A diffusion furnace with an air intake device

Abstract

The present invention provides a diffusion furnace with an air intake device. The air intake device is an air intake device of a distributed diffusion furnace, comprising: a redundant tank and a partition mechanism, wherein an annular tube is fixedly connected to the redundant tank, and the partition mechanism comprises a hydraulic push rod and a hollow partition, wherein a sliding partition is slidably installed in the hollow partition, and an output rod of the hydraulic push rod extends into the hollow partition and is fixedly connected to one end of the sliding partition. The present invention can achieve uniform diffusion of the reaction gas, so that the reaction gas can uniformly contact the silicon wafer.

Description

Technical Field

[0001] The invention belongs to the technical field of diffusion furnaces, and in particular relates to a diffusion furnace with an air intake device. Background Art

[0002] In the process of manufacturing semiconductor chips, silicon wafers need to go through processes such as texturing, diffusion, etching, coating and printing in sequence. The diffusion process is to place the silicon wafer into a diffusion furnace with a quartz boat as a carrier, and introduce reaction gas into the diffusion furnace at a certain temperature to diffuse and deposit PN junctions on the surface of the silicon wafer. When the silicon wafer is diffusing, the reaction gas will enter the diffusion furnace through the air inlet pipe at the top of the diffusion furnace, and then be discharged through the exhaust pipe at the bottom of the diffusion furnace. In this process, the reaction gas will pass between the silicon wafers, so as to diffuse and deposit PN junctions on the surface of the silicon wafer.

[0003] However, in the production process of semiconductors, the thickness and quality of the thin film grown on the surface of all silicon wafers in the diffusion furnace are required to be as consistent as possible. This requires that the reaction gas be diffused more evenly when it is introduced into the diffusion furnace through the air inlet pipe. However, when the space inside the diffusion furnace is expanded to achieve batch processing, the reaction gas in the air inlet pipe is difficult to be evenly distributed to various areas of the diffusion furnace. Because of the distance relationship, the closer the area is to the delivery port, the greater the concentration of the reaction gas, and vice versa. At the same time, the delivery volume of the reaction gas is not completely uniform, and the problem of weakened delivery volume may occur. Therefore, it is easy to cause the silicon wafers at different positions in the diffusion furnace to have inconsistent contact flow rates with the reaction gas, resulting in differences in the thickness and quality of the thin film grown on the surface of the silicon wafers at different positions. Summary of the invention

[0004] The technical problem solved by the present invention is to provide a diffusion furnace containing an air intake device which allows the reaction gas to contact the crystalline silicon wafer more uniformly.

[0005] In order to solve the above technical problems, the present invention provides a diffusion furnace with an air intake device, wherein the air intake device is an air intake device of a decentralized diffusion furnace, including: a redundant tank and a partition mechanism, an annular tube is fixedly connected to the redundant tank, the partition mechanism includes a hydraulic push rod and a hollow partition, a sliding partition is slidably installed in the hollow partition, and the output rod of the hydraulic push rod extends into the hollow partition and is fixedly connected to one end of the sliding partition.

[0006] The annular tube is provided with a plurality of transversely distributed air inlet holes, and the hollow partition and the sliding partition are both provided with a plurality of discharge ports, and the discharge ports on the hollow partition are opposite to the discharge ports on the sliding partition.

[0007] The diffusion furnace includes a furnace body, one side of the furnace body is fixedly connected to a dustproof operating chamber, a displacement mechanism is arranged in the dustproof operating chamber, a furnace door is installed on the displacement mechanism, one side of the furnace door extends into the furnace mouth of the furnace body and seals the furnace mouth, a first motor is fixedly installed on one side of the furnace body, a turning cylinder is rotatably installed in the furnace body, the first motor is transmission-connected to the turning cylinder, a quartz boat mechanism is slidably installed on the turning cylinder, and the quartz boat mechanism is rotationally connected to the furnace door.

[0008] The displacement mechanism includes a third motor fixedly installed at one end of the dustproof operation chamber, a screw is rotatably installed in the dustproof operation chamber, the third motor is transmission-connected to the screw, a driving block is provided on the threaded sleeve of the screw, and the driving block is fixedly connected to the furnace door.

