively, and an inner cylinder (41) arranged in the reaction cavity shell, and a reaction gas passage (51) is formed between the inner cylinder (41) and the reaction cavity shell, wherein the reaction gas passage (51) has substantially the same cross section along the direction of the reaction gas. The MOCVD device of the present application has improved temperature uniformity, gas flow uniformity and / or gas concentration uniformity, can improve the deposition quality of semiconductor devices, and can increase the production capacity.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of semiconductor technology, in particular to the semiconductor epitaxial film vapor deposition technology, and more particularly to a novel MOCVD (Metal Organic Chemical Vapor Deposition) equipment. BACKGROUND

[0002] At present, MOCVD (Metal Organic Chemical Vapor Deposition) is one of the key technologies for preparing semiconductor compound materials, generally using organic compounds of group III, group II elements and hydrides of group V, group VI elements as source materials for epitaxial film growth, and growing thin layer single crystal materials of various III-V, II-VI compound semiconductors and their multi-element solid solution through chemical reaction for vapor deposition on a substrate. MOCVD is widely used in the preparation of various thin film materials including semiconductor devices, optical devices, gas sensitive elements, superconducting thin film materials, ferroelectric / ferromagnetic thin films, high dielectric materials, etc. MOCVD equipment is an important equipment that must be used in the upstream of the semiconductor industry.

[0003] The commonly used MOCVD reaction chambers on the market at present mainly include planetary reaction chambers, vertical near-coupling spray reaction chambers, and vertical high-speed rotating disc reaction chambers, etc. The characteristics of these types of MOCVD reaction chambers are that the substrates to be deposited are horizontally placed on a horizontal disc, and the reaction gas enters the reaction chamber to deposit on the horizontally placed substrate to obtain the product. Taking the German AIXTRON planetary reaction chamber as an example, a graphite susceptor capable of rotating is arranged in the reaction chamber, the graphite susceptor is in the form of a disc, a plurality of substrates form a group, and a plurality of substrate groups are uniformly arranged in a circle on the graphite susceptor. The graphite susceptor can revolve, and each substrate group can rotate. Group III and group V reactants enter from the center of the upper cover, flow horizontally along the annular space between the graphite susceptor and the ceiling in a radial manner to the outer edge, and the uniform growth rate of each substrate surface is obtained by using rotation and revolution.

[0004] Since the deposition of semiconductor thin films has high requirements on the temperature field, velocity field and concentration field of the reaction gas, and as the performance requirements of semiconductor chips are improved, the requirement for uniformity of multiple fields is also increasing. At the same time, the semiconductor industry has a very urgent demand for large-area, high-capacity and high-quality thin film deposition equipment. The limitation of the existing reaction chamber structure is that it is difficult to improve the capacity, because in order to improve the capacity, the size of the reaction chamber needs to be increased, and with the increase of the size of the reaction chamber, the uniformity of the temperature field, velocity field and concentration field will decrease, and it is very difficult to achieve high capacity.

[0005] First, the increasing size of the susceptor in the conventional MOCVD reaction chamber poses challenges to the temperature uniformity. In the reaction chamber, a stable high-temperature environment is required to promote the epitaxial film growth. When the size of the disc-shaped susceptor increases, the temperature distribution in the reaction chamber becomes more and more uneven, resulting in an increased temperature gradient during the growth process. Therefore, the epitaxial growth uniformity is sensitive to the size of the susceptor. On a smaller susceptor, the growth of the epitaxial film is relatively easy to achieve uniformity, while when the size of the susceptor increases, the distribution of the epitaxial film on the surface of the susceptor becomes more complex, which can lead to uneven deposition thickness and material composition distribution, thereby affecting the performance and consistency of the device.

[0006] Secondly, the requirement for gas composition control during the MOCVD film growth process is also very high, and the composition and flow uniformity of the gas plays an important role in the reaction rate and material transport during the film growth process. The increasing size of the susceptor leads to a greater difference in the uniformity of the flow distribution of the central gas inlet at different diameters of the susceptor, thereby affecting the atmosphere control during the material growth process, which can lead to inconsistencies in the quality of the grown material, thereby affecting the performance of the device.

[0007] In summary, for the existing MOCVD equipment, the capacity of the MOCVD equipment can be improved by increasing the size of the susceptor, but problems such as flow uniformity, temperature uniformity, gas composition control, etc. Therefore, the obtained capacity growth is limited. SUMMARY

[0008] The purpose of the present application is to at least partially overcome the defects of the prior art and provide a new type of MOCVD equipment. The purpose of the present application can be multiple, but is not intended to solve all problems and achieve all purposes, as long as one of the technical problems is solved, the purpose of the present application is achieved.

[0009] The purpose of the present application is also to provide a MOCVD equipment with improved temperature uniformity, gas flow uniformity and / or gas concentration uniformity.

[0010] The purpose of the present application is also to provide a MOCVD equipment capable of improving the deposition quality of semiconductor devices.

[0011] The purpose of the present application is also to provide a MOCVD equipment, which can increase the capacity or easily increase the capacity while obtaining high-quality and high-performance deposition products.

