A SiC epitaxial vertical reaction chamber structure

Abstract

The present application relates to the field of SiC epitaxy technology, and mainly relates to a SiC epitaxy vertical reaction chamber structure, comprising: a liner tube, which is a cylindrical structure with openings at both ends, one end for process gas to enter, and the other end for process gas to flow out; a process tube, which is a sleeve structure with only one end open, the opening being downwardly sleeved outside the liner tube, with a sandwich formed between the process tube and the liner tube for process gas to pass through; a wafer boat, which is arranged in the liner tube and is used to carry multiple layers of wafers; a gas supply assembly, which is used to deliver process gas to the liner tube; and a heating assembly, which is arranged outside the process tube and is used to heat the wafer boat. The present application arranges a wafer boat capable of carrying multiple layers of wafers in the liner tube, the gas supply assembly passes process gas into the liner tube, and the heating assembly heats the liner tube, so that SiC can be epitaxially grown on multiple layers of wafers, and the process gas then flows out smoothly from the sandwich between the liner tube and the process tube. This structure can significantly improve the production efficiency of SiC epitaxy and reduce the cost of epitaxy.

Description

Technical Field

[0001] The present application relates to the field of SiC epitaxial technology, and mainly to a SiC epitaxial vertical reaction chamber structure. Background Art

[0002] The SiC (silicon carbide) reaction growth chamber is the core component of the entire epitaxial furnace equipment. The uniformity, growth rate and defect density of SiC epitaxial growth are closely related to it. Currently, the epitaxial furnace reaction chamber structures on the market are mainly divided into two types: horizontal and vertical. Figure 1 , Figure 1 This is a schematic diagram of the structure of an existing horizontal hot wall reactor model. The reactor structure is monolithic, with the wafer placed on a graphite base. Ultra-high temperatures are achieved by induction heating, while the graphite parts surrounding the reactor are heated to form a hot wall to maintain the temperature inside the reactor and the uniformity of the temperature field in the substrate placement area. The growth source gas enters and exits from one end to the other to achieve horizontal laminar flow, and the substrate is rotated at a low speed by air flotation to offset the growth unevenness caused by the exhaustion of the reaction source along the way. The reactor structure is relatively simple and can perform ultra-fast epitaxial growth. Figure 2 , Figure 2 This is a structural schematic diagram of an existing vertical hot-wall reaction chamber model. The reaction chamber structure is also monolithic. The wafer is placed on a graphite base and uses zoned resistance heating. The bottom heating part acts on the wafer tray area, and the upper heating part acts on the upper middle part of the reaction chamber wall. This temperature field design can achieve good temperature uniformity within the wafer area and achieve better growth uniformity control. In terms of flow field, the reactant gas source is sprayed vertically from a long distance combined with high-speed rotation of the wafer carrier to accelerate the growth rate and improve uniformity.

[0003] Currently, these two epitaxial growth methods are only suitable for single-wafer growth. While some patents have been filed domestically and internationally to optimize their reaction chamber structures, these methods can only be scaled up to two, three, or four wafers. Production efficiency remains limited, and they cannot meet the growing market demand for cost control of SiC power devices. Therefore, it is necessary to develop a reactive structure capable of growing multiple wafers simultaneously to improve efficiency. Therefore, existing technologies still need improvement and development. Summary of the Invention

[0004] In view of the above-mentioned deficiencies in the prior art, the purpose of the present application is to provide a SiC epitaxial vertical reaction chamber structure, aiming to solve the problem that the existing reactive structures are mostly monolithic, resulting in low epitaxial efficiency.

[0005] The technical solution of this application is as follows:

[0006] The present application provides a SiC epitaxial vertical reaction chamber structure, which includes:

[0007] The liner is a cylindrical structure with two ends open, one end for process gas to enter and the other end for process gas to flow out;

[0008] The process pipe is in the shape of a sleeve structure with only one end open, and the opening is downwardly sleeved outside the liner pipe, and a sandwich is formed between the process pipe and the liner pipe for the process gas to pass through;

[0009] a wafer boat, disposed in the liner tube and used for carrying multiple layers of wafers;

[0010] a gas supply assembly for delivering process gas to the liner;

[0011] A heating component is arranged outside the process tube and is used for heating the wafer boat.

