Mocvd apparatus with reaction gas preheating

Abstract

The application provides a reaction gas preheating MOCVD device, comprising: a reaction cavity shell for providing an environment for chemical reaction of reaction gas; a gas inlet and a gas outlet for supplying reaction gas into the reaction cavity shell and discharging gas from 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 MOCVD device is configured to enable relative rotation between the inner cylinder (41) and the reaction cavity shell; and wherein the MOCVD device is configured to preheat the reaction gas before entering the reaction cavity shell through the gas inlet. The reaction gas preheating MOCVD device can reduce the huge energy consumption of the MOCVD device, reduce the operation cost of the device, has improved temperature uniformity, gas flow uniformity and / or gas concentration uniformity, can improve the deposition quality of the semiconductor device, and can increase the production capacity.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of semiconductor technology, in particular to the field of semiconductor epitaxial film vapor deposition technology, and more particularly to a novel reaction gas preheating MOCVD (metal organic chemical vapor deposition) equipment. BACKGROUND

[0002] MOCVD (metal organic chemical vapor deposition) is a key equipment for manufacturing semiconductor epitaxial wafers, and the performance and productivity of the epitaxial wafers are one of the key determinants of the performance and yield of semiconductor chips. The advantage of using MOCVD technology to prepare epitaxial films is that the composition and flow rate of the reactants can be accurately controlled, the thickness of the film can be accurately controlled, and a relatively large-area uniform film can be prepared more easily, which is suitable for industrial production.

[0003] Currently, the commonly used MOCVD reaction chambers on the market mainly include planetary reaction chambers, vertical near-coupling spray reaction chambers, and vertical high-speed rotating disc reaction chambers. 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 substrates 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 circumferentially and uniformly arranged 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 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 continue to improve, 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-productivity and high-quality film deposition equipment. The limitation of the existing reaction chamber structure is that it is difficult to improve the productivity, because in order to improve the productivity, the size of the reaction chamber needs to be increased, and as the size of the reaction chamber increases, the uniformity of the temperature field, velocity field and concentration field will decrease, and it is very difficult to achieve high productivity.

[0005] In addition, when using the MOCVD equipment in the prior art, after the gas enters the internal passage, it needs to be heated by the high-temperature graphite susceptor wall surface, so that the gas temperature is very high at the outlet position, and the gas is directly discharged to the environment, resulting in a great waste of energy. SUMMARY

[0006] The present application aims to at least partially overcome the defects of the prior art, and provides a novel MOCVD device. 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.

[0007] The present application also aims to provide a MOCVD device for preheating reaction gas, reduce the huge energy consumption of the MOCVD device, and reduce the operating cost of the device.

[0008] The present application also aims to provide a MOCVD device for preheating reaction gas, which has improved temperature uniformity, gas flow uniformity and / or gas concentration uniformity.

[0009] The present application also aims to provide a MOCVD device for preheating reaction gas, which can improve the deposition quality of semiconductor devices.

[0010] The present application also aims to provide a MOCVD device for preheating reaction gas, which can increase the production capacity, or in other words, can easily increase the production capacity while obtaining high-quality and high-performance deposition products.

[0011] In order to achieve the above-mentioned purpose or one of the purposes, the technical solution of the present application is as follows:

[0012] A MOCVD device for preheating reaction gas, the MOCVD device comprising:

[0013] A reaction cavity shell for providing an environment for chemical reaction of reaction gas;

[0014] A gas inlet and a gas outlet for supplying reaction gas into the reaction cavity shell and discharging gas from the reaction cavity shell, respectively; and

[0015] An inner cylinder arranged in the reaction cavity shell, and a reaction gas passage is formed between the inner cylinder and the reaction cavity shell,

[0016] Wherein, the MOCVD device is configured to enable relative rotation between the inner cylinder and the reaction cavity shell; and

[0017] Wherein, the MOCVD device is configured to preheat the reaction gas before entering the reaction cavity shell through the gas inlet.

[0018] According to one 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

[0019] At least a portion of the reaction cavity shell is configured to be rotatable around a longitudinal axis of the reaction cavity shell, and the inner cylinder is configured to be stationary during operation of the MOCVD device; or

[0020] At least a portion of the reaction cavity shell and the inner cylinder are configured to be rotatable simultaneously, but the rotation direction or rotation speed of the inner cylinder and the reaction cavity shell are different.

