A spin coating chamber structure for stabilizing the chamber flow field and improving the chamber cleanliness

Abstract

The present invention belongs to the technical field of spin coaters, and discloses a spin coating chamber structure for stabilizing the chamber flow field and improving the chamber cleanliness. The synchronous cover module, the air pressure adjustment module, and the spin coating turntable module arranged from top to bottom are concentric structures; there is a flow channel for the spin coating liquid to flow out between the spin coating turntable module and the air pressure adjustment module, and the spin coating turntable module and the synchronous cover module rotate at the same speed during spin coating. Before spin coating, an air pump is connected to the air duct of the air pressure adjustment module, and the impurities in the spin coating chamber are carried away from the substrate surface by the air flow to improve the chamber cleanliness. During the spin coating process, supersaturated gas is introduced through the air inlet hole of the synchronous cover module, the gas passes through the cylindrical chamber, and enters the spin coating chamber through the air outlet hole, improving the atmosphere environment in the spin coating chamber, enhancing the evaporation uniformity, and improving the film thickness uniformity. During the spin coating process, the synchronous cover module and the spin coating module rotate synchronously, and the trapezoidal flow disturbing plate 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 and ensuring the film thickness uniformity.

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] To solve the above problems existing in the spin coating technology, the present invention is designed to provide a high-performance spin coating chamber that can effectively improve the stability of the flow field in the chamber and 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, including a synchronous cover module 6, a pressure adjustment module 7, and a spin coating turntable module 8; the synchronous cover module 6, the pressure adjustment module 7, and the spin coating turntable module 8 arranged from top to bottom are concentric structures; there is a flow channel for the spin coating liquid to flow out between the spin coating turntable module 8 and the pressure adjustment module 7, and the spin coating turntable module 8 and the synchronous cover module 6 rotate at the same speed during spin coating.

[0008] The upper surface of the spin coating turntable module 8 is designed with a circular substrate carrier 2, and 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, and the circular substrate carrier 2 and the turntable edge area are connected by a sloped surface, 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 to adsorb the circular substrate carrier 2 through vacuum pumping.

[0009] The pressure adjustment module 7 is an annular structure, and its inner wall surface is transitioned from a plane to a sloped surface from top to bottom. The plane cooperates with the synchronous cover module 6, and the sloped surface has the function of preventing the spin coating liquid from splashing during spin coating. After the spin coating liquid is thrown onto the sloped surface, it flows out along the sloped surface from the flow channel; a rectangular protrusion is designed on the outer surface of the pressure adjustment module 7, and a pressure adjustment inlet 3 is designed on the outer surface of the rectangular protrusion. The center height of the pressure adjustment inlet 3 is the same as the upper surface of the spin coating substrate; the pressure adjustment module 7 is provided with an air channel, which is composed of two parts. The first part is a part with an equal rectangular cross-section, and the second part is a part with a linearly increasing rectangular cross-section. The two parts form a complete air channel from the outside to the inside.

[0010] The synchronous cover module 6 can move up and down in the vertical direction. An air inlet hole is opened above the synchronous cover module 6, and gas is introduced into the synchronous cover module 6 through the air inlet hole; the inside of the synchronous cover module 6 is a cavity; annular uniformly distributed air outlet holes are opened on the lower surface of the synchronous cover module 6, and the air outlet holes are connected to the cavity. The gas passes through the cavity from the air inlet hole and blows to the upper part of the spin coating turntable module 8 from the air outlet holes.

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

[0012] Further, four symmetrically distributed positioning holes 1 are opened on the upper surface of the circular substrate carrier 2.

[0013] Furthermore, there are 4 air pressure adjustment module connection holes 12 on the periphery of the upper surface of the air pressure adjustment module 7, which are fixed by bolts and nuts in cooperation with the spin coater frame.

[0014] Furthermore, the air pressure adjustment inlet 3 of the air pressure adjustment module 7 is not directly below the air pressure adjustment module connection 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. The included angle between the spoilers 5 can be adjusted within the range of 60° - 90°. There are no air outlet holes 4 at the positions where the spoilers 5 exist on the lower surface of the synchronization cover module 6, and there are no air outlet holes 4 on the trapezoidal spoilers.

