CN117966122A

CN117966122A - Positive pressure difference MOCVD equipment and positive pressure difference MOCVD method

Info

Publication number: CN117966122A
Application number: CN202410269427.5A
Authority: CN
Inventors: 徐国强; 张丽娜; 闻洁
Original assignee: Hangzhou Longsheng Extension Technology Co ltd
Current assignee: Hangzhou Longsheng Extension Technology Co ltd
Priority date: 2024-03-10
Filing date: 2024-03-10
Publication date: 2024-05-03

Abstract

The invention provides a positive pressure difference MOCVD device, comprising: a decompression chamber (61), the decompression chamber (61) being configured to be able to provide an environment below atmospheric pressure; a reaction chamber housing disposed in the decompression chamber (61) for providing an environment in which a reaction gas is chemically reacted; an air inlet and an air outlet for supplying and exhausting a reaction gas into and from the reaction chamber housing, respectively; and an inner working unit disposed within the reaction chamber housing and forming a reaction gas passage (51) therebetween, wherein the MOCVD apparatus is configured to enable a first pressure within the reaction chamber housing to be higher than a second pressure within the decompression chamber (61), and both the first pressure and the second pressure are lower than an atmospheric pressure. The invention also provides a positive pressure difference MOCVD method. The positive pressure difference MOCVD equipment and the method can avoid the waste of raw material gas, ensure that no external impurity gas enters the reaction cavity shell, improve the deposition quality of semiconductor devices and increase the productivity.

Description

Positive pressure difference MOCVD equipment and positive pressure difference MOCVD method

Technical Field

The invention relates to the technical field of semiconductors, in particular to a semiconductor epitaxial thin film vapor deposition technology, and specifically relates to positive pressure difference MOCVD equipment and a positive pressure difference MOCVD method.

Background

Metal organic chemical vapor deposition, MOCVD (Metalorganic Chemical Vapor Deposition), is a key technology for preparing compound semiconductor thin films, and is widely used in the semiconductor field and the photovoltaic field. And introducing a III-group organic metal reactant and a V-group hydride into MOCVD equipment, heating to enable the III-group organic metal reactant and the V-group hydride to react chemically, and depositing a reaction product of the III-group organic metal reactant and the V-group hydride on a heated substrate to generate a required product, namely a III-group compound film and a V-group compound film.

MOCVD technology is commonly implemented using MOCVD reactors, and existing typical commercial MOCVD reactors include planetary reactors, vertical spray MOCVD reactors, and high-speed rotating MOCVD reactors. The main working principle of the vertical spray type MOCVD reactor is that a spray header is used for uniformly spraying reaction gas (mixed gas of III family organic metal reactant and V family hydride), so that the reaction gas reacts on a heated substrate, and the reaction gas which completes chemical reaction grows a required compound film on the substrate; the reaction gas which does not participate in the reaction and the product gas are discharged out of the MOCVD reactor as waste gas; for the planetary reactor, a rotatable graphite base is arranged in a reaction chamber, the graphite base is disc-shaped, a plurality of substrates form a group, a plurality of substrate groups are circumferentially and uniformly arranged on the graphite base, the graphite base can revolve, each substrate group rotates at the same time, III-group and V-group reactants enter from the center of an upper cover and horizontally flow along the annular space between the graphite base and a ceiling in a radial mode through a grid, and the uniform growth speed of each substrate surface is obtained by utilizing rotation and revolution.

The equipment commonly used in MOCVD at present needs to continuously extract a large amount of reaction gas into the external environment so as to maintain a stable low-pressure environment of the reaction chamber, but this causes waste of raw material gas (i.e. MO source), and because the pressure of the reaction chamber is lower than the external environment, the external impurity gas in the reaction chamber is at risk of entering the polluted reaction gas. At the same time, low pressure reaction chambers often require more complex process designs and control systems to ensure their stability and safety. The above cases greatly increase the manufacturing and operating costs of the MOCVD apparatus.

The existing MOCVD reaction chamber mostly adopts a static design, namely, the reaction chamber always keeps a static state in the running process of equipment. However, the cross-sectional area of the gas channel can be changed in the flowing process of the gas, the uniformity of the flow field and the speed field of the gas flow cannot be ensured, the along-path loss of the concentration of the reaction gas is obvious, and the concentration of the reaction gas reaching the substrate can not be ensured to be consistent everywhere, so that the uniformity of the thickness and the uniformity of components of the compound film growing on the substrate are seriously influenced, and the yield of the compound film product is reduced.

In addition, the requirements of the semiconductor film deposition on the temperature field, the speed field and the concentration field of the reaction gas are higher, and the requirements of multi-field uniformity are still continuously improved along with the improvement of the performance requirements of semiconductor chips. Meanwhile, the demand of the semiconductor industry for a large-area, high-productivity and high-quality thin film deposition apparatus is urgent. The limitation of the existing reaction chamber structure is that it is difficult to increase the productivity because the size of the reaction chamber needs to be increased to increase the productivity, and the uniformity of the temperature field, the velocity field and the concentration field is reduced with the increase of the size of the reaction chamber, so that it is very difficult to achieve higher productivity.

First, the increasing size of the susceptor of current conventional MOCVD reactor presents challenges for temperature uniformity. In the reaction chamber, a stable high temperature environment is required to promote epitaxial film growth, and as the disc-shaped susceptor increases in size, the temperature distribution in the reaction chamber becomes more and more uneven, resulting in an increase in the temperature gradient during growth. Thus, epitaxial growth uniformity is more sensitive to susceptor size, and on smaller susceptors, epitaxial film growth is relatively easy to achieve uniformity, while as susceptor size increases, epitaxial film distribution on the susceptor surface becomes more complex, which can result in uneven deposition thickness and material composition distribution, thereby affecting device performance and uniformity.

Secondly, in the MOCVD film growth process, the requirement on gas component control is very high, and the composition and flow uniformity of the gas play an important role in the reaction rate and material transportation in the film growth process. The increased dimensions of the susceptor result in greater and greater uniformity of the distribution of the gas flow of the central inlet gas at different diameters of the susceptor, thereby affecting the atmosphere control during material growth, which can lead to non-uniformity in the quality of the grown material, and thus device performance.

In summary, with the existing MOCVD equipment, the capacity of the MOCVD equipment can be increased by increasing the size of the susceptor, but with problems of flow uniformity, temperature uniformity, gas composition control, etc., the increase in the capacity obtained is limited.

Disclosure of Invention

The invention aims to at least partially overcome the defects of the prior art and provide a novel MOCVD equipment. The object of the present invention may be plural, but it is not intended to solve all problems, and achieve all objects, and the object of the present invention is achieved by solving one of the technical problems.

The invention also aims to provide the positive pressure difference MOCVD equipment and the positive pressure difference MOCVD method, which can avoid the waste of raw material gas.

The invention also aims to provide the positive pressure difference MOCVD equipment and the positive pressure difference MOCVD method, which can ensure that no external impurity gas enters the reaction cavity shell and improve the cleanliness in the reaction cavity shell.

The invention also aims to provide a positive pressure difference MOCVD device and a positive pressure difference MOCVD method, which have improved temperature uniformity, gas flow uniformity and/or gas concentration uniformity.

The invention also aims to provide the positive pressure difference MOCVD equipment and the positive pressure difference MOCVD method, which can improve the deposition quality of the semiconductor device.