[0012] The present application arranges a wafer boat capable of carrying multiple layers of wafers in a liner tube, a gas supply assembly introduces process gas into the liner tube, and a heating assembly heats the liner tube to ensure the epitaxial temperature of the wafer boat, thereby enabling epitaxial SiC growth on multiple layers of wafers. The process gas after epitaxy then flows out smoothly from the interlayer between the liner tube and the process tube.

[0013] Furthermore, the wafer boat comprises:

[0014] The bottom plate is in the shape of a disc structure;

[0015] The top plate is in the shape of a disc structure and is arranged above the bottom plate;

[0016] A column, wherein a plurality of wafer placement grooves are evenly formed on the inner side of the column along the extension direction, the bottom end of the column is detachably connected to the bottom plate, and the top end of the column is detachably connected to the top plate;

[0017] Through holes for process gas to pass through are opened in the middle of the bottom plate and the top plate.

[0018] Furthermore, the SiC epitaxial vertical reaction chamber structure further includes a rotating assembly for driving the wafer boat to rotate along the circumference of the base plate.

[0019] Furthermore, the wafer placement groove includes a placement surface for placing the wafer, and a first downward-inclined slope is provided at one end of the placement surface close to the middle of the wafer, and a second upward-inclined slope is provided at one end of the placement surface away from the middle of the wafer, and the top of the second slope is used to abut against the bottom edge of the wafer.

[0020] Furthermore, the SiC epitaxial vertical reaction chamber structure further includes:

[0021] The heat insulation layer is arranged below the wafer boat, and the heat insulation layer comprises a plurality of heat insulation sheets stacked at intervals, and a through hole for process gas to pass through is opened in the middle of the heat insulation sheet.

[0022] Furthermore, the heating component includes:

[0023] A top heater, which is in the shape of a flat plate structure and is arranged on the top of the process tube;

[0024] A middle heater, which is cylindrical in shape and is sleeved outside the process tube and corresponds to the position of the wafer boat;

[0025] The lower heater is cylindrical in shape, is sleeved outside the process pipe, and is arranged below the middle heater.

[0026] Furthermore, the SiC epitaxial vertical reaction chamber structure further includes:

[0027] The heat-insulating layer is arranged outside the heating assembly and covers the sides and top of the process pipe.

[0028] Furthermore, the insulation layer includes:

[0029] an upper insulation layer, covering the top of the process pipe and corresponding to the position of the top heater;

[0030] The middle insulation layer is cylindrical in shape and is sleeved outside the process pipe, corresponding to the position of the middle heater;

[0031] The lower insulation layer is cylindrical in shape and is sleeved outside the process pipe, corresponding to the position of the lower heater;

[0032] The bottom insulation layer is cylindrical in shape and is sleeved outside the process pipe to cover the remaining part of the side of the process pipe;

[0033] Through holes for installing infrared pyrometers are provided in the middle of the upper thermal insulation layer, the side surfaces of the middle thermal insulation layer and the lower thermal insulation layer.

[0034] Furthermore, the layer height of each layer of the wafer placement groove is 4.75 mm, and the gap of the wafer placement groove is 2.25 mm;

[0035] The surface of the wafer boat is coated with a SiC coating with a thickness of 100 μm;

[0036] The surfaces of the liner pipe and the process pipe are plated with a SiC coating with a thickness of 100 μm.

[0037] Furthermore, the layer height of each layer of the thermal insulation sheet is 4 mm, and the thickness of the thermal insulation sheet is 2 mm;

[0038] The surface of the heat insulation sheet is plated with a SiC coating with a thickness of 100 μm.