[0009] Two sliding bars are fixedly installed in the dustproof operation chamber, and both sliding bars penetrate the driving block and are slidably connected with the driving block.

[0010] A filter box is fixedly installed on the top of the dustproof operation chamber, a fan is fixedly installed in the filter box, an air inlet pipe is fixedly connected to the air outlet of the fan, the other end of the air inlet pipe extends into the dustproof operation chamber and is fixedly installed with two shunt pipes, and air outlets are provided at the bottom of the two shunt pipes.

[0011] The quartz boat mechanism includes a convex disk rotatably mounted on the furnace door and a circular disk slidably mounted on the turning cylinder. A plurality of arc-shaped frame rods are fixedly mounted between the convex disk and the circular disk. A second motor is fixedly mounted inside the convex disk. The same limiting rod is rotatably mounted on the convex disk and the circular disk. The shaft rod of the limiting rod is fixedly connected to the output shaft of the second motor. A plurality of clamping grooves are provided on the plurality of frame rods and the limiting rods.

[0012] As a further solution of the present invention, a first exhaust pipe is fixedly installed in the furnace body, three connecting pipes are fixedly connected to the bottom of the first exhaust pipe, the bottom ends of the three connecting pipes extend outside the furnace body and are fixedly installed with the same second exhaust pipe, and the first exhaust pipe is provided with a plurality of exhaust holes arranged horizontally.

[0013] As a further solution of the present invention, two operation ports are provided on the dustproof operation chamber, and transparent partition windows are hinged on the two operation ports.

[0014] Compared with the related art, the diffusion furnace with the air intake device provided by the present invention has the following beneficial effects:

[0015] The present invention forms an air intake device for a diffusion furnace by cooperating with redundant tanks, annular tubes, hydraulic push rods, hollow partitions, and sliding partitions. The redundant tanks can realize temporary storage of the reaction gas, so that when the delivery amount of the reaction gas delivery source is weakened, the reaction gas in the redundant tank can be used as a supplement after the flow is weakened, thereby ensuring that the delivery amount of the reaction gas remains stable, so that the reaction gas delivered to the diffusion furnace can be more uniform;

[0016] Since both ends of the annular tube are connected to the redundant tank, the reaction gas can enter the annular tube from both ends. Compared with single-end delivery, the two-end delivery has higher flow stability and is less likely to have the problem of some inlet holes being too far away from the delivery end, resulting in reduced discharge, so that the reaction gas can be discharged more evenly to all areas inside the diffusion furnace;

[0017] The hydraulic push rod, hollow partition and sliding partition are part of the air intake device, which mainly serve as the partition mechanism of the diffusion furnace. Since the internal space of the diffusion furnace is too large compared to the delivery volume of the reaction gas, if the reaction gas is directly delivered to the diffusion furnace, it is easy to cause the reaction gas to be relatively thin when it just enters the diffusion furnace, and it cannot be evenly diffused, and thus cannot evenly contact all silicon wafers;

[0018] Through the flipping mechanism composed of the first motor and the flipping cylinder and other structures, the quartz boat mechanism can be driven to flip while not affecting the normal extension and opening of the quartz boat mechanism, so that the silicon wafer can rotate in the diffusion furnace to contact the reaction gas, so that all angles of the silicon wafer can be evenly in contact with the reaction gas, avoiding the situation where the contact degree at the bottom or side is lower than that at the top. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is an overall display diagram of a diffusion furnace including an air intake device;

[0020] Figure 2 It is a partial display diagram of a diffusion furnace including an air inlet device;

[0021] Figure 3 A partial cross-sectional view of a diffusion furnace including an air inlet device;

[0022] Figure 4 This is a partial disassembled diagram of a diffusion furnace including an air inlet device;

[0023] Figure 5 It is a display diagram of the turning cylinder and quartz boat mechanism in the diffusion furnace including the air inlet device;

[0024] Figure 6 It is a partial cross-sectional disassembly diagram of the turning cylinder and quartz boat mechanism in the diffusion furnace including the air inlet device;

[0025] Figure 7 A cross-sectional view showing a partition mechanism in a diffusion furnace including an air inlet device;

[0026] Figure 8 The present invention is a disassembled cross-sectional view showing a partition mechanism in a diffusion furnace including an air inlet device;

[0027] Fig. 9A front view showing a dustproof operation chamber and a filter box in a diffusion furnace including an air intake device;

[0028] Fig.10 A rear view showing a dustproof operation chamber and a filter box in a diffusion furnace including an air intake device;

[0029] Fig.11 It is a cross-sectional view showing the dustproof operation chamber and filter box in the diffusion furnace including the air intake device.

