Top plate and epitaxial growth apparatus including same

Abstract

The invention relates to a top plate and an epitaxial growth device comprising the same. Specifically, the invention relates to an epitaxial growth device, which comprises a wafer bearing platform and a reaction cavity. Wherein the wafer bearing table is used for bearing at least one wafer, and the reaction cavity is used for accommodating the wafer bearing table and comprises a top plate and an air supply device. The top plate is arranged at the top of the reaction cavity, and the gas supply device provides reaction gas to at least one wafer on the wafer bearing table. Wherein the top plate comprises a plurality of sunken structures, so that the friction resistance between the reaction gas and the surface of the top plate can be reduced when the reaction gas flows through the sunken structures.

Description

Technical Field

[0001] The invention relates to a semiconductor growth device, in particular to an epitaxial growth device. Background Art

[0002] The demand for semiconductor epitaxial materials is becoming more and more widespread. Typical III-V compound semiconductors such as gallium nitride can be used in light-emitting diodes and power devices. They can be grown in a variety of different ways, including molecular beam epitaxy (MBE), hydride vapor phase epitaxy (HVPE), metal-organic chemical vapor deposition (MOCVD), etc. Among them, MOCVD reactor is the best equipment for producing epitaxial thin films of sufficient quality for III-V compound semiconductors.

[0003] The MOCVD reactor includes a reaction chamber, a rotatable wafer tray is arranged at the bottom of the reaction chamber, and the wafer to be manufactured and processed is arranged on the wafer tray. A gas supply device is arranged above the inside of the reaction chamber. The reaction gas flowing in from the gas supply device flows to the wafer arranged on the upper surface of the tray, and grows the required epitaxial thin film on the upper surface of the wafer.

[0004] However, when the epitaxial thin film is formed on the surface of the wafer by the MOCVD process, residual deposits will be left on the inner wall of the reaction chamber, the surface of the gas nozzle, etc. These residual deposits will generate impurities in the reaction chamber, such as Figure 1 The top surface of the reaction chamber is smooth. Figure 1 The inner circle of the ceiling is the air supply area, and deposits are easily attached to the surface. In the subsequent process, they may be peeled off from the attachment due to factors such as gravity or airflow, and finally fall on the wafer to be processed, causing defects in the thin film generated on the surface of the wafer during the process, such as Figure 2 As shown, the electrical properties of the final compound semiconductor are affected and the production yield is reduced. In view of this, the common response method in the industry is to suspend the operation of the MOCVD device after a period of production and use a reaction chamber cleaning procedure to remove the residual deposits in the reaction chamber. However, the MOCVD device needs to be cooled down in advance during cleaning, which consumes a lot of time and thus reduces production capacity. In order to overcome the above problems, the industry is in urgent need of an innovative epitaxial growth device to improve the above problems. Summary of the invention

[0005] The main purpose of the present invention is to provide an innovative epitaxial growth device, in which a plurality of recessed structures are arranged on the top plate of the epitaxial growth device, so as to reduce the chance of sediments adhering to the surface of the top plate during the epitaxial growth process, and also reduce the chance of residual sediments subsequently adhering to the top plate peeling off due to factors such as gravity or airflow and contaminating the wafer.

[0006] To achieve the above-mentioned purpose, the present invention provides an epitaxial growth device, which includes a wafer carrier and a reaction chamber. The wafer carrier is used to carry at least one wafer, and the reaction chamber accommodates the wafer carrier, and includes a top plate and a gas supply device. The top plate is arranged on the top of the reaction chamber, and the gas supply device provides a reaction gas to at least one wafer on the wafer carrier. The top plate includes a plurality of recessed structures, so that when the reaction gas flows through the recessed structures, the friction resistance with the surface of the top plate can be reduced. .

[0007] In one embodiment of the epitaxial growth device, the depth of each recessed structure is approximately between 0.2 mm and 2 mm.

[0008] In one embodiment of the epitaxial growth device, the diameter of each recessed structure is approximately between 0.2 mm and 25 mm.

[0009] In one implementation of the epitaxial growth device, the spacing between the recessed structures is no greater than the diameter of each recessed structure.

