Spin coating chamber atmosphere control structure based on gas assistance and variable angle rectifier plate

Abstract

The application discloses a kind of based on gas auxiliary and variable angle rectifier plate's spin coating chamber atmosphere control structure, including synchronous cover module and main chuck;The synchronous cover module and main chuck are concentric structure;The synchronous cover module is installed on the upper portion of main chuck.The application is by the variable angle rectifier plate structure driven by bevel gear transmission in spin coating chamber, realizes the adjustable control of the direction and intensity of airflow inside chamber.By adjusting the inclination of rectifier plate, make chamber internal radial and axial flow field distribution more uniform, effectively weaken the flow instability caused by vortex, shear layer mutation etc in spin coating process, to improve the flow field uniformity in chamber, provide stable airflow condition for spin coating film thickness control.The application can dynamically adjust the solvent vapor concentration inside chamber, inhibit solvent too fast volatilization, significantly weaken the film thickness uneven caused by edge effect and local concentration gradient, to improve the uniformity of solvent volatilization.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of spin coater, and relates to a spin coating chamber atmosphere control structure based on gas assistance and variable angle rectifier plate, which is used for improving the airflow uniformity and solvent volatilization uniformity in the chamber during the spin coating process. BACKGROUND

[0002] As a common technology for preparing uniform thin films and functional coatings, the spin coating method is widely used in the preparation process of various micro-nano structures such as sensors, gratings and organic optoelectronic devices due to its simple process, fast film forming speed, controllability of film thickness and other advantages. In the spin coating process, the high-speed rotation of the substrate produces strong centrifugal driving, which causes significant shearing and radial flow of the solution on the substrate surface, accompanied by rapid solvent volatilization and solute diffusion migration, and finally forms a solidified thin film with the target thickness and structure. Although a large number of theoretical models and engineering practices have tried to control the rotation speed, solution viscosity, chamber pressure and temperature and other parameters to improve the film thickness uniformity, the flow field inside the spin coating chamber is still very complex in actual industrial and scientific research applications. Due to the uneven distribution of solvent vapor in the chamber, the obvious gas concentration gradient and the frequent local flow field disturbance, there are still problems such as uneven film thickness distribution, large difference in solvent volatilization rate, which seriously affect the film forming quality, interface flatness and process repeatability

[0003] The fundamental reasons for the above unevenness include the difference between the radial and axial flow velocity profiles in the chamber, the formation of local vortexes and the local enrichment of solvent vapor in the chamber. In the spin coating process, the main flow zone and the near-wall laminar flow formed under the action of centrifugal force are prone to sudden changes in velocity gradient, thereby inducing shear layer and vortex structure, which causes obvious differences in solvent volatilization rate in different regions. At the same time, the temperature gradient and surface tension gradient also induce the Marangoni effect, making the solute migration and evaporation mass transfer process more complex, leading to further deviation of the film thickness from the expected distribution. In the prior art, fixed rectifier plates, closed covers or whole temperature control chambers are usually used to improve the flow stability and temperature uniformity of the spin coating environment. However, the fixed structure is difficult to realize individualization and real-time control when facing different substrate sizes, rotation speeds, solution formulations or chamber atmosphere conditions, resulting in a limited flow field adjustment range. In addition, the existing chambers are in a natural volatilization environment, and the solvent vapor concentration in the chamber cannot be effectively controlled. When the external airflow or local solvent volatilization is too fast, it is easy to cause edge effects, stripes, spots and other defects.

