Silicon-based epitaxial wafer thickness uniformity control device and control method

Abstract

The present invention discloses a silicon-based epitaxial wafer thickness uniformity control device and control method, which relates to the field of epitaxial wafer processing technology, including a workbench and a furnace body, wherein the furnace body is fixedly arranged on the top of the workbench, and also includes an air inlet portion, which is sealed and arranged at one end of the furnace body, and the air inlet portion includes an air inlet flange. The present invention also discloses a silicon-based epitaxial wafer thickness uniformity control method, which includes the following steps: wafer placement, furnace body pre-cleaning, epitaxial growth and wafer removal. The present invention simplifies the steps of cleaning the inside of the furnace body by allowing dust particles to accumulate at the bottom of the furnace body and adhere to the side of the partition during the epitaxial growth process; during the cleaning process, the furnace body is divided into two independent closed cavities, and dust particles will not diffuse upward, thereby ensuring the cleaning effect of the inside of the furnace body. At the same time, the space required for cleaning is greatly reduced, thereby improving the cleaning effect and cleaning efficiency, and improving the thickness uniformity of the epitaxial wafer.

Description

Technical Field

[0001] The invention relates to the technical field of epitaxial wafer processing, and in particular to a device and method for controlling thickness uniformity of a silicon-based epitaxial wafer. Background Art

[0002] Epitaxial wafer refers to a wafer with an epitaxial layer deposited on the surface. Epitaxial wafers usually include a substrate and an epitaxial layer deposited on the substrate. By depositing the epitaxial layer, the defects of traditional wafers during crystal growth and mechanical processing can be eliminated. Therefore, epitaxial wafers are of better quality than traditional wafers and can be better suited for high-precision and small-size devices, but this also puts higher requirements on the quality of epitaxial wafers. Generally speaking, the uniformity of the thickness of the epitaxial layer has a greater impact on the quality of epitaxial wafers.

[0003] A CVD reaction module of a silicon carbide epitaxial device with publication number CN111636098A includes a quartz shell, an air inlet flange and a tail flange. A heating layer and a heat-insulating layer are arranged in the quartz shell. The heating layer has a plurality of replacement parts, and the curvature of the internal top surface of the replacement parts is different. A tray for holding wafers is also arranged in the working chamber. A liner is also arranged around the corresponding tray in the heating layer. A top plate for supporting the tray is arranged below the tray, and a lifting rod extends outward from the bottom of the top plate. The beneficial effect of the above technical solution is that when the thickness of the liner increases to the point that the tray cannot normally perform the CVD process, the position of the tray is slightly raised to ensure that the CVD process can continue, and finally the purpose of extending the service life of the liner is achieved. By replacing the heating layer with a top surface of different curvatures, the temperature field in the working chamber can be adjusted, so that the temperature in the working chamber is more uniform, and then the thickness of the film formed on the wafer is more uniform.

[0004] Although the above patent can continue the CVD process by raising the position of the tray to achieve the purpose of extending the service life of the lining, it is unable to clean the dust particles inside the furnace body before each epitaxial growth. The lining can only be replaced when a large amount of dust particles accumulate, which will reduce the cleanliness of the epitaxial growth environment and cause the thickness uniformity of the epitaxial wafer to decrease. At the same time, dust particles will adhere to the inner wall of the furnace body, and a larger area needs to be cleaned each time, which increases the difficulty of cleaning the inside of the furnace body and reduces the cleaning efficiency of the inside of the furnace body.

[0005] Therefore, it is necessary to invent a silicon-based epitaxial wafer thickness uniformity control device and a control method to solve the above problems. Summary of the invention

[0006] The object of the present invention is to provide a device and method for controlling the thickness uniformity of a silicon-based epitaxial wafer, so as to solve the problems raised in the above-mentioned background technology.

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a silicon-based epitaxial wafer thickness uniformity control device, comprising a workbench and a furnace body, wherein the furnace body is fixedly arranged on the top of the workbench, and further comprising: an air inlet portion, which comprises an air inlet flange sealed at one end of the furnace body, a side of the air inlet flange away from the furnace body being connected with a reaction gas inlet pipe and a protective gas inlet pipe, and the protective gas inlet pipe is located below the reaction gas inlet pipe; an air outlet portion, which comprises an air outlet flange sealed at the other end of the furnace body, through which the reaction gas and protective gas in the furnace body can be discharged to the outside; a bearing portion, which comprises a loading tray arranged inside the furnace body, through which the epitaxial wafer can be supported and placed; a cleaning group The invention discloses a component, comprising two partitions symmetrically rotatably arranged in the furnace body, a cleaning port is provided on the side of the air inlet flange close to the furnace body, and the cleaning port is communicated with the furnace body, and a plurality of air passages communicated with the cleaning port are evenly provided inside the air inlet flange; an air guide component is arranged inside the air inlet flange, and can control the on-off of the airflow between the cleaning component and the air inlet part, and when the air guide component is in a connected state, the cleaning component can clean the inside of the furnace body; a switching component is arranged inside the air inlet flange, and when the switching component is in a closed state, the air guide component is in a connected state to clean the inside of the furnace body, and when the switching component is in a connected state, the air guide component is in a closed state, and an epitaxial growth process is carried out in the furnace body.

[0008] Preferably, the air inlet part also includes: a reaction gas inlet cavity, which is opened inside the air inlet flange and connected to the reaction gas inlet pipe; a reaction gas inlet, which is opened on a side of the air inlet flange close to the furnace body, and its two ends are respectively connected to the furnace body and the reaction gas inlet cavity.

[0009] Preferably, the air inlet part also includes: a protective gas inlet cavity, which is opened in the interior of the air inlet flange and is connected to the protective gas inlet pipe; a protective gas introduction cavity, which is opened in the interior of the air inlet flange and is located above the protective gas inlet cavity; an air guide groove, which is opened in the interior of the air inlet flange, and its upper and lower ends are respectively connected to the protective gas introduction cavity and the protective gas inlet cavity; and air holes, which are evenly surrounded by the periphery of the reaction gas inlet, and a plurality of the air holes are connected to the protective gas introduction cavity.

[0010] Preferably, the cleaning assembly further comprises: a sewage outlet, which passes through the gas outlet flange and is in communication with the furnace body; and a sewage pipe, which is fixedly arranged on a side of the gas outlet flange away from the furnace body.