[0010] In one embodiment of the epitaxial growth device, each recessed structure has one of a bowl-shaped structure, a cone-shaped structure, a quadrilateral structure, a trapezoidal structure, and a polygonal structure.

[0011] In one embodiment of the epitaxial growth device, the recessed structures are arranged on the top plate in one of radial, concentric, and spiral arrangements.

[0012] In one embodiment of the epitaxial growth device, the top plate is made of one of graphite, quartz, and graphite with a silicon carbide layer on its surface.

[0013] To achieve the above-mentioned purpose, the present invention provides a top plate used in an epitaxial growth device, wherein the epitaxial growth device has a reaction chamber, a reaction gas is provided, and the top plate is arranged on the top of the reaction chamber. The top plate is characterized in that the top plate includes a plurality of concave structures, so that when the reaction gas flows through the concave structures, the friction resistance with the top plate surface can be reduced.

[0014] In one embodiment of the top plate, the depth of each recessed structure is approximately between 0.2 mm and 2 mm.

[0015] In one embodiment of the top plate, the diameter of each recessed structure is approximately between 0.2 mm and 25 mm.

[0016] In one embodiment of the top plate, the spacing between the recessed structures is no greater than the diameter of the recessed structures.

[0017] After referring to the accompanying drawings and the embodiments described below, a person skilled in the art will be able to understand other objects, technical means and implementation schemes of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a ceiling plate in an existing epitaxial growth device;

[0019] Figure 2 A schematic diagram of defect distribution on a wafer surface after epitaxial growth using an existing epitaxial growth device;

[0020] Figure 3 A schematic diagram of the structure of an epitaxial growth device according to an embodiment of the present invention;

[0021] Figure 4 It is a partial three-dimensional schematic diagram of an epitaxial growth device according to an embodiment of the present invention;

[0022] Figure 5 A schematic diagram of the structure of a top plate in an epitaxial growth device according to an embodiment of the present invention;

[0023] Figure 6 A schematic diagram of the airflow between the top plate and the wafer in an epitaxial growth device according to an embodiment of the present invention;

[0024] Figure 7 A schematic diagram showing the reduction of surface defects of a wafer after epitaxial growth using the epitaxial growth device of the present invention;

[0025] Figure 8 Schematic cross-sectional view of the recessed structure on the top plate in various embodiments of the present invention;

[0026] Fig. 9 A schematic diagram of the distribution of a plurality of recessed structures on a top plate in one embodiment of the present invention;

[0027] Fig.10 Schematic diagram of the distribution of multiple recessed structures in different arrangements on the top plate in various embodiments of the present invention;

[0028] Fig.11 Schematic diagram of different recessed structure distribution designs on the top plate in two embodiments of the present invention;

[0029] Fig.12 Schematic diagram of the distribution of a plurality of recessed structures on the top plate in various embodiments of the present invention; and

[0030] Fig.13 Schematic diagram of the distribution of multiple recessed structures on the top plate in multiple implementation schemes.

[0031] Description of Reference Numerals

[0032] 1Epitaxial growth device

[0033] 10 Reaction chamber

[0034] 20 Wafer carrier

[0035] 30 Wafer

[0036] 40 Top Plate

[0037] 42 Concave structure

[0038] 50 Air supply device

[0039] 52 Air outlet

[0040] 100 Ceiling

[0041] V small vortex. DETAILED DESCRIPTION

[0042] The present invention will be explained below by way of examples, and the examples of the present invention are not intended to limit the present invention to any specific environment, application or special method as described in the examples. Therefore, the description of the examples is only for the purpose of explaining the present invention, and is not intended to limit the present invention. It should be noted that in the following examples and drawings, elements that are not directly related to the present invention have been omitted and are not shown, and the dimensional relationship between the elements in the drawings is only for easy understanding, and is not intended to limit the actual proportion.