[0012] In order to achieve the above purpose or one of the purposes, the technical solution of the present application is as follows:

[0013] A MOCVD equipment, the MOCVD equipment comprising:

[0014] a reaction cavity shell configured to provide an environment for the reaction gas to chemically react;

[0015] a gas inlet and a gas outlet configured to supply the reaction gas into the reaction cavity shell and discharge the gas from the reaction cavity shell, respectively; and

[0016] an inner cylinder disposed in the reaction cavity shell, and a reaction gas passage is formed between the inner cylinder and the reaction cavity shell,

[0017] wherein the reaction gas passage has substantially the same cross section along the direction of travel of the reaction gas.

[0018] According to a preferred embodiment of the present application, the reaction gas passage is substantially annular.

[0019] According to a preferred embodiment of the present application, the inner cylinder is substantially cylindrical, and the inner wall surface of the reaction cavity shell is substantially cylindrical.

[0020] The inner cylinder is coaxially disposed in the reaction cavity shell.

[0021] According to a preferred embodiment of the present application, a cross section of the inner cylinder perpendicular to the longitudinal axis of the inner cylinder is a regular polygon, such that the inner cylinder forms a polygonal prism; and a cross section of the inner wall surface of the reaction cavity shell perpendicular to the longitudinal axis of the reaction cavity shell is a regular polygon, such that the inner wall surface of the reaction cavity shell forms a polygonal prism.

[0022] The inner cylinder is coaxially disposed in the reaction cavity shell.

[0023] According to a preferred embodiment of the present application, the MOCVD device is configured such that the inner cylinder and the reaction cavity shell are capable of relative rotation.

[0024] According to a preferred embodiment of the present application, the inner cylinder is configured to be rotatable around the longitudinal axis of the inner cylinder, and the reaction cavity shell is configured to remain stationary during the operation of the MOCVD device; or

[0025] At least a portion of the reaction cavity shell is configured to be rotatable around the longitudinal axis of the reaction cavity shell, and the inner cylinder is configured to remain stationary during the operation of the MOCVD device; or

[0026] At least a portion of the reaction cavity shell and the inner cylinder are configured to be rotatable simultaneously, but the rotation direction or the rotation speed of the inner cylinder and the reaction cavity shell is different.

[0027] According to a preferred embodiment of the present application, the gas inlet is provided with a gas inlet element configured to guide the reaction gas into the reaction gas passage and flow along the reaction gas passage towards the gas outlet.

[0028] According to a preferred embodiment of the present application, the gas outlet of the gas inlet element is a longitudinal gas outlet, which is located in the reaction gas passage and extends along the longitudinal axis of the inner cylinder; or

[0029] The number of the gas inlet elements is multiple, the gas outlets of the multiple gas inlet elements are located in the reaction gas passage, and the multiple gas inlet elements are uniformly distributed along the longitudinal axis of the inner cylinder.

[0030] According to a preferred embodiment of the present application, the reaction cavity shell is provided with the gas inlet element, the gas outlet element and the partition element; the gas inlet element and the gas outlet element extend into the reaction gas passage through the cavity wall of the reaction cavity shell; the partition element is located in the reaction gas passage between the gas inlet element and the gas outlet element.

[0031] According to a preferred embodiment of the present application, the outer periphery of the inner cylinder is provided with a mounting position for mounting a substrate; and / or

[0032] The inner side of the reaction cavity shell is provided with a mounting position for mounting a substrate.

[0033] According to the MOCVD equipment of the present application, the inner cylinder is arranged in the reaction cavity shell, the reaction gas passage is formed between the inner cylinder and the reaction cavity shell, and based on the shape of the inner wall surface of the inner cylinder and the reaction cavity shell, the reaction gas passage with constant cross section is easily obtained, thus the reaction gas supplied into the reaction gas passage through the gas inlet port can maintain a uniform velocity field and concentration field, and the layout of the heating element around the inner periphery of the cavity wall of the inner cylinder or the reaction cavity shell can also easily obtain a uniform temperature field, thus the MOCVD equipment of the present application has improved temperature uniformity, gas flow uniformity and / or gas concentration uniformity, thereby the deposition quality of the semiconductor device can be improved. More importantly, the inner cylinder and the reaction cavity shell are coaxially arranged, and the capacity increase can be easily realized by increasing the axial and radial dimensions of the equipment (the area for carrying the substrate is increased), and the increase of the equipment size has little effect on the uniformity of the velocity field, concentration field and temperature field of the gas in the reaction cavity shell, and can well solve the problem that the large-scale production of the epitaxial equipment in the semiconductor industry is limited. Therefore, the MOCVD equipment of the present application can increase the capacity, and can also ensure the high quality and high performance of the deposition product at the same time. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 is a schematic view of the cross section of a prior art planetary reaction chamber;

[0035] Figure 2 is a top view of a graphite susceptor of the planetary reaction chamber in Figure 1

[0036] Figure 3 is a schematic view of the cross section of a MOCVD equipment according to an embodiment of the present application;​

[0037] Figure 4 A-A sectional view of the MOCVD apparatus in Figure 3 ;

[0038] Figure 5 A MOCVD apparatus according to another embodiment of the present application is shown, corresponding to Figure 4 ;