[0004] Therefore, designing a spin coating chamber atmosphere control structure with gas assistance and a variable-angle rectifier has become a critical issue that urgently needs to be addressed in the spin coating film formation industry. This requires not only that the chamber environment control structure can actively introduce or extract gas or solvent vapor to adjust the solvent concentration distribution within the chamber, thereby suppressing excessively rapid evaporation, but also that the structure can use the variable-angle rectifier to directionally correct and homogenize the flow field within the chamber, achieving precise control of radial and axial flow under different operating conditions. This significantly improves the uniformity of the flow field and evaporation during spin coating, reduces film thickness variations, and enhances product yield and process stability. Summary of the Invention

[0005] To address the aforementioned problems in spin coating technology, this invention aims to design a spin coating chamber atmosphere control structure based on gas assistance and a variable tilt angle rectifier plate, which can effectively improve both the uniformity of the flow field within the chamber and the uniformity of solvent evaporation within the chamber.

[0006] The technical solution of the present invention is as follows:

[0007] A gas-assisted, variable-angle rectifier-based atmosphere control structure for a spin coating chamber includes a synchronization hood module and a main chuck; the synchronization hood module and the main chuck are concentric circles; the synchronization hood module is mounted on the upper part of the main chuck; the synchronization hood module and the main chuck are driven by friction through a sealing ring.

[0008] The synchronization cover module, from top to bottom, consists of a connector, a chamber cover, a large bevel gear, a steam chamber guide, a flow divider, a small bevel gear, and a rectifier plate. The connector is bolted to the chamber cover; the chamber cover is screwed to the flow divider; the flow divider is bolted to the steam chamber guide; the rectifier plate is threaded to the small bevel gear; the small bevel gear is mounted on the flow divider; the large bevel gear is mounted on the steam chamber guide; and the small bevel gear meshes with the large bevel gear.

[0009] The main chuck has a vacuum hole at its center; the bottom surface of the main chuck is a mounting plane for the base support platform.

[0010] The main chuck is provided with a main chuck mounting and positioning ring on the outer side of its bottom; the main chuck mounting and positioning ring is a circular protrusion on the bottom of the main chuck; the top of the main chuck has a sealing ring mounting groove.

[0011] The upper part of the inner wall of the main chuck is cylindrical and the lower part is an expanded conical surface; the expanded conical surface is a splash-proof inclined surface; the bottom of the splash-proof inclined surface is a drain hole.

[0012] Further, the base carrying table installation plane is a finished plane; the cross section of the sealing ring installation groove is rectangular; the main chuck bottom is provided with a main chuck fixing hole and a base fixing bolt hole; the position of the main chuck fixing hole is closer to the center of the main chuck than the position of the base fixing bolt hole.

[0013] Further, the material of the main chuck is nylon material; the material of the connecting piece is stainless steel; the material of the chamber upper cover is aluminum alloy.

[0014] Further, the structure of the connecting piece is a three-layer cylindrical structure, the highest layer has the smallest diameter, and the lowest layer has the largest diameter; the highest layer is connected with the bearing; the lowest layer is connected with the chamber upper cover.

[0015] Further, the top of the chamber upper cover is provided with radial reinforcing ribs; the number of reinforcing ribs is 8, which are uniformly distributed in the circumferential direction; the chamber upper cover is provided with a chamber upper cover installation hole matched with the connecting piece; the chamber upper cover is provided with a temperature sensor; the chamber upper cover is provided with 8 temperature sensor installation holes, of which 6 temperature sensor installation holes are located near the edge of the chamber upper cover, and 2 temperature sensor installation holes are located near the center of the chamber upper cover; the inner side edge of the chamber upper cover is a stepped structure; the most edge is matched with the main chuck transmission; the second step of the inner side edge of the chamber upper cover is provided with a shunt layer installation hole.

[0016] Further, the modulus of the large bevel gear is 1.25, the number of teeth is 60, and the pressure angle is 20 degrees; the large bevel gear is a straight bevel gear; the upper end of the shaft of the large bevel gear is a hollow shaft; the hollow shaft serves as a central air inlet; the bottom of the hollow shaft is provided with two rings of steam chamber air inlet holes; each ring has 4 steam chamber air inlet holes, which are uniformly distributed in the circumferential direction; the centers of adjacent two rings of steam chamber air inlet holes are staggered at an angle of 45 degrees.

