Spin coating chamber structure for stabilizing chamber flow field and improving chamber cleanliness

Abstract

The invention belongs to the technical field of spin-coating machines, and discloses a spin-coating chamber structure capable of stabilizing a chamber flow field and improving chamber cleanliness. The synchronous cover module, the air pressure adjusting module and the spin-coating turntable module which are arranged from top to bottom are of a concentric structure; a flow channel allowing spin-coating liquid to flow out is reserved between the spin-coating rotary table module and the air pressure adjusting module, and the spin-coating rotary table module and the synchronous cover module are synchronous in rotating speed during spin-coating. Before spin-coating, an air pump is connected to an air channel of the air pressure adjusting module, impurities in the spin-coating cavity are taken away from the surface of a substrate through airflow, and the cleanliness of the cavity is improved. And in the spin-coating process, supersaturated gas is introduced from the air inlet of the synchronous cover module, passes through the cylindrical cavity and is introduced into the spin-coating cavity from the air outlet, so that the atmosphere environment in the spin-coating cavity is improved, the evaporation uniformity is improved, and the film thickness uniformity is improved. In the spin-coating process, the synchronous cover module and the spin-coating module rotate synchronously, and the trapezoidal spoiler of the synchronous cover module can improve the air flow speed in the spin-coating chamber, so that the air flow speed in the spin-coating chamber is more uniform, and the film thickness uniformity is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of spin coating machines and relates to a spin coating chamber structure which can improve chamber cleanliness and stabilize chamber flow field. Background Art

[0002] Spin coating is a key technology widely used in thin film preparation. Its advantages are that it can efficiently and quickly coat thin films on the surface of substrates, and it is simple to operate and low in cost. The principle of spin coating is to drop liquid materials onto the surface of a rotating substrate. When the substrate rotates at high speed, the centrifugal force causes the liquid to be thrown out along the surface of the substrate, and finally forms a thin film. The thickness and uniformity of the film are closely related to factors such as rotation rate, time, chamber environment and liquid viscosity, so that the thickness and uniformity of the film can be controlled according to demand. Spin coating technology has a wide range of applications in the fields of microelectronics and optoelectronics, especially in the photoresist coating of integrated circuits, the photoelectric absorption layer of solar cells, and the preparation of anti-reflective coatings for optical lenses. In addition, spin coating is also used in many fields such as nanofilms, sensors and liquid crystal displays. The ability to efficiently prepare thin film materials with specific functions is the basis for improving the quality, precision and performance of modern electronic equipment. Therefore, spin coating technology occupies an important position in modern science and technology and industrial production.

[0003] However, the existing spin coating technology faces the problem of uneven film thickness distribution in practical applications, which has become a key factor affecting subsequent processes such as photolithography and the quality of the final product. In the process of spin coating film formation, there are two main ways to reduce the film thickness. One is flow thinning, which is due to the centrifugal force that causes the liquid to gradually expand from the center of the substrate to the edge, and the film thickness eventually becomes thinner. The second is evaporation thinning, which is due to the rapid evaporation of the solvent during the film formation process, resulting in the concentration of the solution and the gradual thinning of the film layer. The uniformity of film thickness is closely related to the uniformity of evaporation, and the evaporation process is determined by the atmosphere, temperature, humidity and solvent volatilization rate in the chamber. Evaporation and flow jointly affect the uniformity of film thickness and the final quality. In addition, some special occasions also put forward strict requirements on the cleanliness of the chamber. For example, in the process of spin coating silica sol-gel on the surface of KDP crystal to prepare an anti-reflective coating, if there are pollutants or particles on the crystal surface, it will affect the uniform coating and adhesion of the silica sol-gel, resulting in unstable film quality, and even problems such as shedding, bubbles or cracks.

[0004] Therefore, designing a high-performance spin coating chamber that can ensure the stability of the flow field in the spin coating chamber and meet the cleanliness requirements has become a key issue that needs to be solved in the spin coating film forming industry. This requires that the chamber structure can not only maintain the stability of the air pressure and air flow rate in the chamber during the spin coating process, but also effectively remove dust and other pollutants in the chamber to improve the uniformity of the film thickness, ensure the cleanliness of the chamber environment, optimize the process and improve product quality. Summary of the invention

[0005] In order to solve the above problems existing in the spin coating technology, the present invention aims to design a high-performance spin coating chamber which can not only effectively improve the stability of the flow field in the chamber, but also effectively remove pollutants such as dust in the chamber.

