Spin coating chamber structure for improving edge effect defect of rectangular substrate

Abstract

The invention discloses a spin-coating chamber structure for improving edge effect defects of a rectangular substrate. The spin-coating chamber structure comprises a chamber side wall, a rounding plate, a spin-coating bottom plate and a chamber top cover, a rectangular hole, a pressure relief groove and a drainage channel are formed in the rounding plate. Due to the fact that the drainage channels composed of the contraction sections, the throats and the diffusion sections are arranged outside the four corners of the rectangular hole of the rounding plate, spin-coating external tangential airflow is accelerated in the drainage channels, negative pressure areas are formed at the four corners of the base plate, liquid accumulated at the corners is promoted to be discharged outwards, and the volume of edge effect accumulated liquid is reduced. Due to the fact that the pressure relief groove is formed outside the drainage channel, a low-resistance relief channel is provided for airflow passing through the throat in the rotating process. Meanwhile, air at the outer edge flows at a high linear speed to form high dynamic pressure driving in the pressure relief groove, the venturi suction flow field characteristic is shown in the drainage channel, and the liquid at the angular point of the base plate is further promoted to flow out in the radial direction under the pressure effect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of spin coater film forming, and particularly relates to a spin coating chamber structure for improving edge effect defects of a rectangular substrate. BACKGROUND

[0002] As the most commonly used method for preparing a large-area high-uniformity photoresist film on the surface of a rectangular substrate, the spin coating method has been widely used in the field of functional coating preparation of solar cells, organic semiconductors and optical elements. With the increasing demand for the performance of film devices in various fields, higher requirements are put forward for the quality and effective use area of the spin coating film. In the spin coating of a rectangular substrate, the direct cutting of the substrate corners into the air in the chamber intensifies the degree of flow field turbulence, and serious film thickness unevenness stripes and edge thick glue defects are generated in the corner area. In order to weaken the shape characteristics of the substrate but affect the flow field, a round-plate-in-square-plate structure is generally used in the design of the spin coating chamber. Even if the round-plate-in-square-plate structure is used, liquid accumulation will still be formed along the four sides of the rectangular substrate under the joint action of surface tension and centrifugal force during the spin coating process. When the spin coating is completed and the centrifugal force is removed, the accumulated liquid flows back inward under the driving of the surface tension, significantly increasing the width of the edge effect and reducing the effective use area of the device, which has an adverse effect on the overall uniformity of the film and the performance of the device. In the prior art, exhaust holes or wind tunnels are opened in the spin coating chamber, exhaust modules or additional pressure control and ventilation devices are added, and local pressure regulation is realized to reduce the width of the edge effect. However, the above structures or devices often introduce new air flow disturbances in the asymmetric substrate rotating chamber, resulting in more complex air flow distribution in the chamber, and weakening the edge defects at the expense of the film thickness uniformity in the central area. In addition, such hole structures, pressure control and air path devices increase the complexity of the spin coating chamber system, and greatly increase the chamber modification cost. Therefore, there is an urgent need for a chamber structure that can reduce the amount of liquid accumulation at the edge of the substrate and thus improve the edge effect defects. SUMMARY

[0003] To solve the above problems existing in the prior art, the present application provides a spin coating chamber structure for improving edge effect defects of a rectangular substrate, which can reduce the amount of liquid accumulation at the edge of the substrate by the action of the air flow generated by the chamber structure characteristics during the rotation, thereby reducing the influence range of the edge effect defects.

[0004] To achieve the above-mentioned purpose, the basic idea of the present application is as follows: The specific technical scheme of the present application is as follows: a spin coating chamber structure for improving edge effect defects of a rectangular substrate, comprising a chamber side wall, a round-plate-in-square-plate, a spin coating bottom plate and a chamber top cover; the chamber top cover and the upper side of the chamber side wall are fixedly connected, the spin coating bottom plate and the lower side of the chamber side wall are fixedly connected, and the round-plate-in-square-plate is installed on the spin coating bottom plate; the spin coating bottom plate is connected with a transmission shaft. The rectangular hole is used for placing the rectangular substrate.

[0005] Further, the outer diameter of the rounding plate is D r , and the thickness is H r ; The rectangular hole is a through hole, and the length and width of the rectangular hole are greater than the length and width of the rectangular substrate S 0; when the rectangular substrate is placed in the rectangular hole, a gap structure with a width of S 0 is formed between the periphery of the rectangular substrate and the wall of the rectangular hole; The pressure relief groove is an annular groove arranged at the outer edge of the rounding plate, and the groove depth is H g = H r / 2, the groove width in the radial direction is w g , and satisfies 13.6≤ D r / w g ≤34; The drainage channel has four, and the inlets of the four drainage channels are respectively communicated with the four corners of the rectangular hole, and the outlets are respectively communicated with the pressure relief grooves.

