Device for improving photoresist coating uniformity

Abstract

The utility model provides a device for improving photoresist coating uniformity, which belongs to the technical field of photoresist coating and comprises a multi-layer conical tube, a wafer is arranged below the multi-layer conical tube, the multi-layer conical tube comprises an outer layer, a middle layer and an inner layer are sequentially sleeved on the outer layer, pressure circulating pumps are respectively mounted on the outer layer and the middle layer, the outer layer is a feeding layer, and the inner layer is a discharging layer. The middle layer is an air flow layer, the air flow layer is provided with an air inlet, the air inlet is provided with an air inlet flow meter, the air inlet flow meter is arranged on the air inlet, the bottom of the air flow layer is provided with a filtering and defoaming ball, the bottom of the filtering and defoaming ball is connected with a discharging opening, and the discharging opening is provided with a flow meter switch; ultrasonic vibrators are mounted on the inner walls of the two sides of the inner layer respectively; according to the utility model, the photoresist can be dispersed into uniform and fine liquid drops, so that the non-uniformity of solution distribution is reduced, the film thickness is uniform during spin coating, and the precision and consistency of patterns are ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of photoresist coating, in particular to a device for improving the uniformity of photoresist coating. Background Art

[0002] In the semiconductor lithography process, the photoresist coating process is a key step. The uniformity of the coating will affect the accuracy and uniformity of the line width, which will further affect the device's optical and electrical properties such as color saturation and resolution.

[0003] The most widely used method in the photoresist coating process is spin coating, which is to disperse the photoresist on the surface of the wafer by high-speed rotation. The solvent and excess photoresist will be thrown out of the wafer, and the remaining photoresist will form a thin film of varying thickness on the wafer surface. During the rotation process, the liquid is affected by centrifugal force and adhesion, and disperses in all directions. Since bubbles or sedimentation will be generated during the transportation of the coating material, the uniform distribution of the solution is destroyed, and the strength of the force applied is different, which leads to uneven film thickness and poor coating quality. Utility Model Content

[0004] The purpose of the utility model is to provide a device for improving the uniformity of photoresist coating to overcome the problems existing in the prior art. The utility model can make the flow directions of photoresist and gas opposite to each other, and ultrasound uses gas as a medium, which can quickly disperse the photoresist into uniform and fine droplets in the form of longitudinal waves. The countercurrent gas can also reduce the influence of heat generated during the ultrasonic treatment on the properties of the photoresist; at the same time, the photoresist is secondary treated by filtering defoaming balls, and the bubbles in the solution are punctured by a needle, which reduces the uneven distribution of the solution, makes the film thickness uniform during spin coating, ensures the accuracy and consistency of the pattern, and solves the problem of uneven film thickness of photoresist spin coating in the prior art.

[0005] In order to achieve the above-mentioned purpose, the technical solutions adopted by the present invention are as follows:

[0006] A device for improving photoresist coating uniformity includes a multi-layer tapered tube, a wafer is arranged below the multi-layer tapered tube, the multi-layer tapered tube includes an outer layer, the outer layer is sequentially covered with a middle layer and an inner layer, and the outer layer and the middle layer are respectively equipped with a pressure circulation pump;

[0007] The outer layer is a feed layer, the feed layer is provided with a feed port, a feed flow meter is installed on the feed port, a filter defoaming ball is provided at the bottom of the feed layer, the bottom of the filter defoaming ball is connected to a discharge port, and a flow meter switch is installed at the discharge port;

[0008] The middle layer is an air flow layer, the air flow layer is provided with an air inlet, and an air inlet flow meter is installed on the air inlet;

[0009] Ultrasonic vibrators are respectively installed on the inner walls of both sides of the inner layer;

[0010] Furthermore, the width of the feed layer is greater than the width of the airflow layer;

[0011] Furthermore, the bottom of the multi-layered tapered tube is provided with a curvature;

[0012] Furthermore, the arc is 110°~130°;

[0013] Furthermore, the filtering and defoaming ball is a spherical screen;

[0014] Furthermore, the surface of the spherical screen is provided with needles;

[0015] Furthermore, the diameter of the filtering and defoaming balls is equal to the width of the feed layer;

[0016] Furthermore, the ultrasonic vibrator includes an ultrasonic output portion, which contacts the inner walls on both sides of the inner layer;

[0017] Furthermore, the feed port is connected to a liquid pressure circulation pump;

[0018] Furthermore, the air inlet is connected to a gas pressure circulation pump.