[0017] The modulus of the small bevel gear is 1.25, the number of teeth is 12, and the pressure angle is 20 degrees; the small bevel gear is a straight bevel gear; there are 4 small bevel gears, which are distributed in the circumferential direction of the large bevel gear and meshed for transmission; the small bevel gear shaft is connected with the rectifier plate to change the inclination angle when the small bevel gear rotates; the rectifier plate is an elongated rectangular plate; the shunt layer and the steam chamber flow guide form a closed space for installing the large bevel gear and the small bevel gear.

[0018] Further, the steam chamber flow guide is composed of a central plane, an inclined transition surface and a bottom plane; the central plane is provided with a bevel gear mounting hole; the bottom plane is provided with a steam chamber flow guide mounting hole; the steam chamber flow guide is mounted on the flow distribution layer through the steam chamber flow guide mounting hole; the mounting height of the steam chamber flow guide is lower than the steam chamber air inlet hole on the bevel gear; the edge position of the flow distribution layer is designed with a boss which is matched with the step of the chamber upper cover for installation; the boss protrudes towards the upper side of the flow distribution layer; the boss is provided with a through hole which is matched with the chamber upper cover for installation; the flow distribution layer is provided with flow distribution holes; the flow distribution holes are distributed in 7 circles along the radial direction, and each circle has 16 flow distribution holes; the center of the flow distribution layer has a cylindrical space; the cylindrical space is a bevel gear mounting rack; the side wall of the bevel gear mounting rack is provided with four bevel gear mounting holes.

[0019] Further, the chamber upper cover, the steam chamber flow guide and the flow distribution layer form a steam chamber; the steam chamber has eight air inlets; the steam chamber flow guide forms a horn-shaped air inlet space for the steam chamber.

[0020] Compared with the prior art, the present application has the following beneficial effects:

[0021] 1. By arranging the variable angle fairing plate structure driven by the bevel gear transmission in the spin coating chamber, the present application realizes the adjustable control of the flow direction and intensity in the chamber. By adjusting the angle of the fairing plate, the radial and axial flow field distribution in the chamber is more uniform, effectively weakening the flow instability caused by vortex, shear layer mutation and the like in the spin coating process, thereby improving the uniformity of the flow field in the chamber and providing stable air flow conditions for the spin coating film thickness control.

[0022] 2. By arranging the gas-assisted steam chamber structure between the chamber upper cover and the flow distribution layer, and combining the multi-hole air inlet channel on the bevel gear shaft body and the horn-shaped flow guide, the present application realizes the directional delivery and uniform distribution of inert gas or solvent vapor. The structure can dynamically adjust the solvent vapor concentration in the chamber, inhibit the rapid evaporation of the solvent, significantly weaken the film thickness unevenness caused by the edge effect and local concentration gradient, thereby improving the uniformity of the solvent evaporation.

[0023] 3. By the synergistic effect of the variable angle fairing system and the gas-assisted chamber structure through gear linkage, the present application realizes the synchronous and uniform adjustment of the gas flow field in the spin coating chamber, forming a stable and controllable atmosphere environment. The integrated control structure effectively reduces the film thickness difference in the spin coating process, improves the uniformity and process repeatability of the thin film, and provides reliable chamber environment guarantee for the preparation of high-precision functional thin film. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a front view of the overall structure of the present application;

[0025] Figure 2 This is a rear bottom view of the overall structure of the present invention;

[0026] Figure 3 This is a cross-sectional schematic diagram of the overall structure of the present invention;

[0027] Figure 4 This is a top view of the flow distribution layer of the present invention;

[0028] Figure 5 This is a bottom view of the back of the flow divider layer of the present invention;

[0029] Figure 6 This is a schematic diagram of the steam chamber guide of the present invention;

[0030] Figure 7 This is a schematic diagram of the connector of the present invention;

