Air extraction device

Abstract

The present invention discloses a vacuum device, including: a reactor, a graphite tray, a support tube, a lifting rod, a lifting plate and an outer tube, the outer tube including a first vertical section, an inclined section and a second vertical section, the two ends of the inclined section are respectively connected to the first vertical section and the second vertical section, the diameter of the first vertical section is smaller than the diameter of the second vertical section, and the inclined section is arranged relative to the graphite tray in the horizontal direction; a vacuum port is arranged at the lower end of the side wall of the reactor and is connected to the reaction chamber. When the present invention is actually used, when the reaction chamber of the reactor is vacuumed from the vacuum port, the outer tube has an inclined section, and the particles entrained in the airflow will rebound downward after hitting the inner wall of the inclined outer tube, and will not rebound to the substrate surface, which greatly reduces the defects of material growth caused by the particles.

Description

Technical Field

[0001] The invention relates to the field of chemical vapor deposition (CVD) equipment, and in particular to a gas extraction device. Background Art

[0002] CVD equipment (such as MOCVD, SiC-CVD and other equipment) used to prepare thin film materials is a high-tech equipment that integrates vacuum, high temperature, high-speed rotation and other technologies. The reaction gas flows through the surface of the heated substrate (i.e., the substrate is placed on a graphite tray for heating), and a chemical reaction occurs to generate a single crystal film of GaN, AlN, SiC or other materials. The deposition process is usually a low-pressure growth mode, and the growth pressure needs to be precisely controlled. The accuracy of pressure control and the uniformity of the airflow in the reaction chamber of the reactor determine the thickness uniformity, crystal quality, electrical properties, optical properties and other physical and chemical properties of the thin film material. In addition to the influence of the air intake system on the flow field and temperature field, the exhaust system also has a greater influence on the flow field and temperature field.

[0003] At present, the existing technology adopts Figure 1 The exhaust device shown includes a reactor 4, an outer tube 6, a lifting plate 8, a lifting rod 9 and an exhaust port 13.

[0004] The following problems may occur when using the above-mentioned air extraction device:

[0005] (1) The vertical side wall of the outer tube 6 is not conducive to the downward turning of the airflow, and the reaction particles are prone to rebound at point a, affecting the growth quality;

[0006] (2) The air extraction port 13 is eccentric relative to the graphite tray, resulting in uneven local airflow at point b;

[0007] (3) Poor air flow uniformity affects the uniformity of the temperature field, resulting in uneven film thickness of the growing material;

[0008] (4) Dust easily enters the gap c of the lifting rod, causing the lifting to be not smooth. Summary of the invention

[0009] The object of the present invention is to provide an air extraction device to solve at least one of the above-mentioned technical problems.

[0010] To this end, a technical solution adopted by the present invention is to provide an air extraction device, comprising:

[0011] A reactor having a reaction chamber and an air inlet connected to the reaction chamber;

[0012] A graphite tray is arranged in the reaction chamber, and a substrate is arranged on the graphite tray;

[0013] A support tube, one end of which is connected to the graphite tray, and the other end of which is connected to the inner side of the bottom wall of the reactor;

[0014] A lifting rod is movably arranged on the bottom wall of the reactor in a vertical direction;

[0015] A lifting plate, arranged on the lifting rod;

[0016] An outer cylinder is sleeved on the outer side of the graphite tray and is arranged on the lifting plate, the outer cylinder comprises a first vertical section, an inclined section and a second vertical section, two ends of the inclined section are respectively connected to the first vertical section and the second vertical section, the diameter of the first vertical section is smaller than the diameter of the second vertical section, and the inclined section is arranged opposite to the graphite tray in the horizontal direction;

[0017] The gas extraction port is arranged at the lower end of the side wall of the reactor and is communicated with the reaction chamber.

[0018] In one embodiment of the present invention, the air extraction device further comprises an air equalizing ring, which is arranged on the lifting plate and located between the supporting tube and the outer tube, and has a plurality of air equalizing holes evenly arranged in the vertical direction on the air equalizing ring.