[0039] Beneficial Effects: This application places a wafer boat capable of carrying multiple layers of wafers within a cylindrical liner tube, introduces process gas into the liner tube via a gas supply assembly, and heats the liner tube with a heating assembly to enable epitaxial growth of SiC on the multiple layers of wafers. Furthermore, after passing through the liner tube and reaching the top of the process tube, the epitaxial process gas can flow smoothly out from the interlayer between the liner tube and the process tube, thus avoiding affecting the epitaxial growth process. The epitaxial vertical reactive structure provided by this application facilitates the simultaneous epitaxial growth of SiC on multiple layers of wafers, significantly improving production efficiency and reducing epitaxial costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 Schematic diagram of the existing horizontal hot wall reaction chamber model structure.

[0041] Figure 2 Schematic diagram of the existing vertical hot wall reaction chamber model structure.

[0042] Figure 3 This is one of the structural schematic diagrams of the SiC epitaxial vertical reaction chamber structure of this application.

[0043] Figure 4 This is the second structural diagram of the SiC epitaxial vertical reaction chamber structure of this application.

[0044] Figure 5 This is the third structural diagram of the SiC epitaxial vertical reaction chamber structure of this application.

[0045] Figure 6 This is a top view of the wafer boat of the SiC epitaxial vertical reaction chamber structure of this application.

[0046] Figure 7 This is a schematic diagram of the structure of the wafer placement slot of the SiC epitaxial vertical reaction chamber structure of this application.

[0047] Figure 8 This is a schematic diagram of the structure of the top heater of the SiC epitaxial vertical reaction chamber structure of this application.

[0048] Figure 9 This is a schematic structural diagram of the middle heater of the SiC epitaxial vertical reaction chamber structure of this application.

[0049] Figure 10 This is a schematic structural diagram of the lower heater of the SiC epitaxial vertical reaction chamber structure of this application.

[0050] Explanation of reference numerals: 100, liner; 200, process tube; 300, wafer boat; 310, bottom plate; 320, top plate; 330, column; 331, wafer placement slot; 332, placement surface; 333, first inclined surface; 334, second inclined surface; 400, heating assembly; 410, top heater; 420, middle heater; 430, lower heater; 500, thermal insulation layer; 510, thermal insulation sheet; 600, thermal insulation layer; 610, upper thermal insulation layer; 620, middle thermal insulation layer; 630, lower thermal insulation layer; 640, bottom thermal insulation layer. DETAILED DESCRIPTION

[0051] The present application provides a SiC epitaxial vertical reaction chamber structure. To make the purpose, technical solution, and effects of the present application clearer and more specific, the present application is further described below. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0052] The technical solution of this application is as follows:

[0053] Reference Figure 3-Figure 10 The present application provides a SiC epitaxial vertical reaction chamber structure, which includes:

[0054] The liner 100 is a cylindrical structure with two ends open, one end for process gas to enter and the other end for process gas to flow out;

[0055] The process pipe 200 is in the form of a sleeve structure with only one end open. The opening is downwardly sleeved outside the liner 100, forming an interlayer between the process pipe 200 and the liner 100 for the process gas to pass through.

[0056] The wafer boat 300 is disposed in the liner 100 and is used to carry multiple layers of wafers;

[0057] A gas supply assembly (not shown in the figure) for delivering process gas to the liner 100;

[0058] The heating assembly 400 is disposed outside the process tube 200 and is used to heat the wafer boat 300 .

[0059] Reference Figure 4 The present application places a wafer boat 300 capable of carrying multiple layers of wafers in a cylindrical liner 100, introduces process gas into the liner 100 through a gas supply assembly, and heats the liner 100 with a heating assembly 400 to enable epitaxial growth of SiC on the multiple layers of wafers. Furthermore, the epitaxial process gas, after passing through the liner 100 and reaching the top of the process tube 200, can flow smoothly out from the interlayer between the liner 100 and the process tube 200, thus avoiding affecting the epitaxial growth process. The epitaxial vertical reactive structure provided by the present application facilitates the simultaneous epitaxial growth of SiC on multiple layers of wafers, significantly improving production efficiency and reducing epitaxial costs.