The invention also aims to provide the positive pressure difference MOCVD equipment and the positive pressure difference MOCVD method, and the equipment can be used for increasing the productivity, or can obtain high-quality and high-performance deposition products and simultaneously easily increase the productivity.

In order to achieve one of the above objects or purposes, the technical solution of the present invention is as follows:

a positive pressure differential MOCVD tool, said MOCVD tool comprising:

A decompression chamber configured to be capable of providing an environment below atmospheric pressure;

the reaction cavity shell is arranged in the decompression chamber and is used for providing an environment for chemical reaction of the reaction gas;

an air inlet and an air outlet for supplying and exhausting a reaction gas into and from the reaction chamber housing, respectively; and

An inner working unit arranged in the reaction chamber shell, and a reaction gas channel is formed between the inner working unit and the reaction chamber shell,

Wherein the MOCVD apparatus is configured to enable a first pressure within the reaction chamber housing to be higher than a second pressure within the depressurization chamber, and both the first pressure and the second pressure are lower than atmospheric pressure.

According to a preferred embodiment of the present invention, the inner working unit includes an inner cylinder, and the MOCVD equipment is configured such that the inner cylinder and the reaction chamber housing can be relatively rotated.

According to a preferred embodiment of the present invention, the inner cylinder is configured to be rotatable about a longitudinal axis of the inner cylinder, and the reaction chamber shell is configured to remain stationary during operation of the MOCVD tool; or alternatively

At least a portion of the reaction chamber housing is configured to be rotatable about a longitudinal axis of the reaction chamber housing, and the inner barrel is configured to remain stationary during operation of the MOCVD tool; or alternatively

At least a portion of the reaction chamber housing and the inner tube are configured to be rotatable simultaneously, but the rotational direction or rotational speed of the inner tube and the reaction chamber housing is different.

According to a preferred embodiment of the present invention, the MOCVD equipment further comprises a first vacuum pump in fluid communication with the decompression chamber for generating and maintaining the second pressure in the decompression chamber.

According to a preferred embodiment of the present invention, the MOCVD equipment further comprises a first vacuum pump and a second vacuum pump, the first vacuum pump being in fluid communication with the decompression chamber for causing the decompression chamber to generate and maintain the second pressure; the second vacuum pump is in fluid communication with the reaction chamber formed by the reaction chamber housing for generating and maintaining a first pressure in the reaction chamber.

According to a preferred embodiment of the present invention, the reaction chamber housing includes a first housing and a second housing, which are changeable between a first state of being coupled to each other to close the inner cylinder and a second state of being separated from each other to expose the inner cylinder; and

A seal assembly is disposed between the first housing and the second housing.

According to another aspect of the present invention, there is provided a positive pressure differential MOCVD method using the positive pressure differential MOCVD apparatus according to any of the previous embodiments, the MOCVD method comprising:

Generating a second pressure within the depressurization chamber that is lower than atmospheric pressure; and

A first pressure is generated within the reaction chamber housing that is lower than atmospheric pressure but higher than a second pressure.

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

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

The reaction chamber housing is maintained at a first pressure higher than a second pressure by supplying a reaction gas into the reaction chamber housing.

According to a preferred embodiment of the present invention, the MOCVD method further comprises: before the second pressure lower than the atmospheric pressure is generated in the decompression chamber, the reaction chamber shell is in an unsealed state; and closing the reaction chamber shell after generating a second pressure lower than the atmospheric pressure in the depressurization chamber; or alternatively

The MOCVD method further comprises the following steps: the reaction chamber shell is closed before a second pressure below atmospheric pressure is generated within the depressurization chamber and then depressurized to a pressure below atmospheric pressure using a separate vacuum pump.

According to the positive pressure differential MOCVD apparatus and method of the present invention, the reaction chamber shell is disposed in the decompression chamber, and the pressure in the reaction chamber shell is slightly higher than the pressure in the decompression chamber, so that the reaction chamber shell is under the working pressure (lower than the atmospheric pressure), but the micro positive pressure is maintained, higher than the pressure in the decompression chamber outside the reaction chamber shell. Therefore, the low-pressure state of the reaction chamber shell can be maintained without continuously exhausting air from the reaction chamber shell like the prior art, and the low-pressure state of the reaction chamber shell can be maintained only by exhausting air in the decompression chamber, so that the waste of raw material gas is reduced, and meanwhile, the external impurity gas can be prevented from entering the reaction chamber shell due to micro positive pressure, namely, the pressure in the reaction chamber shell is slightly higher than the pressure in the decompression chamber, the cleanliness in the reaction chamber shell is improved, and the compound film with high yield can be obtained.

Further, in the MOCVD apparatus and method of the present invention, the inner cylinder is provided in the reaction chamber housing, the reaction gas passage is formed between the inner cylinder and the reaction chamber housing, the reaction gas passage having a constant cross section is easily obtained based on the shapes of the inner cylinder and the inner wall surface of the reaction chamber housing, and therefore, the reaction gas supplied into the reaction gas passage through the gas inlet can maintain a uniform velocity field and concentration field, and the layout of the heating element in the circumferential direction in the inner cylinder or the cavity wall of the reaction chamber housing is also easily obtained with a uniform temperature field, and therefore, the positive pressure MOCVD apparatus and method of the present invention has improved temperature uniformity, gas flow uniformity and/or gas concentration uniformity, and thus can improve the deposition quality of the semiconductor device. More importantly, the inner cylinder and the reaction cavity shell are coaxially arranged, the increase of the productivity can be easily realized by increasing the axial and radial dimensions of the equipment (the area capable of bearing the substrate is increased), and the increase of the size of the equipment has no influence on the uniformity of the speed field, the concentration field and the temperature field of the gas in the reaction cavity shell, so that the problem that the mass production of epitaxial equipment in the semiconductor industry is limited at present can be well solved. Therefore, the positive pressure differential MOCVD apparatus and method of the present invention can increase productivity and can simultaneously ensure high quality and high performance of deposited products.

The positive pressure difference MOCVD equipment provided by the invention can provide a very large-scale and expandable reaction cavity shell, realize high-yield and high-quality chemical reaction, expand the axial length dimension and diameter of the reaction cavity shell according to the yield requirement, and ensure the uniformity of a speed field, a temperature field and a flow field in the reaction cavity shell.