[0019] In one embodiment of the present invention, the sum of the cross-sectional areas of the air equalizing holes is 1.2-1.5 times the sum of the cross-sectional areas of the air suction ports.

[0020] In one embodiment of the present invention, the air extraction device further comprises a heat-insulating tube, which is arranged on the air-equalizing ring and sleeved on the outer side of the supporting tube.

[0021] In one embodiment of the present invention, the vacuum device also includes a dustproof component, which is sleeved on the outside of the lifting rod. The dustproof component includes a plurality of dustproof sleeves, which are sleeved on each other in a vertical direction. The diameter of the dustproof sleeve located on the upper side is larger than the diameter of the dustproof sleeve located on the lower side. The upper end of the dustproof sleeve located on the uppermost side is connected to the lifting plate, and the lower end of the dustproof sleeve located on the lowermost side is connected to the bottom wall of the reactor.

[0022] In one embodiment of the present invention, a first protrusion is extended inwardly from the lower end of the dust cover on the upper side, and a second protrusion is extended outwardly from the upper end of the dust cover on the lower side, and the second protrusion is interlocked with the first protrusion.

[0023] In one embodiment of the present invention, the plurality of dust covers are coaxially arranged with the center line of the lifting rod.

[0024] In one embodiment of the present invention, the dustproof assembly includes a first dustproof cover, a second dustproof cover and a third dustproof cover, the upper end of the first dustproof cover is connected to the lifting plate, and the lower end of the first dustproof cover is provided with the first protrusion; the upper end of the second dustproof cover is provided with the second protrusion, and the lower end of the second dustproof cover is provided with the first protrusion, and the second protrusion of the second dustproof cover and the first protrusion of the first dustproof cover are interlocked; the upper end of the third dustproof cover is provided with the second protrusion, and the lower end of the third dustproof cover is connected to the bottom wall of the reactor, and the second protrusion of the third dustproof cover and the first protrusion of the second dustproof cover are interlocked; the diameter of the first dustproof cover is smaller than the diameter of the second dustproof cover, and the diameter of the second dustproof cover is smaller than the diameter of the third dustproof cover.

[0025] In one embodiment of the present invention, the graphite tray, the supporting tube, the heat-insulating tube, the gas-balancing ring, the lifting plate and the reactor are coaxially arranged.

[0026] The present invention is beneficial in that:

[0027] Different from the prior art, the technical solution of the present invention is applied. In actual use, when the reaction chamber of the reactor is evacuated from the exhaust port, the outer cylinder has an inclined section. The particles entrained in the air flow will rebound downward after hitting the inner wall of the inclined outer cylinder, and will not rebound to the surface of the substrate, thereby greatly reducing the defects of material growth caused by the particles. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 It is a cross-sectional schematic diagram of an air extraction device in the prior art;

[0030] Figure 2 1 is a schematic cross-sectional view of an air extraction device in one embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0032] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0033] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0034] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0036] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0037] See also Figure 2 As shown, an exhaust device provided in one embodiment of the present invention comprises: a graphite tray 1, a support tube 3, a reactor 4, an outer tube 6, a lifting plate 8, a lifting rod 9 and an exhaust port 13. The reactor 4 has a reaction chamber and an air inlet 41 connected to the reaction chamber. The graphite tray 1 is arranged in the reaction chamber, and a substrate 2 is arranged on the graphite tray 1. One end of the support tube 3 is connected to the graphite tray 1, and the other end of the support tube 3 is connected to the inner side of the bottom wall 14 of the reactor 4. The lifting rod 9 is movably arranged on the bottom wall 14 of the reactor 4 in the vertical direction. The lifting plate 8 is arranged on the lifting rod 9. The outer tube 6 is sleeved on the outer side of the graphite tray 1 and is arranged on the lifting plate 8. The outer tube 6 comprises a first vertical section 61, an inclined section 62 and a second vertical section 63. The two ends of the inclined section 62 are respectively connected to the first vertical section 61 and the second vertical section 63. The diameter of the first vertical section 61 is smaller than the diameter of the second vertical section 63. The inclined section 62 is arranged relative to the graphite tray 1 in the horizontal direction. The gas extraction port 13 is disposed at the lower end of the side wall of the reactor 4 and is communicated with the reaction chamber.

