A supporting device for SiC ceramic furnace tube surface plated with SiC film

Abstract

A kind of SiC ceramic furnace tube surface plating SiC film's supporting device, including center turntable, it is characterized in that: the center turntable is distributed with multiple air nozzle assemblies, the air nozzle assembly is sleeved with object platform, the center turntable below is provided with the center rotating motor of driving center turntable rotation, center turntable below is also provided with the belt drive mechanism for driving object platform rotation.The utility model is driven by center rotating motor center turntable revolution, and object platform is driven by belt drive mechanism to revolve on center turntable, ensures the uniformity of chemical vapor deposition;By the design mode of object platform radiating from center to periphery, the number of coating furnace tube is greatly increased, efficiency is increased, and the cost of coating is effectively reduced.

Description

Technical Field

[0001] This utility model relates to the semiconductor field, specifically to a support device for a SiC ceramic furnace tube with a SiC thin film coated on its surface. Background Technology

[0002] A semiconductor oxidation furnace is a device that uses oxidizing gases to oxidize the surface of semiconductor wafers. It primarily involves placing the semiconductor wafer into a high-temperature oxidation furnace, heating it, and adding oxidizing gases (such as nitrogen oxides or water vapor) to cause an oxidation reaction on the wafer surface, thereby forming an oxide layer. During the oxidation process, a SiO2 protective layer forms on the wafer surface. This layer serves to protect the wafer surface, provide insulation, and prevent impurities, making it crucial for semiconductor manufacturing.

[0003] Silicon carbide (SiC) ceramic furnace tubes are essential components used in semiconductor oxidation processes. Because they come into direct contact with the wafer, a silicon carbide (SiC) thin film must be deposited on both the inner and outer surfaces using chemical vapor deposition to ensure the purity of the ceramic furnace tube. Since silicon carbide (SiC) ceramic furnace tubes are generally quite long—≥1000mm for 6-inch wafers and ≥2000mm for 12-inch structures—it is difficult for reactive gases to enter the interior of the tube during chemical vapor deposition.

[0004] Existing methods for chemically vapor-depositing a silicon carbide (SiC) thin film onto silicon carbide (SiC) ceramic furnace tubes simply involve placing the furnace tube in a furnace chamber through which the reaction gas is introduced. It is difficult for the reaction gas to enter the interior of the furnace tube, especially when the silicon carbide (SiC) ceramic furnace tube is a blind hole, where the reaction gas does not circulate at all, making it difficult to form an effective and uniform thin film inside. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings and deficiencies of the prior art and provide a support device for coating SiC thin films on the surface of SiC ceramic furnace tubes, which has a simple structure, uniform chemical vapor deposition, high coating efficiency, and low cost.

[0006] To achieve the above objectives, the technical solution of this utility model is: a support device for coating a SiC ceramic furnace tube with a SiC thin film, comprising a central turntable, characterized in that: the central turntable is provided with a plurality of air nozzle assemblies, a loading platform is sleeved on the air nozzle assembly, a central rotary motor for driving the central turntable to rotate is provided below the central turntable, and a belt drive mechanism for driving the loading platform to rotate is also provided below the central turntable.

[0007] The nozzle assembly includes a central nozzle assembly located at the center of the central turntable and peripheral nozzle assemblies surrounding the central nozzle assembly. The peripheral nozzle assemblies are symmetrically distributed with respect to the central nozzle assembly. The central nozzle assembly is fitted with a central loading platform, and the peripheral nozzle assemblies are fitted with peripheral loading platforms.

[0008] The belt drive mechanism includes a belt motor and rollers. The rollers are sleeved on the outer wall of the air nozzle assembly, and the motor shaft of the belt motor is connected to the rollers via a belt.

[0009] The air nozzle assembly includes a No. 1 air nozzle, a No. 2 air nozzle, and a No. 3 air nozzle that are interconnected. The No. 1 air nozzle is fitted onto the outer wall of the No. 2 air nozzle, and the No. 2 air nozzle is inserted into the No. 3 air nozzle.

[0010] The No. 1 and No. 2 air nozzles are provided with two main air channels along the axial direction. The No. 1 and No. 2 air nozzles are interconnected through the main air channels. The inner wall and end face of the No. 1 air nozzle are provided with multiple air holes that are connected to the main air channels.

[0011] Both the central loading platform and the outer loading platform are provided with three evenly distributed grooves, and each groove contains a rotating ball that can rotate freely within the groove.

[0012] The first air nozzle is made of high-purity isostatic graphite with a purity of ≤5ppm.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0014] 1. This utility model uses a central rotary motor to drive the central turntable to revolve, and a belt drive mechanism to drive the loading platform to rotate on the central turntable, ensuring the uniformity of chemical vapor deposition; the loading platform design that radiates from the center to the surrounding areas greatly increases the number of coating furnace tubes, increases efficiency, and effectively reduces the cost of coating.

