Automatic feeding and discharging system of SIC epitaxial equipment

Abstract

The invention provides an automatic feeding and discharging system of SIC epitaxial equipment, which comprises a tray conveying mechanical arm and a wafer conveying mechanical arm, and is used for conveying graphite trays, coating rings and wafers; the graphite disc cleaning and positioning device is used for blowing, cleaning and positioning the graphite disc; the coating ring and wafer separating and positioning device is used for separating and positioning the coating ring and the wafer; the wafer feeding device is used for storing wafers of which the process is not completed; the wafer discharging device is used for storing the wafers subjected to the process; the graphite disc cleaning and positioning device, the wafer feeding device, the wafer discharging device and the wafer separating and positioning device are all arranged on the outer sides of the disc conveying and the wafer conveying mechanical arm; the graphite disc cleaning and positioning device and the coating ring and wafer separation and positioning device are respectively provided with a positioner for identifying the direction of the graphite disc and calibrating the positioning edges of the coating ring and the wafer; the graphite disc cleaning and positioning device comprises an air blowing device and an air extracting device, the air blowing device blows the disc face of the stone mill disc, and the air extracting device extracts blown particles.

Description

Technical Field

[0001] The invention relates to silicon carbide epitaxial equipment, and in particular to an automatic loading and unloading system for SIC epitaxial equipment. Background Art

[0002] Silicon carbide semiconductors have excellent properties such as large bandgap, excellent stability, high thermal conductivity, high critical breakdown field strength, and high saturated electron drift velocity. They are ideal semiconductor materials for making high-temperature, high-frequency, high-power and strong radiation power electronic devices. The silicon carbide material used to make silicon carbide devices is usually a silicon carbide epitaxial wafer grown on a silicon carbide substrate.

[0003] Silicon carbide epitaxial growth has been commercialized, and CVD (chemical vapor deposition) is usually used to grow silicon carbide epitaxial wafers. Currently, most of the commercialized epitaxial furnaces are horizontal reactor epitaxial furnaces. Currently, most of the horizontal reactor epitaxial furnaces (LPE) are semi-automatic equipment. During production, a large number of production personnel are required to perform manual loading and unloading operations such as manual wafer placement and graphite disk cleaning. On the one hand, the work efficiency is low, and on the other hand, human operating errors / incomplete cleaning of graphite disks are prone to occur during the loading and unloading operations, resulting in chip damage / wafer contamination, resulting in reduced yield. What needs to be considered in the commercialization of silicon carbide epitaxial growth is how to improve the automation process, thereby improving the production capacity and quality of epitaxial wafers. Summary of the invention

[0004] Aiming to solve the problem of manual operation in existing silicon carbide epitaxial equipment, the present invention provides an automatic loading and unloading system for SIC epitaxial equipment, which can automatically separate and clean graphite disks, individually position graphite disks, coating rings and wafers, realize automatic wafer transmission, have high efficiency and little human interference factors.

[0005] In order to solve the above technical problems, the present invention provides an automatic loading and unloading system for SIC epitaxial equipment, comprising:

[0006] The disk transfer and wafer transfer robot arm is composed of a disk transfer robot arm and a wafer transfer robot arm. The disk transfer robot arm is used to transfer graphite disks, coating rings, and wafers, and the wafer transfer robot arm is used to load, unload and transfer wafers.

[0007] Graphite disk cleaning and positioning device, for blowing, cleaning and positioning the graphite disk;

[0008] A coating ring and wafer separation and positioning device is used to separate and position the coating ring and wafer;

[0009] Wafer loading device, used to store wafers that have not completed the process;

[0010] Wafer unloading device, used to store the wafers that have completed the process;

[0011] The graphite disk cleaning and positioning device, the wafer loading device, the wafer unloading device and the wafer separation and positioning device are all arranged on the outside of the disk transfer and wafer transfer mechanical arm;

[0012] The graphite disk cleaning positioning device and the coating ring and wafer separation positioning device are both provided with positioners for identifying the direction of the graphite disk and calibrating the coating ring and wafer positioning edges;

[0013] The graphite disk cleaning and positioning device comprises a cleaning device, and the cleaning device comprises an air blowing device and an air exhausting device. The air blowing device is used for blowing the disk surface of the stone mill disk, and the air exhausting device is used for extracting the blown particles.