[0011] Preferably, the cleaning component also includes: two guide grooves, which are provided with two guide grooves symmetrically opened on the side of the gas outlet flange close to the furnace body; a sliding cavity, which is opened inside the gas outlet flange, and the sliding cavity is connected with the bottom ends of the two guide grooves; a slide frame, which is slidably arranged inside the sliding cavity, and the bottom of the slide frame passes through the sewage outlet; a first elastic member, which is fixedly arranged between the slide frame and the sliding cavity, and the first elastic member can provide an upward pulling force to the slide frame; a dust guard plate, which is fixedly arranged at the bottom end of the slide frame and can block the sewage outlet; a first receiving groove, which is opened at the bottom of the sewage outlet and can receive the dust guard plate; two driving pins, which are provided with two driving pins, which are respectively fixedly arranged on the side of the corresponding partition close to the gas outlet flange, and the two driving pins are both located in the guide grooves on the corresponding sides, and when the driving pin moves downward along the guide groove, it can drive the slide frame to move downward.

[0012] Preferably, the air guide assembly includes: two piston blocks, which are symmetrically and sealingly slidably arranged inside the protective gas inlet chamber, and both of the piston blocks are hollow structures; two connecting plates, which are fixedly arranged on the sides of the two piston blocks close to each other, and sealed and slidably arranged between the two connecting plates and the bottom of the protective gas inlet chamber; two driven gears, which are fixedly arranged on the sides of the corresponding side partitions close to the inlet flange, and the driven gears are fixedly arranged on the sides of the corresponding side partitions close to the inlet flange. The driven gear is located in the middle of the piston block on the corresponding side; the tooth segment is fixedly arranged on the inner bottom wall of the piston block on the corresponding side, and the tooth segment is meshed with the driven gear on the corresponding side; there are two second elastic members, and the two second elastic members are respectively fixedly arranged between the piston block on the corresponding side and the side wall of the protective gas inlet chamber, and the second elastic member can provide a thrust for the two piston blocks to approach each other; there are multiple through holes, and the multiple through holes are evenly penetrated and opened on the connecting plate. When the through holes are aligned with the airway, the protective gas can flow from the protective gas inlet chamber to the cleaning port.

[0013] Preferably, the switching assembly includes: a reaction gas baffle, which is slidably arranged inside the reaction gas inlet, and when the side of the reaction gas baffle away from the furnace body is in contact with the inner wall of the reaction gas inlet, the reaction gas inlet cavity can be blocked; a third elastic member, which is fixedly arranged between the reaction gas baffle and the inlet flange, and the third elastic member can provide a pulling force for the reaction gas baffle to move toward the side away from the furnace body; a second receiving groove, which is opened inside the inlet flange; a protective gas baffle, which is slidably arranged inside the second receiving groove, and when it slides out of the second receiving groove, the gas guide groove can be blocked; a transmission rod, which is fixedly arranged between the reaction gas baffle and the protective gas baffle, and the reaction gas baffle can drive the protective gas baffle to move synchronously through the transmission rod.

[0014] Preferably, the gas outlet portion further comprises: a gas outlet pipe, which is arranged on a side of the gas outlet flange away from the furnace body and is connected to the furnace body, and can discharge the gas in the furnace body;

[0015] The bearing part also includes: a lifting platform, which is fixedly arranged at the bottom of the workbench; a rotating motor, which is fixedly arranged at the top of the lifting platform; a rotating shaft, which is fixedly arranged at the top of the power output shaft of the rotating motor, and the top end of the rotating shaft penetrates into the interior of the furnace body, and the rotating shaft and the furnace body are sealed and rotatably connected; a supporting tray, which is fixedly arranged at the top of the rotating shaft, and the loading tray is placed on the top of the supporting tray, and the supporting tray can drive the loading tray to rotate and lift synchronously.

[0016] Preferably, it also includes: a heat-insulating layer, which is fitted on the inner wall of the furnace body and can insulate the furnace body; a heating layer, which is fitted on the inner wall of the heat-insulating layer and can heat the inside of the furnace body; and a lining, which is fitted on the inner wall of the heating layer and can protect the heating layer.

[0017] A method for controlling thickness uniformity of a silicon-based epitaxial wafer is also provided, comprising the following steps:

[0018] Step 1: Place the epitaxial wafer on the carrier plate;

[0019] Step 2: Pre-clean the furnace body. Introduce protective gas separately, make the switching component in a closed state, and the gas guide component in a connected state. The two partitions are combined to divide the furnace body into two independent closed cavities, the protective gas cleans the dust particles in the lower closed cavity, and the furnace body is pre-cleaned.

[0020] Step 3, epitaxial growth, after pre-cleaning, the protective gas and the reaction gas are introduced at the same time, so that the switching component is in a connected state, the gas guide component is in a closed state, the two partitions are respectively attached to the inner wall of the furnace body, the protective gas wraps the reaction gas and blows it into the furnace body, and the epitaxial growth provides a uniform and stable reaction gas flow;

[0021] Step 4: Take out the epitaxial wafer after the epitaxial growth process is completed from the furnace body.

[0022] Technical effects and advantages of the present invention:

[0023] 1. The present invention uses a protective gas inlet cavity, a partition, a cleaning port, an air duct, a sewage outlet and a through hole in a coordinated manner, so that dust particles accumulate at the bottom of the furnace body and adhere to the sides of the partition during epitaxial growth, but do not adhere to the side walls of the furnace body, thereby keeping the inner wall of the furnace body in a clean state at all times, simplifying the steps of cleaning the inside of the furnace body; during the cleaning process, the furnace body is divided into two independent closed cavities, and the protective gas is blown out from the cleaning port through the through hole and the air duct to clean the dust particles in the closed cavity, and the dust particles do not diffuse upward, thereby ensuring the cleaning effect of the inside of the furnace body, and at the same time, the space that needs to be cleaned is greatly reduced, thereby greatly improving the cleaning effect and cleaning efficiency; through the above measures, the inside of the furnace body is always in a clean state when epitaxial growth is carried out, thereby ensuring the environmental cleanliness of the epitaxial growth, optimizing the effect of the epitaxial growth, and improving the thickness uniformity of the epitaxial wafer.