[0021] According to a preferred embodiment of the present application, the MOCVD device further comprises a heat exchanger, which is arranged on a gas supply pipeline in communication with the gas inlet and a gas exhaust pipeline in communication with the gas outlet.

[0022] According to a preferred embodiment of the present application, a flow valve is arranged on the gas supply pipeline for controlling the flow of reaction gas supplied into the reaction cavity shell; and / or

[0023] A pressure control valve is arranged on the gas exhaust pipeline.

[0024] According to a preferred embodiment of the present application, a filter and / or a gas storage tank are arranged on the gas exhaust pipeline upstream of the heat exchanger.

[0025] According to a preferred embodiment of the present application, a filter, a gas storage tank and a pressure control valve are arranged in sequence along the exhaust direction on the gas exhaust pipeline.

[0026] According to a preferred embodiment of the present application, downstream of the heat exchanger, the gas exhaust pipeline is connected to a tail gas treatment unit.

[0027] According to a preferred embodiment of the present application, a gas inlet element is arranged on the gas inlet, which is configured to guide the reaction gas into the reaction gas passage and flow along the reaction gas passage to 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 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 a gas inlet element, a gas outlet element and a 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] Compared with the prior art, the reaction gas preheating MOCVD equipment has the following beneficial effects: the reaction gas preheating MOCVD equipment adds a regenerator / heat exchanger in the system, so that the gas in the reaction cavity shell is not directly discharged into the tail gas treatment system through the exhaust port, but is filtered to remove solid particles, and then enters the heat exchanger as the hot side gas through the pressure control valve to heat the cold side gas (the reaction gas to be introduced into the reaction gas channel), so that the cold side gas at room temperature can be preheated to a higher temperature that meets the process requirements, thereby greatly reducing the heating power of the heating element, greatly reducing the huge energy consumption of the MOCVD equipment, and reducing the operation cost of the equipment. It has great advantages for improving the operation cost and temperature uniformity of the MOCVD device.

[0032] In addition, according to the reaction gas preheating MOCVD equipment of the present application, the inner cylinder is arranged in the reaction cavity shell, and the reaction gas channel is formed between the inner cylinder and the reaction cavity shell. Based on the shape of the inner wall surface of the inner cylinder and the reaction cavity shell, the reaction gas channel with a constant cross section is easily obtained. Therefore, the reaction gas supplied into the reaction gas channel through the gas inlet can maintain a uniform velocity field and concentration field, and the layout of the heating element in the circumferential direction of the cavity wall of the inner cylinder or the reaction cavity shell can also obtain a uniform temperature field. Therefore, the reaction gas preheating MOCVD equipment of the present application has improved temperature uniformity, gas flow uniformity and / or gas concentration uniformity, thereby improving the deposition quality of the semiconductor device. More importantly, the inner cylinder and the reaction cavity shell are coaxially arranged, and the capacity can be easily increased by increasing the axial and radial dimensions of the equipment (the area that can carry the substrate is increased), and the increase in the size of the equipment has little effect on the uniformity of the velocity field, concentration field and temperature field of the gas in the reaction cavity shell. It can well solve the problem that the large-scale production of the semiconductor industry epitaxial equipment is limited. Therefore, the reaction gas preheating MOCVD equipment of the present application can increase the capacity, and at the same time ensure the high quality and high performance of the deposition product. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a schematic view of the cross section of the planetary reaction chamber of the prior art;

[0034] Figure 2 is a top view of the graphite base of the planetary reaction chamber in Figure 1

[0035] Figure 3 is a schematic view of the cross section of the MOCVD equipment according to one embodiment of the present application;

[0036] Figure 4 is the A-A cross-sectional view of the MOCVD equipment in Figure 3 ​​

[0037] Figure 5 A MOCVD apparatus according to another embodiment of the present application is shown, corresponding to Figure 4 ;

[0038] Figure 6 A cross-sectional 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;

[0039] Figure 7 A C-C cross-sectional view of the MOCVD apparatus in Figure 6 ;

[0040] Figure 8 A cross-sectional 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;

[0041] Figure 9 A D-D cross-sectional view of the MOCVD apparatus in Figure 8 ;

[0042] 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;

[0043] Figure 11 A cross-sectional 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;

[0044] Figure 12 An E-E cross-sectional view of the MOCVD apparatus in Figure 11 ;