[0039] Figure 6 A cross-sectional schematic view of a MOCVD apparatus according to an embodiment of the present application, wherein the substrates are mounted on the outer periphery of the inner cylinder;

[0040] Figure 7 C-C sectional view of the MOCVD apparatus in Figure 6 ;

[0041] Figure 8 A cross-sectional schematic view of a MOCVD apparatus according to an embodiment of the present application, wherein the substrates are mounted on both the outer periphery of the inner cylinder and the inner side of the reaction chamber shell;

[0042] Figure 9 D-D sectional view of the MOCVD apparatus in Figure 8 ;

[0043] Figure 10 A MOCVD apparatus according to another embodiment of the present application is shown, corresponding to Figure 9 , but with a different arrangement of the second heating element;

[0044] Figure 11 A cross-sectional schematic view of a MOCVD apparatus according to an embodiment of the present application, wherein the substrates are mounted on the inner side of the reaction chamber shell;

[0045] Figure 12 E-E sectional view of the MOCVD apparatus in Figure 11 ;

[0046] Figure 13 An arrangement of mounting positions on the outer cylinder for mounting substrates is shown;

[0047] Figure 14 Fixing means on the inner cylinder for fixing substrates are shown;

[0048] Figure 15 Fixing means on the inner and outer cylinders for fixing substrates are shown;

[0049] Figure 16 Fixing means on the outer cylinder for fixing substrates are shown;

[0050] Figure 17A cross-sectional view of a MOCVD apparatus according to an embodiment of the present application;

[0051] Figure 18 A cross-sectional view of a MOCVD apparatus according to an embodiment of the present application;

[0052] Figure 19 A cross-sectional view of a MOCVD apparatus according to an embodiment of the present application; Figure 18

[0053] Figure 20 A cross-sectional view of a MOCVD apparatus according to an embodiment of the present application;

[0054] Figure 21 A cross-sectional view of a MOCVD apparatus according to an embodiment of the present application; Figure 20

[0055] Figure 22 A cross-sectional view of a MOCVD apparatus according to an embodiment of the present application;

[0056] Figure 23 A cross-sectional view of a MOCVD apparatus according to an embodiment of the present application;

[0057] Figure 24 A cross-sectional view of a MOCVD apparatus according to an embodiment of the present application;

[0058] Figure 25 A cross-sectional view of a MOCVD apparatus according to an embodiment of the present application.

[0059] List of reference numerals:

[0060] 11 actuating device; 12 transmission shaft; 13 driving rotation unit; 14 driven rotation unit; 15 rotation shaft; 16 bearing; 17 support 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 band; 48 end heat insulation material; 49 center support ring; 50 fixing assembly; 51 reaction gas passage; 52 gas inlet element; 53 gas outlet element; 54 partition element; 55 center support shaft; 56 insulation sheet; 57 support cylinder; 58 support rod; 60 rotation seal; 61 pressure reduction cabin; 62 first vacuum pump; 63 second vacuum pump; 64 fixing groove; 65 clamp; 66 double-layer water cooling pipe; 67 outer passage; 68 inner passage; 69 current collecting 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 coupling element; 103 second housing coupling element. DETAILED DESCRIPTION​​

[0061] 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.

[0062] Figure 3 , 4 The basic structure of an MOCVD apparatus according to an embodiment of the present invention is shown. This MOCVD apparatus is a rotary MOCVD apparatus, so named because the inner cylinder and the reaction chamber shell of the MOCVD apparatus can rotate relative to each other, as will be discussed later. As shown in the figure, the MOCVD apparatus mainly includes a reaction chamber shell, an inlet and an outlet, an inner cylinder 41, an actuator 11, and a transmission mechanism. The reaction chamber shell is used to provide an environment for the chemical reaction of the reaction gases, typically a high-temperature, low-pressure environment; the inner cylinder 41 is disposed inside the reaction chamber shell, and a reaction gas channel 51 is formed between the inner cylinder 41 and the reaction chamber shell, such as... Figures 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.

[0063] 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.

[0064] At least the portions of the inner cylinder 41 or the reaction chamber shell facing each other comprise a graphite material coated with a SiC coating, or a tungsten material, or a molybdenum material. In order to make the inner cylinder 41 and the outer cylinder 44 resistant to high temperatures, they are usually graphite cylinders coated with a SiC coating, and can also use high-temperature-resistant tungsten, molybdenum and other metal materials. The thickness of the coating can be determined according to the mechanical properties of the material.

[0065] The gas inlet and the gas outlet are provided on the reaction chamber shell for supplying reaction gas into the reaction chamber shell and discharging gas from the reaction chamber shell, respectively. In this embodiment, the gas inlet element 52 is provided on the gas inlet, and the gas outlet element 53 is provided on the gas outlet. The gas inlet element 52 and the gas outlet element 53 extend into the reaction gas passage 51 from the outside of the reaction chamber shell through the cavity wall of the reaction chamber shell. The gas inlet element 52 is configured to guide the reaction gas into the reaction gas passage 51 and flow along the reaction gas passage 51 to the gas outlet, as shown by the arrow in the reaction gas passage 51, and the exhaust gas after the reaction in the reaction gas passage 51 is discharged from the gas outlet element 53. Figure 4 In addition to the gas inlet element 52 and the gas outlet element 53, the reaction chamber shell is also provided with a separation element 54 located in the reaction gas passage 51 between the gas inlet element 52 and the gas outlet element 53 to prevent backflow of the exhaust gas to the gas inlet side.