[0024] 2. The present invention uses a cleaning component, an air guide component and a switching component in coordination. When the protective gas is introduced alone, the switching component is closed, the air guide component is connected, the cleaning component and the air inlet are connected to each other, and the two partitions are in a horizontal state and separate the furnace body, so that the inside of the furnace body is quickly and effectively cleaned; when the protective gas and the reaction gas are introduced at the same time, the switching component is connected, the air guide component is closed, the cleaning component and the air inlet are no longer connected, the two partitions are in a vertical state and fit against the inner wall of the furnace body, so as to perform epitaxial growth operations; through the above measures, the inside of the furnace body can be cleaned quickly, and the cleaning state can be quickly switched to the epitaxial growth state without performing other additional operations, thereby improving the switching efficiency between cleaning and production and simplifying the operating steps for cleaning the inside of the furnace body.

[0025] 3. The present invention uses air holes and reaction gas inlets in coordination, and the protective gas blown out from the multiple air holes wraps and guides the reaction gas blown out from the reaction gas inlet, so that the reaction gas enters the furnace body evenly and stably for reaction, thereby improving the mixing uniformity of the reaction gas, avoiding the reaction gas from being deposited at the inlet of the furnace body too early, and improving the epitaxial growth effect.

[0026] 4. The present invention adjusts the height of the epitaxial wafer through the bearing part, which can facilitate the picking up and placement of the carrier plate, and at the same time can make the epitaxial wafer at the optimal height according to the actual needs of epitaxial growth; the epitaxial wafer is driven to rotate by the bearing part, so that the epitaxial growth is more uniform, and the effect of epitaxial growth is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0028] Figure 2 It is a schematic diagram of the overall cross-sectional structure of the present invention.

[0029] Figure 3 It is a schematic diagram of the installation position of the partition of the present invention.

[0030] Figure 4 The cross-sectional structure of the air intake flange of the present invention is shown in FIG. Figure 1 .

[0031] Figure 5 The cross-sectional structure of the air intake flange of the present invention is shown in FIG. Figure 2 .

[0032] Figure 6 It is a schematic structural diagram of the air outlet flange of the present invention.

[0033] Figure 7 It is a schematic diagram of the cross-sectional structure of the air outlet flange of the present invention.

[0034] Figure 8 It is a schematic diagram of the positional relationship of the partition plate and / or the piston block of the present invention.

[0035] Fig. 9 It is a structural schematic diagram of the piston block of the present invention.

[0036] Fig.10 It is a schematic structural diagram of the reaction gas baffle of the present invention.

[0037] Fig.11 For the present invention Figure 2 Schematic diagram of the enlarged structure at point A in the middle.

[0038] Fig.12 For the present invention Figure 2 Schematic diagram of the enlarged structure at point B in the middle.

[0039] Fig.13 It is a structural schematic diagram of the bearing part of the present invention.

[0040] Fig.14 It is a schematic diagram of the state when the partition of the present invention is in a vertical position.

[0041] Fig.15 It is a schematic diagram of the state when the partition of the present invention is in a horizontal position.

[0042] In the figure: 1, workbench; 2, furnace body; 3, air inlet; 4, air outlet; 5, bearing part; 6, cleaning component; 7, air guide component; 8, switching component; 9, insulation layer; 10, heating layer; 11, lining; 301, air inlet flange; 302, reaction gas air inlet pipe; 303, reaction gas air inlet cavity; 304, reaction gas inlet; 305, protective gas air inlet pipe; 306, protective gas air inlet cavity; 307, protective gas passage cavity; 308, air guide groove; 309, air hole; 401, air outlet flange; 402, air outlet pipe; 501, loading tray; 502, lifting platform; 503, rotating motor; 504, rotating shaft; 505, supporting tray; 601, partition; 602, cleaning port; 603, airway; 604, sewage outlet; 605, sewage pipe; 606, guide groove; 607, sliding cavity; 608, slide; 609, first elastic member; 610, dust shield; 611, first receiving groove; 612, driving pin; 701, piston block; 702, connecting plate; 703, driven gear; 704, tooth segment; 705, second elastic member; 706, through hole; 801, reaction gas baffle; 802, third elastic member; 803, second receiving groove; 804, protective gas baffle; 805, transmission rod. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] Embodiment 1, the present invention provides as follows Figures 1 to 15 The silicon-based epitaxial wafer thickness uniformity control device shown comprises a workbench 1 and a furnace body 2 , wherein the furnace body 2 is fixedly arranged on the top of the workbench 1 .

[0045] The air inlet part 3 is sealed at one end of the furnace body 2. The air inlet part 3 includes an air inlet flange 301. The air inlet flange 301 is fixedly arranged at one end of the furnace body 2 and a seal is maintained between the two. Reaction gas and protective gas can be introduced into the furnace body 2 through the air inlet flange 301.

[0046] Specifically, the air inlet part 3 also includes a reaction gas inlet pipe 302, which is connected and arranged on the side of the air inlet flange 301 away from the furnace body 2. Multiple reaction gas inlet pipes 302 can be arranged to introduce multiple reaction gases; a reaction gas inlet cavity 303, which is opened inside the air inlet flange 301 and is connected to the reaction gas inlet pipe 302; a reaction gas inlet port 304, which is opened on the side of the air inlet flange 301 close to the furnace body 2, and its two ends are respectively connected to the furnace body 2 and the reaction gas inlet cavity 303; the reaction gas passes through the reaction gas inlet pipe 302 and the reaction gas inlet cavity 303, and then enters the interior of the furnace body 2 from the reaction gas inlet port 304 to perform epitaxial growth operations.