[0045] Figure 13 An arrangement of mounting positions on the outer cylinder for mounting substrates is shown;

[0046] Figure 14 A cross-sectional view of a MOCVD apparatus according to an embodiment of the present application;

[0047] Figure 15 An enlarged view of the region K in Figure 14 ;

[0048] Figure 16 A cross-sectional view of a MOCVD apparatus according to an embodiment of the present application;

[0049] Figure 17 A cross-sectional view of a MOCVD apparatus according to an embodiment of the present application;

[0050] Figure 18A cross-sectional view of a MOCVD apparatus according to an embodiment of the present application;

[0051] Figure 19 A cross-sectional view of a MOCVD apparatus according to an embodiment of the present application; Figure 18 A G-G cross-sectional view of a MOCVD apparatus in FIG. 1;

[0052] Figure 20 A cross-sectional view of a MOCVD apparatus according to an embodiment of the present application;

[0053] Figure 21 A cross-sectional view of a MOCVD apparatus according to an embodiment of the present application; Figure 20 A H-H cross-sectional view of a MOCVD apparatus in FIG. 1;

[0054] Figure 22 A cross-sectional view of a MOCVD apparatus according to an embodiment of the present application;

[0055] Figure 23 A cross-sectional view of a MOCVD apparatus according to an embodiment of the present application;

[0056] Figure 24 A cross-sectional view of a MOCVD apparatus according to an embodiment of the present application.

[0057] BRIEF DESCRIPTION OF DRAWINGS

[0058] 11 actuating means; 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; 59 flange; 60 rotation seal; 64 fixing groove; 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; 101 lifting assembly; 102 first housing coupling element; 103 second housing coupling element; 121 gas storage tank; 122 filter; 123 pressure control valve; 124 heat exchanger; 125 exhaust pipe; 126 flow valve; 127 gas supply pipe; 128 exhaust gas treatment unit. DETAILED DESCRIPTION

[0059] Exemplary embodiments of the present application are described in detail below with reference to the attached drawing figures, wherein the same or like reference numerals and characters designate the same or like components. Additionally, in the detailed description of embodiments, a plurality of specific details are set forth in order to provide a thorough understanding of embodiments of the present disclosure. However, it will be apparent to one skilled in the art that one or more embodiments of the present application can be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the present disclosure.

[0060] Figure 3 、 4 The basic structure of a MOCVD apparatus according to an embodiment of the present application is shown, which is a rotary MOCVD apparatus, so called because the inner cylinder and the reaction cavity shell can rotate relative to each other, as will be described later. As shown, the MOCVD apparatus mainly comprises a reaction cavity shell, an air inlet and an air outlet, an inner cylinder 41, an actuating device 11 and a transmission mechanism. The reaction cavity shell is used to provide an environment for the chemical reaction of the reaction gas, which is usually a high-temperature, low-pressure environment; the inner cylinder 41 is arranged in the reaction cavity shell, and a reaction gas passage 51 is formed between the inner cylinder 41 and the reaction cavity shell, as shown, the inner cylinder 41 is substantially cylindrical, the inner wall of the reaction cavity shell is also substantially cylindrical, and the inner cylinder 41 and the reaction cavity shell are coaxially arranged, so that the reaction gas passage 51 is substantially annular. In addition to the above several parts, the complete MOCVD apparatus also comprises a gas delivery system, a base support, an exhaust gas treatment system, etc. Figures 3-4

[0061] The reaction cavity shell is hollow, so that the inner cylinder 41 can be placed in the reaction cavity shell, and the reaction cavity shell is mainly composed of a cavity wall, which includes an outer shell, an outer cylinder 44 arranged in the outer shell and fixed relative to the outer shell, and a second thermal insulation material 45 arranged between the outer shell and the outer cylinder 44. The outer shell as the outermost layer of the reaction cavity shell includes a first shell 31 and a second shell 32, which can change between a first state of combining with each other to enclose the inner cylinder 41 and a second state of separating from each other to expose the inner cylinder 41, and the first shell 31 and the second shell 32 ensure the sealing of the inside of the reaction cavity shell from the outside environment. Since the outer shell is divided into two parts, correspondingly, the outer cylinder 44 and the second thermal insulation material 45 between the outer shell and the outer cylinder 44 should also be composed of two parts. Optionally, end covers are installed at both ends of the outer cylinder to form a cavity and ensure the air tightness of the inside of the reaction cavity shell.