[0006] Further, the drainage channel includes a contraction section, a throat and a diffusion section, and the contraction section, the diffusion section and the throat adopt a continuous smooth curve transition; The width of the narrowest part of the throat is b t , and satisfies 0.5≤ b t / S 0≤1; The inlet of the contraction section is communicated with the rectangular hole, and the length of the contraction section along the center line direction of the channel is L c , the inlet width of the contraction section is b c , and satisfies tan10°≤ b c / L c ≤tan45°; One end of the diffusion section is smoothly transitioned with the throat, and the other end is communicated with the pressure relief groove, and the length of the diffusion section along the center line direction of the channel is L d , and the outlet width of the diffusion section is b d , and satisfies tan10°≤ b d / L d≤tan30°.

[0007] Compared with the prior art, the present invention has the following beneficial effects: 1. Because the present invention provides a flow channel consisting of a contraction section, a throat and a diffusion section outside the four corners of the rectangular hole of the supplementary round plate, it causes the tangential airflow outside the spin coating to accelerate in the flow channel, thereby forming a negative pressure zone at the four corners of the substrate, causing the liquid accumulated at the corners to be discharged outward, reducing the volume of liquid accumulated at the edge effect.

[0008] 2. Because the present invention provides a pressure relief groove outside the drainage channel, it provides a low-resistance relief channel for the airflow through the throat during rotation. At the same time, the high linear velocity flow of the outer edge air forms a high dynamic pressure drive in the pressure relief groove, exhibiting the characteristics of a Venturi suction flow field in the drainage channel, further promoting the radial outflow of liquid at the corner of the substrate under pressure.

[0009] 3. By setting a drainage groove and a pressure relief groove structure on the round plate, the present invention eliminates the need for an additional exhaust module or external pressure control. Without affecting the film formation quality in the central area, it effectively reduces the influence range of edge defects in spin-coated films on rectangular substrates. Furthermore, it can be extended to edge effect control in spin-coating of irregularly shaped substrates, and has good application value. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the structure of the present invention.

[0011] Figure 2 This is an isometric view of the circular patch of the present invention.

[0012] Figure 3 This is a top view of the circular plate after the rectangular substrate has been placed in this invention.

[0013] Figure 4 This is a central half-sectional view of the present invention.

[0014] In the figure: 1. Pressure relief groove, 2. Rectangular hole, 3. Drainage channel, 4. Gap, 5. Rectangular base plate, 21. Chamber side wall, 22. Filler plate, 23. Chamber top cover, 24. Drive shaft, 25. Spin coating base plate, 31. Contraction section, 32. Throat, 33. Diffusion section. Detailed Implementation

[0015] The invention will now be further described with reference to the accompanying drawings. Figures 1-4 As shown, a spin coating chamber structure for improving edge effect defects in rectangular substrates includes a chamber sidewall 21, a rounding plate 22, a spin coating base plate 25, and a chamber top cover 23; the chamber top cover 23 is fixedly connected to the upper side of the chamber sidewall 21, the spin coating base plate 25 is fixedly connected to the lower side of the chamber sidewall 21, and the rounding plate 22 is mounted on the spin coating base plate 25; the spin coating base plate 25 is connected to a drive shaft 24. The rectangular hole 2, pressure relief groove 1 and drainage channel 3 are arranged on the rounding plate 22; the rectangular hole 2 is used for placing the rectangular substrate 5.

[0016] Further, the outer diameter of the rounding plate 22 is D r , and the thickness is H r ; The rectangular hole 2 is a through hole, and the length and width of the rectangular hole 2 are greater than the length and width of the rectangular substrate 5 respectively S 0; when the rectangular substrate 5 is placed in the rectangular hole 2, a gap 4 structure with a width of S 0 is formed between the four sides of the rectangular substrate 5 and the wall of the rectangular hole 2; The pressure relief groove 1 is an annular groove arranged at the outer edge of the rounding plate 22, and the groove depth is H g = H r / 2, and the groove width in the radial direction is w g , satisfying 13.6≤ D r / w g ≤34; The drainage channel 3 has four channels, and the inlets of the four channels are respectively communicated with the four corners of the rectangular hole 2, and the outlets are respectively communicated with the pressure relief grooves 1.