[0060] The liner 100 and process tube 200 can be made of semiconductor-grade graphite and coated with a SiC coating with a thickness of 100 μm. This coating enhances surface purity and density, preventing metal diffusion contamination at high temperatures and particle contamination from high thermal shock.

[0061] The process gases include a carbon source gas, a silicon source gas, a dopant gas, and a carrier gas. The carbon source gas can be ethylene (C2H4) with a purity of 6N, a pressure of 0.2-0.4 MPa, and a maximum flow rate of 500 sccm. The silicon source gas can be trichlorosilane (SiHCl3) with a purity of 6N, a pressure of 0.2 MPa, and a maximum flow rate of 500 sccm. The dopant gas includes nitrogen (N2) with a purity of 6N, a pressure of 0.2-0.4 MPa, and a maximum flow rate of 5 SLM. The carrier gas includes hydrogen (H2) and argon (Ar) with a purity of 9N, a pressure of 0.2-0.4 MPa, and a maximum flow rate of 110 SLM. The argon has a purity of 5N, a pressure of 0.2-0.4 MPa, and a maximum flow rate of 15 SLM. Specifically, by providing corresponding gas supply pipelines and gas premixing chamber structures in the gas supply assembly, the gas components are premixed to form the process gas, which is then delivered into the liner tube 100. The arrangement of the gas supply pipeline and the gas premixing chamber may refer to the prior art and will not be described in detail here.

[0062] Reference Figure 5 and Figure 6 In a specific embodiment of the present application, the wafer boat 300 includes:

[0063] The bottom plate 310 is in the shape of a disc structure;

[0064] The top plate 320 is in the shape of a disc structure and is disposed above the bottom plate 310;

[0065] A column 330 has a plurality of wafer placement grooves 331 formed evenly along the inner side of the column 330 along the extension direction. The bottom end of the column 330 is detachably connected to the bottom plate 310, and the top end of the column 330 is detachably connected to the top plate 320.

[0066] Through holes are provided in the middle of the bottom plate 310 and the top plate 320 for the process gas to pass through.

[0067] In this application, multiple wafer placement slots 331 are provided to facilitate stacking and suspending multiple wafers, facilitating simultaneous epitaxial SiC growth. Through-holes are provided in the bottom plate 310 and top plate 320 to facilitate the entry of process gas and its direct application to the wafers. Depending on the direction of process gas entry, the gas disperses after acting on the first layer of wafers and continues to flow to subsequent wafers for epitaxial growth, facilitating simultaneous epitaxial SiC growth on multiple layers of wafers.

[0068] The wafer placement groove 331 can be oriented toward the center of the wafer, and multiple columns 330 can be provided to ensure that the wafer can be placed and the wafer can be kept stable, so as to facilitate uniform epitaxy of SiC on the wafer. Figure 5 and Figure 6 , the number of columns 330 in this application is set to 3. If too many columns 330 are set, the gas circulation effect will be affected. Setting 3 can simultaneously ensure the stability of multi-layer wafers and the circulation of process gases. Among them, if 3 or more columns 330 are set to be evenly distributed along the circumference of the base plate 310, the size of the wafer that can be directly placed will be limited, or disassembly operations will be required when placing it. Specifically, after setting one column 330, the other two columns 330 can be set symmetrically with its direction as the axis, with an angle greater than 90° and generally not greater than 100°, so that wafers of corresponding sizes can be directly placed into the wafer placement groove 331, and it is also beneficial to keep the wafer stable during the subsequent epitaxial process.

[0069] Among them, the shape of the through holes arranged in the middle of the bottom plate 310 and the top plate 320 is preferably circular, so that the airflow is blocked by the first wafer when entering the wafer boat rack 300, and the airflow with an overall circular cross-section can easily disperse toward the circumference of the wafer, thereby improving the uniformity of the airflow flowing through the circumference of the wafer boat rack 300, which is beneficial to improving the uniformity of the SiC epitaxial growth.