[0062] ​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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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 for the reaction gas, and each layer of the sleeve passes different gases.

[0069] 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 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.

[0070] 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

[0071] 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.

[0072] 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℃.

[0073] ​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.

[0074] 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.

[0075] 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.

[0076] The heating strips in the application can be designed in series and parallel combination according to process requirements, and the design has the following two advantages: one is that the energy consumption can be reduced to the maximum, and the series-parallel scheme with the least energy consumption is selected for each working condition; the other is that the temperature field uniformity at different positions of the inner cylinder has different requirements, and the design can adjust the electric heating power accordingly. The heating element of the application is arranged in the inner cylinder of the bearing substrate, and the inner and outer cylinders are designed with double heat preservation and insulation structure on both sides to ensure that the heat of the heating element is almost difficult to dissipate to the outside environment, the energy consumption loss of the equipment is reduced to the minimum, and compared with the current traditional MOCVD equipment, the energy consumption is at least reduced by one order of magnitude, from the perspective of operation, the equipment operation cost and substrate epitaxial deposition cost are greatly reduced.

[0077] The transmission mechanism is introduced below, the actuating device 11 is used to drive the inner cylinder 41 to rotate, the transmission mechanism can be a simple transmission shaft or a magnetic coupler, so that the actuating device 11 is in transmission connection with the inner cylinder 41 through the magnetic coupler, as shown in Figure 3 , or the actuating device 11 is in transmission connection with the inner cylinder 41 through the transmission shaft 12, as shown in Figure 23 , the transmission shaft 12 is connected with the rotating shaft 15, and the rotating sealing member 60 is arranged on the part of the transmission shaft 12 penetrating through the reaction cavity shell. The transmission mechanism can also have other structures. The magnetic coupler comprises a driving rotation unit 13 arranged outside the reaction cavity shell and a driven rotation unit 14 arranged inside the reaction cavity shell, the driving rotation unit 13 drives the driven rotation unit 14 in a non-contact manner; the driving rotation unit 13 is connected with the actuating device 11, and the driven rotation unit 14 is connected with the inner cylinder 41.

[0078] As shown in Figure 6 , 7 , the outer periphery of the inner cylinder 41 is provided with a first mounting position 71 for mounting the substrate 72, as shown in Figure 11 , 12 , the inner side (the outer cylinder 44) of the reaction cavity shell is provided with a second mounting position 75 for mounting the substrate 72, specifically, the mounting position is arranged on the surface of the outer cylinder 44 facing the inner cylinder 41, as shown in Figures 8-10 , the outer periphery of the inner cylinder 41 is provided with a first mounting position 71 for mounting the substrate 72, and the inner side (the outer cylinder 44) of the reaction cavity shell is provided with a second mounting position 75 for mounting the substrate 72.

[0079] The number of mounting positions on the inner cylinder 41 or the reaction cavity shell is multiple, and the multiple mounting positions are uniformly distributed, specifically, the multiple mounting positions can be arranged in a matrix type, as shown in Figure 13 , or the multiple mounting positions form multiple rows, and the mounting positions of adjacent rows are arranged staggeredly. Each mounting position can be as shown in Figure 13The fixed recess 64 is shown to function as a fixing function to keep the substrate fixed during rotation of the inner cylinder around the axis.

[0080] In the case of the inner cylinder rotation, the inner cylinder is rotated at a uniform speed during operation to ensure uniformity of the temperature of the large-size cylinder wall, thereby achieving uniformity of 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 selected to be stationary without rotation. The annular reaction gas passage of the cylindrical reaction chamber has a constant cross-sectional area along the flow direction, thereby ensuring uniformity of the gas velocity field. Meanwhile, the inner cylinder carrying the substrate is designed to rotate, which can ensure uniformity of the temperature of the inner cylinder and the substrate surface, as well as 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 thin film deposition reaction gas of the MOCVD equipment, thereby greatly improving the productivity of the MOCVD 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.