[0066] As shown in Figure 4 , the gas inlet element 52 and the gas outlet element 53 extend into the reaction gas passage 51 from the outside of the reaction chamber shell through the cavity wall of the reaction chamber shell in the radial direction of the inner cylinder 41, and the gas inlet element 52 and the gas outlet element 53 are arranged adjacent to each other in the circumferential direction of the reaction chamber shell. The gas inlet element 52, the gas outlet element 53 and the separation element 54 between the gas inlet element 52 and the gas outlet element 53 adjacent to each other in the circumferential direction of the reaction chamber shell form a set of ventilation elements. In the embodiment shown in Figure 4 , the MOCVD device only includes one set of ventilation elements (whole-circle flow). In this set of ventilation elements, the gas outlet of the gas inlet element 52 can be a longitudinal gas outlet, i.e. only one gas inlet element and one gas outlet, the gas outlet is located in the reaction gas passage 51 and extends in the longitudinal axis direction of the inner cylinder 41, preferably extends along the entire longitudinal length of the inner cylinder 41, so as to ensure the uniformity of the reaction gas in the reaction gas passage 51. Alternatively, in this set of ventilation elements, the number of gas inlet elements 52 can be multiple, and the gas outlets of the multiple gas inlet elements 52 are located in the reaction gas passage 51, and the multiple gas inlet elements 52 are uniformly distributed along the longitudinal axis direction of the inner cylinder 41, so as to ensure the uniformity of the reaction gas in the reaction gas passage 51. The gas outlet element 53 can have the same form and arrangement as the gas inlet element 52.

[0067] As shown in Figure 4The 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.

[0068] 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.

[0069] The position of the gas inlet element 52 can be designed at different positions according to the working environment and specific working conditions. In actual use, it can be arranged at a position below the outer shell of the reaction cavity shell, which is beneficial to inhibit the natural convection in the channel. The reaction gas enters the reaction gas channel through the gas inlet element, is heated and chemically reacts in the channel, and thin film deposition is carried out. Since the cross-sectional area of the channel remains unchanged during the flow process of the reaction gas, the flow uniformity of the gas is very good. It should be noted that since the inner cylinder and the reaction cavity shell can rotate relative to each other, in the case of rotation of the inner cylinder 41, a gap should be provided between the separation element 54 and the inner cylinder 41, which is a small gap to prevent affecting the rotation of the inner cylinder. The separation element 54 can be a thin-walled baffle fixed on the outer cylinder, and the function of the separation element 54 is to prevent the mixing of the inlet and outlet gas. In a preferred embodiment, gas holes can be provided on both sides of the separation element 54, and a certain speed of carrier gas (nitrogen) is injected into the gas holes to form a gas barrier layer. On the one hand, the gas holes on the inlet side are used to block the flow of the inlet gas flow in the direction of the outlet gas flow, to avoid waste of organometallic sources; on the other hand, the gas holes on the outlet side are used to block the flow of the outlet gas flow in the direction of the inlet gas flow, to avoid contamination of the source gas.

[0070] Advantageously, the channel at the gas outlet of the gas inlet element 52 is curved relative to the axial direction of the gas inlet element 52, so that the flow direction of the reaction gas supplied from the gas outlet is substantially tangent to a circle with a point on the longitudinal axis of the inner cylinder 41 as the center, and in addition, the gas inlet element 52 is a gas inlet element with multiple channels, and the multiple channels exist in the form of a sleeve. The multiple channels are three channels or more, because there are multiple gases of the reaction gas, and each layer of the sleeve passes different gases.

[0071] Further, the part of the gas inlet element 52 extending into the reaction gas channel 51 includes a radial section and a bent section bent relative to the radial section; the bent section is provided with a first gas outlet and a second gas outlet, the flow direction of the reaction gas supplied from the first gas outlet is substantially tangent to a circle with a point on the longitudinal axis of the inner cylinder 41 as the center, and the flow direction of the reaction gas supplied from the second gas outlet is substantially directed to the longitudinal axis of the inner cylinder 41 to form a gas curtain. These downward vertical nozzles (second gas outlets) on the inlet side prevent the leakage of the exhaust gas into the inlet part, forming a gas curtain to block the exhaust gas from entering the inlet side through the gap of the separation element 54.