[0070] Furthermore, the height of each layer of wafer placement slots 331 can be set to 4.75mm, and the gap between wafer placement slots 331 can be set to 2.25mm. The number of wafer placement slots 331 can range from 10 to 50, depending on the number of epitaxy cells required. The wafer boat 300 can be made of semiconductor-grade graphite, and can be coated with a SiC coating with a thickness of 100μm.

[0071] Reference Figure 5 Specifically, the SiC epitaxial vertical reaction chamber structure of the present application can be placed on the base of an epitaxial furnace. The base can be provided with a gas chamber, which has a through hole connected to the interlayer between the liner tube 100 and the process tube 200. The process gas after epitaxy can be discharged through the gas chamber.

[0072] Reference Figure 4 ( Figure 4The straight trajectory arrows in the middle indicate the flow direction of the process gas at the two end openings of the liner 100, and the elliptical trajectory arrows indicate that the wafer boat 300 is rotatable). In a specific embodiment of the present application, the SiC epitaxial vertical reaction chamber structure also includes a rotating component (not shown in the figure) for driving the wafer boat 300 to rotate circumferentially along the base plate 310.

[0073] In the present application, since the process gas will be blocked by the first layer of wafers after entering and then dispersed before acting on the subsequent wafers, when the wafer boat 300 is driven by the rotating assembly to rotate along the circumference of the bottom plate 310, the columns 330 and the wafer placement grooves 331 can, through rotation, guide and pressurize part of the process gas flowing from bottom to top into the gaps between subsequent adjacent wafers, thereby improving the uniformity of the airflow. At the same time, the process gas continuously flows circumferentially around the wafer boat 300 to ensure the flow effect of the gaps between the wafers. The present application can effectively reduce the asymmetry of the thermal field and flow field through the dynamic rotation of the wafer boat 300, improve the uniformity of epitaxy, and help ensure the uniformity of epitaxial growth of subsequent wafers.

[0074] Among them, by setting corresponding dimensions, the distance between the outer contour of the wafer boat 300 and the inner wall of the liner 100 can be controlled at a smaller scale, thereby reducing the tendency of the process gas to flow out directly from the gap between the column 330 and the liner 100, so as to facilitate the flow of air into the through hole set in the bottom plate 310, and then flow through the wafer boat 300 from bottom to top, and then flow out from the through hole set on the top plate 320 after acting on the multi-layer wafers carried, which is conducive to ensuring that the multi-layer wafers are epitaxially grown at the same time.

[0075] The same rotation direction is generally maintained during the epitaxial process to avoid disturbances to the flow of process gases caused by reversal.

[0076] Specifically, the rotating assembly may include a circular flange, a motor and a synchronous belt. The wafer boat 300 may be mounted on the circular flange. The circular flange is driven by the motor and the synchronous belt to drive the wafer boat 300 to rotate.

[0077] Reference Figure 7 In a specific embodiment of the present application, a wafer placement groove 331 includes a placement surface 332 for placing a wafer. A downwardly inclined first slope 333 is provided at one end of the placement surface 332 near the center of the wafer. An upwardly inclined second slope 334 is provided at one end of the placement surface 332 away from the center of the wafer. The top of the second slope 334 is configured to abut against the bottom edge of the wafer. The top surface of the wafer does not contact the wafer placement groove 331.

[0078] In the present application, by abutting the top of the second bevel 334 against the bottom edge of the wafer, the wafer can be suspended to ensure the coverage of the epitaxial SiC on the wafer, and gaps are formed between the two sides of the suspended wafer and the wafer placement groove 331. By rotating the wafer boat 300, the process gas flowing into the wafer can also pass smoothly through these gaps and perform epitaxy. By setting the first bevel 333, the flow trend of the process gas to the gap can be maintained, and the circulation effect of the process gas can be improved. Through the setting of the present application, even after stacking multiple layers of wafers at intervals, the epitaxial effect and epitaxial quality of the multi-layer wafers can be guaranteed.