[0047] More specifically, the air inlet portion 3 also includes a protective gas inlet pipe 305, which is connected and arranged on the side of the air inlet flange 301 away from the furnace body 2 and is located below the reaction gas inlet pipe 302; a protective gas inlet cavity 306, which is opened inside the air inlet flange 301 and is connected to the protective gas inlet pipe 305; a protective gas inlet cavity 307, which is opened inside the air inlet flange 301 and is located above the protective gas inlet cavity 306; a gas guide groove 308, which is opened inside the air inlet flange 301, and its upper and lower ends are respectively connected to the protective gas inlet cavity 307 and the protective gas inlet cavity 306; and air holes 309, which are uniformly surrounded by the protective gas inlet cavity 307. It is opened on the periphery of the reaction gas inlet 304, and multiple air holes 309 are connected with the protective gas inlet cavity 307; the protective gas enters the protective gas inlet cavity 306 through the protective gas inlet pipe 305, and evenly enters the furnace body 2 from the air holes 309 via the gas guide grooves 308 and the protective gas inlet cavity 307, and the protective gas sprayed from the air holes 309 wraps the reaction gas sprayed from the reaction gas inlet 304 inside and guides it, so that the reaction gas enters the furnace body 2 evenly and stably for reaction, thereby improving the mixing uniformity of the reaction gas, avoiding the reaction gas from being deposited at the entrance of the furnace body 2 too early, and improving the epitaxial growth effect.

[0048] The gas outlet portion 4 is sealed at the other end of the furnace body 2. The gas outlet portion 4 includes a gas outlet flange 401. The gas outlet flange 401 is fixedly arranged at the other end of the furnace body 2 and the two are sealed, through which the reaction gas and protective gas in the furnace body 2 can be discharged to the outside.

[0049] Specifically, the gas outlet portion 4 also includes a gas outlet pipe 402, which is connected to the side of the gas outlet flange 401 away from the furnace body 2 and is connected to the furnace body 2, and can discharge the gas in the furnace body 2; by setting the gas outlet pipe 402, it is convenient to collect the reaction gas and protective gas after epitaxial growth.

[0050] The supporting part 5 is arranged inside the furnace body 2 , and the supporting part 5 includes a loading plate 501 , which can support and place the epitaxial wafer.

[0051] Specifically, the bearing part 5 also includes a lifting platform 502, which is fixedly arranged at the bottom of the workbench 1, and the lifting platform 502 can be lifted and lowered by an electric telescopic rod; a rotating motor 503, which is fixedly arranged at the top of the lifting platform 502; a rotating shaft 504, which is fixedly arranged at the top of the power output shaft of the rotating motor 503, and the top of the rotating shaft 504 penetrates into the interior of the furnace body 2, and the rotating shaft 504 is sealed and rotatably connected with the furnace body 2. During the rotation and lifting process of the rotating shaft 504, it always maintains a seal with the furnace body 2, so as to ensure the airtightness and heat preservation of the furnace body 2; a supporting tray 505, which is fixedly arranged at the top of the rotating shaft 504, and the loading tray 501 is placed At the top of the supporting tray 505, the supporting tray 505 can drive the loading tray 501 to rotate and rise and fall synchronously. A card slot can be opened at the inner bottom of the supporting tray 505, and a card block is fixedly set at the bottom of the loading tray 501. Through the mutual cooperation of the card slot and the card block, the loading tray 501 can stably follow the supporting tray 505 to rotate and rise and fall synchronously; the height of the supporting tray 505 can be adjusted by the lifting platform 502, which can facilitate the picking up and placement of the loading tray 501. At the same time, the epitaxial wafer can be placed at the optimal height according to the actual needs of epitaxial growth. The supporting tray 505 is driven to rotate by the rotating motor 503, so that the epitaxial growth is more uniform, thereby improving the effect of epitaxial growth.

[0052] It should be noted that a window is provided on the air inlet flange 301 for the robot to pass through when taking the carrier plate 501, and a cover that can be opened and closed is provided at the window. This is a prior art and will not be described in detail here and is not shown in the figure.

[0053] The cleaning component 6 is arranged inside the furnace body 2. The cleaning component 6 includes two partitions 601 symmetrically rotatably arranged inside the furnace body 2. The two ends of the partition 601 are rotatably connected to the sides of the air inlet flange 301 and the air outlet flange 401 through pin shafts. Notches are symmetrically opened on the sides close to each other in the middle of the two partitions 601. When the two partitions 601 are combined with each other, that is, when the two partitions 601 are rotated to a horizontal state inside the furnace body 2, the partition 601 and the supporting tray 505 are in the same horizontal plane, and at this time, the notches in the middle of the two partitions 601 are butted against each other, the supporting tray 505 is located between the two butted notches, and the supporting tray 505 is in approximately sealed contact with the side walls of the notch, thereby dividing the furnace body 2 into two independent closed cavities above and below. When the two partitions 601 are separated from each other, that is, when the two partitions 601 are rotated to a vertical state inside the furnace body 2, the two partitions 601 are respectively fitted with the inner walls of the furnace body 2 on the corresponding sides, thereby cleaning the inner walls of the furnace body 2 Shielding is performed; when the two partitions 601 are rotated to a horizontal state, the furnace body 2 is divided into two independent closed cavities, so that when the lower closed cavity is cleaned, the dust particles will not spread upward, thereby ensuring the cleaning effect of the dust particles, and since only the lower closed cavity needs to be cleaned, the space that needs to be cleaned is greatly reduced, thereby greatly improving the cleaning effect and cleaning efficiency, and when the two partitions 601 are rotated to a vertical state, they fit with the inner wall of the corresponding side furnace body 2, so that the dust particles carried by the source gas itself and generated during the epitaxial growth process can only be scattered to the bottom of the furnace body 2 and attached to the side of the partition 601, but not attached to the side wall of the furnace body 2, and the dust particles attached to the side of the partition 601 will be cleaned during the cleaning process, which simplifies the steps and procedures for cleaning the inside of the furnace body 2, and also makes the inside of the furnace body 2 always in a clean state during epitaxial growth, thereby improving the uniformity of the epitaxial growth thickness of the epitaxial wafer.

[0054] Specifically, the cleaning component 6 also includes a cleaning port 602, which is opened on the side of the air inlet flange 301 close to the furnace body 2 and is connected to the furnace body 2; a plurality of air ducts 603, which are evenly opened inside the air inlet flange 301, and the upper and lower ends of each air duct 603 are respectively connected to the protective gas inlet cavity 306 and the cleaning port 602; a sewage outlet 604, which passes through the air outlet flange 401 and is connected to the furnace body 2; a sewage pipe 605, which is fixedly arranged on the side of the air outlet flange 401 away from the furnace body 2; the protective gas in the protective gas inlet cavity 306 can be blown out from the cleaning port 602 through the plurality of air ducts 603, so as to clean the dust particles at the bottom of the furnace body 2, and the protective gas carrying the dust particles is discharged from the sewage outlet 604 and the sewage pipe 605 to the outside of the furnace body 2, so as to clean the dust particles inside the furnace body 2.