[0072] Advantageously, the MOCVD apparatus is configured to enable relative rotation between the inner cylinder 41 and the reaction cavity shell. This relative rotation can be achieved in the following ways: the inner cylinder 41 is configured to be rotatable around the longitudinal axis of the inner cylinder 41, and the reaction cavity shell is configured to remain stationary during the operation of the MOCVD apparatus; or at least a portion of the reaction cavity shell (the outer cylinder or the entire reaction cavity shell) is configured to be rotatable around the longitudinal axis of the reaction cavity shell, and the inner cylinder 41 is configured to remain stationary during the operation of the MOCVD apparatus; or at least a portion of the reaction cavity shell (the outer cylinder or the entire reaction cavity shell) and the inner cylinder 41 are configured to be rotatable simultaneously, but the rotation direction or rotation speed of the inner cylinder 41 and the reaction cavity shell is different. In the embodiment shown in the drawings, the inner cylinder 41 is actively rotatable, while the reaction cavity shell remains stationary. Figure 3

[0073] It should be noted that the relative rotation of the inner cylinder 41 and the reaction cavity shell is not necessary, and they can also remain relatively stationary, for example, they both remain absolutely stationary during the operation of the MOCVD apparatus, which can also achieve the effect of the present application to some extent, as long as the reaction gas passage 51 has substantially the same cross section along the direction of travel of the reaction gas. In the case of an equal cross section, the flow speed of the reaction gas in the passage remains substantially unchanged, thereby obtaining a uniform flow field along the flow direction. However, the relative rotation can make the concentration of the carrier gas / reaction gas contacted by the wafer substrate more uniform.

[0074] To achieve the working temperature of the MOCVD, the MOCVD apparatus further comprises a heating element, which can be arranged in the interior of the inner cylinder 41 and / or in the cavity wall of the reaction cavity shell. In general, the heating element can include: a plurality of heating strips arranged in parallel, each of which is parallel to the longitudinal axis of the inner cylinder 41 and distributed circumferentially with respect to the longitudinal axis of the inner cylinder 41, as shown in Figures 3-4 ; or a plurality of annular heating bands arranged in parallel, which are distributed axially with respect to the longitudinal axis of the inner cylinder 41, as shown in Figure 23 ; or a plurality of heating blocks uniformly distributed on a selected circumferential surface around the longitudinal axis of the inner cylinder 41, not shown in the drawings; or a combination of any two of the plurality of heating strips, the plurality of annular heating bands, and the plurality of heating blocks, as shown in Figures 18-21 . The heating element can be a silicon molybdenum rod, a tungsten wire, or a molybdenum wire, and the material can be silicon molybdenum, tungsten, or molybdenum, and the shape can be a block, a band, a strip, 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 passage, and the heating power can be adjusted to ensure that the temperature difference on the surface of the substrate is less than 1°C.

[0075] ​Since the reaction cavity shell and the inner cylinder 41 are both substantially cylindrical, the heating elements are substantially uniformly arranged in the interior of the inner cylinder 41 and / or in the cavity wall of the reaction cavity shell, so that the heat generated by the heating elements is transmitted to the reaction gas passage 51 along the radial direction of the reaction cavity shell or the inner cylinder 41. The heating elements are preferably silicon-molybdenum rods, tungsten wires or molybdenum wires.

[0076] The interior of the inner cylinder 41 and the cavity wall of the reaction cavity shell are both provided with heat insulation materials, such as Figures 3-4 As shown, the center of the inner cylinder 41 is penetrated by the rotating shaft 15, and the inner cylinder 41 is relatively fixed with the rotating shaft 15 so that the inner cylinder 41 can rotate together with the rotating shaft 15. Heat insulation materials are arranged between the outer wall of the inner cylinder 41 and the rotating shaft 15, and the inner cylinder 41 is connected and fixed with the first heating element 41, the first heat insulation material 42 and the rotating shaft 15 into an integral whole through the support element 17; the support element 17 should be made of a material with good rigidity and small thermal conductivity, such as a high-temperature-resistant and non-decomposable ceramic material such as zirconia. The first heating element 41 and the first heat insulation material 42 are combined by a mechanical connection mode and are connected and fixed together with the high-temperature-resistant rotating inner cylinder through the support element 17. The other side of the support element 17 is mechanically connected and fixed with the rigid rotating shaft 15. The rotating shaft 15 is provided with bearings 16, and the entire inner cylinder 41 is supported and fixed through the left and right bearings 16. The rotating shaft 15 can be made of stainless steel or other materials, and a cooling structure is arranged in the interior of the rotating shaft 15 to efficiently cool the rigid rotating shaft by liquid cooling or gas cooling.

[0077] With reference to the embodiments of Figures 3-7 , it can be known that the inner cylinder 41 is a hollow inner cylinder, and the heating elements are arranged in the interior of the inner cylinder 41. The heating elements include a plurality of heating strips arranged in parallel, the plurality of heating strips are parallel to the longitudinal axis of the inner cylinder 41 and are distributed in the circumferential direction relative to the longitudinal axis of the inner cylinder 41, and both ends of each heating strip are fixed on both ends of the inner cylinder 41 along the longitudinal axis. Figures 8-12 In the embodiments of , the heating elements are also arranged in the cavity wall of the reaction cavity shell, and the heating elements are second heating elements 73. The second heating elements 73 also include a plurality of heating strips arranged in parallel, the plurality of heating strips are parallel to the longitudinal axis of the reaction cavity shell and are distributed in the circumferential direction relative to the longitudinal axis of the reaction cavity shell, and each heating strip is fixed in the cavity wall of the reaction cavity shell through a heating element fixing part 74.

[0078] 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.

[0079] The transmission mechanism is described below. The actuator 11 drives the inner cylinder 41 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 23 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.