[0081] Preferably, the distribution density or power density of the heating element is greater at a position close to the gas inlet or gas outlet than at a position away from the gas inlet or gas outlet. Referring to Figure 9 、 10 The distribution density of the second heating element 73 is greater near the positions of the gas inlet and gas outlet (the gas inlet element 52 and the gas outlet element 53) than at other positions, because the temperature of the substrate 72 on the outer cylinder 44 near the gas inlet is lower due to the lower temperature of the gas inlet in some schemes, and therefore special heating elements need 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 uniformity of the temperature in the 360° circumferential direction of the entire outer cylinder. Due to the small size of the annular reaction gas passage, the overall temperature difference between the inner and outer cylinders is not large, and the outer cylinder can be arranged with or without an outer cylinder heating element according to the temperature requirement, or only arranged with an outer cylinder heating element in a local part (as shown in Figure 10 The inner and outer cylinders are both 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 outer cylinder substrate.

[0082] 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.

[0083] Figure 14 , 15 The embodiment illustrates the structure of the reaction chamber shell's wall. The reaction chamber shell's wall consists of an outer shell (first shell 31 and second shell 32), an outer cylinder 44, and a second heat-insulating material 45 disposed between them. In addition, the reaction chamber shell's wall also includes a support cylinder 57 disposed between the outer shell and the outer cylinder 44. The support cylinder 57 is provided with a flange 59, which fixes it to the outer shell. Multiple 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 are evenly distributed circumferentially along the reaction chamber shell. The support cylinder 57 and support rods 58 are provided to prevent the outer cylinder from directly contacting the outer shell (first shell 31 and second shell 32) of the reaction chamber shell when fixing it. Since the temperature of the outer cylinder is very high, exceeding 1200°C, direct contact would result in significant heat transfer. Therefore, the support cylinder 57 and support rods 58 are used to reduce heat transfer while fixing the outer cylinder.

[0084] exist Figure 14 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.

[0085] Figure 16 The embodiment of the MOCVD equipment for preheating the reaction gas is given, wherein the structure of the reaction cavity shell is the same as Figure 14 The MOCVD equipment includes a heat exchanger 124 arranged on a gas supply pipeline 127 communicated with the gas inlet and an exhaust pipeline 125 communicated with the gas outlet, the gas supply pipeline 127 is provided with a flow valve 126 for controlling the flow of the reaction gas supplied into the reaction cavity shell, and the exhaust pipeline 125 is provided with a pressure control valve 123. The exhaust pipeline 125 is sequentially provided with a filter 122, a gas storage tank 121 and the pressure control valve 123 along the exhaust direction upstream of the heat exchanger 124, and downstream of the heat exchanger 124, the exhaust pipeline 125 is connected with a tail gas treatment unit 128.

[0086] The working principle and use process of the MOCVD equipment for preheating the reaction gas are as follows: in use, the reaction gas enters the heat exchanger 124 from the gas supply pipeline 127, is heated in the heat exchanger 124, and then enters the gas inlet element 52 after the flow and pressure are controlled by the flow valve 126, starts to react in the vapor deposition reaction cavity shell, and after the gas in the vapor deposition reaction cavity shell completes the reaction and is discharged through the gas outlet element 53, does not directly enter the tail gas treatment system 128, but first enters the filter 122 to filter out solid particles, then enters the gas storage tank 121, and then enters the heat exchanger 124 as the hot side gas through the pressure control valve 123, heats the cold side gas entering from the gas supply pipeline 127, and transfers the high temperature excess heat of about 1000 degrees to the cold side gas, so that the cold side gas in the heat exchanger 124 can be preheated to a higher temperature, thereby greatly reducing the heating power of the late heating element, greatly reducing the energy consumption of the MOCVD equipment, and reducing the overall operation cost; the application utilizes the heat energy of the exhaust gas in the vapor deposition reaction cavity shell to heat the normal temperature reaction gas, preheats the reaction gas to 200℃, and according to the process requirements, can also reach a higher temperature, reduces the temperature difference between the gas and the inner cylinder, which is very beneficial to improve the uniformity of the inner cylinder temperature.

[0087] Figures 17-21The heating elements in the different embodiments are arranged in different forms, different distribution densities or different power densities in at least two regions. 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 far 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 inner cylinder 41 along the longitudinal axis and at the position close to the center of the longitudinal axis of the inner cylinder 41. For example, the heating elements are arranged inside the inner cylinder 41, and the inside of the inner cylinder 41 includes a first region close to the center of the longitudinal axis of the inner cylinder 41 and two second regions close to the two ends of the inner cylinder 41 along the longitudinal axis, and the heating elements have different forms and arrangements in the first region and the second region.

