Epitaxial growth graphite plate of MOCVD (metal organic chemical vapor deposition) equipment

Abstract

The utility model relates to an epitaxial growth graphite plate for MOCVD (Metal Organic Chemical Vapor Deposition) equipment, which belongs to the technical field of semiconductors and comprises a graphite plate body, a substrate ring, a first substrate groove and an airflow groove are arranged on the front surface of the graphite plate body, and a plurality of second substrate grooves are arranged in the substrate ring. The plurality of second substrate grooves are uniformly distributed in the substrate ring by taking the circle center of the graphite plate body as the center, and a first cylindrical groove, a second cylindrical groove and a third cylindrical groove are formed in the back surface of the graphite plate body. According to the utility model, the second substrate groove is arranged in the substrate ring, so that the contact benefit of the wafer and the edge is reduced, the wavelength standard deviation uniformity is greatly improved, the growth benefit of the epitaxial wafer can be improved, and the edge effect is better; the problem that the wavelength of the edge of the outer ring of an epitaxial wafer growing on the graphite plate body is too short or too long is solved through the airflow grooves, the semicircular protrusions and the semicircular grooves, so that the light-emitting wavelengths of all areas of the epitaxial wafer are consistent.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductors, in particular to an MOCVD device for epitaxially growing a graphite disk. Background Art

[0002] Light Emitting Diode (LED) is a semiconductor diode that can convert electrical energy into light energy. LED has the advantages of high efficiency, energy saving and environmental protection, and is widely used in traffic signs, outdoor full-color display and other fields. In particular, the use of high-power LED to achieve semiconductor solid-state lighting is expected to become a new generation of light source entering thousands of households, causing a revolution in the history of human lighting.

[0003] Epitaxial wafers are the primary finished products in the LED manufacturing process. When forming epitaxial wafers, the substrate is placed on a tray in the reaction chamber of the Metal Organic Chemical Vapor Deposition (MOCVD) device. The heat energy provided by the heating wire in the MOCVD device is conducted to the substrate through the tray. At the same time, raw materials are introduced into the reaction chamber to epitaxially grow semiconductor materials on the substrate to form epitaxial wafers. Most of the current trays use a graphite tray body 1. The graphite tray body 1 is provided with a plurality of grooves, and one groove can accommodate one substrate.

[0004] The graphite disc body 1 rotates at high speed during the epitaxial wafer formation process. There is gas flow on the surface of the graphite disc body 1 at high speed, which will affect the gas distribution of the Mo source introduced into the reaction chamber during the epitaxial wafer growth process. And the farther away from the center of the graphite disc body 1, the uneven distribution of the MO source will appear. In particular, the edge of the graphite disc body 1 is subjected to the greatest centrifugal force and the greatest linear velocity, which will increase the flow rate of the MO source gas flow, resulting in the abnormally short or long wavelength of the edge of the graphite disc body 1. Utility Model Content

[0005] The utility model aims to solve the above technical problems and provides a MOCVD device for epitaxially growing a graphite disk.

[0006] In order to solve the above technical problems, the technical solution provided by the utility model is:

[0007] An MOCVD device for epitaxially growing a graphite disk comprises a graphite disk body, a substrate ring, a first substrate groove and an airflow groove are provided on the front of the graphite disk body, and a second substrate groove is provided in the substrate ring;

[0008] The plurality of first substrate slots and airflow grooves are evenly distributed on the graphite disc body with the center of the graphite disc body as the center;

[0009] A plurality of the second substrate grooves are evenly distributed in the substrate ring with the center of the graphite disk body as the center;

[0010] The back side of the graphite disc body is provided with a first cylindrical groove, a second cylindrical groove and a third cylindrical groove.

[0011] Preferably, the number of the first substrate slots and the number of the airflow grooves are the same.

[0012] Preferably, the first substrate slots and the airflow grooves are arranged alternately.

[0013] Preferably, the first cylindrical groove, the second cylindrical groove and the third cylindrical groove are arranged concentrically with the graphite disk body.

[0014] Preferably, a raised ring is provided on the back edge of the graphite disk body.

[0015] Preferably, one side of the inner circle of the raised ring is chamfered.

[0016] Preferably, a first step protrusion is installed in the first substrate groove, and a second step protrusion is installed on the first step protrusion.

[0017] Preferably, a semicircular groove is provided on the first step protrusion, and a semicircular protrusion is installed in the first substrate groove.

[0018] Preferably, the semicircular protrusion and the semicircular groove form a circular structure.

[0019] After adopting the above structure, the utility model has the following advantages:

[0020] The utility model reduces the benefit of wafer-edge contact by arranging the second substrate groove in the substrate ring, greatly improves the uniformity of wavelength standard deviation, can improve the growth benefit of epitaxial wafer, makes edge effect better, improves the problem of short or long wavelength at the edge of the outer ring of epitaxial wafer grown on the graphite disk body by airflow grooves, semicircular protrusions and semicircular grooves, makes the luminous wavelength of each area of ​​the epitaxial wafer consistent.