[0031] Figure 8 This is a schematic diagram of the bevel gear transmission mechanism of the present invention;

[0032] In the diagram: 1-Cavity top cover; 2-Reinforcing rib; 3-Temperature sensor mounting hole; 4-Drain hole; 5-Main chuck; 6-Cavity top cover mounting hole; 7-Connector; 8-Central air inlet; 9-Large bevel gear; 10-Steam chamber guide; 11-Steam chamber; 12-Flow divider mounting hole; 13-Main chuck mounting positioning ring; 14-Vacuum hole; 15-Base support platform mounting plane; 16-Anti-splash slope; 17-Sealing ring mounting groove; 18-Base fixing bolt hole; 19-Main chuck fixing hole; 20-Flow divider; 21-Flow divider hole; 22-Steam chamber guide mounting hole; 23-Small bevel gear mounting hole; 24-Small bevel gear mounting bracket; 25-Large bevel gear mounting hole; 26-Steam chamber air inlet; 27-Small bevel gear; 28-Rectifier plate. Detailed Implementation

[0033] The specific embodiments of the present invention are further described below with reference to the accompanying drawings and technical solutions. For example... Figures 1-8 As shown, a gas-assisted, variable-angle rectifier-based atmosphere control structure for a spin coating chamber includes a synchronization hood module and a main chuck 5; the synchronization hood module and the main chuck 5 are concentric circles; the synchronization hood module is mounted on the upper part of the main chuck 5; the synchronization hood module and the main chuck 5 are driven by friction through a sealing ring.

[0034] The synchronization cover module is sequentially connected piece 7, chamber upper cover 1, bevel gear 9, vapor chamber flow guide 10, shunt layer 20, bevel gear 27 and rectifier plate 28 from top to bottom;The connecting piece 7 is connected with chamber upper cover 1 by bolt;The chamber upper cover 1 is connected with shunt layer 20 by screw;The shunt layer 20 is connected with vapor chamber flow guide 10 by bolt;The rectifier plate 28 is connected with bevel gear 27 by thread;The bevel gear 27 is installed on shunt layer 20;The bevel gear 9 is installed on vapor chamber flow guide 10;The bevel gear 27 is engaged with bevel gear 9;

[0035] The main chuck 5 is provided with a vacuum hole 14 in the center;The inner bottom surface of the main chuck 5 is a substrate loading platform installation plane 15.

[0036] The outer side of the bottom of the main chuck 5 is provided with a main chuck mounting positioning ring 13;The main chuck mounting positioning ring 13 is a circular ring protrusion at the bottom of the main chuck 5;The top of the main chuck 5 has a sealing ring installation groove 17.

[0037] The inner side wall of the main chuck 5 is a cylindrical surface at the top and an expanding conical surface at the bottom;The expanding conical surface is a splash-proof slope 16;The bottom of the splash-proof slope 16 is a liquid discharge hole 4.

[0038] Further, the substrate loading platform installation plane 15 is a finish machining plane;The cross section of the sealing ring installation groove 17 is rectangular;The bottom of the main chuck 5 is provided with a main chuck fixing hole 19 and a substrate fixing bolt hole 18;The position of the main chuck fixing hole 19 is closer to the center of the main chuck 5 than the position of the substrate fixing bolt hole 18.

[0039] Further, the material of the main chuck 5 is nylon material;The material of the connecting piece 7 is stainless steel;The material of the chamber upper cover 1 is aluminum alloy.

[0040] Further, the structure of the connecting piece 7 is a three-layer cylindrical structure, the highest layer has the smallest diameter, and the lowest layer has the largest diameter;The highest layer is connected with the bearing;The lowest layer is connected with the chamber upper cover 1.