[0088] In Figures 17-19 In the embodiment, the rotating shaft 15 is arranged on the two ends of the inner cylinder 41 along the longitudinal axis, the rotating shaft 15 does not pass through 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 can rotate together with the rotating shaft 15. The heating elements are fixedly arranged inside the inner cylinder 41, and the heating elements include a first heating element 43 and an annular heating band 47, the first heating element 43 is arranged in the first region and is designed as 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 the annular heating band 47 is arranged in the second region and has an axis parallel to the longitudinal axis of the inner cylinder 41. An end heat insulation material 48 is arranged outside the annular heating band 47, two are axially installed, the end heat insulation material 48 is vertically located at the two ends of the inner cylinder and tightly fits with the end cover of the inner cylinder, and can be connected together through a mechanical device. The end heat insulation material 48 can be composed of one to multiple layers of heat insulation materials or radiation heat shields, and each layer has an optimal heat insulation thickness at a temperature resistant temperature through optimized design. The annular heating band 47 is located between the end heat insulation material 48 and the heating strips and has a certain spacing from both, and the spacing can be determined according to the simulation calculation result. In addition, in the figure, the heating strips are arranged in a single row, but they can also be arranged in multiple rows.

[0089] The plurality of heating strips and the annular heating band can be fixed in various ways inside the inner cylinder 41 and rotate with the inner cylinder 41, for example, the plurality of heating strips are fixed on the inner circumferential surface of the inner cylinder 41, or the annular heating band is fixed on the inner circumferential surface of the inner cylinder 41 or fixed on the two ends of the inner cylinder 41 along the longitudinal axis or fixed on the end heat 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 of the two ends of the inner cylinder and the middle position is small, and the deposition of the epitaxial wafer at the two ends is also of high quality.

[0090] In Figures 20-21 The form, combination and position of the heating elements in the embodiment are the same as those in the previous embodiment, including a plurality of heating strips and an annular heating band, but their support and fixation are different. The center support shaft 55 penetrates the center of the inner cylinder 41 and extends from the two ends of the inner cylinder 41 along the longitudinal axis, and the center support shaft 55 is configured to be fixed relative to the reaction cavity shell, so that the inner cylinder 41 can rotate relative to the center support shaft 55, for example, the center support shaft 55 is directly fixed on the outer shell of the reaction cavity shell, and the center support shaft 55 is supported in the center of the rotating shaft 15 through a bearing, so that the rotating shaft 15 can rotate around the center support shaft 55; the plurality of heating strips and the annular heating band are fixed through the center support shaft 55, so that the plurality of heating strips and the annular heating band do not rotate with the inner cylinder 41 during the operation of the MOCVD equipment.

[0091] A plurality of center support rings 49 are arranged on the center support shaft 55, and a plurality of heating element support rods 46 extending radially along the center support ring 49 are arranged on each center support ring 49, and the plurality of heating element support rods 46 are uniformly distributed along the circumference of the center support ring 49; the plurality of heating strips and the annular heating band are directly or indirectly fixed on the ends of the heating element support rods 46 away from the center support ring 49. 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 the annular heating band are fixed on the fixing plates by screws, and the fixing plates and the 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 band 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 The form, combination and position of the heating elements in the embodiment are the same as those in the previous embodiment, including a plurality of heating strips and an annular heating band, but their support and fixation are different. The center support shaft 55 penetrates the center of the inner cylinder 41 and extends from the two ends of the inner cylinder 41 along the longitudinal axis, and the center support shaft 55 is configured to be fixed relative to the reaction cavity shell, so that the inner cylinder 41 can rotate relative to the center support shaft 55, for example, the center support shaft 55 is directly fixed on the outer shell of the reaction cavity shell, and the center support shaft 55 is supported in the center of the rotating shaft 15 through a bearing, so that the rotating shaft 15 can rotate around the center support shaft 55; the plurality of heating strips and the annular heating band are fixed through the center support shaft 55, so that the plurality of heating strips and the annular heating band do not rotate with the inner cylinder 41 during the operation of the MOCVD equipment. Figure 18The embodiments shown are different, the heating elements in the inner cylinder 41 are all composed of annular heating strips, a certain distance is left between two adjacent annular heating strips, the size and heating power of the annular heating strips can be adjusted according to process requirements. The annular heating strips can be designed in zones according to the temperature uniformity of the inner cylinder, which can be divided into middle zone and edge zone in the axial direction. Because the heat loss is different at the edge and the middle, different power can be loaded in different zones, and through the axial different zones, the surface temperature of the inner cylinder is more uniform, and the surface temperature difference of the substrate at both ends and the middle 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 gas inlet, because the gas 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 whole reaction chamber.