[0017] Advantages of the present invention:

[0018] 1. Before spin coating, an air pump can be connected to the air duct of the air pressure adjustment module of the present invention, and the dust and other impurities that may contaminate the film in the spin coating chamber are carried away from the substrate surface by the flow of high-speed air, ensuring the cleanliness of the chamber.

[0019] 2. During spin coating, a supersaturated gas is introduced through the air inlet hole of the synchronization cover module. The supersaturated gas passes through the cylindrical chamber and uniformly enters the spin coating chamber through the air outlet holes, improving the atmosphere environment in the spin coating chamber, enhancing the evaporation uniformity, and thus improving the film thickness uniformity.

[0020] 3. During spin coating, the synchronization cover module rotates synchronously with the spin coating module. The trapezoidal spoilers of the synchronization 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, and thus ensuring the film thickness uniformity. Description of the drawings

[0021] Figure 1 is the overall structure schematic diagram (exploded view) of the present invention;

[0022] Figure 2 in which (a) is the cross-sectional schematic diagram of the overall structure of the present invention; Figure 2 in which (b) is the partial enlarged view of the flow channel of (a); where dl is the flow channel inlet size.

[0023] Figure 3 is the cross-sectional view of the air duct of the air pressure adjustment module;

[0024] Figure 4 in which (a) is the front view of the air outlet distribution and spoiler mechanism of the synchronization cover module, Figure 4 in which (b) is the side view of the air outlet distribution and spoiler mechanism of the synchronization cover module.

[0025] In the figure: 1 - Spin - coating substrate positioning hole; 2 - High - precision circular substrate carrier; 3 - Air pressure regulation inlet; 4 - Synchronous cover air outlet; 5 - Trapezoidal spoiler; 6 - Synchronous cover module; 7 - Air pressure regulation module; 8 - Spin - coating turntable module; 9 - Vacuum pumping hole; 10 - Cylindrical cavity; 11 - Synchronous cover air inlet; 12 - Air pressure regulation module mounting hole; 13 - Anti - splash inclined plane. Detailed implementation mode

[0026] The following further describes the specific implementation mode of the present invention in combination with the attached drawings and technical solutions.

[0027] A spin - coating chamber structure for improving the stability of the chamber flow field and removing pollutants such as dust in the chamber, including a synchronous cover module 6, an air pressure regulation module 7, and a spin - coating turntable module 8;

[0028] The three parts of the synchronous cover module 6, the air pressure regulation module 7, and the spin - coating turntable module 8 have concentricity requirements, and are, from top to bottom, the synchronous cover module 6, the air pressure regulation module 7, and the spin - coating turntable module 8; further, there is no contact between the outer wall of the synchronous cover module 6 and the inner wall of the air pressure regulation module 7; the inner diameter of the air pressure regulation module 7 is larger than the outer diameter of the spin - coating turntable module 8, so there is a gap between the air pressure regulation module 7 and the spin - coating turntable module 8. 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 the same rotation speed during the spin - coating process; the air pressure regulation module 7 does not rotate during the spin - coating process;

[0029] The upper surface of the spin - coating turntable module 8 is designed with a high - precision circular substrate carrier 2. The circular substrate carrier 2 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. High precision is not required for other areas except the circular substrate carrier 2; further, the height of the area of the high - precision circular substrate carrier 2 is slightly higher than that of the spin - coating turntable module, and the height difference is transitioned by an inclined plane structure;

[0030] Four spin - coating substrate positioning holes 1 symmetrically distributed around the center are opened in the area of the high - precision circular substrate carrier 2. During spin - coating, the spin - coating substrate is fixed to the high - precision circular substrate carrier 2 by using positioning pins;

[0031] Further, a vacuum pumping hole 9 is left at the center of the high - precision circular substrate carrier 2. The vacuum pumping hole 9 is used to pump vacuum to adsorb the spin - coating substrate. The spin - coating substrate is fixed or positioned by vacuum adsorption, or when the spin - coating speed is relatively high, the two fixing methods can be used in combination for fixing;