[0019] The above technical solution has the following advantages or beneficial effects:

[0020] The utility model provides a device for improving the uniformity of photoresist coating. By designing a multi-layer tapered tube structure, the flow directions of the photoresist and the gas are opposite, and the counterflow helps to enhance the dispersing effect of ultrasonic vibration on the photoresist; the ultrasonic vibrator uses gas as a medium and quickly acts on the photoresist in the form of longitudinal waves, so that it forms more uniform and fine particles, further improving the uniformity of coating; the filtering defoaming ball can effectively deal with bubbles in the photoresist, puncture the bubbles with a needle, reduce the influence of bubbles on the uniformity of the coating, and thus improve product quality.

[0021] Furthermore, the width of the feed layer is greater than the width of the air flow layer, which helps to form a smoother flow when the photoresist enters the multi-layer conical tube, reduces fluid impact and turbulence, and thus is conducive to the uniform distribution of the photoresist; the bottom of the multi-layer conical tube is provided with a curvature, which helps to form a more uniform flow when the photoresist flows out, avoids the accumulation of fluid at the bottom or the formation of an uneven flow pattern, and can also reduce the resistance of the fluid during the outflow process.

[0022] Furthermore, the diameter of the filter defoaming balls is equal to the width of the feed layer, ensuring that the photoresist can be fully contacted and processed when flowing through the filter defoaming balls, which helps to maximize the defoaming effect and reduce the number of bubbles in the photoresist, thereby improving the uniformity and quality of the coating.

[0023] Furthermore, the spherical screen structure of the filter defoaming ball not only provides sufficient surface area for the photoresist to pass through, but its screen design can effectively intercept large particles of impurities in the photoresist. The needles on the surface of the screen further enhance the defoaming effect, and quickly eliminate bubbles in the photoresist by physical puncture, ensuring the purity and uniformity of the photoresist.

[0024] Furthermore, the direct contact between the ultrasonic output portion and the inner walls on both sides of the inner layer ensures that the ultrasonic energy can be efficiently transferred to the photoresist, reduces the energy loss during the transfer process, and improves the effect of the ultrasonic treatment.

[0025] Furthermore, the introduction of liquid pressure circulation pumps and gas pressure circulation pumps enables the device to more accurately control the flow and pressure of photoresist and gas, helping to ensure the stable flow of photoresist and gas in the multi-layer conical tube, and reducing the problem of uneven coating caused by flow or pressure fluctuations. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the structure of a device for improving the uniformity of photoresist coating according to the present invention;

[0027] Figure 2 This is a partial structural diagram of a filtering and defoaming ball device for improving the uniformity of photoresist coating according to the present invention;

[0028] Figure 3 This is a schematic diagram of the principle of ultrasound acting on photoresist;

[0029] In the figure, 1-multi-layer conical tube; 2-feed layer; 21-feed port; 22-liquid pressure circulation pump; 23-feed flow meter; 3-air flow layer; 31-air inlet; 32-gas pressure circulation pump; 33-air inlet flow meter; 4-filter defoaming ball; 5-discharge port; 6-flow meter switch; 7-ultrasonic vibrator; 71-ultrasonic output part; 8-wafer. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below with reference to specific embodiments, which are intended to explain rather than limit the present invention.