[0041] Further, the top of the chamber upper cover 1 is provided with a reinforcing rib 2 along the radial direction;There are 8 reinforcing ribs 2, which are evenly distributed along the circumferential direction;The chamber upper cover 1 is provided with a chamber upper cover mounting hole 6 for cooperating with the connecting piece 7;The chamber upper cover 1 is provided with a temperature sensor;The chamber upper cover 1 is provided with 8 temperature sensor mounting holes 3, of which 6 temperature sensor mounting holes 3 are located at the edge of the chamber upper cover 1, and 2 temperature sensor mounting holes 3 are located at the center of the chamber upper cover 1;The inner edge of the chamber upper cover 1 is a stepped structure;The outermost edge is in transmission cooperation with the main chuck 5;The second step of the inner edge of the chamber upper cover 1 is provided with a shunt layer mounting hole 12.

[0042] Further, the modulus of the large bevel gear 9 is 1.25, the number of teeth is 60, and the pressure angle is 20 degrees. The large bevel gear 9 is a straight-toothed bevel gear; the upper end of the shaft of the large bevel gear 9 is a hollow shaft; the hollow shaft serves as the central air inlet 8; the bottom of the hollow shaft is provided with two rings of steam chamber air inlet holes 26; each ring of the steam chamber air inlet holes 26 has 4 holes, and the steam chamber air inlet holes 26 in the same ring are uniformly distributed in the circumferential direction; the centers of the steam chamber air inlet holes 26 in adjacent two rings are staggered at an angle of 45 degrees.

[0043] The modulus of the small bevel gear 27 is 1.25, the number of teeth is 12, and the pressure angle is 20 degrees; the small bevel gear 27 is a straight-toothed bevel gear; the small bevel gear 27 has 4 gears, which are distributed in the circumferential direction of the large bevel gear 9 and mesh to drive; the shaft of the small bevel gear 27 is connected with the rectifier plate 28 to change the inclination angle when the small bevel gear 27 rotates; the rectifier plate 28 is an elongated rectangular plate; the flow distribution layer 20 and the steam chamber flow guide 10 form a closed space for installing the large bevel gear 9 and the small bevel gear 27.

[0044] Further, the steam chamber flow guide 10 is composed of a central plane, an inclined transition surface and a bottom plane; the central plane is provided with a large bevel gear mounting hole 25; the bottom plane is provided with a steam chamber flow guide mounting hole 22; the steam chamber flow guide 10 is installed on the flow distribution layer 20 by means of the steam chamber flow guide mounting hole 22; the installation height of the steam chamber flow guide 10 is lower than the steam chamber air inlet holes 26 on the large bevel gear 9; the edge position of the flow distribution layer 20 is designed with a boss which is matched with the step of the chamber upper cover 1 for installation; the boss protrudes towards the upper side of the flow distribution layer 20; the boss is provided with a through hole matched with the chamber upper cover 1 for installation; the flow distribution layer 20 is provided with a flow distribution hole 21; the flow distribution holes 21 are distributed in 7 rings along the radial direction, and each ring has 16 flow distribution holes 21; the center of the flow distribution layer 20 has a cylindrical space; the cylindrical space is a small bevel gear mounting rack 24; the side wall of the small bevel gear mounting rack 24 is provided with 4 small bevel gear mounting holes 23.

[0045] Further, the chamber upper cover 1, the steam chamber flow guide 10 and the flow distribution layer 20 form a steam chamber 11; the steam chamber 11 has 8 air inlets; the steam chamber flow guide 10 forms a horn-shaped air inlet space for the steam chamber 11.

[0046] The operation mode of the present application is as follows:

[0047] Before the spin coating starts, the angle of the rectifier plate and the air inlet flow rate are determined according to the target film thickness, the solution viscosity, the spin coating speed, the spin coating time, the type of solvent and other parameters; after the preparation process before spin coating is completed, the spin coating film preparation can be started.