[0055] More specifically, the cleaning component 6 also includes a guide groove 606, of which there are two, and the two guide grooves 606 are symmetrically opened on one side of the gas outlet flange 401 close to the furnace body 2; a sliding cavity 607, which is opened inside the gas outlet flange 401, and the sliding cavity 607 is connected to the bottom ends of the two guide grooves 606; a slide 608, which is slidably set inside the sliding cavity 607, and the bottom of the slide 608 passes through the sewage outlet 604; a first elastic member 609, which is fixedly set between the slide 608 and the sliding cavity 607, and the first elastic member 609 can provide an upward pulling force to the slide 608; a dust shield 610, which is fixedly set at the bottom end of the slide 608 and can block the sewage outlet 604; a first receiving groove 611, which is opened at the bottom of the sewage outlet 604 and can receive the dust shield 610; a driving pin 612, of which there are two, two The driving pins 612 are respectively fixedly arranged on one side of the corresponding partition 601 close to the air outlet flange 401, and the two driving pins 612 are both located in the guide groove 606 on the corresponding side. When the driving pin 612 moves downward along the guide groove 606, it can drive the slide 608 to move downward; when the two partitions 601 are in a vertical state, the slide 608 is not subjected to the downward pressure of the driving pin 612. Under the pulling force of the first elastic member 609, the dust shield plate 610 is located above the first receiving groove 611. At this time, the dust shield plate 610 blocks the sewage outlet 604. When the two partitions 601 are in a horizontal state, the slide 608 slides downward under the pressure of the driving pin 612, so that the dust shield plate 610 drops to be completely accommodated in the first receiving groove 611. At this time, the dust shield plate 610 no longer blocks the sewage outlet 604, and the sewage outlet 604 is in a connected state.

[0056] The air guide component 7 is arranged inside the air inlet flange 301, and can control the on-off of the airflow between the cleaning component 6 and the air inlet part 3. When the air guide component 7 is in a connected state, the cleaning component 6 can clean the inside of the furnace body 2.

[0057] Specifically, the air guide assembly 7 includes two piston blocks 701, which are provided in two numbers. The two piston blocks 701 are symmetrically sealed and slidably arranged inside the protective gas inlet chamber 306, and the two piston blocks 701 are both hollow structures; two connecting plates 702 are provided in two numbers. The two connecting plates 702 are respectively fixedly arranged on the sides of the two piston blocks 701 close to each other, and the two connecting plates 702 are sealed and slidably arranged with the bottom of the protective gas inlet chamber 306; two driven gears 703 are provided in two numbers, and the two driven gears 703 are respectively fixedly arranged on the sides of the corresponding side partitions 601 close to the inlet flange 301, that is, from The driven gear 703 is fixedly arranged at one end of the rotating pin shaft of the partition 601, the driven gear 703 and the pin shaft of the corresponding side partition 601 are on the same axis, and the driven gear 703 is located in the middle of the corresponding side piston block 701; the tooth segment 704 is fixedly arranged on the inner bottom wall of the corresponding side piston block 701, and the tooth segment 704 is meshed with the driven gear 703 on the corresponding side; the second elastic member 705 is provided with two, and the two second elastic members 705 are respectively fixedly arranged between the corresponding side piston block 701 and the side wall of the protective gas inlet chamber 306, and the second elastic member 705 can provide a thrust for the two piston blocks 701 to approach each other; There are multiple through holes 706, and the multiple through holes 706 are evenly penetrated and opened on the connecting plate 702. The spacing between two adjacent through holes 706 is the same as the spacing between two adjacent air passages 603, and the apertures of the through holes 706 and the air passages 603 are consistent. When the through holes 706 are aligned with the air passages 603, the protective gas can flow from the protective gas inlet cavity 306 to the cleaning port 602; when the two piston blocks 701 are only subjected to the thrust of the second elastic member 705, the two connecting plates 702 are close to each other. At this time, the multiple through holes 706 are staggered with the air passages 603, and the air passages 603 are in a closed state. The air pipe 305 introduces protective gas into the protective gas inlet chamber 306, so that the air pressure between the two piston blocks 701 increases, thereby pushing the two piston blocks 701 to drive the connecting plate 702 away from each other, and through the cooperation of the tooth segment 704 and the driven gear 703, the two partitions 601 are synchronously rotated to a horizontal state, thereby dividing the furnace body 2 into two independent closed cavities through the two partitions 601, and at this time, multiple through holes 706 are connected with the corresponding air ducts 603, and the protective gas is blown out from the cleaning port 602 through the through holes 706 and the air duct 603 to clean the dust attached to the bottom of the furnace body 2 and the side of the partition 601.

[0058] The switching component 8 is arranged inside the air inlet flange 301, and can switch the on and off state of the air guide component 7. When it is in the closed state, the air guide component 7 is in the connected state, and the interior of the furnace body 2 is cleaned. When it is in the connected state, the air guide component 7 is in the closed state, and the epitaxial growth process is carried out in the furnace body 2.

[0059] Specifically, the switching assembly 8 includes a reaction gas baffle 801, which is slidably arranged inside the reaction gas inlet 304. When the side of the reaction gas baffle 801 away from the furnace body 2 is in contact with the inner wall of the reaction gas inlet 304, the reaction gas inlet cavity 303 can be blocked; a third elastic member 802, which is fixedly arranged between the reaction gas baffle 801 and the inlet flange 301. The third elastic member 802 can provide a pulling force for the reaction gas baffle 801 to move toward the side away from the furnace body 2. When the reaction gas baffle 801 is only subjected to the pulling force of the third elastic member 802, the reaction gas baffle 801 blocks the reaction gas inlet cavity 303; the second receiving groove 803 is opened inside the inlet flange 301; the protective gas baffle 804 is slidably arranged inside the second receiving groove 803, and when it slides out of the second receiving groove 803, it can block the gas guide groove 308; the transmission rod 805 is fixedly arranged between the reaction gas baffle 801 and the protective gas baffle 804. The reaction gas baffle 801 can drive the protective gas baffle 804 to move synchronously through the transmission rod 805; by introducing the reaction gas from the reaction gas inlet pipe 302 to the reaction gas inlet cavity 303, the gas pressure in the reaction gas inlet cavity 303 increases, pushing the reaction gas baffle 801 to slide, so that the reaction gas inlet cavity 303 is in an open state, and the reaction gas enters the furnace body 2 through the reaction gas inlet cavity 303 and the reaction gas inlet 304. At the same time, the reaction gas baffle 801 is While the plate 801 slides, the reaction gas baffle 801 drives the protective gas baffle 804 to slide into the second receiving groove 803 through the transmission rod 805, so that the gas guide groove 308 is in an open state, and the protective gas inlet chamber 306 and the protective gas entry chamber 307 are interconnected. The protective gas in the protective gas inlet chamber 306 is blown out from the multiple air holes 309 through the gas guide groove 308 and the protective gas entry chamber 307, so as to wrap and guide the reaction gas blown out from the reaction gas inlet 304.