[0021] The above summary is for the purpose of description only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the utility model will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is the first structural schematic diagram of the utility model.

[0024] Figure 2 It is a second structural schematic diagram of the utility model.

[0025] Figure 3 It is the front view of the utility model.

[0026] Figure 4 It is a cross-sectional view of the utility model at point AA.

[0027] Figure 5 It is an enlarged view of point B of the utility model.

[0028] Figure 6 It is a schematic diagram of the cross-sectional structure of the utility model at point AA.

[0029] As shown in the figure: 1. Graphite disk body; 2. Substrate ring; 3. First substrate groove; 4. Air flow groove; 5. Second substrate groove; 6. First cylindrical groove; 7. Second cylindrical groove; 8. Third cylindrical groove; 9. Raised ring; 10. First step protrusion; 11. Second step protrusion; 12. Semicircular groove; 13. Semicircular protrusion. DETAILED DESCRIPTION

[0030] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0031] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0032] The utility model is further described in detail below in conjunction with the full text.

[0033] Combined with Figure 1-Figure 6 A MOCVD device for epitaxially growing a graphite disk comprises a graphite disk body 1, a substrate ring 2, a first substrate groove 3 and an airflow groove 4 are provided on the front of the graphite disk body 1, and a second substrate groove 5 is provided in the substrate ring 2; a plurality of first substrate grooves 3 and airflow grooves 4 are evenly distributed on the graphite disk body 1 with the center of the graphite disk body 1 as the center; specifically, the inner and outer grooves of the substrate ring 2 and the first substrate groove 3 are arranged to replace the three-circle distribution of the substrate grooves on the existing graphite disk, corresponding to the position of the heating wire of the heating system under the graphite plate, and well matching the temperature field of the heating system, the diameter of the graphite disk body 1 is 470-480mm, the outer circle diameters of the first substrate groove 3 and the substrate ring 2 are the same, which are 145-155mm, and the groove depth is 2mm, which further reduces the benefit of wafer-edge contact, so that the uniformity of wavelength standard deviation is greatly improved.

[0034] The second substrate grooves 5 are evenly distributed in the substrate ring 2 with the center of the graphite disk body 1 as the center. The second substrate grooves 5 are arranged in the substrate ring 2, which reduces the efficiency of the wafer contacting the edge, greatly improves the uniformity of the wavelength standard deviation, and can improve the growth efficiency of the epitaxial wafer, making the edge effect better.

[0035] The number of the first substrate slots 3 and the number of the airflow grooves 4 are the same, and the first substrate slots 3 and the airflow grooves 4 are staggered. In the specific implementation of the utility model, the number of the first substrate slots 3 and the airflow grooves 4 is 6.

[0036] When the utility model is implemented, Figure 2 and Figure 4 As shown, the back of the graphite disc body 1 is provided with a first cylindrical groove 6, a second cylindrical groove 7 and a third cylindrical groove 8, and the first cylindrical groove 6, the second cylindrical groove 7 and the third cylindrical groove 8 are arranged concentrically with the graphite disc body 1. The diameter of the first cylindrical groove 6 is 20-28 mm, the diameter of the second cylindrical groove 7 is 170-180 mm, and the diameter of the third cylindrical groove 8 is 440-450 mm. A raised ring 9 is arranged on the back edge of the graphite disc body 1. The inner diameter of the raised ring 9 is 455-465 mm, and one side of the inner circle of the raised ring 9 is chamfered, and the angle R1 is 30-40°.

[0037] When the utility model is implemented, Figure 1 and Figure 6As shown, a first step protrusion 10 is installed in the first substrate groove 3, a second step protrusion 11 is installed on the first step protrusion 10, a semicircular groove 12 is opened on the first step protrusion 10, and a semicircular protrusion 13 is installed in the first substrate groove 3. The semicircular protrusion 13 and the semicircular groove 12 form a circular structure. Since the closer to the edge of the graphite disk body 1, the greater the linear velocity, the flow rate of the MO source airflow will be aggravated. The edge chamfer of the airflow groove 4 is set, and the angle R2 is 30-40°. The deeper the depth of the airflow groove 4, the better the buffering and deceleration effect on the MO source airflow. Therefore, in this implementation, the closer the airflow groove 4 is to the edge of the graphite disk body 1, the deeper the depth of the multiple airflow grooves 4 thereon is, which is conducive to maintaining the uniformity of the MO source airflow in the center and edge areas of the graphite disk body 1. At the same time, the semicircular protrusion 13 and the semicircular groove 12 form a circular structure, and the circular structure is half protrusion and half groove, which can evenly disperse the MO source airflow, so that the incoming airflow reduces the flow rate, and then flows from both sides of the semicircular protrusion 13 and the semicircular groove 12, thereby effectively solving the wavelength non-uniformity problem in the windward area. At the same time, the semicircular protrusion 13 and the semicircular groove 12 provide normal thrust to the wafer to overcome the relative rotation and sliding between the groove and the wafer, effectively preventing the flying and jamming of the epitaxial wafer during the process, improving the uniformity of the epitaxial process, and extending the service life of the graphite tray 1.