Drawings

FIG. 1 is a schematic cross-sectional view of a planetary reaction chamber of the prior art;

FIG. 2 is a top view of a graphite susceptor of the planetary reaction chamber of FIG. 1;

FIG. 3 is a schematic cross-sectional view of a positive pressure differential MOCVD apparatus according to one embodiment of the present invention;

FIG. 4 is a B-B cross-sectional view of the positive pressure differential MOCVD apparatus of FIG. 3;

Fig. 5 shows an MOCVD tool according to another embodiment of the present invention, corresponding to fig. 4, but with the decompression chamber removed;

FIG. 6 is a schematic cross-sectional view of a positive pressure differential MOCVD apparatus according to one embodiment of the present invention;

FIG. 7 is a schematic cross-sectional view of an MOCVD apparatus according to an embodiment of the present invention, wherein the substrate is mounted on the outer circumference of the inner cylinder;

FIG. 8 is a C-C cross-sectional view of the MOCVD apparatus of FIG. 7;

FIG. 9 is a schematic cross-sectional view of an MOCVD apparatus according to an embodiment of the present invention, wherein the substrate is mounted on the outer circumference of the inner cylinder and the inner side of the reaction chamber housing at the same time;

FIG. 10 is a D-D sectional view of the MOCVD apparatus of FIG. 9;

FIG. 11 shows an MOCVD apparatus according to another embodiment of the present invention, corresponding to FIG. 10, but with a second heating element having a different arrangement;

FIG. 12 is a schematic cross-sectional view of an MOCVD apparatus according to an embodiment of the present invention, wherein the substrate is mounted on the inner side of the reaction chamber housing;

FIG. 13 is an E-E cross-sectional view of the MOCVD apparatus of FIG. 12;

FIG. 14 shows one arrangement of mounting locations on the outer cartridge for mounting substrates;

FIG. 15 shows a securing means for securing a substrate on an inner barrel;

FIG. 16 is a schematic cross-sectional view of an MOCVD apparatus according to an embodiment of the present invention;

FIG. 17 is a schematic cross-sectional view of an MOCVD apparatus according to an embodiment of the present invention;

FIG. 18 is a G-G cross-sectional view of the MOCVD apparatus of FIG. 17;

FIG. 19 is a schematic cross-sectional view of an MOCVD apparatus according to an embodiment of the present invention;

FIG. 20 is a H-H cross-sectional view of the MOCVD apparatus of FIG. 19;

FIG. 21 is a schematic cross-sectional view of a spindle of a MOCVD apparatus according to an embodiment of the present invention;

FIG. 22 is a schematic cross-sectional view of an MOCVD apparatus according to an embodiment of the present invention;

FIG. 23 is a schematic cross-sectional view of an MOCVD apparatus according to an embodiment of the present invention;

fig. 24 is a schematic cross-sectional view of an MOCVD tool according to one embodiment of the present invention.

List of reference numerals:

11 actuation means; 12 transmission shafts; 13 an active rotation unit; 14a driven rotation unit; a 15-axis rotation; a 16 bearing; 17 a support element; 31 a first housing; 32 a second housing; 41 inner cylinder; 42a first insulating material; 43 a first heating element; 44 an outer cylinder; 45 a second insulating material; 46 heating element support rods; 47 an annular heating belt; 48 end insulation; 49 a central support ring; 50 fixing the assembly; 51a reaction gas channel; 52 an air intake element; 53 exhaust element; 54 a separation element; 55 a central support shaft; 56 insulating sheets; 57 a support cylinder; 58 struts; 60 rotating the seal; 61 decompression chamber; a first vacuum pump 62; 63 a second vacuum pump; 64 fixing grooves; 65 clamping devices; 66 double-layer water cooling pipes; 67 outside channels; 68 an inboard channel; 69 collector rings; 70 wires; 71 a first mounting location; a 72 substrate; 73 a second heating element; 74 heating element fixing portion; 75 a second mounting location; 97 base; 98 support frames; 101 a lifting assembly; 102 a first housing coupling member; 103 a second housing coupling member.

Detailed Description

Exemplary embodiments of the present invention are described in detail below with reference to the attached drawing figures, wherein the same or similar reference numerals denote the same or similar elements. Furthermore, in the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. It may be evident, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are shown in the drawings in order to simplify the drawings.

Fig. 3 and 4 show the basic structure of a positive pressure differential MOCVD equipment according to an embodiment of the present invention, and as shown, the positive pressure differential MOCVD equipment mainly includes a decompression chamber 61, a reaction chamber housing, an air inlet and outlet port, an inner cylinder 41, an actuating means 11, and a transmission mechanism. The decompression chamber 61 is configured to be capable of providing an environment lower than atmospheric pressure, and the reaction chamber housing is provided in the decompression chamber 61 for providing an environment in which a chemical reaction of a reaction gas occurs, typically, the environment is a high-temperature, low-pressure environment; the inner tube 41 is disposed in the reaction chamber housing, and a reaction gas channel 51 is formed between the inner tube 41 and the reaction chamber housing, as shown in fig. 3 to 4, the inner tube 41 is substantially cylindrical, and the inner wall surface of the reaction chamber housing is also substantially cylindrical, and the inner tube 41 and the reaction chamber housing are coaxially arranged, so that the reaction gas channel 51 is substantially annular. In addition to the above parts, the complete MOCVD apparatus also includes a gas delivery system, a base support, an exhaust gas treatment system, and the like.

The reaction chamber housing is hollow, so that the inner cylinder 41 can be placed in the reaction chamber housing, and the reaction chamber housing is mainly composed of a chamber wall, wherein the chamber wall comprises: a housing; an outer cylinder 44 provided in the housing and fixed with respect to the housing; and a second heat insulating material 45 provided between the housing and the outer cylinder 44. The outer case, which is the outermost layer of the reaction chamber case, includes a first case 31 and a second case 32, the first case 31 and the second case 32 being changeable between a first state of being coupled to each other to close the inner tube 41 and a second state of being separated from each other to expose the inner tube 41, the first case 31 and the second case 32 ensuring sealability of the reaction chamber case interior from the external environment. Since the outer shell is divided into two parts, the outer shell 44 and the second insulation material 45 between the outer shell and the outer shell 44 should also be composed of two parts, accordingly. Optionally, end covers are arranged at two ends of the outer cylinder to form a cavity, so that the air tightness inside the reaction cavity shell is ensured.

The main reaction equipment of the MOCVD equipment is all positioned in the decompression chamber 61, the decompression chamber 61 is externally exhausted through a vacuum pump, so that the inside reaches lower pressure, and the pressure is controlled to be the optimal pressure environment required by the epitaxial process. In particular, the MOCVD equipment is configured to enable a first pressure inside the reaction chamber shell to be higher than a second pressure inside the decompression chamber 61, and both the first pressure and the second pressure are lower than the atmospheric pressure. The MOCVD equipment further comprises a first vacuum pump 62, the first vacuum pump 62 being in fluid communication with the decompression chamber 61 for causing the decompression chamber 61 to generate and maintain a second pressure, as shown in fig. 3.

Correspondingly, the invention also provides a positive pressure difference MOCVD method, and the positive pressure difference MOCVD equipment is used, and the MOCVD method comprises the following steps: a second pressure lower than the atmospheric pressure is generated in the decompression chamber 61; and causing a first pressure to be generated within the reaction chamber housing that is lower than the atmospheric pressure but higher than the second pressure. Here, the first pressure is at least 200Pa or 300Pa higher than the second pressure. Continuously pumping the decompression chamber 61 during the operation of the MOCVD equipment to maintain the second pressure in the decompression chamber 61; and maintaining a first pressure higher than a second pressure in the reaction chamber housing by supplying a reaction gas into the reaction chamber housing. With the above-described apparatus, the MOCVD method can place the reaction chamber shell in an unsealed state before the second pressure lower than the atmospheric pressure is generated in the decompression chamber 61; then, after the second pressure lower than the atmospheric pressure is generated in the decompression chamber 61, the reaction chamber housing is closed, so that the reaction chamber housing obtains a proper working pressure while the decompression chamber is caused to generate the working pressure, and when the MOCVD equipment is operated, the reaction chamber housing naturally forms the first pressure higher than the second pressure due to the supply of the reaction gas into the reaction chamber housing.