[0094] In addition, in the case that 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, the plurality of heating strips and / or annular heating strips can also be directly fixed on the rotating shaft 15.

[0095] As shown in Figure 22 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. The rotating shaft 15 is a hollow rotating shaft, and the double-layer water cooling channel exists in the form of a double-layer water cooling pipe 66 which is arranged in the hollow part of the rotating shaft 15.

[0096] As shown in Figure 24 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 collector ring 69 is arranged at the end of the rotating shaft 15, the current collector ring 69 is connected with the external power supply through a wire 70, and the first heating element 43 is connected with the current collector ring 69 through a wire penetrating the center of the rotating shaft 15, so as to realize dynamic and static conversion.

[0097] Although the embodiments of the present application have been shown and described, it can be understood by those skilled in the art that changes can be made in these embodiments without departing from the principles and spirit of the present application. The scope of application of the present application is defined by the appended claims and their equivalents.

Claims

1. An MOCVD apparatus for preheating reactant gases, characterized in that, The MOCVD device comprises: a reaction cavity shell for providing an environment for chemical reaction of reaction gas; a gas inlet and a gas outlet for supplying reaction gas into the reaction cavity shell and discharging gas from 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 MOCVD device is configured to enable relative rotation between the inner cylinder (41) and the reaction cavity shell; and the reaction cavity shell is provided with a gas inlet element (52), a gas outlet element (53) and a partition element (54); the partition element (54) is located in the reaction gas passage (51) between the gas inlet element (52) and the gas outlet element (53); the gas inlet element (52) and the gas outlet element (53) are arranged adjacent in the circumferential direction of the reaction cavity shell; the partition element (54) has a gap between the inner cylinder (41); gas holes are arranged on both sides of the partition element (54), and carrier gas is injected into the gas holes to form a gas barrier layer; the part of the gas inlet element (52) extending into the reaction gas passage (51) comprises 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; wherein the MOCVD device is configured to preheat the reaction gas before entering the reaction cavity shell through the gas inlet.

2. The reaction gas preheating MOCVD device according to claim 1, wherein: 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 device; or the 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 device; or the 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.

3. The reaction gas preheating MOCVD device according to claim 1, wherein: the MOCVD device further comprises a heat exchanger (124) arranged on a gas supply pipeline (127) communicating with the gas inlet and a gas discharge pipeline (125) communicating with the gas outlet.

4. The reaction gas preheating MOCVD device according to claim 3, wherein: a flow valve (126) is arranged on the gas supply pipeline (127) for controlling the flow of reaction gas supplied into the reaction cavity shell; and / or a pressure control valve (123) is arranged on the gas discharge pipeline (125).

5. The reaction gas preheating MOCVD device according to claim 3, wherein: ​ A filter (122) and / or a gas storage tank (121) are arranged on the exhaust pipe (125) upstream of the heat exchanger (124). 6.The MOCVD device for preheating reaction gas according to claim 3, wherein: A filter (122), a gas storage tank (121) and a pressure control valve (123) are sequentially arranged on the exhaust pipe (125) along the exhaust direction. 7.The MOCVD device for preheating reaction gas according to claim 3, wherein: Downstream of the heat exchanger (124), the exhaust pipe (125) is connected with a tail gas treatment unit (128). 8.The MOCVD device for preheating reaction gas according to any one of claims 1-7, wherein: An air inlet element (52) is arranged on the air inlet, and the air inlet element (52) is configured to guide the reaction gas into the reaction gas channel (51) and flow along the reaction gas channel (51) to the air outlet. 9.The MOCVD device for preheating reaction gas according to claim 8, wherein: The number of the air inlet elements (52) is multiple, the air outlets of the multiple air inlet elements (52) are located in the reaction gas channel (51), and the multiple air inlet elements (52) are uniformly distributed along the longitudinal axis direction of the inner cylinder (41).

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