[0038] When the above-mentioned exhaust device is actually used, when the reaction chamber of the reactor 4 is evacuated from the exhaust port 13, the outer tube 6 has an inclined section 62. The particles entrained in the air flow will rebound downward after hitting the inner wall of the inclined outer tube 6, and will not rebound to the surface of the substrate 2, thereby greatly reducing the defects of material growth caused by the particles.

[0039] In an embodiment of the present invention, the exhaust device further comprises an air-equalizing ring 7, which is arranged on the lifting plate 8 and between the support tube 3 and the outer tube 6, and a plurality of air-equalizing holes are evenly arranged in the vertical direction on the air-equalizing ring 7. In this way, a certain resistance will be formed when the airflow passes through the air-equalizing holes on the air-equalizing ring 7, so that a certain pressure difference will be formed above and below the air-equalizing ring 7, so that most of the gas can be prevented from flowing through the shortest route, and the air-equalizing effect can be achieved, that is, the gas coming down from the upper part of the reaction chamber can flow more evenly to the edge of the substrate 2; due to the improvement of the uniformity of the airflow, the heat taken away by the airflow in the circumferential direction of the substrate 2 is also more uniform, thereby improving the temperature uniformity of the graphite tray 1 and the substrate 2.

[0040] Furthermore, the sum of the cross-sectional areas of the air equalization holes is 1.2-1.5 times the sum of the cross-sectional areas of the air extraction ports 13. In this way, the air equalization effect is optimal.

[0041] In the embodiment of the present invention, the exhaust device further comprises a heat preservation tube 5, which is arranged on the gas uniformity ring 7 and sleeved on the outer side of the support tube 3. In this way, the temperature uniformity of the graphite tray 1 and the substrate 2 can be improved.

[0042] In the embodiment of the present invention, the exhaust device further includes a dustproof component, which is sleeved on the outer side of the lifting rod 9. The dustproof component includes a plurality of dustproof sleeves, which are sleeved on each other in the vertical direction. The diameter of the dustproof sleeve located on the upper side is greater than the diameter of the dustproof sleeve located on the lower side. The upper end of the dustproof sleeve located on the uppermost side is connected to the lifting plate 8, and the lower end of the dustproof sleeve located on the lowermost side is connected to the bottom wall 14 of the reactor 4. In this way, in the process of the lifting rod 9 moving up and down in the vertical direction, the plurality of dustproof sleeves can flexibly shrink and move up and down, effectively preventing particles from entering the gap of the lifting rod 9, and greatly extending the equipment maintenance cycle.

[0043] Furthermore, a first protrusion is provided at the lower end of the upper dust cover extending inwardly, and a second protrusion is provided at the upper end of the lower dust cover extending outwardly, and the second protrusion is interlocked with the first protrusion. In this way, multiple dust covers are mutually sleeved.

[0044] Furthermore, a plurality of dust covers are coaxially arranged with the center line of the lifting rod 9 .

[0045] Specifically in the embodiment, the dustproof assembly includes a first dustproof cover 10, a second dustproof cover 11 and a third dustproof cover 12. The upper end of the first dustproof cover 10 is connected to the lifting plate 8 by screws, and the lower end of the first dustproof cover 10 is provided with a first protrusion; the upper end of the second dustproof cover 11 is provided with a second protrusion, and the lower end of the second dustproof cover 11 is provided with a first protrusion, and the second protrusion of the second dustproof cover 11 and the first protrusion of the first dustproof cover 10 are mutually buckled; the upper end of the third dustproof cover 12 is provided with a second protrusion, and the lower end of the third dustproof cover 12 is connected to the bottom wall 14 of the reactor by screws, and the second protrusion of the third dustproof cover 12 and the first protrusion of the second dustproof cover 12 are mutually buckled. The diameter of the first dustproof cover 10 is smaller than the diameter of the second dustproof cover 11, and the diameter of the second dustproof cover 11 is smaller than the diameter of the third dustproof cover 12.