[0014] In a preferred embodiment, the disc transfer and film transfer robot also includes a linear drive module, which includes a first lateral moving guide rail and a second lateral moving guide rail, and a movable platform is installed on the second lateral moving guide rail, and the disc transfer robot and film transfer robot are arranged up and down on the movable platform.

[0015] In a preferred embodiment, the movable platform is provided with a lifting device and a first telescopic device and a second telescopic device, and the lifting device allows the disk transfer robot arm and the film transfer robot arm to move up and down;

[0016] The first telescopic device allows the disk transfer robot arm to extend or retract horizontally; the second telescopic device allows the film transfer robot arm to extend or retract horizontally.

[0017] In a preferred embodiment, the moving platform is rotatably mounted on the second transverse moving guide rail, and the moving platform is connected to a rotating motor.

[0018] In a preferred embodiment, the wafer loading device and the wafer unloading device both include a placement cavity, in which guide transverse grooves are arranged at intervals up and down, and the guide transverse grooves are symmetrically arranged on both sides of the placement cavity;

[0019] The two symmetrical groups of guide transverse grooves are used to cooperate in placing a wafer, and the interval is used for the grabbing part of the wafer transfer robot arm to extend in and out.

[0020] In a preferred embodiment, a positioning frame is provided on one side of the millstone cleaning positioning device and the coating ring and wafer separation positioning device, the positioner is fixed on the positioning frame, and the positioner is arranged above the millstone cleaning positioning device or the coating ring and wafer separation positioning device.

[0021] In a preferred embodiment, the locator is a camera.

[0022] In a preferred embodiment, a rotating downward pressure cylinder is provided on the side of the stone millstone cleaning and positioning device for driving the cleaning device to clean the stone millstone.

[0023] In a preferred embodiment, the cleaning device includes a cleaning cover, and the cleaning cover is used to cover the graphite disk;

[0024] An air inlet and an air extraction port are arranged in the cleaning cover. The air inlet is connected to the air blowing device, and the air extraction port is connected to the air extraction device.

[0025] In a preferred embodiment, argon gas is introduced into the blowing device.

[0026] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0027] 1. By setting up a plate transfer and wafer transfer robot arm, a graphite plate cleaning and positioning device, a coating ring and wafer separation and positioning device, a wafer loading device, and a wafer unloading device, the wafer loading and unloading process is automated, and the problem of human operation errors in the growth process is solved, thereby improving the production capacity of the LPE epitaxial furnace and the surface yield of the epitaxial wafer.

[0028] 2. By setting an air blowing device and an air exhaust device on the graphite disk cleaning and positioning device, the automatic cleaning of the graphite disk can be achieved, avoiding the damage of the epitaxial wafer / reduction of the yield due to substandard operation when manually cleaning the graphite disk with an air gun. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is an overall diagram of the automatic loading and unloading system in the preferred embodiment of the present invention;

[0030] Figure 2 It is a structural diagram of a wafer loading device and a wafer unloading device in a preferred embodiment of the present invention;

[0031] Figure 3 It is a structural diagram of the disk transfer and film transfer mechanical arms in the preferred embodiment of the present invention;

[0032] Figure 4 It is a structural diagram of a graphite disk cleaning and positioning device in a preferred embodiment of the present invention;

[0033] Figure 5 Schematic diagram of the cleaning device in a preferred embodiment of the present invention.