[0048] First, the cleaned substrate carrier is installed in the corresponding installation position of the main chuck 5, and the substrate to be coated is accurately placed in the center area of the carrier. After confirming that the substrate position is coaxial with the rotation center of the main chuck 5, the substrate is fixed by the substrate fixing bolt to ensure that it remains stable during the spin coating process. A predetermined volume of spin coating liquid is uniformly arranged on the surface of the substrate, so that the solution covers the entire effective area in a static state to form an initial liquid film. After completing the liquid distribution operation, the synchronous cover module is installed on the main chuck 5 and the gas auxiliary system is started, and the solvent vapor matched with the composition of the spin coating liquid is slowly introduced into the spin coating chamber to adjust the atmosphere in the chamber. By accurately controlling the gas flow and concentration, a uniform solvent vapor distribution is gradually established in the chamber, effectively reducing the local volatilization rate difference and inhibiting the volatilization unevenness of the liquid film edge and center area. After a short atmospheric stabilization period, the concentration gradient of the solvent vapor in the chamber tends to be balanced, and the vapor partial pressure distribution above the liquid film surface tends to be consistent, making the solvent volatilization rate of the liquid film interface layer consistent. Finally, after setting the spin coating process parameters, the spin coating can begin.

[0049] The above describes that for those skilled in the art, various corresponding changes and modifications can be made according to the technical solutions and technical concepts of the present application, and all these changes and modifications shall belong to the protection scope of the claims of the present application.

Claims

1. A spin-coating chamber atmosphere control structure based on gas assistance and variable-tilt rectification plate, characterized by: The application relates to a synchronous cover module and a main chuck (5); the synchronous cover module and the main chuck (5) are in a concentric circle structure; the synchronous cover module is installed on the upper portion of the main chuck (5); the synchronous cover module and the main chuck (5) are in friction transmission through a sealing ring. The synchronous cover module comprises, from top to bottom, a connecting piece (7), a chamber upper cover (1), a large bevel gear (9), a steam chamber flow guide (10), a shunt layer (20), a small bevel gear (27) and a rectifier plate (28); the connecting piece (7) is connected with the chamber upper cover (1) through bolts; the chamber upper cover (1) is connected with the shunt layer (20) through screws; the shunt layer (20) is connected with the steam chamber flow guide (10) through bolts; the rectifier plate (28) is connected with the small bevel gear (27) through threads; the small bevel gear (27) is installed on the shunt layer (20); the large bevel gear (9) is installed on the steam chamber flow guide (10); the small bevel gear (27) is engaged with the large bevel gear (9). The main chuck (5) is provided with a vacuum extraction hole (14) in the center; the inner bottom surface of the main chuck (5) is a substrate bearing platform installation plane (15). The outer side of the bottom of the main chuck (5) is provided with a main chuck installation positioning ring (13); the main chuck installation positioning ring (13) is a circular ring protrusion on the bottom of the main chuck (5); the top of the main chuck (5) is provided with a sealing ring installation groove (17). The inner side wall of the main chuck (5) is a cylindrical surface on the upper portion and is an expanded conical surface on the lower portion; the expanded conical surface is a splash-proof inclined surface (16); the bottom of the splash-proof inclined surface (16) is a liquid discharge hole (4). The steam chamber flow guide (10) is composed of a central plane, an inclined transition surface and a bottom plane; the central plane is provided with a large bevel gear installation hole (25); the bottom plane is provided with a steam chamber flow guide installation hole (22); the steam chamber flow guide (10) is installed on the shunt layer (20) through the steam chamber flow guide installation hole (22); the installation height of the steam chamber flow guide (10) is lower than that of the steam chamber air inlet hole (26) on the large bevel gear (9); the edge position of the shunt layer (20) is designed with a boss matched with the step of the chamber upper cover (1) for installation; the boss protrudes towards the upper portion of the shunt layer (20); the boss is provided with a through hole matched with the chamber upper cover (1) for installation; the shunt layer (20) is provided with shunt holes (21); the shunt holes (21) are distributed in 7 circles along the radial direction, and each circle has 16 shunt holes (21); the center of the shunt layer (20) has a cylindrical space; the cylindrical space is a small bevel gear installation rack (24); the side wall of the small bevel gear installation rack (24) is provided with four small bevel gear installation holes (23).