[0015] 2. This utility model divides the gas nozzle assembly into three gas nozzle sections, two gas channels, and two gas channels, allowing the gas to be directly introduced into the interior of the sintering SiC ceramic furnace tube. This allows the gas to mix evenly and react fully, forming a uniform thin film on the inner wall of the furnace tube.

[0016] 3. The No. 1 air nozzle in this utility model is made of graphite material, which is resistant to high temperature, with a maximum temperature of over 2000℃, and the purity of graphite is ≤5ppm; it can effectively ensure the purity of SiC film, avoid interference from metal ions, and ensure the service life of air nozzle.

[0017] 4. This utility model has grooves for built-in rotating balls on the central and outer loading platforms. During operation, the end face of the furnace tube directly contacts the rolling ball. This contact is a point contact. Furthermore, due to the rotation of the loading platform, the end face of the furnace tube and the rolling ball also slide, which avoids the contact position from blocking the deposition of SiC. This achieves the goal of coating a layer of SiC film on both the inner and outer surfaces of the furnace tube in one go. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of this utility model.

[0019] Figure 2 This is a cross-sectional view of the gas flow in this utility model.

[0020] Figure 3 A cross-sectional view of a partial component in this utility model.

[0021] Figure 4 This is a schematic diagram of the structure of the cargo platform in this utility model.

[0022] Figure 5 This is a schematic diagram of the structure of the No. 1 air nozzle in this utility model.

[0023] In the diagram: 1. Central turntable; 2. Air nozzle assembly; 21. Central air nozzle assembly; 22. Peripheral air nozzle assembly; 3. Loading platform; 31. Central loading platform; 32. Peripheral loading platform; 4. Central rotary motor; 5. Belt motor; 6. Roller; 7. No. 1 air nozzle; 8. No. 2 air nozzle; 9. No. 3 air nozzle; 10. Main air passage; 11. Air hole; 12. Groove; 13. Rotating ball; 14. Air inlet connector; 15. Bearing seat; 16. Rolling bearing; 17. SiC ceramic furnace tube. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] See Figures 1-5 A support device for coating a SiC ceramic furnace tube with a SiC thin film includes a central turntable 1. A central air nozzle assembly 21 is disposed at the center of the central turntable 1. Multiple peripheral air nozzle assemblies 22 are symmetrically distributed around the central air nozzle assembly 21. A central loading platform 31 is sleeved on the central air nozzle assembly 21, and peripheral loading platforms 32 are sleeved on the peripheral air nozzle assemblies 22. Three evenly distributed grooves 12 are provided on both the central loading platform 31 and the peripheral loading platforms 32. A rotating ball 13 that can rotate freely within the groove 12 is provided in each groove. A central rotary motor 4 is disposed below the central turntable 1. The central rotary motor 4 is connected to the central turntable 1 through a motor shaft and drives the central turntable 1 to revolve. A belt drive mechanism for driving the rotation of the loading platforms 3 is also disposed below the central turntable 1.

[0026] The belt drive mechanism includes a belt motor 5 and multiple sets of rollers 6. The belt motor 5 is mounted on a belt motor bracket, and the rollers 6 are sleeved on the outer wall of the air nozzle assembly 2. The motor shaft of the belt motor 5 is connected to the rollers 6 via a belt.

[0027] The nozzle assembly 2 includes a first nozzle 7, a second nozzle 8, and a third nozzle 9 that are interconnected. The first nozzle 7 is sleeved on the outer wall of the second nozzle 8, and the second nozzle 8 is inserted into the third nozzle 9. The first nozzle 7 is made of high-purity isostatic graphite with a purity ≤5ppm. The second nozzle 8 is made of high-strength stainless steel and has a bearing mounting structure, which includes a bearing seat 15 and two rolling bearings 16.

[0028] The first air nozzle 7 and the second air nozzle 8 have two main air passages 10 arranged axially inside them. The first air nozzle 7 and the second air nozzle 8 are interconnected through the main air passages 10. The main air passage 10 of the second air nozzle 8 is connected to the air passage in the third air nozzle 9. The air passage in the third air nozzle 9 is connected to the air intake pipe through the air intake connector 14. In actual operation, the air intake pipe is very long, and in order to avoid the air intake pipes from getting tangled, the central turntable 1 will rotate clockwise at a certain angle and then flip back. The inner wall of the first air nozzle 7 has a plurality of air holes 11 evenly arranged axially and connected to the main air passages 10. The top surface of the first air nozzle 7 is provided with two air holes, which are connected to the two main air passages 10 respectively.