[0034] Explanation of the reference numerals in the accompanying drawings: 1. disk and wafer transfer robot arm; 11. disk transfer robot arm; 12. wafer transfer robot arm; 13. first lateral moving guide rail; 14. second lateral moving guide rail; 15. moving platform; 16. lifting device; 17. first telescopic device; 18. second telescopic device; 2. graphite disk cleaning and positioning device; 21. cleaning device; 22. rotary downward pressure cylinder; 23. cleaning cover; 3. coating ring and wafer separation and positioning device; 4. wafer loading device; 41. placement cavity; 42. guide transverse groove; 43. wafer; 5. wafer unloading device; 6. positioning frame; 61. camera. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0036] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0037] In the description of the present invention, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connection" can be a wall-mounted 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 components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] At present, in the process of epitaxial growth of silicon carbide using an LPE horizontal epitaxial furnace, when feeding the wafer, it is necessary to manually use a jig to pick up, position and place the wafer; when taking out the wafer, it is still necessary to manually use a jig to pick up the wafer and use an air gun to clean the graphite disk. During this operation, if the personnel operate improperly and the cleaning of the jig / graphite disk is not up to standard, it may cause damage to the epitaxial wafer / reduced yield. In response to the problem of defective rate, the present embodiment provides an automatic loading and unloading system for silicon carbide epitaxial equipment that can automatically separate and clean the graphite disk, individually position the graphite disk, coating ring and wafer, and realize automatic wafer transfer, with high efficiency and few human interference factors. It can realize the automation of the loading and unloading process of the LPE horizontal epitaxial furnace, thereby improving the production capacity of the LPE epitaxial furnace and the quality of the epitaxial wafers.

[0039] refer to Figure 1-Figure 5 , the automatic loading and unloading system of SIC epitaxial equipment comprises:

[0040] The disk transfer and wafer transfer robot 1 is composed of a disk transfer robot 11 and a wafer transfer robot 12. The disk transfer robot 11 can be used to transfer graphite disks, coating rings, and wafers 43, and the wafer transfer robot 12 can be used to load, unload and transfer wafers 43;

[0041] The graphite disk cleaning and positioning device 2 is capable of blowing, cleaning and positioning the graphite disk;

[0042] The coating ring and wafer separation and positioning device 3 can separate and position the coating ring and wafer 43;

[0043] A wafer loading device 4, used to store wafers 43 that have not been processed yet;

[0044] The wafer unloading device 5 is used to store the wafers 43 that have completed the process.

[0045] Among them, the wafer loading device 4 and the wafer unloading device 5 are mainly used for the protection and placement of the wafer 43, and the graphite disk cleaning and positioning device 2, the wafer loading device 4, the wafer unloading device 5 and the wafer 43 separation and positioning device are all arranged on the outside of the disk transfer and wafer transfer robot arm 1. The graphite disk cleaning and positioning device 2, the coating ring and the wafer separation and positioning device 3 are all provided with positioners for identifying the direction of the graphite disk and calibrating the coating ring and the positioning edge of the wafer 43. The graphite disk cleaning and positioning device 2 includes a cleaning device 21, and the cleaning device 21 includes an air blowing device and an air extraction device. The air blowing device is used to blow the surface of the millstone, and the air extraction device is used to extract the blown particles. The automatic loading and unloading system of the SIC epitaxial equipment can realize the automation of the loading and unloading process, solve the problem of human operation errors in the growth process, and thus improve the production capacity of the LPE epitaxial furnace and the surface yield of the epitaxial wafer.

[0046] The disk transfer and wafer transfer robot 1 also includes a linear drive module, which is used as the main driving component for the disk transfer and wafer transfer robot 1 to transfer the graphite disk, coating ring, and wafer 43. The linear drive module includes a first transverse moving guide rail 13 and a second transverse moving guide rail 14, and a moving platform 15 is installed on the second transverse moving guide rail 14, and the disk transfer robot 11 and the wafer transfer robot 12 are arranged on the moving platform 15 in an upper and lower manner.

[0047] The moving platform 15 is rotatably mounted on the second transverse moving guide rail 14, and a rotating motor is connected and arranged below the moving platform. The rotating motor provides the moving platform 15 with respect to the second transverse moving guide rail 14, so as to facilitate the plate transfer robot arm 11 and the wafer transfer robot arm 12 to perform the turning and transmission of the wafer 43. A lifting device 16 and a first telescopic device 17 and a second telescopic device 18 are arranged on the moving platform 15, wherein the lifting device 16 allows the plate transfer robot arm and the wafer transfer robot arm to move up and down, the first telescopic device 17 allows the plate transfer robot arm to extend or retract horizontally, and the second telescopic device 18 allows the wafer transfer robot arm to extend or retract horizontally, so as to facilitate the plate transfer robot arm 11 and the wafer transfer robot arm 12 to perform the loading and unloading movement of the wafer 43.