[0043] Please also read Figure 3 and Figure 4 As shown, Figure 3 is a schematic structural diagram of an epitaxial growth device in one embodiment of the present invention, Figure 4 It is a partial three-dimensional schematic diagram of an epitaxial growth device in one embodiment of the present invention. In the embodiment shown in the figure, the epitaxial growth device 1 of the present invention includes a reaction chamber 10 and a wafer carrier 20. Among them, the wafer carrier 20 is used to carry at least one wafer 30 to be processed. The reaction chamber 10 has a accommodating space defined by a closed side wall to accommodate the wafer carrier 20. The reaction chamber 10 also includes a top plate 40 and a gas supply device 50, wherein the top plate 40 is arranged on the side wall at the top end of the reaction chamber 10, and the top plate 40 can be made of one of graphite, quartz, and a silicon carbide layer on the graphite surface. The gas supply device 50 provides reaction gas to the reaction chamber 10 through a gas supply pipeline and a gas outlet 52, so that the wafer 30 to be processed on the wafer carrier 20 undergoes epitaxial growth of, for example, III-V compounds.

[0044] Please refer to the combined Figure 5, which shows a schematic diagram of the structure of the top plate 40 in one embodiment of the present invention. One of the features of the epitaxial growth device 1 of the present invention is that the top plate 40 includes a plurality of recessed structures 42, each recessed structure 42 has a recess of a specific size and is recessed to a specific depth from the surface of the top plate 40. In a preferred embodiment, the diameter of each recessed structure 42 is approximately between 0.2 mm and 25 mm, and the depth of each recessed structure 42 is approximately between 0.2 mm and 2 mm. Moreover, the spacing between each recessed structure 42 is not greater than the diameter of each recessed structure 42, that is, the spacing between each recessed structure 42 is substantially between 0.2 mm and 25 mm. Please refer to Figure 6 , which shows a schematic diagram of the airflow between the top plate 40 and the wafer 30 in one embodiment of the present invention. The arrows in the figure only represent the direction of the airflow, which is used to illustrate the technical features of the top plate of the present invention, and is not the actual direction and strength of the airflow. Figure 6 As shown, when the reaction gas flows into the reaction chamber 10 from the gas outlet 52 of the gas supply device 50, a small vortex V (vortex) will be formed in the recessed structure 42 when the gas flow passes through the top plate 40, so that the gas flow on the surface of the top plate 40 actually "jumps over" the recessed structure, thereby reducing the friction resistance with the surface of the top plate. In other words, the gas flow of the reaction gas in the boundary layer of the gas flow on the surface of the top plate 40 is relatively "slippery", so that the friction resistance between the reaction gas and the surface of the top plate can be reduced when the reaction gas flows through each recessed structure 42, thereby reducing the chance of the reaction gas forming deposits on the surface of the top plate 40, and also reducing the chance of residual deposits attached to the top plate being peeled off due to gravity or airflow and contaminating the wafer. Figure 7 As shown, it shows that the epitaxial growth device with the top plate containing the concave structure disclosed in the present invention is used, and the defect pollution caused by the peeling of the residual deposits on the top plate on the wafer surface after the epitaxial growth process is relatively Figure 2 The surface area of ​​the wafer produced by the conventional process is shown to be substantially reduced.

[0045] As mentioned above, in order to reduce the chance of deposition of reaction gas on the top plate 40, the present invention discloses a design of multiple different recessed structures disposed on the top plate of the epitaxial growth device. Figure 8 , which shows a cross-sectional schematic diagram of a recessed structure 42 on the top plate in multiple embodiments of the present invention. These recessed structures 42 can be, but are not limited to, a bowl-shaped structure, a cone-shaped structure, a quadrilateral structure, a trapezoidal structure, a polygonal structure, or a combination thereof. Any recessed structure design that can reduce the adhesion of reactive gas on the top plate surface is equally covered by the present invention. In addition, please refer to Fig. 9 and Fig.10 ,in, Fig. 9A schematic diagram showing the distribution of a plurality of recessed structures 42 on a top plate in an embodiment of the present invention is shown. In this embodiment, the spacing between the plurality of recessed structures 42 on the top plate 40 of the present invention is not greater than the diameter of the recessed structures 42, and the recessed structures 42 are distributed on the top plate 40 in substantially the same manner. On the other hand, Fig.10 The diagram also shows the distribution of the plurality of recessed structures 42 on the top plate in various embodiments of the present invention in different arrangements. The recessed structures 42 on the top plate 40 may be, for example, but not limited to, Fig.10 The radial arrangement of part (A) in Fig.10 The concentric circles in part (B) of Fig.10 The (C) part in the spiral arrangement is one or a combination thereof. In particular, if Fig.10 As shown in the (B) and (C) parts of FIG. 1 , the concave structures 42 of substantially the same size are not limited to be distributed in a top plate 40. Depending on the gas flow conditions in the reaction chamber 10 of the actual epitaxial growth device 1, the concave structures 42 of different diameters can be distributed on a top plate 40 to substantially reduce the residual deposits of the reaction gas on the surface of the top plate 40. For example, Fig.11 As shown, two distribution designs of different recessed structures on the top plate are shown, which can distinguish different areas on the surface of the top plate. For example, from the center of the gas outlet to the outside, recessed structures of different sizes (for example, from small to large) and different intervals (for example, from dense to sparse) are arranged to reduce the residual deposits of the reaction gas on the surface of the top plate 40.