[0080] like Figure 6 , 7 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 11 , 12 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. Figures 8-10 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).

[0081] 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 13 As shown, multiple mounting positions can form multiple rows, with adjacent rows of mounting positions staggered. Each mounting position can be as follows: Figure 13The fixed recess 64 shown can play a fixing role, so that the substrate remains stationary during rotation of the inner cylinder around the axis. In addition, the inner cylinder 41 and the outer cylinder 44 as the inner wall surface of the reaction chamber shell can be cylindrical or polygonal, such as Figures 14-16 As shown, the inner cylinder 41 has a cross section perpendicular to the longitudinal axis of the inner cylinder 41 in the shape of a regular polygon, so that the inner cylinder 41 forms a polygonal prism, the inner wall surface of the reaction chamber shell has a cross section perpendicular to the longitudinal axis of the reaction chamber shell in the shape of a regular polygon, so that the inner wall surface of the reaction chamber shell forms a polygonal prism, the mounting position is arranged on the prism surface of the polygonal prism, and in addition, the mounting position is provided with a clamp 65, a clamping groove, and a recess for fixing the substrate 72 on the mounting position. The length of the side of the polygon is determined by the size of the wafer substrate, and the number N of sides of the polygon can be any number greater than or equal to 3. Generally, in order to make the flow field uniform and the cross-sectional area of the annular reaction gas passage change not obviously, N can be slightly larger, and therefore the diameter of the high-temperature-resistant inner cylinder is also relatively large.

[0082] The structure of the double-sided mounted substrate greatly improves the productivity of the MOCVD equipment, the outer surface of the high-temperature-resistant inner cylinder and the inner surface of the high-temperature-resistant outer cylinder are designed to have recesses, clamping grooves, or clamps for placing wafer substrates, and each wafer substrate on the outer surface of the inner cylinder can be opposite to the wafer substrate on the inner surface of the outer cylinder, and the cross section of the reaction gas passage formed between the two is also similar to a regular polygonal passage. When the gas passes through the annular or regular polygonal passage, epitaxial films can be deposited on both sides, the loss of reaction gas is minimized, and the efficiency of epitaxial film growth is high. This method also solves the problem of regular cleaning of the reaction chamber shell wall surface due to easy deposition of chemical reactants.

[0083] Taking the rotation of the inner cylinder as an example, the inner cylinder is uniformly rotated during operation, which can ensure the uniformity of the large-size cylinder wall temperature, thereby realizing the uniformity of the deposition on the surface of the wafer substrate. In practice, the rotation speed of the inner cylinder can be adjusted as needed, or the inner cylinder can be stationary. The cross-sectional area of the annular reaction gas passage of the cylindrical reaction chamber is always constant along the flow direction, thereby ensuring the uniformity of the gas velocity field. Meanwhile, the inner cylinder carrying the substrate is designed to rotate, which can ensure the uniformity of the inner cylinder and the substrate surface temperature, as well as the uniformity of the reactants on the substrate surface, thereby solving the problem of non-uniform deposition on the substrate surface after the MOCVD equipment becomes larger. At the same time, the increase in the axial dimension of the reaction chamber shell has little effect on the temperature field, velocity field, and reactant diffusion concentration field of the MOCVD film deposition reaction gas, thereby greatly improving the productivity of the MOCVD epitaxial wafer while ensuring very high epitaxial deposition quality, effectively breaking through the constraints of the production capacity of the MOCVD equipment in the semiconductor industry.

[0084] Preferably, the distribution density or power density of the heating elements near the position of the gas inlet or gas outlet is greater than that of the position far from the gas inlet or gas outlet. Referring to Figure 9 , 10 , the distribution density of the second heating element 73 near the position of the gas inlet and gas outlet (gas inlet element 52 and gas outlet element 53) is greater than that of other positions, because the lower inlet temperature of the outer cylinder 44 causes the temperature of the substrate 72 on the outer cylinder 44 to be lower near the gas inlet, so a special heating element needs to be arranged or increased near the gas inlet of the outer cylinder 44 to increase the local temperature of the outer cylinder and ensure the temperature uniformity in the 360° circumferential direction of the entire outer cylinder. Because the annular reaction gas channel is small, the overall temperature difference between the inner and outer cylinders is not large, and the outer cylinder heating element can be arranged according to the temperature requirement, or not arranged, or only arranged locally (as shown in Figure 10 ), so that the inner and outer cylinders are heated by the heating elements inside the inner cylinder, and only the heating elements near the gas inlet of the outer cylinder are arranged to compensate, so that the temperature difference of the entire outer cylinder is within 1℃, meeting the temperature range required for high-quality thin film deposition of the substrate on the outer cylinder.

[0085] Even if no substrate is arranged on the outer cylinder 44, the outer cylinder 44 can be heated to compensate for the cooling effect of the lower temperature reaction gas on the inner cylinder. The heating power of the outer cylinder heating element can be uniformly heated or non-uniformly heated along the circumferential direction. Non-uniform heating generally uses larger compensation heating power or more dense heating wire design at the position where the reaction gas inlet temperature is lower. Along the direction of movement of the reaction gas in the gas channel, the gas temperature gradually increases, and the compensation heating power of the outer cylinder heating element gradually decreases to ensure that the temperature of the entire substrate surface is more uniform, creating a more uniform temperature environment for the reaction chamber. Another function of the auxiliary heating element of the outer cylinder is to accelerate the system response speed of MOCVD during temperature switching. According to the surface temperature of the inner cylinder and the temperature switching requirement, the power and switch of the auxiliary heating element are controlled in advance to ensure that the system realizes the temperature rising or falling process in a shorter time.