[0048] The wafer loading device 4 and the wafer unloading device 5 both include a placement cavity 41, in which guide transverse grooves 42 are arranged at intervals from top to bottom, and the guide transverse grooves 42 are symmetrically arranged on both sides of the placement cavity 41. The two symmetrical sets of guide transverse grooves 42 are used to match and place a wafer 43, and the interval arrangement is used for the gripper of the wafer transfer robot arm 12 to extend in and out, so as to facilitate the acquisition and placement of the wafer 43.

[0049] The graphite cleaning and positioning device 2 is a device for cleaning and positioning a graphite disk. The graphite disk, also known as a SiC-coated graphite susceptor or Susceptor, is a key component used to support and heat a single crystal substrate in a metal organic chemical vapor deposition (MOCVD) device. Its thermal stability and thermal uniformity are crucial to the quality of epitaxial material growth. The graphite disk may corrode and lose powder due to corrosive gases and metal organic residues, which not only affects its service life but may also contaminate the chip. Therefore, the graphite disk needs to be cleaned regularly to remove surface contaminants. The graphite cleaning and positioning device is a device used to perform this cleaning task. It improves cleaning efficiency through automation and ensures that the graphite disk can be accurately positioned after cleaning for reuse.

[0050] The graphite disk cleaning and positioning device 2 is used to separate the graphite disk from the coating ring and the wafer 43, and is also used to clean the graphite disk and calibrate the positioning edge of the graphite disk. The graphite cleaning and positioning device is composed of a disk and wafer conveying mechanical arm 1, a linear drive module, a cleaning device 21, and a positioning and alignment mechanism. The positioning and alignment mechanism includes a locator and an alignment mechanism. The alignment mechanism adopts an existing graphite alignment mechanism, and the locator is a camera 61. The direction of the graphite disk can be identified by taking pictures, and the graphite alignment machine rotates and adjusts the direction of the graphite disk according to the identified direction.

[0051] The cleaning device 21 includes a cleaning cover 23, a blowing device and an exhaust device. The cleaning cover 23 is used to cover the graphite disk. An air inlet and an exhaust port are arranged in the cleaning cover 23. The air inlet is connected to the blowing device, and the exhaust port is connected to the exhaust device. The working mode of the cleaning cover is: the cleaning cover covers the graphite disk, and argon gas is introduced to purge the surface of the graphite disk. After the purge is completed, the exhaust starts to suck away the purged particles.

[0052] The cleaning cover 23 is driven by a rotating downward-pressing cylinder 22 provided on the side of the stone millstone cleaning and positioning device, which is used to drive the cleaning device 21 to rotate and press downward to clean the stone millstone.

[0053] The coating ring and wafer separation and positioning device 3 is a device for accurately placing and positioning the wafer 43, which can be used to separate the coating ring and the wafer 43 and calibrate the positioning edge of the coating ring and the wafer 43. A locator is arranged above the coating ring and wafer separation and positioning device 3, and the locator is a camera 61, which calibrates the positioning edge of the coating ring and the wafer 43 by taking pictures to identify and position the coating ring and the wafer 43, so as to ensure that the position of the wafer 43 in the coating ring is correct. The coating ring and the wafer 43 are separated and the calibration equipment of the locator can adopt the existing separation and calibration equipment.

[0054] The installation of the positioner is that a positioning frame 6 is provided on one side of the millstone cleaning positioning device and the coating ring and chip separation positioning device 3, and the camera 61 is fixed on the positioning frame 6, and the camera 61 is arranged above the millstone cleaning positioning device or the coating ring and chip separation positioning device 3.

[0055] The present embodiment provides an automatic loading and unloading system for SIC epitaxial equipment, which realizes the functions of automatically separating graphite disks, coating rings, and wafers, automatically cleaning graphite disks, automatically calibrating positioning edges, and automatically conveying, thereby solving the problem of wafer defects / damage caused by human factors during the manual loading and unloading process, thereby improving the production capacity of the epitaxial furnace and the yield of epitaxial wafers.