[0046] In the embodiment of the present invention, the graphite tray 1, the support tube 3, the heat preservation tube 5, the gas equalizing ring 7, the lifting plate 8 and the reactor 4 are coaxially arranged.

[0047] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0048] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A vacuum device, characterized in that: include: A reactor having a reaction chamber and an air inlet connected to the reaction chamber; A graphite tray is arranged in the reaction chamber, and a substrate is arranged on the graphite tray; A support tube, one end of which is connected to the graphite tray, and the other end of which is connected to the inner side of the bottom wall of the reactor; A lifting rod, movably arranged on the bottom wall of the reactor in a vertical direction; A lifting plate, arranged on the lifting rod; An outer cylinder is sleeved on the outer side of the graphite tray and is arranged on the lifting plate, the outer cylinder comprises a first vertical section, an inclined section and a second vertical section, two ends of the inclined section are respectively connected to the first vertical section and the second vertical section, the diameter of the first vertical section is smaller than the diameter of the second vertical section, and the inclined section is arranged opposite to the graphite tray in the horizontal direction; A gas extraction port, arranged at the lower end of the side wall of the reactor and connected to the reaction chamber; The air extraction device further comprises an air equalizing ring, which is arranged on the lifting plate and located between the supporting tube and the outer tube, and has a plurality of air equalizing holes evenly arranged in the vertical direction on the air equalizing ring; The exhaust device further comprises a dustproof assembly, the dustproof assembly is sleeved on the outer side of the lifting rod, the dustproof assembly comprises a plurality of dustproof sleeves, the plurality of dustproof sleeves are sleeved on each other in a vertical direction, the diameter of the dustproof sleeve located on the upper side is greater than the diameter of the dustproof sleeve located on the lower side, the upper end of the dustproof sleeve located on the uppermost side is connected to the lifting plate, and the lower end of the dustproof sleeve located on the lowermost side is connected to the bottom wall of the reactor; A first protrusion is provided on the lower end of the dust cover located on the upper side and extends inwardly, and a second protrusion is provided on the upper end of the dust cover located on the lower side and extends outwardly, and the second protrusion is buckled with the first protrusion; The plurality of dust covers are coaxially arranged with the center line of the lifting rod; The dustproof assembly includes a first dustproof cover, a second dustproof cover and a third dustproof cover, the upper end of the first dustproof cover is connected to the lifting plate, and the lower end of the first dustproof cover is provided with the first protrusion; the upper end of the second dustproof cover is provided with the second protrusion, and the lower end of the second dustproof cover is provided with the first protrusion, and the second protrusion of the second dustproof cover and the first protrusion of the first dustproof cover are interlocked; the upper end of the third dustproof cover is provided with the second protrusion, and the lower end of the third dustproof cover is connected to the bottom wall of the reactor, and the second protrusion of the third dustproof cover and the first protrusion of the second dustproof cover are interlocked; the diameter of the first dustproof cover is smaller than the diameter of the second dustproof cover, and the diameter of the second dustproof cover is smaller than the diameter of the third dustproof cover.

2. The air extraction device according to claim 1, characterized in that: The sum of the cross-sectional areas of the air balancing holes is 1.2-1.5 times the sum of the cross-sectional areas of the air suction ports.

3. The air extraction device according to claim 1, characterized in that: The air extraction device also includes a heat preservation tube, which is arranged on the air equalizing ring and sleeved on the outer side of the support tube.

4. The air extraction device according to claim 3, characterized in that: The graphite tray, the supporting tube, the heat-insulating tube, the gas-equalizing ring, the lifting plate and the reactor are coaxially arranged.

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