[0006] The technical solution of the present invention:

[0007] A spin coating chamber structure for stabilizing the chamber flow field and improving the chamber cleanliness comprises a synchronous cover module 6, an air pressure regulating module 7 and a spin coating turntable module 8; the synchronous cover module 6, the air pressure regulating module 7 and the spin coating turntable module 8 arranged from top to bottom are concentric structures; a flow channel for the spin coating turntable module 8 and the air pressure regulating module 7 is reserved for the outflow of the spin coating liquid, and the spin coating turntable module 8 and the synchronous cover module 6 rotate synchronously during spin coating;

[0008] The upper surface of the spin coating turntable module 8 is designed with a circular substrate carrier 2, the area of ​​the circular substrate carrier 2 is larger than the area of ​​the substrate to be coated; the area of ​​the spin coating turntable module 8 other than the circular substrate carrier 2 is the turntable edge area, the circular substrate carrier 2 and the turntable edge area are connected by an inclined transition, and the circular substrate carrier 2 is higher than the turntable edge area; a vacuum hole 9 is left in the center of the circular substrate carrier 2, and the circular substrate carrier 2 is adsorbed by vacuuming;

[0009] The air pressure regulating module 7 is an annular structure, and its inner wall surface transitions from a plane to an inclined surface from top to bottom. The plane cooperates with the synchronous cover module 6, and the inclined surface has the function of preventing the spin coating liquid from splashing during the spin coating process. After the spin coating liquid is thrown onto the inclined surface, it flows out from the flow channel along the inclined surface; the outer surface of the air pressure regulating module 7 is designed with a rectangular protrusion, and the outer surface of the rectangular protrusion is designed with an air pressure regulating inlet 3, and the center height of the air pressure regulating inlet 3 is the same as the upper surface of the spin coating substrate; the air pressure regulating module 7 is opened with an airway, and the airway consists of two parts, the first part is an equirectangular cross-section part, and the second part is a linearly enlarged rectangular cross-section part, and the two constitute a complete airway from the outside to the inside;

[0010] The synchronous cover module 6 can move up and down in the vertical direction. An air inlet is opened on the top of the synchronous cover module 6, and gas is introduced into the synchronous cover module 6 from the air inlet; the interior of the synchronous cover module 6 is a cavity; the lower surface of the synchronous cover module 6 is opened with annular and evenly distributed air outlets, which are connected to the cavity. The gas passes through the cavity from the air inlet and is blown from the air outlet to the top of the spin coating turntable module 8.

[0011] Furthermore, the vacuum hole 9 is connected to the hollow shaft hole of the spin coater to the vacuum pump.

[0012] Furthermore, four symmetrically distributed positioning holes 1 are formed on the upper surface of the circular substrate supporting platform 2 .

[0013] Furthermore, four air pressure regulating module connection holes 12 are opened on the periphery of the upper surface of the air pressure regulating module 7, and are fixed with bolts and nuts in cooperation with the spin coater frame.

[0014] Furthermore, the air pressure regulating inlet 3 of the air pressure regulating module 7 is not located directly below the air pressure regulating module connecting hole 12 .

[0015] The shape of the cavity of the synchronization cover module 6 is a cylindrical cavity 10 .

[0016] Furthermore, a trapezoidal spoiler 5 is provided on the lower surface of the synchronization cover module 6, and the angle range between the spoilers 5 can be adjusted between 60°-90°. There is no air outlet 4 at the position where the spoiler 5 is present on the lower surface of the synchronization cover module 6, and there is no air outlet 4 on the trapezoidal spoiler.

[0017] Beneficial effects of the present invention:

[0018] 1. Before spin coating, the present invention can connect an air pump to the airway of the air pressure regulating module, and use the flow of high-speed airflow to remove dust and other impurities that may contaminate the film in the spin coating chamber from the substrate surface to ensure the cleanliness of the chamber.