[0032] Four air pressure regulation module mounting holes 12 are opened on the outer periphery of the upper surface of the air pressure regulation module 7, and the air pressure regulation module 7 is connected and fixed to the whole machine frame of the spin - coater by using bolts;

[0033] Furthermore, the inner wall of the air pressure adjustment 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 effect of preventing the spin coating liquid from splashing during the spin coating process. When the spin coating liquid is thrown onto the wall surface of the inclined surface area, the spin coating liquid can flow down along the wall surface;

[0034] The outer surface of the air pressure adjustment module 7 is designed with a cuboid protrusion, and an air pressure adjustment inlet 3 is opened at the cuboid protrusion structure. During spin coating, the upper surface of the spin coating substrate should be within the inlet range of the air pressure adjustment inlet 3. That is, the gas for realizing air pressure adjustment should satisfy that the gas passing through the surface of the spin coating substrate to be sent in or drawn out from the air pressure adjustment inlet 3 has the function of removing dust and contaminating impurities in the spin coating chamber. Further, the ventilation time of the air pressure adjustment inlet 3 is before the start of spin coating;

[0035] Furthermore, the air pressure adjustment module 7 is provided with an air channel, which is composed of two parts. The first part is a part with an equal rectangular cross-section, and the second part is a part with a linearly increasing rectangular cross-section;

[0036] Furthermore, the air channel of the air pressure adjustment module 7 is not directly below the air pressure adjustment module mounting hole 12;

[0037] A flow channel for the spin coating liquid to flow out is designed between the rotating disk module 8 and the air pressure adjustment module 7, and the minimum size of the flow channel is d1;

[0038] A synchronous cover air inlet hole 11 is opened above the synchronous cover module 6, and the gas for controlling the atmosphere in the chamber is blown in from here during spin coating;

[0039] Furthermore, the inside of the synchronous cover module 6 is a cylindrical cavity 10, and the synchronous cover air inlet hole 11 is connected to the cylindrical cavity 10;

[0040] Furthermore, the lower surface of the synchronous cover module 6 is provided with annularly and uniformly distributed synchronous cover air outlet holes 4. The synchronous cover air inlet hole 11, the cylindrical cavity 10, and the synchronous cover air outlet holes 4 are connected. During spin coating, gas is introduced from the synchronous cover air inlet hole 11 to fill the inside of the cylindrical cavity 10, and finally uniformly injected into the spin coating chamber from the synchronous cover air outlet holes 4 to improve the flow field of the spin coating chamber;

[0041] Furthermore, trapezoidal flow disturbing plates 5 are installed on the lower surface of the synchronous cover module 6. The included angle between the trapezoidal flow disturbing plates 5 can be adjusted within the range of 60° - 90°. There are no air outlet holes at the positions of the lower surface of the synchronous cover module 6 where the flow disturbing plates exist, and there are no openings on the trapezoidal flow disturbing plates;

[0042] The operation mode of the present invention is as follows:

[0043] Before the spin coating starts, select a spin coating substrate and spin coating liquid with appropriate sizes according to the spin coating process and product requirements. Then select appropriate spin coating process parameters according to the thickness of the spin coating film required. After the pre - preparation work for spin coating is completed, the spin coating to prepare the film can be started.

[0044] First, introduce high - speed gas into the spin coating chamber through the gas pressure regulation inlet of the gas pressure regulation module, or use a vacuum pump to extract the gas in the chamber, so as to blow the dust, other pollutants or particles in the chamber away from the chamber and ensure the cleanliness of the chamber. Secondly, move the synchronous cover module upward, arrange the spin coating liquid at the center of the spin coating substrate or cover the entire substrate. Then restore the synchronous cover module to its original position, and at the same time turn on 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. The spin coating liquid flows or is thrown out along the surface of the substrate under the action of centrifugal force, and at the same time, the process of flow and evaporation thinning is realized along with the evaporation of the solvent. At the same time, the supersaturated vapor continuously and evenly injected from the air intake of the synchronous cover reaches the cylindrical chamber of the synchronous cover and is injected into the spin coating chamber through the air outlet holes evenly distributed on the lower surface of the synchronous cover. The evenly injected gas ensures the stability of the atmosphere environment in the chamber, and the trapezoidal spoiler rotating synchronously makes the gas flow velocity in the chamber tend to be consistent, ensuring the stability of the flow field in the chamber. The combined action of the spoiler and the injected gas helps the film flow and evaporation thinning process to be uniform. The film thickness uniformity and film quality can be ensured.