FIG. 6 provides an alternative embodiment of a positive pressure differential MOCVD apparatus wherein the MOCVD apparatus is provided with separate vacuum pumps for the reaction chamber housing, i.e. the MOCVD apparatus comprises a first vacuum pump 62 and a second vacuum pump 63, the first vacuum pump 62 being in fluid communication with the decompression chamber 61 for causing the decompression chamber 61 to generate and maintain the second pressure; the second vacuum pump 63 is in fluid communication with the reaction chamber formed by the reaction chamber housing for generating and maintaining a first pressure in the reaction chamber. With the apparatus of fig. 6, the reaction chamber housing may be closed before the second pressure lower than the atmospheric pressure is generated in the decompression chamber 61, and then the reaction chamber housing may be decompressed to a pressure lower than the atmospheric pressure using a separate second vacuum pump.

At least the portions of the inner cylinder 41 or the reaction chamber housing facing each other include a graphite material, or a tungsten material, or a molybdenum material, surface-coated with a SiC coating. For the inner cylinder 41 and the outer cylinder 44 to resist high temperature, they are usually graphite cylinders coated with SiC coating, or metal materials such as high temperature resistant tungsten, molybdenum and the like can be adopted, and the thickness of the coating can be determined according to the mechanical properties of the materials.

An inlet and an outlet are provided on the reaction chamber housing for supplying and discharging the reaction gas into and from the reaction chamber housing, respectively, in this embodiment an inlet element 52 is provided on the inlet and an outlet element 53 is provided on the outlet, said inlet element 52 and outlet element 53 extending from outside the reaction chamber housing through the chamber wall of the reaction chamber housing into the reaction gas channel 51, said inlet element 52 being configured to guide the reaction gas into the reaction gas channel 51 and along the reaction gas channel 51 to the outlet, as indicated by the arrow in fig. 4, the exhaust gas after reaction in the reaction gas channel 51 being discharged from the outlet element 53. In addition to the gas inlet element 52 and the gas outlet element 53, a partition element 54 is provided on the reaction chamber housing, and the partition element 54 is located in the reaction gas channel 51 between the gas inlet element 52 and the gas outlet element 53 for preventing the back flow of the exhaust gas to the gas inlet side.

As shown in fig. 4, the gas inlet element 52 and the gas outlet element 53 extend into the reaction gas channel 51 from outside the reaction chamber housing through the chamber wall of the reaction chamber housing in the radial direction of the inner cylinder 41, and the gas inlet element 52 and the gas outlet element 53 are disposed adjacently in the circumferential direction of the reaction chamber housing. The gas inlet element 52, the gas outlet element 53, and the partition element 54 between the gas inlet element 52 and the gas outlet element 53 adjacent in the circumferential direction of the reaction chamber housing form a set of venting elements, and in the embodiment of fig. 4, the MOCVD equipment includes only one set of venting elements (full-circle flow). In this group of aeration elements, the outlet of the inlet element 52 may be an elongated outlet, i.e. there is only one inlet element and one outlet located in the reaction gas channel 51 and extending in the direction of the longitudinal axis of the inner cylinder 41, preferably over the entire longitudinal length of the inner cylinder 41, in order to ensure the uniformity of the reaction gas in the reaction gas channel 51. Or alternatively, in the group of ventilation elements, the number of the gas inlet elements 52 may be plural, the gas outlets of the plurality of gas inlet elements 52 are located in the reaction gas passage 51, and the plurality of gas inlet elements 52 are uniformly distributed along the longitudinal axis direction of the inner cylinder 41 so as to ensure uniformity of the reaction gas in the reaction gas passage 51. The exhaust element 53 may have the same form and arrangement as the intake element 52.

The embodiment shown in fig. 4 may be derived from an arrangement of the vent elements, and as such, the inlet element 52, the outlet element 53, and the partition element 54 between the inlet element 52 and the outlet element 53 adjacent in the circumferential direction of the reaction chamber housing form one set of vent elements, and the MOCVD equipment includes a plurality of sets of vent elements, for example, two or three sets, which are uniformly distributed in the circumferential direction of the reaction chamber housing, and if three sets of vent elements are provided on the reaction chamber housing at an angular interval of 120 degrees in the case of three sets, the reaction gas introduced from the inlet element 52 of the first set of vent elements is discharged from the outlet element 53 of the second set of vent elements after flowing through an angle of 120 degrees in the reaction gas passage 51; the reaction gas introduced from the gas inlet element 52 of the second group of ventilation elements flows through an angle of 120 degrees in the reaction gas channel 51 and is discharged from the gas outlet element 53 of the third group of ventilation elements; the reaction gas introduced from the gas inlet element 52 of the third group of ventilation elements flows through an angle of 120 degrees in the reaction gas channel 51 and is discharged from the gas outlet element 53 of the first group of ventilation elements.

Fig. 5 shows an embodiment of another arrangement (half-turn flow) of the intake element 52 and the exhaust element 53, as shown, the intake element 52 comprising a first intake element and a second intake element (intake element 52 on the left and intake element 52 on the right in fig. 5) adjacent in the circumferential direction of the reaction chamber housing, and a partition element 54 being 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 (the left exhaust element 53 and the right exhaust element 53 in fig. 5) that are adjacent in the circumferential direction of the reaction chamber housing, and a partition element 54 is provided between the first exhaust element and the second exhaust element; the intake element 52 and the exhaust element 53 are disposed substantially opposite each other in the radial direction of the reaction chamber housing. In this way, the reactant gas introduced from the first gas inlet element flows through the reactant gas passage 51 at an angle of 180 degrees and is discharged from the first gas outlet element, and the reactant gas introduced from the second gas inlet element flows through the reactant gas passage 51 at an angle of 180 degrees in the opposite direction and is discharged from the second gas outlet element.

The position of the air inlet element 52 can be designed at different positions according to the working environment and specific working conditions, and can be arranged at a position of the lower part of the outer shell of the reaction cavity shell in actual use, so that natural convection in the channel can be restrained. The reaction gas enters the reaction gas channel through the gas inlet element, is heated in the channel and causes chemical reaction to carry out film deposition. Since the sectional area of the passage in the process of flowing the reaction gas remains unchanged, the uniformity of the flow of the gas is very good. Since the inner tube and the reaction chamber housing can rotate relatively, when the inner tube 41 rotates, a gap is provided between the partition member 54 and the inner tube 41, which is a minute gap, so as to prevent the inner tube from being affected by the rotation. The separating element 54 may be a thin wall baffle, and is fixed on the outer cylinder, and the separating element 54 is used for preventing air intake and exhaust from being mixed. In a preferred embodiment, the divider member 54 may be provided with air holes on both sides thereof, into which a carrier gas (nitrogen) is injected at a certain velocity to form a gas barrier. On one hand, the air hole at the air inlet side is used for blocking the flow of the air inlet flow to the direction of the air outlet flow, so that the waste of an organic metal source is avoided; on the other hand, the air hole at the exhaust side is used for blocking the flow of exhaust air flow to the direction of inlet air flow, so that the source gas is prevented from being polluted.

Advantageously, the channels at the outlet of the inlet element 52 are curved with respect to the axial direction of the inlet element 52, so that the flow direction of the reactive gases supplied from the outlet is substantially tangential to a circle centered on a point on the longitudinal axis of the inner cylinder 41, furthermore the inlet element 52 is an inlet element with multiple channels, which are present in the form of a sleeve. The multiple channels are three or more channels because the reactant gas has multiple gases, with each layer of the sleeve running a different gas.