[0086] In Figure 17In the embodiment, the first shell 31 is located vertically above the second shell 32, the second shell 32 remains fixed, and the first shell 31 is configured to be movable relative to the second shell 32; two first shell combination elements 102 are arranged on the first shell 31, two second shell combination elements 103 are arranged on the second shell 32, and the first shell combination elements 102 are configured to be combined with the second shell combination elements 103; the MOCVD device further comprises two lifting assemblies 101 connected with the first shell combination elements 102, for lifting or lowering the first shell 31. The lifting assembly 101 can be a hydraulic rod, and in the process of loading and unloading the substrate, the lifting assembly 101 drives the first shell 31 to rise upward, thereby opening the reaction cavity shell and leaving a space for loading / unloading the wafer substrate.

[0087] Figures 17-21 23. Several different forms, arrangements and support modes of the heating elements are given, which are several embodiments of the partitioned heating elements, the inside of the inner cylinder 41 or the inside of the cavity wall of the reaction cavity shell is divided into different areas, and the heating elements exist in at least two areas in different forms, different distribution densities or different power densities. Specifically, the distribution density or power density of the heating elements at the position close to the air inlet or air outlet can be greater than the distribution density or power density at the position away from the air inlet or air outlet, or the heating elements have different distribution densities or power densities at the position close to the end of the longitudinal axis of the inner cylinder 41 and the position close to the center of the longitudinal axis of the inner cylinder 41. For example, the heating elements are arranged in the inside of the inner cylinder 41, and the inside of the inner cylinder 41 includes a first area close to the center of the longitudinal axis of the inner cylinder 41 and two second areas close to both ends of the longitudinal axis of the inner cylinder 41, and the heating elements have different forms and arrangements in the first area and the second area.

[0088] In Figures 17-19In 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.

[0089] 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.

[0090] exist Figures 20-21 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.

[0091] The center support shaft 55 is provided with a plurality of center support rings 49, each of which is provided with a plurality of heating element support rods 46 extending in the radial direction of the center support ring 49, and the plurality of heating element support rods 46 are uniformly distributed in the circumferential direction of the center support ring 49; the plurality of heating strips and the annular heating bands are respectively fixed on the ends of the heating element support rods 46 away from the center support ring 49, directly or indirectly. The ends of the heating element support rods 46 away from the center support ring 49 are provided with fixing plates, and the heating strips or annular heating bands are fixed on the fixing plates by screws, and the fixing plates and screws constitute a fixing assembly 50. Insulating sheets 56 are arranged between the heating strips and the ends of the heating element support rods 46 (fixing assembly 50), and insulating sheets 56 are arranged between the annular heating bands and the ends of the heating element support rods 46. The material of the center support ring 49 can be selected from stainless steel or other nickel-based metals.

[0092] In Figure 23 Embodiments, unlike the embodiment shown in Figure 18 , the heating elements in the inner cylinder 41 are all composed of annular heating bands, and a certain distance is left between adjacent two annular heating bands. The size and heating power of the annular heating band can be adjusted according to process requirements. The annular heating band can be designed in zones according to the temperature uniformity of the inner cylinder. It can be divided into middle zone and edge zone in the axial direction. Because of the different heat loss of the edge and the middle, different power can be loaded in different zones. Through the axial division of different zones, the surface temperature of the inner cylinder is more uniform, and the temperature difference between the two ends and the middle of the substrate surface is less than 1℃.

[0093] Further, the heating strips can also be designed in zones in the circumferential direction. Such design can independently adjust the electric heating power of different zones. For example, for the position of the air inlet, because the air temperature is low, there is a large difference between the temperature field of this area and the temperature field of the middle position of the reaction chamber. At this time, the electric heating power of the heating strip in this zone can be independently adjusted to increase, so as to ensure the uniformity of the temperature field of the entire reaction chamber.

[0094] In addition, in the case where the center of the inner cylinder 41 is penetrated by the rotating shaft 15 and the inner cylinder 41 is relatively fixed with the rotating shaft 15 so that the inner cylinder 41 and the rotating shaft 15 can rotate together, the plurality of heating strips and / or annular heating bands can also be directly fixed on the rotating shaft 15.

[0095] As Figure 22As shown, the rotating shaft 15 is provided with a water cooling channel, which is a double-layer water cooling channel, including a communicating outer channel 67 and an inner channel 68, 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 water drainage. Wherein, the rotating shaft 15 is a hollow rotating shaft, the double-layer water cooling channel exists in the form of a double-layer water cooling pipe 66, and the double-layer water cooling pipe 66 is arranged in the hollow part of the rotating shaft 15.