[0056] The above is only a preferred specific implementation of the present invention, but the design concept of the present invention is not limited to this. Any technician familiar with the technical field who uses this concept to make non-substantial changes to the present invention within the technical scope disclosed by the present invention shall be deemed to infringe the protection scope of the present invention.

Claims

1. An automatic loading and unloading system for SIC epitaxial equipment, characterized in that: include; The disk transfer and wafer transfer robot arm is composed of a disk transfer robot arm and a wafer transfer robot arm. The disk transfer robot arm is used to transfer graphite disks, coating rings, and wafers, and the wafer transfer robot arm is used to load, unload and transfer wafers. Graphite disk cleaning and positioning device, for blowing, cleaning and positioning the graphite disk; A coating ring and wafer separation and positioning device is used to separate and position the coating ring and wafer; Wafer loading device, used to store wafers that have not completed the process; Wafer unloading device, used to store the wafers that have completed the process; The graphite disk cleaning and positioning device, the wafer loading device, the wafer unloading device and the wafer separation and positioning device are all arranged on the outside of the disk transfer and wafer transfer mechanical arm; The graphite disk cleaning positioning device and the coating ring and wafer separation positioning device are both provided with positioners for identifying the direction of the graphite disk and calibrating the coating ring and wafer positioning edges; The graphite disk cleaning and positioning device comprises a cleaning device, and the cleaning device comprises an air blowing device and an air exhausting device. The air blowing device is used for blowing the disk surface of the stone mill disk, and the air exhausting device is used for extracting the blown particles.

2. The automatic loading and unloading system for SIC epitaxial equipment according to claim 1, characterized in that: The disc transfer and film transfer robot also includes a linear drive module, which includes a first lateral moving guide rail and a second lateral moving guide rail, and a moving platform is installed on the second lateral moving guide rail. The disc transfer robot and the film transfer robot are arranged up and down on the moving platform.

3. The automatic loading and unloading system for SIC epitaxial equipment according to claim 2, characterized in that: The movable platform is provided with a lifting device and a first telescopic device and a second telescopic device, and the lifting device is used for the disc transfer robot arm and the film transfer robot arm to move up and down; The first telescopic device allows the disk transfer robot arm to extend or retract horizontally; the second telescopic device allows the film transfer robot arm to extend or retract horizontally.

4. The automatic loading and unloading system for SIC epitaxial equipment according to claim 3, characterized in that: The moving platform is rotatably mounted on the second transverse moving guide rail, and the moving platform is connected to a rotating motor.

5. The automatic loading and unloading system for SIC epitaxial equipment according to claim 4, characterized in that: The wafer loading device and the wafer unloading device both include a placement cavity, in which guide transverse grooves are arranged at intervals up and down, and the guide transverse grooves are symmetrically arranged on both sides of the placement cavity; The two symmetrical groups of guide transverse grooves are used to cooperate in placing a wafer, and the interval is used for the grabbing part of the wafer transfer robot arm to extend in and out.

6. The automatic loading and unloading system for SIC epitaxial equipment according to claim 5, characterized in that: A positioning frame is provided on one side of the millstone cleaning positioning device and the coating ring and wafer separation positioning device, and the positioner is fixed on the positioning frame, and the positioner is arranged above the millstone cleaning positioning device or the coating ring and wafer separation positioning device.

7. The automatic loading and unloading system for SIC epitaxial equipment according to claim 6, characterized in that: The locator is a camera.

8. The automatic loading and unloading system for SIC epitaxial equipment according to claim 1, characterized in that: A rotating downward pressure cylinder is arranged on the side of the stone millstone cleaning and positioning device, which is used to drive the cleaning device to clean the stone millstone.

9. The automatic loading and unloading system for SIC epitaxial equipment according to claim 1, characterized in that: The cleaning device comprises a cleaning cover, and the cleaning cover is used to cover the graphite disk; An air inlet and an air extraction port are arranged in the cleaning cover. The air inlet is connected to the air blowing device, and the air extraction port is connected to the air extraction device.

10. The automatic loading and unloading system for SIC epitaxial equipment according to claim 9, characterized in that: Argon gas is introduced into the gas blowing device.

Images