[0030] Description of main symbols:

[0031] 1. furnace body; 2. first motor; 3. first bevel gear; 4. turning cylinder; 5. second bevel gear; 6. furnace door; 7. convex disk; 8. round disk; 9. rack rod; 10. second motor; 11. limiting rod; 12. dustproof operation chamber; 13. third motor; 14. third bevel gear; 15. screw rod; 16. fourth bevel gear; 17. sliding rod; 18. filter box; 19. fan; 20. air inlet pipe; 21. shunt pipe; 22. redundant tank; 23. annular pipe; 24. hydraulic push rod; 25. hollow partition; 26. sliding partition; 27. first exhaust pipe; 28. connecting pipe; 29. ​​second exhaust pipe. DETAILED DESCRIPTION

[0032] The present invention is further described below in conjunction with the accompanying drawings and specific implementation methods.

[0033] Please combine Figures 1 to 11 A diffusion furnace including an air intake device, wherein the air intake device is an air intake device of a distributed diffusion furnace, including a redundant tank 22 and a partition mechanism, an annular tube 23 is fixedly connected to the redundant tank 22, the partition mechanism includes a hydraulic push rod 24 and a hollow partition 25, a sliding partition 26 is slidably installed in the hollow partition 25, the output rod of the hydraulic push rod 24 extends into the hollow partition 25 and is fixedly connected to one end of the sliding partition 26, the redundant tank 22 is installed on the top of the diffusion furnace, the two ends of the annular tube 23 are respectively connected to the two sides of the redundant tank 22, and the lower half of the annular tube 23 is in the diffusion furnace and fixedly connected to the diffusion furnace, the partition mechanism is installed in the diffusion furnace, and the interior of the diffusion furnace can be divided into upper and lower parts.

[0034] The annular tube 23 is provided with a plurality of transversely distributed air inlet holes, and the hollow partition 25 and the sliding partition 26 are both provided with a plurality of discharge ports, and the discharge ports on the hollow partition 25 are opposite to the discharge ports on the sliding partition 26 .

[0035] Through the above technical scheme, the air inlet hole allows the reaction gas in the annular tube 23 to enter the diffusion furnace evenly. When the discharge port on the sliding partition 26 is relative to the discharge port on the hollow partition 25, the partition mechanism is in an open state, and the reaction gas gathered in the upper part of the diffusion furnace can evenly enter the lower part area from multiple discharge holes and contact the silicon wafer. When the two are misaligned, the partition mechanism is in a closed state. At this time, the reaction gas can be gathered in the upper part of the diffusion furnace and released to contact the silicon wafer after saturation, thereby ensuring that the reaction gas in contact with the silicon wafer is more and more uniform.

[0036] The diffusion furnace includes a furnace body 1, one side of the furnace body 1 is fixedly connected to a dustproof operation chamber 12, the bottom of the furnace body 1 and the dustproof operation chamber 12 are provided with a plurality of supporting legs, the bottom of the plurality of supporting legs is fixedly installed with the same base, a displacement mechanism is provided in the dustproof operation chamber 12, a furnace door 6 is installed on the displacement mechanism, one side of the furnace door 6 extends into the furnace mouth of the furnace body 1 and blocks the furnace mouth, a first motor 2 is fixedly installed on one side of the furnace body 1, a turning cylinder 4 is rotatably installed in the furnace body 1, a first bevel gear 3 is fixedly installed on the output shaft of the first motor 2, and a first gear 4 is fixedly installed on the shaft rod of the turning cylinder 4. Two bevel gears 5, the first bevel gear 3 is meshed with the second bevel gear 5, a quartz boat mechanism is slidably installed on the turning cylinder 4, the quartz boat mechanism is rotatably connected to the furnace door 6, the turning cylinder 4 is composed of a rotating disk, a rotating ring and a plurality of connecting rods, the shaft of the rotating disk passes through the inner wall of the furnace body 1 and is rotatably connected to the furnace body 1, a fixed ring is fixedly connected to the inner wall of one end of the furnace body 1, the rotating ring is in the fixed ring and is rotatably connected to the fixed ring, the furnace mouth corresponds to the fixed ring and the rotating ring, so that the quartz boat mechanism can be in the turning cylinder 4 and rotate synchronously with the turning cylinder 4, and can also be moved outside the furnace body 1 at the same time.