Further, the portion of the gas inlet element 52 protruding into the reaction gas channel 51 includes a radial section and a bent section bent with respect to the radial section; the bending section is provided with a first air outlet and a second air outlet, the flowing direction of the reaction gas supplied from the first air outlet is approximately tangential to a circle taking a point on the longitudinal axis of the inner cylinder 41 as a center, and the flowing direction of the reaction gas supplied from the second air outlet is approximately directed to the longitudinal axis of the inner cylinder 41 to form an air curtain. The exhaust gas is prevented from leaking to the air intake portion by these nozzles (second air outlets) whose air intake side is vertically downward, and an air curtain is formed to block the exhaust gas from entering the air intake side from the gap of the partition member 54.

Advantageously, the MOCVD apparatus is configured to enable relative rotation between the inner barrel 41 and the reaction chamber housing. This relative rotation may be achieved in several ways: the inner cylinder 41 is configured to be rotatable about a longitudinal axis of the inner cylinder 41, and the reaction chamber housing is configured to remain stationary during operation of the MOCVD apparatus; or at least a portion of the reaction chamber housing (outer cylinder or entire reaction chamber housing) is configured to be rotatable about a longitudinal axis of the reaction chamber housing, and the inner cylinder 41 is configured to remain stationary during operation of the MOCVD tool; or at least a part of the reaction chamber housing (the outer cylinder or the entire reaction chamber housing) and the inner cylinder 41 are configured to be rotatable at the same time, but the rotation direction or rotation speed of the inner cylinder 41 and the reaction chamber housing is different. Taking the embodiment shown in FIG. 3 as an example, the inner cylinder 41 can be actively rotated while the reaction chamber housing remains stationary.

It should be noted that the relative rotation of the inner tube 41 and the reaction chamber shell is not essential, and both may be kept relatively stationary, for example, they may be kept absolutely stationary during the operation of the MOCVD equipment, which also achieves the effect of the present invention to some extent, as long as it is possible to ensure that the reaction gas passages 51 have substantially the same cross section in the traveling direction of the reaction gas. In the case where the reactant gas channels are of uniform cross section, the flow velocity of the reactant gas in the channels is maintained substantially unchanged, so that a uniform flow field in the flow direction can be obtained. But the relative rotation can make the concentration of carrier gas/reactant gas in contact with the wafer substrate more uniform.

To achieve the operating temperature of MOCVD, the MOCVD apparatus further comprises heating elements, which may be disposed inside the inner barrel 41 and/or within the chamber walls of the reaction chamber housing. In general, the heating element may comprise: a plurality of heating strips arranged in parallel, each parallel to the longitudinal axis of the inner barrel 41 and distributed circumferentially with respect to the longitudinal axis of the inner barrel 41, as shown in fig. 3-4; or a plurality of annular heating bands arranged in parallel, which are distributed in the axial direction with respect to the longitudinal axis of the inner tube 41, as shown in fig. 22; or a plurality of heating blocks, not shown, uniformly distributed on a selected circumferential surface about the longitudinal axis of the inner barrel 41; or a combination of any two of a plurality of heating strips, a plurality of endless heating strips, and a plurality of heating blocks, as shown in fig. 17-20. The heating element can be a silicon molybdenum rod, a tungsten wire or a molybdenum wire, the material can be silicon molybdenum, tungsten or molybdenum, and the shape can be a block, a belt, a strip or the like. The heating power can be uniform or nonuniform, the size of the heating element is designed according to the gas temperature in the reaction gas channel, the heating power can be adjusted, and the temperature difference of the substrate surface is ensured to be less than 1 ℃.

Since both the reaction chamber housing and the inner tube 41 are substantially cylindrical, the heating elements are substantially uniformly disposed inside the inner tube 41 and/or in the chamber wall of the reaction chamber housing, so that heat generated by the heating elements is transferred to the reaction gas channel 51 in the radial direction of the reaction chamber housing or the inner tube 41. The heating element is preferably a silicon molybdenum rod, tungsten wire or molybdenum wire.

The inner cylinder 41 and the inner wall of the reaction cavity shell are both provided with heat insulating materials, as shown in fig. 3-4, the center of the inner cylinder 41 is penetrated by the rotating shaft 15, the inner cylinder 41 and the rotating shaft 15 are relatively fixed so that the inner cylinder 41 and the rotating shaft 15 can rotate together, the heat insulating materials are arranged between the outer wall of the inner cylinder 41 and the rotating shaft 15, and the inner cylinder 41 connects and fixes the inner cylinder 41 with the first heating element 41, the first heat insulating material 42 and the rotating shaft 15 into a whole through the supporting element 17; the supporting element 17 should be made of a material with good rigidity and small thermal conductivity, such as zirconia, which is resistant to high temperature and does not decompose. The first heating element 41 and the first heat insulating material 42 are combined in a mechanical connection manner, and are fixedly connected with the high-temperature-resistant rotary inner cylinder through the supporting element 17, and meanwhile, the other side of the supporting element 17 is fixedly connected with the rigid rotary shaft 15 through mechanical connection. The bearing 16 is installed on the rotating shaft 15, the whole inner cylinder 41 is supported and fixed through the left bearing 16 and the right bearing 16, the rotating shaft 15 can be made of stainless steel or other materials, a cooling structure is arranged in the rotating shaft, and the rigid rotating shaft is efficiently cooled in a liquid cooling or air cooling mode.

Referring to the embodiment of fig. 3-8, it can be seen that the inner cylinder 41 is a hollow inner cylinder, and the heating element is disposed inside the inner cylinder 41; the heating element comprises a plurality of heating strips arranged in parallel, each parallel to the longitudinal axis of the inner barrel 41 and distributed circumferentially with respect to the longitudinal axis of the inner barrel 41; and both ends of each heating strip are fixed to both ends of the inner tube 41 along the longitudinal axis. In the embodiment of fig. 9-13, the heating element is also provided in the chamber wall of the reaction chamber housing, the heating element being a second heating element 73, the second heating element 73 also comprising a plurality of heating strips arranged in parallel, each of the plurality of heating strips being parallel to and circumferentially distributed with respect to the longitudinal axis of the reaction chamber housing, and each of the plurality of heating strips being secured in the chamber wall of the reaction chamber housing by a heating element securing portion 74.

The heating strips can be designed in a combined mode in series and parallel according to process requirements, and the design has the following advantages: firstly, the energy consumption can be reduced to the maximum extent, and a series-parallel scheme with the minimum energy consumption is selected according to each working condition; secondly, the uniformity of the temperature fields at different positions of the inner cylinder has different requirements, so that the electric heating power can be adjusted in a targeted manner through the design. The heating element is arranged in the inner cylinder of the bearing substrate to uniformly heat the inner cylinder, and meanwhile, the double heat-preservation heat-insulation structure design of the two sides of the inner cylinder and the outer cylinder is adopted, so that the heat of the heating element is hardly dissipated into the external environment, the energy loss of equipment is reduced to the minimum, compared with the traditional MOCVD equipment at present, the energy consumption is reduced by at least one order of magnitude, and the equipment operation cost and the substrate epitaxial deposition cost are greatly reduced from the operation angle.