[0060] More specifically, a plurality of spoilers are fixedly arranged around one side of the reaction gas baffle 801 close to the reaction gas inlet chamber 303, and the adjacent spoilers are staggered. A plurality of slots are correspondingly opened on one side of the reaction gas inlet chamber 303, and the spoilers can be inserted into the corresponding slots. When the reaction gas baffle 801 slides to open the reaction gas inlet chamber 303, the plurality of spoilers slide out from the corresponding slots to disturb the mixed gas flowing between the reaction gas baffle 801 and the reaction gas inlet chamber 303, so that the reaction gas is mixed more evenly. After the spoilers are inserted into the corresponding slots, their sealing effect on the reaction gas inlet chamber 303 will not be affected.

[0061] It should be noted that when the protective gas is blown out from the multiple air holes 309 through the air guide groove 308 and the protective gas inlet cavity 307, the gas pressure in the protective gas inlet cavity 306 decreases accordingly. The air pressure at this time will be insufficient to push the two piston blocks 701 away from each other, and the two piston blocks 701 will return to their initial positions under the thrust of the second elastic member 705, so that the multiple through holes 706 and the air channel 603 are re-misaligned with each other, and the air guide component 7 is in a closed state. The protective gas can only be blown out from the multiple air holes 309 through the air guide groove 308 and the protective gas inlet cavity 307, thereby realizing automatic adjustment and switching of the flow direction of the protective gas.

[0062] The heat-insulating layer 9 is attached to the inner wall of the furnace body 2 and can keep the furnace body 2 warm.

[0063] The heating layer 10 is provided in close contact with the inner wall of the heat-insulating layer 9 , and can heat the interior of the furnace body 2 .

[0064] The lining 11 is arranged in close contact with the inner wall of the heating layer 10 and can protect the heating layer 10 .

[0065] In summary, when the protective gas and the reaction gas are not introduced, the reaction gas baffle 801 blocks the reaction gas inlet cavity 303 under the pulling force of the third elastic member 802, and the protective gas baffle 804 blocks the gas guide groove 308. The two piston blocks 701 are in a state of being close to each other under the thrust of the second elastic member 705, and the multiple gas channels 603 and the through holes 706 are in a state of being misaligned with each other. The two partitions 601 are in a vertical state and are attached to the inner wall of the furnace body 2. At this time, the position of the partition 601 is as shown in FIG. Fig.14 As shown, the slide 608 drives the dust shield 610 to block the sewage outlet 604 under the pulling force of the first elastic member 609;

[0066] Before epitaxial growth, a protective gas is first introduced separately. At this time, since the gas guide groove 308 is in a blocked state, the protective gas will push the two piston blocks 701 away from each other, so that the multiple gas channels 603 and the through holes 706 are connected to each other. At the same time, the tooth segment 704 drives the driven gear 703 and the partition 601 to rotate, so that the two partitions 601 rotate to a horizontal state, and two independent closed cavities are formed in the furnace body 2. At this time, the position of the partition 601 is as shown in FIG. Fig.15As shown, the dust particles attached to one side of the partition 601 and the dust particles accumulated at the bottom of the furnace body 2 are all in the closed cavity below, and, in the process of the partition 601 rotating to a horizontal state, the driving pin 612 will force the slide 608 to drive the dust shield 610 to slide downward into the first receiving groove 611, and the drain port 604 is in an open state. At this time, the protective gas is blown out from the cleaning port 602 to clean the dust particles in the closed cavity below, and discharged from the drain port 604 to the outside of the furnace body 2, so as to pre-clean the furnace body 2 before epitaxial growth.

[0067] After the furnace body 2 is pre-cleaned, the protective gas and the reaction gas are introduced at the same time. At this time, the reaction gas inlet cavity 303 and the gas guide groove 308 are both in an open state, the two piston blocks 701 are restored to the initial position, the through hole 706 and the gas channel 603 are re-staggered, and the two partitions 601 are rotated again to fit the inner wall of the furnace body 2. At this time, the position of the partition 601 is as shown in FIG. Fig.14 As shown, the drain port 604 is in a closed state, and the protective gas and the reaction gas enter the furnace body 2 from the gas holes 309 and the reaction gas inlet 304 to perform the epitaxial growth operation.

[0068] By using the protective gas inlet cavity 306, the partition 601, the cleaning port 602, the airway 603, the drain port 604 and the through hole 706 in coordination, during the epitaxial growth process, the partition 601 is in a vertical state and fits against the inner wall of the furnace body 2, and the dust particles generated during the epitaxial growth will accumulate at the bottom of the furnace body 2 and adhere to the sides of the partition 601, but will not adhere to the side walls of the furnace body 2, so that the inner wall of the furnace body 2 is always in a clean state, and there is no need to clean the inner wall of the furnace body 2, thereby simplifying the steps of cleaning the inside of the furnace body 2; during the cleaning process of the inside of the furnace body 2, the two partitions 601 are in a horizontal state and divide the furnace body 2 into two independent closed cavities, and the side of the partition 601 with dust particles attached and the dust particles scattered at the bottom of the furnace body 2 are all at the bottom. In the closed cavity, the protective gas in the protective gas inlet cavity 306 is blown out from the cleaning port 602 through the through hole 706 and the air duct 603 to clean the dust particles in the closed cavity and discharge them from the drain port 604 to clean the inside of the furnace body 2. Due to the separation effect of the partition 601, the dust particles blown up in the lower closed cavity will not spread to the upper closed cavity, thereby ensuring the cleaning effect of the inside of the furnace body 2. At the same time, since only the lower closed cavity needs to be cleaned, the space that needs to be cleaned is greatly reduced, thereby greatly improving the cleaning effect and cleaning efficiency. Through the above measures, the inside of the furnace body 2 is always in a clean state when epitaxial growth is carried out, thereby ensuring the cleanliness of the environment for epitaxial growth, optimizing the effect of epitaxial growth, and improving the thickness uniformity of the epitaxial wafer.