[0037] The displacement mechanism includes a third motor 13 fixedly mounted at one end of a dustproof operating chamber 12, a screw 15 is rotatably mounted in the dustproof operating chamber 12, a third bevel gear 14 is fixedly mounted on the output shaft of the third motor 13, a fourth bevel gear 16 is fixedly mounted at one end of the screw 15, the third bevel gear 14 is meshed with the fourth bevel gear 16, a driving block is threadedly sleeved on the screw 15, and the driving block is fixedly connected to the furnace door 6.

[0038] Through the above technical solution, the moving mechanism can automatically open the furnace door 6 and bring the quartz boat mechanism out of the furnace body 1 through the furnace door 6, thereby realizing the storage of silicon wafers.

[0039] Two slide bars 17 are fixedly installed in the dustproof operation chamber 12 , and both slide bars 17 penetrate the driving block and are slidably connected to the driving block.

[0040] Through the above technical solution, both ends of the two slide rods 17 are fixedly connected to the inner walls on both sides of the dust-proof operation chamber 12. The two slide rods 17 can improve the stability of both the driving block and the furnace door 6 while not affecting their movement.

[0041] A filter box 18 is fixedly installed on the top of the dust-proof operation chamber 12. The filter box 18 is composed of a box body and a dust-proof filter screen installed on the box body. When the fan 19 sucks in external air through the dust-proof filter screen, the dust-proof filter screen can play a role in filtering dust. A fan 19 is fixedly installed in the filter box 18. An air inlet pipe 20 is fixedly connected to the air outlet of the fan 19. The other end of the air inlet pipe 20 extends into the dust-proof operation chamber 12 and is fixedly installed with two shunt pipes 21. Blow openings are provided at the bottoms of the two shunt pipes 21.

[0042] Through the above technical solution, by输送气流 into the dust-proof operation chamber 12, when the transparent partition window on the dust-proof operation chamber 12 is opened, the air flow in the dust-proof operation chamber 12 will diffuse towards the outside, and the formed air flow can prevent external dust from entering the dust-proof operation chamber 12. Thus, the packaging work of the silicon wafers can be completed in the dust-proof operation chamber 12 to facilitate subsequent transfer.

[0043] The quartz boat mechanism includes a convex disk 7 rotatably installed on the furnace door 6 and a disk 8 slidably sleeved on the turnover cylinder 4. A plurality of arc-shaped distributed support rods 9 are fixedly installed between the convex disk 7 and the disk 8. A second motor 10 is fixedly installed in the convex disk 7. There is a motor slot on one side of the convex disk 7. The second motor 10 is located in the motor slot. And there is a rotation slot on one side of the furnace door 6. The protruding part of the convex disk 7 extends into the rotation slot and is rotatably connected to the rotation slot. And there is a valve cover on the furnace door 6. Opening the valve cover can reach the second motor 10. The same limiting rod 11 is rotatably installed on the convex disk 7 and the disk 8. The shaft rod of the limiting rod 11 is fixedly connected to the output shaft of the second motor 10. A plurality of clamping grooves are provided on the plurality of support rods 9 and the limiting rod 11. The limiting rod 11 is similar to a C shape and is composed of two connecting bars and a cross bar. The clamping grooves enable the silicon wafers to be stably placed on the quartz boat mechanism.