[0079] Reference Figure 3-Figure 5 In a specific embodiment of the present application, the SiC epitaxial vertical reaction chamber structure further includes:

[0080] The heat insulating layer 500 is disposed below the wafer boat 300 . The heat insulating layer 500 includes a plurality of heat insulating sheets 510 stacked at intervals. A through hole is provided in the middle of the heat insulating sheet 510 for the process gas to pass through.

[0081] In the epitaxial process of the present application, the temperature inside the epitaxial furnace needs to reach 1600°C, but since the furnace door of the epitaxial furnace is arranged below the process tube 200, a sealing ring is generally provided here to ensure the airtightness of the reaction chamber structure. By providing an insulation layer 500, the temperature at the furnace door is ensured to be no higher than 200°C for protection.

[0082] The thermal insulation layer 500 includes multiple layers of thermal insulation sheets 510 stacked at intervals. The thermal insulation sheets 510 can be made of a carbon-carbon composite material, which is highly heat-resistant and provides excellent thermal insulation. The surface of the thermal insulation sheet 510 can be coated with a SiC coating, and the thickness of the SiC coating can be set to 100μm to prevent contamination of the wafer during the epitaxial growth process. The thickness of the thermal insulation sheet 510 can be set to 2mm, and the spacing between two adjacent layers of thermal insulation sheets 510 can be set to 2mm. Testing has shown that the required thermal insulation effect can be achieved after at least 40 layers of thermal insulation sheets 510 are installed.

[0083] Specifically, a through hole is also opened in the middle of the thermal insulation sheet 510 for the process gas to pass through. At the same time, the process gas will be gradually preheated by the thermal insulation layer 500 after entering. The gas can reach a relatively uniform initial temperature when entering the wafer boat rack 300 area, reducing the uneven epitaxial growth problem caused by gas temperature differences, and further ensuring the epitaxial quality.

[0084] Among them, after setting the insulation layer 500, the wafer boat 300 and the insulation sheet 510 can be installed on the same circular flange for rotation, and the process gas flows from bottom to top into the liner 100, passes through the through holes in the middle of multiple insulation sheets 510, and reaches the wafer boat 300 after passing through the through holes of the bottom plate 310, and performs epitaxial growth on the wafers it carries. After leaving the top plate 320 of the wafer boat 300, the process gas rises to the top of the process tube 200. The top of the process tube 200 is closed, and the process gas reaching here will be discharged downward from the interlayer between the liner 100 and the process tube 200.

[0085] Reference Figures 8-10 In a specific embodiment of the present application, the heating assembly 400 includes:

[0086] The top heater 410 is a flat plate structure and is installed on the top of the process tube 200;

[0087] The middle heater 420 is cylindrical in shape and is mounted outside the process tube 200 , corresponding to the position of the wafer boat 300 ;

[0088] The lower heater 430 is cylindrical in shape, is sleeved outside the process tube 200 , and is disposed below the middle heater 420 .

[0089] In the present application, the middle heater 420 is in the shape of a cylindrical structure, which is wrapped around the outside of the process tube 200. It acts as the main heater to generate heat to heat the entire process tube 200. The length of the constant temperature zone is mainly determined by the middle heater 420. The length can be set to be greater than the height of the wafer boat 300 to ensure that the wafer is epitaxially grown in the constant temperature zone; the top heater 410 is in the shape of a flat plate structure, which is installed on the top surface of the process tube 200 and mainly serves as an auxiliary heating function; the lower heater 430 is in the shape of a cylindrical structure, is shorter in length, and is installed below the middle heater 420 to serve as an auxiliary heating function.

[0090] The three temperature zones, each formed by a different heater, can be individually closed-loop controlled. A cascaded control loop effectively ensures the heating system's rapid responsiveness and stability. Each zone is independently controlled, and the upper and lower zones compensate for the central constant temperature zone to maintain uniformity. The temperature settings of the three zones can be maintained consistently, ensuring consistent temperatures throughout the entire constant temperature zone.