[0019] 2. During the spin coating process, supersaturated gas is introduced from the air inlet of the synchronous cover module, and the supersaturated gas passes through the cylindrical chamber and evenly enters the spin coating chamber from the air outlet, thereby improving the atmosphere in the spin coating chamber, improving the evaporation uniformity, and thus improving the film thickness uniformity.

[0020] 3. During the spin coating process, the synchronous cover module rotates synchronously with the spin coating module. The trapezoidal spoiler of the synchronous cover module can improve the air flow velocity in the spin coating chamber, making the gas flow velocity in the spin coating chamber more uniform, thereby ensuring the uniformity of film thickness. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the present invention (explosion diagram);

[0022] Figure 2 (a) is a schematic cross-sectional view of the overall structure of the present invention;

[0023] Figure 2 (b) Figure 2 (a) is a partial enlarged view of the flow channel; where dl is the size of the flow channel inlet.

[0024] Figure 3 is a cross-sectional view of the airway of the air pressure regulating module;

[0025] Figure 4 (a) is the front view of the synchronous cover module air outlet distribution and spoiler mechanism.

[0026] Figure 4(b) is the side view of the synchronous cover module air outlet distribution and spoiler mechanism.

[0027] In the figure: 1-spin coating substrate positioning hole; 2-high-precision circular substrate support platform; 3-air pressure adjustment inlet; 4-synchronous cover air outlet; 5-trapezoidal spoiler; 6-synchronous cover module; 7-air pressure adjustment module; 8-spin coating turntable module; 9-vacuum hole; 10-cylindrical cavity; 11-synchronous cover air inlet; 12-air pressure adjustment module mounting hole; 13-anti-splash slope. DETAILED DESCRIPTION

[0028] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and technical solutions.

[0029] A spin coating chamber structure for improving chamber flow field stability and removing dust and other pollutants in the chamber, comprising a synchronous cover module 6, an air pressure regulating module 7, and a spin coating turntable module 8;

[0030] The synchronous cover module 6, the air pressure regulating module 7 and the spin coating turntable module 8 are concentric, and are the synchronous cover module 6, the air pressure regulating module 7 and the spin coating turntable module 8 from top to bottom; further, the outer wall of the synchronous cover module 6 is not in contact with the inner wall of the air pressure regulating module 7; the inner wall diameter of the air pressure regulating module 7 is larger than the outer wall diameter of the spin coating turntable module 8, so there is a gap between the air pressure regulating module 7 and the spin coating turntable module 8, and this gap is the flow channel for the spin coating liquid to flow out, and the minimum size of the flow channel is d1, and the size of d1 is determined by the properties of the spin coating liquid; the synchronous cover module 6 and the spin coating turntable module 8 have a synchronous rotation speed during the spin coating process; the air pressure regulating module 7 does not rotate during the spin coating process;

[0031] The upper surface of the spin coating turntable module 8 is designed with a high-precision circular substrate carrier 2, which is located at the center of the spin coating turntable module 8 and has an area smaller than the upper surface area of ​​the spin coating turntable module 8. Except for the circular substrate carrier 2, other areas do not require high precision; further, the height of the high-precision circular substrate carrier 2 area is slightly higher than the spin coating turntable module, and the height difference is transitioned by an inclined structure;

[0032] The high-precision circular substrate carrier 2 is provided with four spin-coated substrate positioning holes 1 symmetrically distributed around the center. During spin coating, the spin-coated substrate is fixed to the high-precision circular substrate carrier 2 using positioning pins.

[0033] Furthermore, a vacuum hole 9 is reserved in the center of the high-precision circular substrate carrier 2, and the vacuum hole 9 is used to vacuum and adsorb the spin-coated substrate. The spin-coated substrate is fixed by vacuum adsorption or positioning pins. When the spin-coating speed is high, the two fixing methods can be used to fix it;

[0034] The air pressure regulating module 7 is provided with four air pressure regulating module mounting holes 12 on the periphery of the upper surface thereof, and bolts are used to realize the connection and fixation between the air pressure regulating module 7 and the whole frame of the spin coating machine;

[0035] Furthermore, the inner wall of the air pressure regulating module 7 transitions from a plane to an inclined surface from top to bottom, the plane area cooperates with the synchronous cover module 6, and a flow channel for the spin coating liquid to flow out is formed between the inclined surface area and the spin coating turntable module 8; this inclined surface structure has the function of preventing the spin coating liquid from splashing during the spin coating process, and when the spin coating liquid is thrown to the wall surface of the inclined surface area, the spin coating liquid can flow down along the wall surface;