[0029] The working process of this utility model is as follows:

[0030] The SiC ceramic furnace tube 17 to be coated is placed on the central platform 31 and the outer platform 32. The furnace tube makes point contact with the rotating balls 13 on the platform. There are three rotating balls 13, so there are three actual contact points, which ensures the stability of the SiC ceramic furnace tube. During the chemical vapor deposition process, hydrogen and methyltrichlorosilane are respectively introduced into the two gas inlets 14 connected to the third gas nozzle 9. The flow rate ratio of hydrogen to methyltrichlorosilane is 5:1 to 15:1. The reaction gas flows through the third gas nozzle 9 into the second gas nozzle 8, and then into the first gas nozzle 7. The first gas nozzle 7 has two rows of axially distributed gas holes 11 connected to the main gas channel 10. The reactant gas flows uniformly along the gas holes 11 until it fills the entire inner cavity of the SiC ceramic furnace tube 17. The inner cavity pressure is 1-5 kPa, the deposition time is 3600-4800 s, and the deposition temperature is 1200-1600℃. During the chemical vapor deposition process, the inner cavity undergoes three stages: heating, deposition, and cooling. The heating stage is further divided into two phases: heating from room temperature to a first temperature (450-600℃, 10-15℃ / min) at a first heating rate; and heating from the first temperature to a second temperature (1000-1600℃, 8-10℃ / min) at a second heating rate. Hydrogen gas introduced into the inner cavity and methyltrichlorosilane undergo an atomic layer reaction during this process to form a SiC thin film. As time progresses, the SiC thin film gradually thickens. To increase the uniformity of deposition, a central turntable 1 is provided. Under the action of the central rotary motor 4, the central turntable 1 will revolve. Because the central turntable 1 revolves under the action of the central rotary motor 4, the central carrying platform 31 is locked to the central turntable 1 and also revolves along the central axis with the central turntable 1. Rollers 6 are provided under the outer carrying platform 32, and a tensioned belt is provided on the rollers 6. Under the action of the belt motor 5, the outer carrying platform 32 rotates on the central turntable 1, ensuring the uniformity of chemical vapor deposition. Moreover, under the rotation of the outer carrying platform 32, the end face of the SiC ceramic furnace tube 17 also slides with the rolling ball 13, avoiding the contact position from blocking the deposition of SiC, so that SiC film can be deposited at every position of the SiC ceramic furnace tube 17, thereby achieving a uniform coating of a SiC film on the inner and outer surfaces of the furnace tube in one go.

Claims

1. A support device for a SiC ceramic furnace tube coated with a SiC thin film, comprising a central turntable (1), characterized in that: The central turntable (1) is provided with multiple air nozzle assemblies (2), and a cargo platform (3) is sleeved on the air nozzle assembly (2). A central rotary motor (4) for driving the central turntable (1) to rotate is provided below the central turntable (1), and a belt drive mechanism for driving the cargo platform (3) to rotate is also provided below the central turntable (1).

2. The support device for SiC ceramic furnace tube surface coated with SiC thin film according to claim 1, characterized in that: The nozzle assembly (2) includes a central nozzle assembly (21) located at the center of the central turntable (1) and peripheral nozzle assemblies (22) surrounding the central nozzle assembly (21). The peripheral nozzle assemblies (22) are symmetrically distributed with the central nozzle assembly (21) as the center. The central nozzle assembly (21) is fitted with a central loading platform (31), and the peripheral nozzle assembly (22) is fitted with a peripheral loading platform (32).

3. The support device for SiC ceramic furnace tube surface coated with SiC thin film according to claim 2, characterized in that: The belt drive mechanism includes a belt motor (5) and a roller (6). The roller (6) is sleeved on the outer wall of the air nozzle assembly (2). The motor shaft of the belt motor (5) is connected to the roller (6) via a belt.

4. The support device for SiC ceramic furnace tube surface coated with SiC thin film according to claim 3, characterized in that: The nozzle assembly (2) includes a first nozzle (7), a second nozzle (8) and a third nozzle (9) that are interconnected. The first nozzle (7) is sleeved on the outer wall of the second nozzle (8), and the second nozzle (8) is inserted into the third nozzle (9).

5. The support device for SiC ceramic furnace tube surface coated with SiC thin film according to claim 4, characterized in that: The No. 1 air nozzle (7) and the No. 2 air nozzle (8) are provided with two main air passages (10) along the axial direction. The No. 1 air nozzle (7) and the No. 2 air nozzle (8) are interconnected through the main air passages (10). The inner wall and end face of the No. 1 air nozzle (7) are provided with multiple air holes (11) that are connected to the main air passages (10).

6. The support device for SiC ceramic furnace tube surface coated with SiC thin film according to claim 2, characterized in that: The central loading platform (31) and the peripheral loading platform (32) are each provided with three evenly distributed grooves (12), and each groove (12) contains a rotating ball (13) that can rotate freely within the groove (12).

7. The support device for SiC ceramic furnace tube surface coated with SiC thin film according to claim 4, characterized in that: The first air nozzle (7) is made of high-purity isostatic graphite with a purity of ≤5ppm.

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