[0091] The top heater 410, middle heater 420, and lower heater 430 can be made of high-purity graphite resistors. Conventional furnaces often use Kanthal nickel-chromium alloys and iron-chromium-aluminum alloys, with a maximum heating temperature of 1200°C, which cannot meet the requirements of the SiC epitaxial process. Heaters made of tungsten and graphite materials can reach temperatures exceeding 2000°C, but tungsten metal heaters may pose a risk of metal contamination. This application, however, uses high-purity graphite resistors for heating. These resistors have a low resistance and can generate high current at a relatively low voltage, fully meeting heating requirements of 1600°C and above.

[0092] Reference Figure 4 In a specific embodiment of the present application, the SiC epitaxial vertical reaction chamber structure further includes:

[0093] The insulation layer 600 is disposed outside the heating assembly 400 and covers the sides and top of the process tube 200 .

[0094] In the present application, by providing the thermal insulation layer 600 and the thermal insulation sheet 510 , it is possible to ensure that the reaction chamber is maintained at a constant temperature for epitaxial growth.

[0095] Reference Figure 4 In a specific embodiment of the present application, the thermal insulation layer 600 includes:

[0096] The upper insulation layer 610 covers the top of the process tube 200 and corresponds to the position of the top heater 410;

[0097] The middle insulation layer 620 is cylindrical in shape and is sleeved outside the process pipe 200, corresponding to the position of the middle heater 420;

[0098] The lower insulation layer 630 is cylindrical in shape and is sleeved outside the process pipe 200, corresponding to the position of the lower heater 430;

[0099] The bottom insulation layer 640 is cylindrical in shape and is sleeved outside the process pipe 200 to cover the remaining portion of the side of the process pipe 200;

[0100] The upper insulation layer 610, middle insulation layer 620, lower insulation layer 630, and bottom insulation layer 640 can be positioned sequentially from top to bottom based on the orientation of the process tube 200. The upper insulation layer 610 corresponds to the position of the top heater 410, and is primarily positioned adjacent to the top heater 410, and so on. The insulation layer 600 can be made of graphite carbon felt. The four-part insulation layer 600 facilitates installation and removal while ensuring consistent temperature within the constant temperature zone.

[0101] Specifically, through-holes for installing infrared pyrometers are provided in the middle of upper insulation layer 610, on the side of middle insulation layer 620, and on the side of lower insulation layer 630. By installing infrared pyrometers in corresponding through-holes of insulation layer 600, the temperature of the entire reaction chamber can be monitored, enabling timely control of the corresponding heaters.

[0102] This application proposes a novel SiC epitaxial vertical reaction chamber structure, employing graphite resistance heaters in the upper, middle, and lower zones for heating, with independent control of the zones. While maintaining a temperature uniformity of 1600°C for epitaxy, the traditional graphite tray is replaced with a wafer boat 300 for carrying multiple layers of wafers. This allows the original single-wafer or dual-wafer reaction chamber to be expanded to a chamber with up to 50 wafers, significantly improving production efficiency and reducing epitaxy costs. The air intake is directed upward from the center of the liner 100, and then downward from the outer periphery of the liner 100. The air is guided to a certain extent by the columns 330. In conjunction with the rotatable wafer boat 300, the uniformity of the airflow field can be greatly improved, thereby significantly improving the uniformity of epitaxial growth.

[0103] It should be understood that the application of this application is not limited to the above examples. For ordinary technicians in this field, they can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of this application.