The actuator 11 is disposed outside the reaction chamber housing, in the decompression chamber 61, directly or indirectly connected to the inner cylinder 41 or the reaction chamber housing for driving the inner cylinder 41 or the reaction chamber housing to rotate, and the actuator 11 may be a simple transmission shaft or a magnetic coupler, so that the actuator 11 is in transmission connection with the inner cylinder 41 through the magnetic coupler, as shown in fig. 3, or the actuator 11 is in transmission connection with the inner cylinder 41 through the transmission shaft 12, as shown in fig. 22, the transmission shaft 12 is connected to the rotation shaft 15, and a rotary seal 60 is disposed at a portion of the transmission shaft 12 passing through the reaction chamber housing. The transmission mechanism may 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 in the reaction cavity shell, wherein the driving rotation unit 13 drives the driven rotation unit 14 in a non-contact mode; the driving rotation unit 13 is connected to the actuator 11, and the driven rotation unit 14 is connected to the inner cylinder 41.

In the embodiment of fig. 3, 6, the actuating means 11 is arranged inside the decompression chamber 61, as an alternative embodiment the actuating means 1 may also be arranged outside the decompression chamber 61, using similar transmission means and sealing means.

As shown in fig. 7 and 8, the inner cylinder 41 is provided on its outer circumference with a first mounting position 71 for mounting the substrate 72, as shown in fig. 12 and 13, the inner side of the reaction chamber housing (outer cylinder 44) is provided with a second mounting position 75 for mounting the substrate 72, specifically, the mounting position is provided on the surface of the outer cylinder 44 facing the inner cylinder 41, as shown in fig. 9 to 11, the inner cylinder 41 is provided on its outer circumference with the first mounting position 71 for mounting the substrate 72, and the inner side of the reaction chamber housing (outer cylinder 44) is provided with the second mounting position 75 for mounting the substrate 72.

The number of the mounting sites on the inner tube 41 or the reaction chamber shell is plural, and the plurality of the mounting sites are uniformly distributed, specifically, the plurality of the mounting sites may be arranged in a matrix as shown in fig. 14, or the plurality of the mounting sites may be formed in a plurality of rows, and the mounting sites of adjacent rows are arranged to be offset from each other. Each mounting location may be a securing recess 64 as shown in fig. 14, which may act to secure the substrate in place during rotation of the inner barrel about the axis. In addition, the inner cylinder 41 and the outer cylinder 44 as the inner wall surface of the reaction chamber housing may be cylindrical or polygonal, as shown in fig. 15, the cross section of the inner cylinder 41 perpendicular to the longitudinal axis of the inner cylinder 41 is regular polygonal such that the inner cylinder 41 forms a polygonal column, and similarly, the cross section of the inner wall surface of the reaction chamber housing perpendicular to the longitudinal axis of the reaction chamber housing is regular polygonal such that the inner wall surface of the reaction chamber housing forms a polygonal column, and the mounting position is provided on the prismatic surface of the polygonal column, and in addition, a jig 65, a clamping groove, a groove are provided on the mounting position for fixing the substrate 72 on the mounting position. The side length scale of the polygon is determined by the size of the wafer substrate, the number N of the polygon can be 3 or any number above 3, and generally, in order to make the flow field uniform and the change of the annular reaction gas channel cross section area not obvious, the value of N can be slightly larger, so that the diameter of the high-temperature resistant inner cylinder can be correspondingly larger.

The structure of the double-side mounting substrate greatly improves the productivity of 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 be provided with grooves, clamping grooves or clamps for placing wafer substrates, 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 section of a reaction gas channel formed between the two substrates is similar to a regular polygon channel. When the gas passes through the annular or regular polygon channel, the epitaxial film can be obtained by deposition on both sides, the loss of the reaction gas is minimum, the growth efficiency of the epitaxial film is high, and the method also solves the problems that the chemical reactant is easy to deposit on the wall surface of the reaction cavity shell and needs to be cleaned regularly.

Taking the rotation of the inner cylinder as an example, in the working process, the inner cylinder is rotated at a constant speed, so that the temperature uniformity of the large-size cylinder wall can be ensured, and the deposition uniformity of the surface of the wafer substrate is realized. In practice, the rotational speed of the inner barrel can be adjusted as required, or the inner barrel can be selected to be stationary and not rotated. The annular reaction gas channel of the cylindrical reaction chamber has the constant cross section along the flowing direction, thereby ensuring the uniformity of a gas velocity field, and simultaneously, the inner cylinder for bearing the substrate adopts a rotary design, thereby ensuring the uniformity of the temperature of the inner cylinder and the surface of the substrate, the uniformity of reactants on the surface of the substrate, and solving the problem of uneven deposition on the surface of the substrate after the MOCVD equipment is enlarged. Meanwhile, the increase of the size of the reaction cavity shell along the axial direction hardly has obvious influence on the temperature field, the speed field and the reactant diffusion concentration field of the film deposition reaction gas of the MOCVD equipment, so that the productivity of the MOCVD epitaxial wafer can be greatly improved, simultaneously, the very high epitaxial deposition quality is ensured, and the restriction of the production capacity of the MOCVD equipment in the semiconductor industry is effectively broken through.

Preferably, the distribution density or power density of the heating element at a location near the air inlet or outlet is greater than the distribution density or power density at a location remote from the air inlet or outlet. Referring to fig. 10 and 11, the distribution density of the second heating element 73 is greater near the inlet and outlet (inlet element 52 and outlet element 53) than at other locations because, in some arrangements, the lower inlet air temperature results in a lower temperature of the substrate 72 on the outer barrel 44 near the inlet, and therefore, a special heating element needs to be provided or added near the inlet of the outer barrel 44 to increase the local temperature of the outer barrel and ensure temperature uniformity across the 360 ° circumference of the outer barrel. Because the annular reaction gas channel is very small, the overall difference of the temperature of the inner cylinder and the outer cylinder is not large, the outer cylinder heating elements can be arranged at other positions of the outer cylinder according to the temperature requirement, or the outer cylinder heating elements are not arranged, or the outer cylinder heating elements are only arranged locally (as shown in figure 11), so that the inner cylinder and the outer cylinder are heated by the heating elements inside the inner cylinder, and the heating elements are only arranged locally near the air inlet of the outer cylinder to compensate, so that the temperature difference of the whole outer cylinder is within 1 ℃, and the temperature range required by the deposition of the high-quality thin film of the outer cylinder substrate is satisfied.

Even if the outer cylinder 44 is not provided with a substrate, the outer cylinder 44 can be heated, so as to compensate the cooling effect of the reaction gas with lower temperature on the inner cylinder, the heating power of the heating element of the outer cylinder can be uniformly heated or non-uniformly heated along the circumferential direction, and the non-uniform heating is generally realized at the lower temperature part of the reaction gas inlet, and larger compensating heating power or denser heating wire design is adopted; along the movement direction of the reaction gas in the gas channel, the gas temperature gradually rises, and the heating element of the outer cylinder gradually reduces the compensation heating power so as to ensure that the temperature of the surfaces of all the substrates is more uniform and create a more uniform temperature environment for the reaction chamber. The other function of the auxiliary heating element of the outer cylinder is to accelerate the system response speed of MOCVD in temperature switching, and the power and the switch of the auxiliary heating element are controlled in advance according to the surface temperature condition of the inner cylinder and the temperature switching requirement, so that the system is ensured to realize the heating or cooling process in a faster time.