[0036] The outer surface of the air pressure regulating module 7 is designed with a rectangular protrusion, and an air pressure regulating inlet 3 is opened at the rectangular protrusion structure. During spin coating, the upper surface of the spin-coated substrate should be within the inlet range of the air pressure regulating inlet 3. That is, the gas for air pressure regulation must pass through the surface of the spin-coated substrate to achieve the function of removing dust and contaminating impurities in the spin-coating chamber by sending or extracting the gas from the air pressure regulating inlet 3; further, the ventilation time of the air pressure regulating inlet 3 is before the start of spin coating;

[0037] Furthermore, the air pressure regulating module 7 is provided with an air passage, and the air passage is composed of two parts, the first part is an equirectangular cross-section part, and the second part is a linearly increasing rectangular cross-section part;

[0038] Further, the air passage of the air pressure regulating module 7 is not located directly below the air pressure regulating module mounting hole 12;

[0039] A flow channel for the spin coating liquid to flow out is designed between the rotating disk module 8 and the air pressure regulating module 7, and the minimum size of the flow channel is d1;

[0040] The synchronous cover module 6 has a synchronous cover air inlet 11 above it, and the gas for controlling the atmosphere in the chamber during spin coating is blown in from here;

[0041] Furthermore, the interior of the synchronization cover module 6 is a cylindrical cavity 10, and the synchronization cover air inlet hole 11 is connected to the cylindrical cavity 10;

[0042] Furthermore, the synchronous cover module 6 has an annular evenly distributed synchronous cover air outlet 4, and the synchronous cover air inlet 11, the cylindrical cavity 10 and the synchronous cover air outlet 4 are connected. During the spin coating, the gas is introduced from the synchronous cover air inlet 11 to fill the cylindrical cavity 10, and finally injected into the spin coating chamber evenly from the synchronous cover air outlet 4, thereby improving the flow field of the spin coating chamber.

[0043] Furthermore, a trapezoidal spoiler 5 is installed on the lower surface of the synchronous cover module 6, and the angle between the trapezoidal spoilers 5 can be adjusted within the range of 60°-90°. There is no air outlet at the position where the spoiler exists on the lower surface of the synchronous cover module 6, and there is no opening on the trapezoidal spoiler.

[0044] The operation mode of the present invention is:

[0045] Before the spin coating begins, select the appropriate size of the spin coating substrate and the spin coating liquid according to the spin coating process and product requirements. Then select the appropriate spin coating process parameters according to the required spin coating film thickness. After the spin coating preparatory work is completed, the spin coating preparation of the film can begin.

[0046] First, high-speed gas is passed into the spin coating chamber from the air pressure regulating inlet of the air pressure regulating module, or the air in the chamber is extracted by an air pump, so as to blow away the dust and other pollutants or particles in the chamber from the chamber to ensure the cleanliness of the chamber. Secondly, the synchronous cover module is moved upward, and the spin coating liquid is arranged at the center of the spin coating substrate or covers the entire substrate. After that, the synchronous cover module is restored to its original position, and the power switch for controlling the spin coating turntable module and the synchronous cover module and the switch for controlling the air intake of the synchronous cover module are turned on at the same time. The spin coating liquid flows or is thrown out along the surface of the substrate under the action of centrifugal force, and the flow and evaporation thinning are realized at the same time with the evaporation process of the solvent. At the same time, the supersaturated steam continuously and evenly injected from the synchronous cover air inlet reaches the cylindrical chamber of the synchronous cover, and is injected into the spin coating chamber from the air outlets evenly distributed on the lower surface of the synchronous cover. The uniformly injected gas ensures the stability of the atmosphere in the chamber, and the synchronously rotating trapezoidal spoiler makes the gas flow rate in the chamber tend to be consistent, ensuring the stability of the flow field in the chamber. The spoiler and the introduced gas work together to help the film flow and evaporation thinning process become uniform, thus ensuring the uniformity of film thickness and film quality.