[0044] Through the above technical solution, the quartz boat mechanism is both slidably connected to the turnover cylinder 4 and rotatably connected to the furnace door 6. This enables it to rotate synchronously with the turnover cylinder 4 and at the same time can be moved out of the diffusion furnace under the drive of the furnace door 6. The limiting rod 11 can adjust the angle under the drive of the second motor 10, which can not only ensure the stability of the silicon wafers during turnover but also not affect the normal storage of the silicon wafers.

[0045] A first exhaust pipe 27 is fixedly installed in the furnace body 1, and three connecting pipes 28 are fixedly connected to the bottom of the first exhaust pipe 27. The bottom ends of the three connecting pipes 28 extend outside the furnace body 1 and are fixedly installed with the same second exhaust pipe 29. The first exhaust pipe 27 is provided with a plurality of exhaust holes arranged horizontally.

[0046] Through the above technical solution, the first exhaust pipe 27 cooperates with the three connecting pipes 28 and the second exhaust pipe 29 to form an exhaust pipe that can exhaust evenly. Its specific structure can make the absorption capacity more uniform, ensuring that each exhaust hole has a similar absorption effect, so that the reaction gas in the diffusion furnace is evenly absorbed and discharged through multiple exhaust holes, and then combined with the air intake device, the reaction gas can fall evenly over a large range like a waterfall, and then evenly enter the first exhaust pipe 27 through multiple exhaust holes, and finally be discharged, thereby ensuring that the silicon wafer can be evenly in contact with the reaction gas.

[0047] The dustproof operation chamber 12 is provided with two operation openings, and transparent partition windows are hinged on the two operation openings.

[0048] Through the above technical solution, the transparent partition window is composed of a window frame and transparent tempered glass, which can not only shield the operation port, but also allow the internal situation of the dustproof operation chamber 12 to be intuitively seen.

[0049] The implementation principle of a diffusion furnace with an air intake device in the embodiment of the present application is:

[0050] Step 1: When the silicon wafer needs to be processed, the transparent partition window of the dustproof operation chamber 12 is opened, the silicon wafer is placed on the quartz boat mechanism, and then the second motor 10 is started, and the second motor 10 drives the limiting rod 11 to rotate, so that the limiting rod 11 rotates to the top of the silicon wafer, so as to cooperate with the multiple rack rods 9 and the silicon wafer for limiting. At the same time, before use, the partition mechanism is in a closed state;

[0051] The second step: start the third motor 13, the third motor 13 drives the screw 15 to rotate through the third bevel gear 14 and the fourth bevel gear 16, the screw 15 drives the quartz boat mechanism and the silicon wafer confined on the quartz boat mechanism to move through the driving block and the furnace door 6, until the quartz boat mechanism enters the furnace body 1, and the furnace door 6 seals the furnace mouth of the furnace body 1, then start the first motor 2, the first motor 2 drives the first bevel gear 3 to rotate through the output shaft, the first bevel gear 3 drives the turning cylinder 4 to rotate through the second bevel gear 5, and the turning cylinder 4 drives the quartz boat mechanism and the silicon wafer to turn slowly;

[0052] The third step: connect the delivery pipe of the reaction gas to the inlet of the redundant tank 22, and connect the second exhaust pipe 29 to the external exhaust pipe to ensure the normal circulation of the reaction gas. When the reaction gas enters the redundant tank 22, it will be dispersed into the annular pipe 23 from both sides, and then evenly enter the furnace body 1 from multiple air inlets on the annular pipe 23, and gather in the area above the partition mechanism in the furnace body 1 until the area above the partition mechanism is full of reaction gas. At this time, the upper half of the furnace body 1 is saturated, which causes the reaction gas originally delivered to the furnace body 1 to gather in the redundant tank 22 until the redundant tank 22 is also saturated and the hydraulic push rod 24 is started;

[0053] Step 4: The hydraulic push rod 24 drives the sliding partition 26 to move, so that the discharge port on the sliding partition 26 is aligned with the discharge port on the hollow partition 25, thereby opening the partition mechanism, so that the reaction gas in the upper half of the furnace body 1 will evenly pass through multiple discharge ports to enter the lower half of the furnace body 1. At the same time, under the influence of the external discharge extraction force, the reaction gas will evenly pass through multiple exhaust holes into the first exhaust pipe 27 after entering the lower half of the furnace body, and then enter the second exhaust pipe 29 through three connecting pipes 28, and then enter the external exhaust pipe through the second exhaust pipe 29, thereby achieving uniform flow of the reaction gas, and combined with the flipped quartz boat mechanism, the contact between the silicon wafer and the reaction gas is more uniform, and when the delivery amount of the reaction gas source is weakened, the reaction gas in the redundant tank 22 can be used as a temporary supplement to ensure that the reaction gas flowing into the furnace body 1 maintains a stable flow rate;