[0069] Through the coordinated use of the cleaning component 6, the gas guide component 7 and the switching component 8, when it is necessary to clean the inside of the furnace body 2, only the protective gas needs to be introduced. At this time, the switching component 8 is in a closed state, the gas guide component 7 is in a connected state, the cleaning component 6 and the air inlet 3 are in a connected state, and at this time, the two partitions 601 are automatically in a horizontal state and separate the furnace body 2, so as to quickly and effectively clean the inside of the furnace body 2; when it is necessary to perform epitaxial growth, the protective gas and the reaction gas are introduced at the same time, at this time, the switching component 8 automatically changes to a connected state, and the gas guide component 7 changes to a closed state. In the closed state, the cleaning component 6 is no longer connected to the air inlet 3, and at this time the two partitions 601 are automatically in a vertical state and fit against the inner wall of the furnace body 2, and the protective gas and the reaction gas enter the furnace body 2 through the air holes 309 and the reaction gas inlet 304 respectively, so as to perform epitaxial growth operations; through the above measures, the inside of the furnace body 2 can be cleaned quickly, and the cleaning state can be quickly switched to the epitaxial growth state without other additional operations, which improves the switching efficiency between cleaning and production and simplifies the operating steps for cleaning the inside of the furnace body 2.

[0070] Embodiment 2, the present invention also provides a method for controlling thickness uniformity of a silicon-based epitaxial wafer, comprising the following steps:

[0071] Step 1: Place the epitaxial wafer on the carrier plate 501;

[0072] Step 2: Pre-clean the furnace body 2. A protective gas is introduced separately, the switching component 8 is in a closed state, the gas guide component 7 is in a connected state, the two partitions 601 are combined to divide the furnace body 2 into two independent closed cavities, the sewage outlet 604 is in an open state, and the protective gas blown out from the cleaning port 602 cleans the dust particles in the lower closed cavity and is discharged from the sewage outlet 604, thereby pre-cleaning the furnace body 2;

[0073] Step 3, epitaxial growth, after pre-cleaning, the protective gas and the reaction gas are introduced at the same time, the switching component 8 is in a connected state, the gas guide component 7 is in a closed state, the two partitions 601 are respectively attached to the inner wall of the furnace body 2, the drain port 604 is in a closed state, the reaction gas is blown out from the reaction gas inlet 304, and the protective gas is blown out from the air hole 309, and the protective gas wraps the reaction gas, thereby providing a uniform and stable reaction gas flow for epitaxial growth;

[0074] Step 4: Take out the epitaxial wafer after the epitaxial growth process is completed from the furnace body 2.

[0075] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A silicon-based epitaxial wafer thickness uniformity control device, comprising a workbench (1) and a furnace body (2), wherein the furnace body (2) is fixedly arranged on the top of the workbench (1), characterized in that: Also includes: An air inlet portion (3), comprising an air inlet flange (301) sealed at one end of the furnace body (2), a side of the air inlet flange (301) away from the furnace body (2) being connected with a reaction gas inlet pipe (302) and a protective gas inlet pipe (305), and the protective gas inlet pipe (305) is located below the reaction gas inlet pipe (302); The air intake portion (3) further comprises: A reaction gas inlet cavity (303), which is opened inside the inlet flange (301) and is connected to the reaction gas inlet pipe (302); A reaction gas inlet (304), which is provided on a side of the gas inlet flange (301) close to the furnace body (2), and whose two ends are respectively connected to the furnace body (2) and the reaction gas inlet cavity (303); A protective gas inlet cavity (306), which is opened inside the inlet flange (301) and is connected to the protective gas inlet pipe (305); A protective gas inlet cavity (307), which is opened inside the gas inlet flange (301) and is located above the protective gas inlet cavity (306); An air guide groove (308) is provided inside the air inlet flange (301), and its upper and lower ends are respectively connected to the protective gas inlet cavity (307) and the protective gas inlet cavity (306); Air holes (309) are evenly arranged around the outer circumference of the reaction gas inlet (304), and a plurality of the air holes (309) are connected to the protective gas inlet cavity (307); A gas outlet portion (4), comprising a gas outlet flange (401) sealed at the other end of the furnace body (2), through which the reaction gas and the protective gas in the furnace body (2) can be discharged to the outside; A carrying part (5), comprising a carrying plate (501) arranged inside the furnace body (2), through which the epitaxial wafer can be supported and placed; A cleaning assembly (6), comprising two partitions (601) symmetrically arranged in rotation within the furnace body (2), notches being symmetrically provided on one side of the middle of the two partitions (601) close to each other, a cleaning port (602) being provided on the side of the air inlet flange (301) close to the furnace body (2), the cleaning port (602) being communicated with the furnace body (2), and a plurality of air passages (603) being evenly provided inside the air inlet flange (301) and being communicated with the cleaning port (602); An air guide component (7) is arranged inside the air inlet flange (301) and is capable of controlling the on / off of the air flow between the cleaning component (6) and the air inlet portion (3). When the air guide component (7) is in a connected state, the cleaning component (6) is capable of cleaning the inside of the furnace body (2). The air guide component (7) comprises: There are two piston blocks (701), the two piston blocks (701) are symmetrically sealed and slidably arranged inside the protective gas inlet chamber (306), and the two piston blocks (701) are both hollow structures; There are two connecting plates (702), the two connecting plates (702) are respectively fixedly arranged on the sides of the two piston blocks (701) close to each other, and the two connecting plates (702) are sealed and slidably arranged with the bottom of the protective gas inlet cavity (306); There are two driven gears (703), and the two driven gears (703) are respectively fixedly arranged on one side of the corresponding side partition plate (601) close to the intake flange (301), and the driven gears (703) are located in the middle of the corresponding side piston block (701); A tooth segment (704) is fixedly arranged on the inner bottom wall of the piston block (701) on the corresponding side, and the tooth segment (704) is meshed with the driven gear (703) on the corresponding side; Two second elastic members (705) are provided, and the two second elastic members (705) are respectively fixedly provided between the corresponding side piston blocks (701) and the side walls of the protective gas inlet chamber (306), and the second elastic members (705) can provide a thrust for the two piston blocks (701) to approach each other; A plurality of through holes (706) are provided, and the plurality of through holes (706) are evenly penetrated and opened on the connection plate (702). When the through holes (706) are aligned with the airway (603), the protective gas can flow from the protective gas inlet cavity (306) to the cleaning port (602); A switching component (8) is arranged inside the air inlet flange (301); when the switching component (8) is in a closed state, the air guide component (7) is in a connected state, and the inside of the furnace body (2) is cleaned; when the switching component (8) is in a connected state, the air guide component (7) is in a closed state, and an epitaxial growth process is carried out in the furnace body (2); the switching component (8) comprises: a reaction gas baffle (801) which is slidably arranged inside the reaction gas inlet (304); when the side of the reaction gas baffle (801) away from the furnace body (2) is in contact with the inner wall of the reaction gas inlet (304), the reaction gas inlet cavity (303) can be blocked; a third elastic member (802) fixedly disposed between the reaction gas baffle (801) and the gas inlet flange (301), the third elastic member (802) being capable of providing a pulling force for the reaction gas baffle (801) to move toward a side away from the furnace body (2); A second receiving groove (803) is provided inside the air inlet flange (301); a protective gas baffle (804) which is slidably disposed inside the second receiving groove (803) and is capable of blocking the gas guide groove (308) when it slides out of the second receiving groove (803); The transmission rod (805) is fixedly arranged between the reaction gas baffle (801) and the protective gas baffle (804); the reaction gas baffle (801) can drive the protective gas baffle (804) to move synchronously via the transmission rod (805).