[0045] As described above, for those of ordinary skill in the art, various corresponding changes and deformations can be made according to the technical solutions and technical concepts of the present invention, and all these changes and deformations should fall within the protection scope of the claims of the present invention.

Claims

1. A spin coating chamber structure for improving the cleanliness of the chamber by stabilizing the chamber flow field, characterized in that The spin coating chamber structure includes a synchronous cover module (6), a gas pressure regulation module (7), and a spin coating turntable module (8); the synchronous cover module (6), the gas pressure regulation module (7), and the spin coating turntable module (8) arranged from top to bottom are concentric structures; there is a flow channel for the spin coating liquid to flow out between the spin coating turntable module (8) and the gas pressure regulation module (7), and the spin coating turntable module (8) and the synchronous cover module (6) rotate at the same speed during spin coating. The upper surface of the spin coating turntable module (8) is designed with a circular substrate carrier (2), and the area of the circular substrate carrier (2) is larger than the area of the substrate to be coated; the area other than the circular substrate carrier (2) of the spin coating turntable module (8) is the turntable edge area, and the circular substrate carrier (2) and the turntable edge area are connected by an inclined plane, 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 vacuum pumping. The gas pressure regulation module (7) is an annular structure, and its inner wall surface transitions from a plane to an inclined plane from top to bottom. The plane cooperates with the synchronous cover module (6), and the inclined plane has the function of preventing the spin coating liquid from splashing during spin coating. The spin coating liquid is thrown onto the inclined plane and then flows out along the inclined plane from the flow channel; the outer surface of the gas pressure regulation module (7) is designed with a cuboid protrusion, and the outer surface of the cuboid protrusion is designed with a gas pressure regulation inlet, and the center height of the gas pressure regulation inlet is the same as the upper surface of the spin coating substrate; the gas pressure regulation module (7) is provided with an air duct, and the air duct consists of two parts. The first part is a part with an equal rectangular cross-section, and the second part is a part with a linearly increasing rectangular cross-section. The two parts form a complete air duct from the outside to the inside. The synchronous cover module (6) can move up and down in the vertical direction. An air inlet hole is opened above the synchronous cover module (6), and gas is introduced into the synchronous cover module (6) through the air inlet hole; the inside of the synchronous cover module (6) is a cavity; an annular and uniformly distributed air outlet hole is opened on the lower surface of the synchronous cover module (6), and the air outlet hole is connected to the cavity. The gas passes through the cavity from the air inlet hole and blows to the upper part of the spin coating turntable module (8) from the air outlet hole. There are trapezoidal flow disturbance plates (5) on the lower surface of the synchronous cover module (6), and the included angle between the flow disturbance plates (5) can be adjusted in the range of 60° - 90°. There are no air outlet holes (4) at the positions where the flow disturbance plates (5) exist on the lower surface of the synchronous cover module (6), and there are no air outlet holes (4) on the trapezoidal flow disturbance plates.

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

3. The spin coating chamber structure for improving the cleanliness of the chamber by stabilizing the chamber flow field according to claim 1, wherein Four symmetrically distributed positioning holes (1) are opened on the upper surface of the circular substrate carrier (2).

4. The spin coating chamber structure for improving the cleanliness of the chamber by stabilizing the chamber flow field according to claim 1, characterized in that, Four connection holes are opened on the periphery of the upper surface of the gas pressure regulation module (7), and are fixed with bolts and nuts in cooperation with the spin coater frame.

5. The spin coating chamber structure for improving the cleanliness of the chamber by stabilizing the chamber flow field according to claim 1, characterized in that, The air duct of the gas pressure regulation module (7) is not located directly below the connection hole.

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

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