[0054] Step 5: When the processing of the silicon wafer is completed, the quartz boat mechanism drives the processed silicon wafer back to the dustproof operation chamber 12, and then starts the fan 19. The fan 19 conveys airflow to the dustproof operation chamber 12 through the air inlet pipe 20 and the two branch pipes 21. During this process, the filter box 18 can filter the conveyed airflow. At this time, after opening the transparent partition window, the airflow in the dustproof operation chamber 12 will diffuse toward the outside. The airflow formed in this way can prevent external dust from entering the dustproof operation chamber 12, so that the packaging of the silicon wafers can be completed in the dustproof operation chamber 12 to facilitate subsequent transfer.

[0055] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A diffusion furnace comprising an air inlet device, characterized in that: The air intake device is an air intake device for a decentralized diffusion furnace, comprising: a redundant tank and a partition mechanism, wherein an annular tube is fixedly connected to the redundant tank, and the partition mechanism comprises a hydraulic push rod and a hollow partition, wherein a sliding partition is slidably installed in the hollow partition, and the output rod of the hydraulic push rod extends into the hollow partition and is fixedly connected to one end of the sliding partition; The annular tube is provided with a plurality of transversely distributed air inlet holes, the hollow partition and the sliding partition are both provided with a plurality of discharge ports, and the discharge ports on the hollow partition are opposite to the discharge ports on the sliding partition; The diffusion furnace comprises a furnace body, a dustproof operation chamber is fixedly connected to one side of the furnace body, a displacement mechanism is arranged in the dustproof operation chamber, a furnace door is installed on the displacement mechanism, one side of the furnace door extends into the furnace opening of the furnace body and blocks the furnace opening, a first motor is fixedly installed on one side of the furnace body, a turning cylinder is rotatably installed in the furnace body, the first motor is transmission-connected to the turning cylinder, a quartz boat mechanism is slidably installed on the turning cylinder, and the quartz boat mechanism is rotationally connected to the furnace door; The displacement mechanism includes a third motor fixedly mounted at one end of the dustproof operation chamber, a screw is rotatably mounted in the dustproof operation chamber, the third motor is transmission-connected to the screw, a driving block is provided on the threaded sleeve of the screw, and the driving block is fixedly connected to the furnace door; Two sliding rods are fixedly installed in the dustproof operation chamber, and both sliding rods penetrate the driving block and are slidably connected to the driving block; A filter box is fixedly installed on the top of the dustproof operation chamber, a fan is fixedly installed in the filter box, an air inlet pipe is fixedly connected to the air outlet of the fan, the other end of the air inlet pipe extends into the dustproof operation chamber and is fixedly installed with two shunt pipes, and the bottoms of the two shunt pipes are provided with air outlets; The quartz boat mechanism comprises a convex disk rotatably mounted on the furnace door and a disc slidably sleeved on the turning cylinder, a plurality of arc-shaped racks are fixedly mounted between the convex disk and the disc, a second motor is fixedly mounted inside the convex disk, a same limiting rod is rotatably mounted on the convex disk and the disc, the shaft of the limiting rod is fixedly connected to the output shaft of the second motor, and a plurality of racks and limiting rods are provided with a plurality of clamping grooves; A first exhaust pipe is fixedly installed inside the furnace body, three connecting pipes are fixedly connected to the bottom of the first exhaust pipe, the bottom ends of the three connecting pipes extend outside the furnace body and are fixedly installed with the same second exhaust pipe, and the first exhaust pipe is provided with a plurality of exhaust holes arranged horizontally.

2. The diffusion furnace with an air inlet device according to claim 1, characterized in that: The dustproof operation chamber is provided with two operation openings, and transparent partition windows are hinged on the two operation openings.

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