[0046] Please refer to the combined Fig.12 and Fig.13 ,in, Fig.12 The schematic diagram of the distribution of the plurality of recessed structures 42 on the top plate 40 in various embodiments of the present invention is shown. In this embodiment, the recessed structures 42 on the top plate 40 of the present invention can be applied as follows: Figure 8 The different cross-sectional structures shown may be, for example, but not limited to, a bowl-shaped structure, a quadrilateral structure, a cone-shaped structure, a triangular structure, and are distributed on the top plate 40 in substantially the same manner with the same spacing. Fig.13 It is shown that in multiple embodiments of the present invention, the top plate can select to arrange and distribute the different recessed structures 42 only in specific areas according to the gas flow conditions in the reaction chamber of the actual epitaxial growth device.

[0047] The above embodiments are only used to illustrate the embodiments of the present invention and to explain the technical features of the present invention, and are not used to limit the protection scope of the present invention. Any changes or equivalent arrangements that can be easily completed by a person skilled in the art belong to the scope claimed by the present invention, and the scope of protection of the present invention shall be subject to the attached claims.

Claims

1. An epitaxial growth device, comprising: a wafer carrying platform for carrying at least one wafer; and A reaction chamber is provided to accommodate the wafer carrier, the reaction chamber comprises a top plate and a gas supply device, the top plate is arranged on the top of the reaction chamber, the gas supply device provides a reaction gas to the at least one wafer on the wafer carrier, in, The top plate includes a plurality of concave structures, so that the friction resistance between the reaction gas and the surface of the top plate can be reduced when the reaction gas flows through the concave structures. 2 . The epitaxial growth device as claimed in claim 1 , wherein a depth of each of the recessed structures is approximately between 0.2 mm and 2 mm. 3 . The epitaxial growth device as claimed in claim 1 , wherein a diameter of each of the recessed structures is approximately between 0.2 mm and 25 mm. 4 . The epitaxial growth device as claimed in claim 3 , wherein a distance between each of the recessed structures is not greater than a diameter of each of the recessed structures. 5 . The epitaxial growth device as claimed in claim 1 , wherein each of the concave structures has one of a bowl-shaped structure, a cone-shaped structure, a quadrilateral structure, a trapezoidal structure, and a polygonal structure. 6 . The epitaxial growth device as claimed in claim 1 , wherein the recessed structures are arranged on the top plate in one of a radial arrangement, a concentric circle arrangement, and a spiral arrangement.

7. The epitaxial growth device as claimed in claim 1, wherein the top plate is made of one of graphite, quartz, and graphite with a silicon carbide layer on its surface.

8. A top plate used in an epitaxial growth device, wherein the epitaxial growth device has a reaction chamber, a reaction gas is provided, and the top plate is arranged on the top of the reaction chamber, wherein the top plate is characterized in that: The top plate includes a plurality of concave structures, so that the friction resistance between the reaction gas and the surface of the top plate can be reduced when the reaction gas flows through the concave structures. 9 . The top plate for an epitaxial growth device as claimed in claim 8 , wherein the depth of each of the concave structures is approximately between 0.2 mm and 2 mm. 10 . The top plate for an epitaxial growth device as claimed in claim 8 , wherein a diameter of each of the concave structures is approximately between 0.2 mm and 25 mm. 11 . The top plate used in an epitaxial growth device as claimed in claim 10 , wherein the spacing between the recessed structures is not greater than the diameter of the recessed structures.

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