[0038] Embodiment 1:

[0039] The airflow groove 4, the semicircular protrusion 13 and the semicircular groove 12 of the graphite disc body 1 allow the Mo source airflow to flow down from the top of the graphite disc body 1. During the high-speed rotation of the graphite disc body 1, the Mo source airflow is attracted down, and after reaching the first surface of the graphite disc body 1, it flows toward the edge of the graphite disc body 1 under the action of centrifugal force. At this time, due to the airflow groove 4 of the graphite disc body 1, part of the Mo source airflow flowing toward the edge of the graphite disc body 1 will flow into the airflow groove 4. The airflow groove 4 can buffer the airflow, so that the flow rate of the Mo source airflow flowing to the edge of the graphite disc body 1 is reduced, thereby improving the problem of large centrifugal force at the edge of the graphite disc body 1 and too fast Mo source flow rate, and further improving the problem of the outer edge wavelength of the epitaxial wafer grown on the graphite disc body 1 being too short or too long, so that the luminous wavelength of each area of ​​the epitaxial wafer is consistent. The airflow grooves 4 are evenly distributed on the graphite disk body 1 with the center of the graphite disk body 1 as the center, and can buffer and slow down the Mo source airflow flowing to the edge of the graphite disk body 1 multiple times, so that the emission wavelength of the epitaxial wafer can be more consistent.

[0040] Embodiment 2:

[0041] The utility model provides an MOCVD device for epitaxial growth of graphite disk, the diameter of the graphite disk body 1 is 477.15mm, the outer diameter of the first substrate groove 3 and the substrate ring 2 is the same, which is 151.38mm, the groove depth is 2mm, the diameter of the first cylindrical groove 6 is 25.39mm, the diameter of the second cylindrical groove 7 is 178.39mm, the diameter of the third cylindrical groove 8 is 445.43mm, and a raised ring 9 is provided on the back edge of the graphite disk body 1. The inner diameter of the raised ring 9 is 459.6mm, and one side of the inner ring of the raised ring 9 is chamfered, and the angle of R1 is 30°, which further reduces the benefit of the wafer contacting the edge, so that the uniformity of the wavelength standard deviation is greatly improved, and the epitaxial wafer prepared by this method is improved by about 50% compared with the normal upright epitaxial wafer.

[0042] The above describes the utility model and its implementation methods, which is not restrictive. What is shown in the full text is only one of the implementation methods of the utility model, and the actual structure is not limited thereto. In short, if ordinary technicians in this field are inspired by it, without departing from the purpose of the invention of the utility model, they can design a structure and embodiment similar to the technical solution without creativity, which should belong to the protection scope of the utility model.

Claims

1. A MOCVD device for epitaxially growing a graphite disk, comprising a graphite disk body (1), characterized in that: A substrate ring (2), a first substrate groove (3) and an airflow groove (4) are provided on the front side of the graphite disk body (1); a second substrate groove (5) is provided in the substrate ring (2); A plurality of the first substrate grooves (3) and air flow grooves (4) are evenly distributed on the graphite disc body (1) with the center of the graphite disc body (1) as the center; A plurality of the second substrate grooves (5) are evenly distributed in the substrate ring (2) with the center of the graphite disk body (1) as the center; A first cylindrical groove (6), a second cylindrical groove (7) and a third cylindrical groove (8) are provided on the back side of the graphite disc body (1).

2. The MOCVD device for epitaxially growing a graphite disk according to claim 1, characterized in that: The number of the first substrate slots (3) and the number of the airflow grooves (4) are the same.

3. The MOCVD device for epitaxially growing a graphite disk according to claim 1, characterized in that: The first substrate slots (3) and the airflow grooves (4) are arranged alternately.

4. The MOCVD device for epitaxially growing a graphite disk according to claim 1, characterized in that: The first cylindrical groove (6), the second cylindrical groove (7), and the third cylindrical groove (8) are arranged concentrically with the graphite disc body (1).

5. The MOCVD device for epitaxially growing a graphite disk according to claim 1, characterized in that: A raised ring (9) is provided on the back edge of the graphite disk body (1).

6. The MOCVD device for epitaxially growing a graphite disk according to claim 5, characterized in that: One side of the inner circle of the raised ring (9) is chamfered.

7. The MOCVD device for epitaxially growing a graphite disk according to claim 1, characterized in that: A first step protrusion (10) is installed in the first substrate groove (3), and a second step protrusion (11) is installed on the first step protrusion (10).

8. The MOCVD device for epitaxially growing a graphite disk according to claim 7, characterized in that: A semicircular groove (12) is provided on the first step protrusion (10), and a semicircular protrusion (13) is installed in the first substrate groove (3).

9. The MOCVD device for epitaxially growing a graphite disk according to claim 8, characterized in that: The semicircular protrusion (13) and the semicircular groove (12) form a circular structure.

Images