[0017] Further, the drainage channel 3 includes a contraction section 31, a throat 32 and a diffusion section 33, and the contraction section 31, the diffusion section 33 and the throat 32 adopt a continuous smooth curve transition; The width of the narrowest part of the throat 32 is b t , satisfying 0.5≤ b t / S 0≤1; The inlet of the contraction section 31 is communicated with the rectangular hole 2, and the length of the contraction section 31 along the center line of the channel is L c , the inlet width of the contraction section 31 is b c , satisfying tan10°≤ b c / L c ≤tan45°; One end of the diffusion section 33 is smoothly transitioned with the throat 32, and the other end is communicated with the pressure relief groove 1, and the length of the diffusion section 33 along the center line of the channel is L d , and the outlet width of the diffusion section 33 is bd , satisfying tan10°≤ b d / L d ≤tan30°.

[0018] When the present invention is in operation, the rotation drive is transmitted to the spin coating base plate 25 through the transmission shaft 24, thereby driving the entire spin coating chamber to rotate synchronously.

[0019] like Figure 3 As shown, a rectangular substrate 5 is placed in the rectangular hole 2 of the supplementary circular plate 22. A gap 4 is formed between the rectangular substrate 5 and the rectangular hole 2, and it is connected to the drainage channel 3 in the corner area. When the spin coating chamber rotates, the airflow enters the drainage channel 3 through two paths: (1) the circumferential airflow at the outer edge enters the inlet of the contraction section 31; (2) the airflow flowing into the inlet of the contraction section 31 within the gap 4. The airflow entering the contraction section 31 is accelerated when it passes through the narrowed throat 32 and continues to flow to the diffuser section 33 where the channel width increases, and finally merges into the pressure relief groove 1 at the outer edge of the supplementary circular plate 22. Due to the higher dynamic pressure in the outer edge region forming a low-resistance passage in the pressure relief groove 1, the airflow passing through the throat 32 generates a Venturi suction effect, which further promotes the airflow in the diffuser section 33 to merge into the pressure relief groove 1.

[0020] This invention is not limited to this embodiment. Any equivalent concept or modification within the technical scope disclosed in this invention shall be included within the protection scope of this invention.

Claims

1. A spin-coating chamber structure for improving edge effect defects in rectangular substrates, characterized in that: It includes a chamber sidewall (21), a round plate (22), a spin coating base plate (25), and a chamber top cover (23); the chamber top cover (23) is fixedly connected to the upper side of the chamber sidewall (21), the spin coating base plate (25) is fixedly connected to the lower side of the chamber sidewall (21), and the round plate (22) is mounted on the spin coating base plate (25); the spin coating base plate (25) is connected to the drive shaft (24); The round plate (22) is provided with a rectangular hole (2), a pressure relief groove (1) and a drainage channel (3); the rectangular hole (2) is used to place a rectangular substrate (5).

2. The spin-coating chamber structure for improving edge effect defects in rectangular substrates according to claim 1, characterized in that: The outer diameter of the rounding plate (22) is D r Thickness is H r ; The rectangular hole (2) is a through hole, and the length and width of the rectangular hole (2) are greater than the length and width of the rectangular substrate (5), respectively. S 0; When the rectangular substrate (5) is placed inside the rectangular hole (2), a width of is formed between the periphery of the rectangular substrate (5) and the wall of the rectangular hole (2). S 0 gap (4) structure; The pressure relief groove (1) is an annular groove, located on the outer edge of the supplementary circular plate (22), with a groove depth of... H g = H r / 2, the groove width in the radial direction is w g Satisfying 13.6≤ D r / w g ≤34; There are 4 drainage channels (3). The inlets of the 4 drainage channels (3) are connected to the four corners of the rectangular hole (2) respectively, and the outlets are connected to the pressure relief groove (1) respectively.

3. The spin-coating chamber structure for improving edge effect defects in rectangular substrates according to claim 1, characterized in that: The drainage channel (3) includes a constriction section (31), a throat (32) and a diffusion section (33), and the constriction section (31), the diffusion section (33) and the throat (32) are connected by a continuous smooth curve; The width of the narrowest part of the throat (32) is b t , satisfying 0.5≤ b t / S 0≤1; The inlet of the contraction section (31) is connected to the rectangular hole (2), and the length of the contraction section (31) along the center line of the channel is... L c The width of the inlet of the contraction section (31) b c , satisfying tan10°≤ b c / L c ≤tan45°; One end of the diffuser section (33) smoothly transitions to the throat (32), and the other end connects to the pressure relief groove (1). The length of the diffuser section (33) along the center line of the channel is... L d Diffusion section (33) outlet width b d , satisfying tan10°≤ b d / L d ≤tan30°.

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