In fig. 16, the first housing 31 is located on the vertically upper side of the second housing 32, the second housing 32 is kept fixed, and the first housing 31 is configured to be movable with respect to the second housing 32; the first housing 31 is provided with two first housing coupling elements 102, the second housing 32 is provided with two second housing coupling elements 103, and the first housing coupling elements 102 are configured to be coupled with the second housing coupling elements 103; the MOCVD tool further comprises two lifting assemblies 101, said lifting assemblies 101 being connected to the first housing coupling member 102 for lifting or lowering the first housing 31. The lifting assembly 101 may be a hydraulic lever, and the lifting assembly 101 drives the first housing 31 to be lifted upward during loading and unloading of the substrates, thereby opening the reaction chamber housing, leaving a space for loading/unloading the wafer substrates.

Fig. 16-20, 22 show several different forms, arrangements and support of the heating elements, which are several embodiments of the zoned arrangement of the heating elements, the interior of the inner barrel 41 or the interior of the chamber wall of the reaction chamber shell being divided into different zones, the heating elements being present in at least two zones in different forms, in different distribution densities or in different power densities. In particular, the distribution density or power density of the heating element at a location proximate to the air inlet or outlet may be greater than the distribution density or power density at a location distal from the air inlet or outlet, or the heating element may have a different distribution density or power density at a location proximate to the end of the inner barrel 41 along the longitudinal axis and a location proximate to the center of the longitudinal axis of the inner barrel 41. For example, the heating element is disposed inside the inner barrel 41, and the inner barrel 41 includes a first region near the center of the longitudinal axis of the inner barrel 41 and two second regions near the ends of the inner barrel 41 along the longitudinal axis, while the heating element has a different form and arrangement in the first and second regions.

In the embodiment of fig. 16-18, the rotational shafts 15 are provided on both ends of the inner cylinder 41 along the longitudinal axis, the rotational shafts 15 do not penetrate the center of the inner cylinder 41, and the inner cylinder 41 and the rotational shafts 15 are relatively fixed so that the inner cylinder 41 and the rotational shafts 15 can rotate together. The heating elements are fixedly arranged inside the inner drum 41, the heating elements comprising a first heating element 43 and an annular heating band 47, the first heating element 43 being in a first region, which is designed as a plurality of heating strips arranged in parallel, which are each parallel to the longitudinal axis of the inner drum 41 and distributed circumferentially with respect to the longitudinal axis of the inner drum 41, the annular heating band 47 being arranged in a second region, the axis of which is parallel to the longitudinal axis of the inner drum 41. The outside of the annular heating belt 47 is provided with end heat insulating materials 48, two are axially arranged, and the end heat insulating materials 48 are vertically arranged at two ends of the inner cylinder and closely attached to the end covers of the inner cylinder, and can be connected together through mechanical devices. The end insulation 48 may be comprised of one to several layers of insulation or radiant heat shields, each layer being optimally designed to achieve an optimal insulation thickness at the temperatures to which it is subjected. The annular heating belt 47 is positioned between the end insulating material 48 and the heating strip with a certain spacing therebetween, which can be determined from the results of the simulation calculation. Furthermore, in the figures, the heating strip is a single row, but it may also be arranged in multiple rows.

The plurality of heating strips and the annular heating belt may be fixed within the inner tube 41 in various ways to rotate with the inner tube 41, for example, the plurality of heating strips are fixed on the inner circumferential surface of the inner tube 41, or the annular heating belt is fixed on the inner circumferential surface of the inner tube 41 or on both ends of the inner tube 41 along the longitudinal axis or on the end heat insulating material 48. The design of the annular heating belt is also used for guaranteeing the temperature uniformity of the reaction chamber, so that the temperature fields at the two ends of the inner cylinder and the middle position have smaller phase difference, and the deposition of epitaxial wafers at the two ends is guaranteed to be of high quality.

In the embodiment of fig. 19-20, the heating elements are identical in form, combination and location to the previous embodiments, including a plurality of heating strips and endless heating belts, but in a different manner of support and securement. A center support shaft 55 penetrates through the center of the inner cylinder 41 and protrudes from both ends of the inner cylinder 41 along the longitudinal axis, the center support shaft 55 being configured to be fixed with respect to the reaction chamber housing such that the inner cylinder 41 can rotate with respect to the center support shaft 55, for example, the center support shaft 55 is directly fixed to the outer housing of the reaction chamber housing, the center support shaft 55 is supported at the center of the rotation shaft 15 by a bearing such that the rotation shaft 15 can rotate around the center support shaft 55; the plurality of heating strips and the annular heating belt are fixed by the central support shaft 55 so that the plurality of heating strips and the annular heating belt do not rotate with the inner cylinder 41 during the operation of the MOCVD equipment.

The central support shaft 55 is provided with a plurality of central support rings 49, each central support ring 49 is provided with a plurality of heating element support rods 46 extending along the radial direction of the central support ring 49, and the plurality of heating element support rods 46 are uniformly distributed along the circumferential direction of the central support ring 49; the plurality of heating strips and the annular heating band are each directly or indirectly secured to the end of the heating element support rod 46 remote from the central support ring 49. The end of the heating element support bar 46 remote from the central support ring 49 is provided with a fixing plate on which the heating strips or the endless heating belt are fastened by screws, the fixing plate and screws constituting a fixing assembly 50. An insulating sheet 56 is provided between the heating strip and the end of the heating element support rod 46 (the fixing assembly 50), and an insulating sheet 56 is provided between the annular heating belt and the end of the heating element support rod 46. The material of the center support ring 49 may be selected from stainless steel or other nickel-based metals.

In the embodiment of fig. 22, unlike the embodiment shown in fig. 17, the heating elements in the inner cylinder 41 are all composed of annular heating belts, a certain distance is left between two adjacent annular heating belts, and the size and heating power of the annular heating belts can be adjusted according to the process requirements. The arrangement of the annular heating belt can be divided into a middle area and an edge area according to the temperature uniformity of the inner cylinder, different powers can be loaded in the areas due to different heat dissipation losses between the edges and the middle, the surface temperature of the inner cylinder is ensured to be more uniform through the areas with different axial directions, and the surface temperature difference between the two ends and the middle substrate is less than 1 ℃.

Furthermore, the heating strips can be designed in a partitioned manner along the circumferential direction, and the design can enable the electric heating power of different partitions to be independently adjusted. If the temperature of the air inlet is lower, the temperature field of the area is greatly different from the temperature field of the middle position of the reaction chamber, and the electric heating power of the partition heating strip can be independently regulated and increased at the moment so as to ensure the uniformity of the temperature field of the whole reaction chamber.

In addition, in the case where the center of the inner tube 41 is penetrated by the rotation shaft 15 and the inner tube 41 is relatively fixed to the rotation shaft 15 so that the inner tube 41 and the rotation shaft 15 can rotate together, a plurality of heating strips and/or an endless heating belt may be directly fixed to the rotation shaft 15.

As shown in fig. 21, a water cooling passage is provided in the rotary shaft 15, the water cooling passage is a double-layer water cooling passage, and includes an outer passage 67 and an inner passage 68 which are communicated, the outer passage 67 coaxially surrounds the outer periphery of the inner passage 68, the outer passage 67 is used for water supply, and the inner passage 68 is used for water drainage. 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.