[0096] As shown in the figure, Figure 23 As shown, the cavity wall of the reaction cavity shell further includes a support cylinder 57 arranged between the outer shell and the outer cylinder 44; a plurality of support rods 58 are arranged between the support cylinder 57 and the outer cylinder 44, the support rods 58 extend along the radial direction of the reaction cavity shell, and the plurality of support rods 58 are uniformly distributed along the circumferential direction of the reaction cavity shell.

[0097] As shown in the figure, Figure 24 As shown in the figure, the heating element of the MOCVD equipment is an electric heating mode, the heating element is connected with an external power supply, when the inner cylinder 41 rotates, the power supply of the first heating element 43 fixedly arranged on the inner cylinder 41 is realized in the following mode: a current collecting ring 69 is arranged at the end of the rotating shaft 15, the current collecting ring 69 is connected with the external power supply through a wire 70, and the first heating element 43 is connected with the current collecting ring 69 through a wire passing through the center of the rotating shaft 15, so as to realize the dynamic and static conversion.

[0098] In the above-described embodiments, the longitudinal axis of the inner cylinder 41 is arranged along the horizontal direction, and the longitudinal axis of the reaction cavity shell is also arranged along the horizontal direction, so as to form a horizontal MOCVD equipment, however, alternatively, the longitudinal axis of the inner cylinder 41 can also be arranged along the vertical direction, and the longitudinal axis of the reaction cavity shell can also be arranged along the vertical direction, so as to form a vertical MOCVD equipment, Figure 25 That is, the embodiment of the vertical MOCVD equipment, in which a decompression cabin 61 is also shown, the decompression cabin 61 is configured to be able to provide an environment lower than atmospheric pressure, the reaction cavity shell is arranged in the decompression cabin 61, in the working process of the MOCVD equipment, the first pressure in the reaction cavity shell is higher than the second pressure in the decompression cabin 61, and both the first pressure and the second pressure are lower than atmospheric pressure. The MOCVD equipment further includes a first vacuum pump 62 and a second vacuum pump 63, the first vacuum pump 62 is in fluid communication with the decompression cabin 61, and is used to generate and maintain the second pressure in the decompression cabin 61; the second vacuum pump 63 is in fluid communication with the reaction cavity formed by the reaction cavity shell, and is used to generate and maintain the first pressure in the reaction cavity. In addition, the decompression cabin 61 is fixed on the base 97, and the support frame 98 is arranged in the decompression cabin 61, the support frame 98 has a U-shaped groove, the reaction cavity shell is fixed on the support frame 98, and the actuating device 11 and the driving rotating unit 13 of the magnetic coupler are located in the U-shaped groove. In addition,Figure 25 Other settings of the vertical MOCVD apparatus of the present application are the same as the previous embodiments.

[0099] While embodiments of the present application have been shown and described, it is to be understood that the embodiments can be varied, without departing from the spirit and scope of the present application. The scope of the present application is limited by the claims appended hereto and their equivalents.

Claims

1. An MOCVD device, characterized in that, The MOCVD equipment includes: The reaction chamber shell 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 cylinder (41) is disposed inside the reaction chamber shell, and a reaction gas channel (51) is formed between the inner cylinder (41) and the reaction chamber shell. The reaction gas channel (51) has approximately the same cross-section along the direction of travel of the reaction gas; The reaction chamber shell is provided with an air inlet element (52), an air outlet element (53) and a partition element (54); the partition element (54) is located in the reaction gas channel (51) and between the air inlet element (52) and the air outlet element (53); The intake element (52) and the exhaust element (53) are arranged adjacent to each other in the circumferential direction of the reaction chamber shell; There is a gap between the partition element (54) and the inner cylinder (41). 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. 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; MOCVD equipment also includes an exhaust gas treatment system.

2. The MOCVD equipment according to claim 1, characterized in that: The reaction gas channel (51) is generally annular.

3. The MOCVD equipment according to claim 2, characterized in that: The inner cylinder (41) is generally cylindrical, and the inner wall surface of the reaction chamber shell is generally cylindrical; The inner cylinder (41) is coaxially disposed inside the reaction chamber shell.

4. The MOCVD equipment according to claim 2, characterized in that: The cross section of the inner cylinder (41) perpendicular to the longitudinal axis of the inner cylinder (41) is a regular polygon, so that the inner cylinder (41) forms a polygonal prism; the cross section of the inner wall surface of the reaction chamber shell perpendicular to the longitudinal axis of the reaction chamber shell is a regular polygon, so that the inner wall surface of the reaction chamber shell forms a polygonal prism. The inner cylinder (41) is coaxially disposed inside the reaction chamber shell.

5. The MOCVD equipment according to claim 2, 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.

6. The MOCVD equipment according to claim 5, 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.

7. The MOCVD equipment according to claim 2, characterized in that: The number of air intake elements (52) is multiple, and the outlets of the multiple air intake elements (52) are located in the reaction gas channel (51), and the multiple air intake elements (52) are evenly distributed along the longitudinal axis of the inner cylinder (41).

8. The MOCVD apparatus according to any one of claims 1-7, characterized in that: The inner cylinder (41) has mounting positions for mounting a substrate (72) on its outer periphery; and / or The inner side of the reaction chamber shell is provided with a mounting position for mounting the substrate (72).

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