[0047] As described above, for ordinary technicians in this field, various other corresponding changes and modifications can be made based on the technical solutions and technical concepts of the present invention, and all these changes and modifications should fall within the protection scope of the claims of the present invention.

Claims

1. A spin coating chamber structure for stabilizing the chamber flow field and improving the chamber cleanliness, characterized in that: The spin coating chamber structure comprises a synchronous cover module (6), an air pressure regulating module (7) and a spin coating turntable module (8); the synchronous cover module (6), the air pressure regulating module (7) and the spin coating turntable module (8) are arranged from top to bottom and are of a concentric structure; a flow channel for the spin coating turntable module (8) and the air pressure regulating module (7) is reserved for the outflow of the spin coating liquid; and the spin coating turntable module (8) and the synchronous cover module (6) have a synchronous rotation speed during spin coating; The upper surface of the spin coating turntable module (8) is designed with a circular substrate carrier platform (2), the area of ​​the circular substrate carrier platform (2) is larger than the area of ​​the substrate to be coated; the area of ​​the spin coating turntable module (8) other than the circular substrate carrier platform (2) is the turntable edge area, the circular substrate carrier platform (2) and the turntable edge area are connected by an inclined transition, and the circular substrate carrier platform (2) is higher than the turntable edge area; a vacuum hole (9) is reserved in the center of the circular substrate carrier platform (2), and the circular substrate carrier platform (2) is adsorbed by vacuuming; The air pressure regulating module (7) is an annular structure, and its inner wall surface transitions from a plane to an inclined surface from top to bottom, the plane cooperates with the synchronous cover module (6), and the inclined surface has the function of preventing the spin coating liquid from splashing during the spin coating process, and the spin coating liquid flows out from the flow channel along the inclined surface after being thrown onto the inclined surface; the outer surface of the air pressure regulating module (7) is designed with a rectangular protrusion, and the outer surface of the rectangular protrusion is designed with an air pressure regulating inlet, and the center height of the air pressure regulating inlet is the same as the upper surface of the spin coating substrate; the air pressure regulating module (7) is provided with an air channel, and the air channel consists of two parts, the first part is an equirectangular cross-section part, and the second part is a linearly enlarged rectangular cross-section part, and the two constitute a complete air channel from the outside to the inside; The synchronous cover module (6) can move up and down in a vertical direction. An air inlet is provided on the top of the synchronous cover module (6), and gas is introduced into the synchronous cover module (6) through the air inlet. The interior of the synchronous cover module (6) is a cavity. The lower surface of the synchronous cover module (6) is provided with annular air outlets evenly distributed, and the air outlets are connected to the cavity. Gas passes through the cavity from the air inlet and is blown from the air outlet to the top of the spin coating turntable module (8).

2. The spin coating chamber structure for stabilizing the chamber flow field and improving the chamber cleanliness according to claim 1, characterized in that: The vacuum hole (9) is connected to the hollow shaft hole of the spin coater to the vacuum pump.

3. The spin coating chamber structure for stabilizing chamber flow field and improving chamber cleanliness according to claim 1, characterized in that: The upper surface of the circular substrate bearing platform (2) is provided with four symmetrically distributed positioning holes (1).

4. The spin coating chamber structure for stabilizing the chamber flow field and improving the chamber cleanliness according to claim 1, characterized in that: The air pressure regulating module (7) is provided with four connection holes on the periphery of the upper surface thereof, and is fixed with bolts and nuts in cooperation with the frame of the spin coating machine.

5. The spin coating chamber structure for stabilizing chamber flow field and improving chamber cleanliness according to claim 1, characterized in that: The air passage of the air pressure regulating module (7) is not located directly below the connecting hole.

6. The spin coating chamber structure for stabilizing chamber flow field and improving chamber cleanliness according to claim 1, characterized in that: The cavity is in the shape of a cylindrical cavity (10).

7. The spin coating chamber structure for stabilizing chamber flow field and improving chamber cleanliness according to claim 1, characterized in that: The lower surface of the synchronous cover module (6) is provided with a trapezoidal spoiler (5), and the angle between the spoilers (5) can be adjusted within the range of 60°-90°. There is no air outlet (4) at the position where the spoiler (5) is present on the lower surface of the synchronous cover module (6), and there is no air outlet (4) on the trapezoidal spoiler.

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