As shown in fig. 22, the chamber wall of the reaction chamber housing further includes a support tube 57 provided between the outer housing and the outer tube 44; a plurality of struts 58 are provided between the support tube 57 and the outer tube 44, the struts 58 extend in the radial direction of the reaction chamber housing, and the plurality of struts 58 are uniformly distributed in the circumferential direction of the reaction chamber housing.

As shown in fig. 23, the heating element of the MOCVD equipment is in an electric heating mode, the heating element is connected with an external power supply, and 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 collecting ring 69 is arranged at the end part of the rotating shaft 15, the collecting ring 69 is connected with an external power supply through a wire 70, and the first heating element 43 is connected with the collecting ring 69 through a wire penetrating through the center of the rotating shaft 15, so that dynamic and static conversion is realized.

In the above-described embodiments, the longitudinal axes of the inner cylinder 41 are all disposed in the horizontal direction, and the longitudinal axes of the reaction chamber housings are all disposed in the horizontal direction, the actuating device 11 is disposed at one side of the reaction chamber housings, and the resulting MOCVD apparatus is a horizontal MOCVD apparatus, however, alternatively, the longitudinal axis of the inner cylinder 41 may also be disposed in the vertical direction, and the longitudinal axis of the reaction chamber housings may also be disposed in the vertical direction, and the actuating device 11 is disposed at the lower side (or upper side) of the reaction chamber housings, thereby forming an upright MOCVD apparatus, fig. 24 is an embodiment of the upright MOCVD apparatus, in which a decompression chamber 61, configured to be able to provide an environment lower than the atmospheric pressure, is disposed within the decompression chamber 61, and the first pressure within the reaction chamber housing is higher than the second pressure within the decompression chamber 61, and both the first pressure and the second pressure are lower than the atmospheric pressure during the operation of the MOCVD apparatus. The MOCVD equipment further comprises a first vacuum pump 62 and a second vacuum pump 63, the first vacuum pump 62 being in fluid communication with the decompression chamber 61 for causing the decompression chamber 61 to generate and maintain a second pressure; the second vacuum pump 63 is in fluid communication with the reaction chamber formed by the reaction chamber housing for generating and maintaining a first pressure in the reaction chamber. In addition, the decompression chamber 61 is fixed on the base 97, a support frame 98 is further provided at the decompression chamber 61, the support frame 98 has a U-shaped groove, the reaction chamber housing is fixed on the support frame 98, and the actuating device 11 and the active rotation unit 13 of the magnetic coupler are located in the U-shaped groove. Other arrangements of the upright MOCVD equipment of fig. 24 are the same as the previous embodiment except for this.

The decompression chamber is an important component for controlling the pressure environment required by the epitaxial process, and ensures that the chemical reaction carried out in the reaction chamber shell is in a more ideal pressure range. The design has the advantages that: on the one hand, in the use, only need outside decompression chamber continuously bleed can effectively keep low pressure environment, does not have reaction gas in the decompression chamber, does not have the waste of reaction gas. The reaction chamber shell forms a small sealed environment through the first shell and the second shell, the normal process flow can easily maintain the micro-positive pressure environment, and the interior of the reaction chamber shell does not need to continuously exhaust gas, so that less reaction gas can be wasted, and the running cost of MOCVD equipment can be reduced. On the other hand, the micro-positive pressure environment of the reaction cavity shell can ensure that any external gas cannot enter the reaction cavity shell, so that the cleanest space environment is created for the epitaxial deposition process in the reaction cavity shell, the risk of pollution to the epitaxial quality is greatly reduced, and the obtained epitaxial deposition quality is higher.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention. The scope of applicability of the present invention is defined by the appended claims and equivalents thereof.

Claims

1. A positive pressure differential MOCVD tool, characterized in that the MOCVD tool comprises:

a decompression chamber (61), the decompression chamber (61) being configured to be able to provide an environment below atmospheric pressure;

A reaction chamber housing disposed in the decompression chamber (61) for providing an environment in which a reaction gas is chemically reacted;

An inner working unit arranged in the reaction chamber shell, and a reaction gas channel (51) is formed between the inner working unit and the reaction chamber shell,

Wherein the MOCVD apparatus is configured to enable a first pressure in the reaction chamber shell to be higher than a second pressure in the decompression chamber (61), and both the first pressure and the second pressure are lower than an atmospheric pressure.

2. The positive pressure differential MOCVD equipment according to claim 1, wherein:

the inner working unit comprises an inner cylinder (41), and the MOCVD apparatus is configured to enable relative rotation between the inner cylinder (41) and the reaction chamber housing.

3. The positive pressure differential MOCVD equipment according to claim 2, wherein:

The inner barrel (41) is configured to be rotatable about a longitudinal axis of the inner barrel (41), and the reaction chamber housing is configured to remain stationary during operation of the MOCVD tool; or alternatively

At least a portion of the reaction chamber housing is configured to be rotatable about a longitudinal axis of the reaction chamber housing, and the inner barrel (41) is configured to remain stationary during operation of the MOCVD tool; or alternatively

At least a part of the reaction chamber housing and the inner tube (41) are configured to be rotatable at the same time, but the rotation direction or rotation speed of the inner tube (41) and the reaction chamber housing is different.

4. The positive pressure differential MOCVD equipment according to claim 2, wherein:

The MOCVD tool further comprises a first vacuum pump (62), the first vacuum pump (62) being in fluid communication with the decompression chamber (61) for causing the decompression chamber (61) to generate and maintain a second pressure.

5. The positive pressure differential MOCVD equipment according to claim 2, wherein:

The MOCVD equipment further comprises a first vacuum pump (62) and a second vacuum pump (63), the first vacuum pump (62) being in fluid communication with the decompression chamber (61) for causing the decompression chamber (61) to generate and maintain a second pressure; the second vacuum pump (63) is in fluid communication with the reaction chamber formed by the reaction chamber housing for generating and maintaining a first pressure in the reaction chamber.

6. The positive pressure differential MOCVD equipment according to any of claims 2 to 5, wherein:

The reaction chamber housing includes a first housing (31) and a second housing (32), the first housing (31) and the second housing (32) being changeable between a first state in which they are coupled to each other to close the inner cylinder (41) and a second state in which they are separated from each other to expose the inner cylinder (41); and

A sealing assembly is arranged between the first shell (31) and the second shell (32).

7. A positive pressure differential MOCVD method, characterized in that the MOCVD method uses the positive pressure differential MOCVD equipment according to claims 1 to 6, the MOCVD method comprising:

Generating a second pressure lower than the atmospheric pressure in the decompression chamber (61); and

8. The positive pressure differential MOCVD method according to claim 7, wherein:

The first pressure is at least 200Pa higher than the second pressure.

9. The positive pressure differential MOCVD method according to claim 7, wherein:

Continuously pumping air from the decompression chamber (61) to maintain a second pressure in the decompression chamber (61) during the working process of the MOCVD equipment; and

10. The positive pressure differential MOCVD method according to claim 7, wherein:

the MOCVD method further comprises the following steps: before a second pressure lower than the atmospheric pressure is generated in the decompression chamber (61), the reaction chamber shell is in an unsealed state; and closing the reaction chamber shell after generating a second pressure lower than the atmospheric pressure in the decompression chamber (61); or alternatively

The MOCVD method further comprises the following steps: the reaction chamber shell is closed before a second pressure lower than the atmospheric pressure is generated in the decompression chamber (61), and then the reaction chamber shell is decompressed to a pressure lower than the atmospheric pressure by a separate vacuum pump.