2. The silicon-based epitaxial wafer thickness uniformity control device according to claim 1, characterized in that: The cleaning component (6) further comprises: A sewage outlet (604), which passes through the gas outlet flange (401) and is connected to the furnace body (2); A sewage discharge pipe (605) is fixedly arranged on a side of the gas outlet flange (401) away from the furnace body (2).

3. The device for controlling thickness uniformity of silicon-based epitaxial wafer according to claim 2, characterized in that: The cleaning component (6) further comprises: There are two guide grooves (606), and the two guide grooves (606) are symmetrically arranged on a side of the gas outlet flange (401) close to the furnace body (2); A sliding cavity (607) is provided inside the air outlet flange (401), and the sliding cavity (607) is connected to the bottom ends of the two guide grooves (606); A slide frame (608) is slidably disposed inside the slide cavity (607), and the bottom of the slide frame (608) penetrates through the sewage outlet (604); a first elastic member (609) fixedly disposed between the slide frame (608) and the slide cavity (607), the first elastic member (609) being capable of providing an upward pulling force to the slide frame (608); A dust shield (610) fixedly disposed at the bottom end of the slide (608) and capable of blocking the sewage outlet (604); A first receiving groove (611), which is provided at the bottom of the sewage outlet (604) and is capable of receiving the dust shield (610); There are two drive pins (612), and the two drive pins (612) are respectively fixedly arranged on one side of the corresponding partition (601) close to the air outlet flange (401), and the two drive pins (612) are both located in the guide groove (606) on the corresponding side. When the drive pin (612) moves downward along the guide groove (606), it can drive the slide (608) to move downward.

4. The silicon-based epitaxial wafer thickness uniformity control device according to claim 1, characterized in that: The air outlet portion (4) further comprises: an air outlet pipe (402) which is arranged on a side of the air outlet flange (401) away from the furnace body (2) and is in communication with the furnace body (2) and is capable of discharging gas in the furnace body (2); The bearing portion (5) further comprises: A lifting platform (502) fixedly arranged at the bottom of the workbench (1); A rotary motor (503) fixedly disposed on the top of the lifting platform (502); A rotating shaft (504) is fixedly arranged on the top of the power output shaft of the rotating motor (503), and the top end of the rotating shaft (504) penetrates into the interior of the furnace body (2), and the rotating shaft (504) and the furnace body (2) are sealed and rotatably connected; The supporting tray (505) is fixedly arranged on the top of the rotating shaft (504), and the object carrier (501) is placed on the top of the supporting tray (505). The supporting tray (505) can drive the object carrier (501) to rotate and rise and fall synchronously.

5. The silicon-based epitaxial wafer thickness uniformity control device according to claim 1, characterized in that: Also includes: A heat-insulating layer (9) is arranged in close contact with the inner wall of the furnace body (2) and is capable of heat-insulating the furnace body (2); A heating layer (10) is arranged in close contact with the inner wall of the heat-insulating layer (9) and is capable of heating the interior of the furnace body (2); The lining (11) is arranged in close contact with the inner wall of the heating layer (10) and is capable of protecting the heating layer (10).

6. A method for controlling thickness uniformity of a silicon-based epitaxial wafer, applied to a device for controlling thickness uniformity of a silicon-based epitaxial wafer according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: placing the epitaxial wafer on the carrier plate (501); Step 2: pre-cleaning the furnace body (2), introducing protective gas separately, making the switching component (8) in a closed state, the gas guide component (7) in a connected state, and the two partitions (601) are combined to divide the furnace body (2) into two independent closed cavities, the protective gas cleans the dust particles in the lower closed cavity, and the furnace body (2) is pre-cleaned; Step 3: epitaxial growth. After pre-cleaning is completed, protective gas and reaction gas are introduced simultaneously, so that the switching component (8) is in a connected state, the gas guide component (7) is in a closed state, and the two partitions (601) are respectively attached to the inner wall of the furnace body (2). The protective gas wraps the reaction gas and blows it into the furnace body (2), thereby providing a uniform and stable reaction gas flow for epitaxial growth. Step 4: taking out the epitaxial wafer after the epitaxial growth process is completed from the furnace body (2).

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