Claims

1. A SiC epitaxial vertical reaction chamber structure, characterized in that: include: The liner (100) is in the shape of a cylindrical structure with two ends open, one end for allowing process gas to enter and the other end for allowing process gas to flow out; The process pipe (200) is in the shape of a sleeve structure with only one end open, and the opening is downwardly sleeved outside the liner pipe (100), and a sandwich is formed between the process pipe (200) and the liner pipe (100) for the process gas to pass through; A wafer boat (300), arranged in the liner (100) and used for carrying multiple layers of wafers; A gas supply assembly for delivering process gas to the liner (100); a heating assembly (400), disposed outside the process tube (200) and used for heating the wafer boat (300); The wafer boat (300) comprises: The bottom plate (310) is in the shape of a disc structure; A top plate (320) is in the shape of a disc structure and is arranged above the bottom plate (310); A column (330), wherein a plurality of wafer placement grooves (331) are uniformly formed on the inner side of the column (330) along the extension direction, the bottom end of the column (330) is detachably connected to the bottom plate (310), and the top end of the column (330) is detachably connected to the top plate (320); Through holes for process gas to pass through are provided in the middle of the bottom plate (310) and the top plate (320); The SiC epitaxial vertical reaction chamber structure further comprises a rotating assembly for driving the wafer boat (300) to rotate along the circumference of the base plate (310); The wafer placement groove (331) comprises a placement surface (332) for placing the wafer, wherein the placement surface (332) is provided with a first inclined surface (333) inclined downwardly at one end close to the middle of the wafer, and the placement surface (332) is provided with a second inclined surface (334) inclined upwardly at one end away from the middle of the wafer, and the top end of the second inclined surface (334) is used to abut against the bottom edge of the wafer.

2. The SiC epitaxial vertical reaction chamber structure according to claim 1, characterized in that: The SiC epitaxial vertical reaction chamber structure further includes: A heat insulating layer (500) is provided below the wafer boat (300), and the heat insulating layer (500) comprises a plurality of heat insulating sheets (510) stacked at intervals, wherein a through hole for passage of process gas is provided in the middle of the heat insulating sheet (510).

3. The SiC epitaxial vertical reaction chamber structure according to claim 1, characterized in that: The heating assembly (400) comprises: A top heater (410) is in the form of a flat plate structure and is disposed on the top of the process tube (200); A middle heater (420) is cylindrical in shape and is sleeved outside the process tube (200) and corresponds to the position of the wafer boat (300); The lower heater (430) is cylindrical in shape, is sleeved outside the process pipe (200), and is arranged below the middle heater (420).

4. The SiC epitaxial vertical reaction chamber structure according to claim 3, characterized in that: The SiC epitaxial vertical reaction chamber structure further includes: The thermal insulation layer (600) is arranged outside the heating assembly (400) and covers the side and top of the process pipe (200).

5. The SiC epitaxial vertical reaction chamber structure according to claim 4, characterized in that: The thermal insulation layer (600) comprises: an upper insulation layer (610), covering the top of the process pipe (200) and corresponding to the position of the top heater (410); A middle heat-insulating layer (620) is cylindrical in shape and is sleeved outside the process pipe (200) and corresponds to the position of the middle heater (420); A lower insulation layer (630) is cylindrical in shape and is sleeved outside the process pipe (200) and corresponds to the position of the lower heater (430); A bottom insulation layer (640) is cylindrical in shape and is sleeved outside the process pipe (200) to cover the remaining portion of the side surface of the process pipe (200); Through holes for installing infrared pyrometers are provided in the middle of the upper thermal insulation layer (610), the middle thermal insulation layer (620), and the side surfaces of the lower thermal insulation layer (630).

6. The SiC epitaxial vertical reaction chamber structure according to claim 1, characterized in that: The layer height of each layer of the wafer placement groove (331) is 4.75 mm, and the gap of the wafer placement groove (331) is 2.25 mm; The surface of the wafer boat (300) is plated with a SiC coating with a thickness of 100 μm; The surfaces of the liner tube (100) and the process tube (200) are plated with a SiC coating with a thickness of 100 μm.

7. The SiC epitaxial vertical reaction chamber structure according to claim 2, characterized in that: The layer height of each layer of the heat insulation sheet (510) is 4 mm, and the thickness of the heat insulation sheet (510) is 2 mm; The surface of the heat insulation sheet (510) is plated with a SiC coating with a thickness of 100 μm.

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