2. The gas-assisted and variable-tilt-plate-based atmosphere control structure for a spin-coating chamber according to claim 1, wherein: The substrate bearing platform installation plane (15) is a finished plane; the cross section of the sealing ring installation groove (17) is rectangular; the bottom of the main chuck (5) is provided with a main chuck fixing hole (19) and a substrate fixing bolt hole (18); the position of the main chuck fixing hole (19) is closer to the center of the main chuck (5) than that of the substrate fixing bolt hole (18).

3. The gas-assisted and variable-tilt-plate-based atmosphere control structure for a spin-coating chamber of claim 1, wherein: The material of the main chuck (5) is nylon material; the material of the connecting piece (7) is stainless steel; the material of the chamber upper cover (1) is aluminum alloy.

4. The gas-assisted and variable-tilt- angle-iris-based atmosphere control structure for a spin-coating chamber according to claim 1, wherein: The structure of the connecting piece (7) is a three-layer cylindrical structure, the highest layer has the smallest diameter, and the lowest layer has the largest diameter; the highest layer is connected with the bearing; the lowest layer is connected with the chamber upper cover (1).

5. The gas-assisted and variable-tilt- angle-iris-based atmosphere control structure for a spin-coating chamber according to claim 1, wherein: The top of the chamber upper cover (1) is provided with radial reinforcing ribs (2); the number of the reinforcing ribs (2) is eight, which are evenly distributed in the circumferential direction; the chamber upper cover (1) is provided with chamber upper cover mounting holes (6) for cooperating with the connecting piece (7); the chamber upper cover (1) is provided with temperature sensors; the chamber upper cover (1) is provided with eight temperature sensor mounting holes (3), six of which are located near the edge of the chamber upper cover (1), and the other two are located near the center of the chamber upper cover (1); the inner side edge of the chamber upper cover (1) is a stepped structure; the outermost edge is in transmission cooperation with the main chuck (5); the second step of the inner side edge of the chamber upper cover (1) is provided with a shunt layer mounting hole (12).

6. The gas-assisted and variable-tilt- angle-iris-based atmosphere control structure for a spin-coating chamber of claim 1, wherein: The modulus of the large bevel gear (9) is 1.25, the number of teeth is 60, and the pressure angle is 20 degrees; the large bevel gear (9) is a straight bevel gear; the upper end of the shaft of the large bevel gear (9) is a hollow shaft; the hollow shaft serves as a central air inlet (8); the bottom of the hollow shaft is provided with two rings of steam chamber air inlet holes (26); each ring has four steam chamber air inlet holes (26), which are evenly distributed in the circumferential direction; the centers of adjacent two rings of steam chamber air inlet holes (26) are staggered at an angle of 45 degrees; The modulus of the small bevel gear (27) is 1.25, the number of teeth is 12, and the pressure angle is 20 degrees; the small bevel gear (27) is a straight bevel gear; there are four small bevel gears (27), which are distributed in the circumferential direction of the large bevel gear (9) and meshed to drive; the shaft of the small bevel gear (27) is connected with the rectifier plate (28) to change the inclination angle when the small bevel gear (27) rotates; the rectifier plate (28) is an elongated rectangular plate; the shunt layer (20) and the steam chamber flow guide (10) form a closed space for installing the large bevel gear (9) and the small bevel gear (27).

7. The gas-assisted and variable-tilt- angle-iris-based atmosphere control structure for a spin-coating chamber of claim 1, wherein: The chamber upper cover (1), the steam chamber flow guide (10), and the shunt layer (20) form a steam chamber (11); the steam chamber (11) has eight air inlets; the steam chamber flow guide (10) forms a horn-shaped air inlet space for the steam chamber (11).

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