[0031] In order to help those skilled in the art better understand the present invention, the following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0032] It should be noted that the terms "first," "second," and the like in the specification and claims of the present invention and the accompanying drawings are used to distinguish similar items and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, such that the embodiments of the present invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions.

[0033] Example 1:

[0034] like Figure 1 As shown, the utility model provides a device for improving the uniformity of photoresist coating, comprising a multi-layer tapered tube 1, the bottom of the multi-layer tapered tube 1 is provided with a curvature, a wafer 8 is provided below the multi-layer tapered tube 1, the multi-layer tapered tube 1 comprises an outer layer, the outer layer is sequentially covered with a middle layer and an inner layer, the inner layer is in contact with the environment, and the outer layer and the middle layer are respectively installed with pressure circulation pumps, so that the flow directions of the photoresist and the gas are opposite. The counterflow helps the photoresist to fully receive ultrasonic vibration, promotes the dispersion of the photoresist, and can also reduce the influence of heat generated during ultrasonic treatment on the properties of the photoresist;

[0035] The outer layer is a feed layer 2, which is provided with a feed port 21, a feed flow meter 23 is installed on the feed port 21, and the feed port 21 is connected to a liquid pressure circulation pump 22. A filter defoaming ball 4 is provided at the bottom of the feed layer 2, and the diameter of the filter defoaming ball 4 is equal to the width of the feed layer 2, ensuring that the photoresist can be fully contacted and processed when flowing through the filter defoaming ball 4, which helps to maximize the defoaming effect and reduce the number of bubbles in the photoresist, thereby improving the uniformity and quality of the coating. The bottom of the filter defoaming ball 4 is connected to a discharge port 5, and a flow meter switch 6 is installed at the discharge port 5; the middle layer is an airflow layer 3, and the airflow layer 3 is provided with an air inlet 31, and the air inlet 31 An air inlet flow meter 33 is installed on the inner tube 1, and a gas pressure circulation pump 32 is connected to the air inlet 31. The introduction of the liquid pressure circulation pump 22 and the gas pressure circulation pump 32 enables the device to more accurately control the flow and pressure of the photoresist and gas, which helps to ensure the stable flow of the photoresist and gas in the multi-layer tapered tube 1, and reduces the problem of uneven coating caused by flow or pressure fluctuations; ultrasonic vibrators 7 are respectively installed on the inner walls of both sides of the inner layer, and the ultrasonic vibrator 7 includes an ultrasonic output part 71. The ultrasonic vibrator 7 uses gas as a medium and quickly acts on the photoresist in the form of longitudinal waves, so that it forms more uniform and fine particles, further improving the uniformity of the coating;

[0036] Preferably, the width of the feed layer 2 is greater than the width of the air flow layer 3, which helps to form a smoother flow when the photoresist enters the multi-layer tapered tube 1, reduces fluid impact and turbulence, and is conducive to the uniform distribution of the photoresist;

[0037] Preferably, the curvature of the bottom of the multi-layer tapered tube 1 is 110° to 130°, which helps to form a more uniform flow when the photoresist flows out, avoids the accumulation of fluid at the bottom or the formation of an uneven flow pattern, and can also reduce the resistance of the fluid during the outflow process;

[0038] Preferably, Figure 2 As shown, the filtering defoaming ball 4 is a spherical screen, which not only provides sufficient surface area for the photoresist to pass through, but also its screen design can effectively intercept large particles of impurities in the photoresist. The surface of the screen has needles, which further enhances the defoaming effect. The bubbles in the photoresist are quickly eliminated by physical puncture, ensuring the purity and uniformity of the photoresist.

[0039] Preferably, the ultrasonic output portion 71 contacts the inner wall surface closest to the inner center of the multi-layer conical tube 1, ensuring that the ultrasonic energy can be efficiently transmitted to the photoresist, reducing energy loss during the transmission process, and improving the effect of ultrasonic treatment.

[0040] Example 2:

[0041] A device for improving the uniformity of photoresist coating comprises a multi-layer tapered tube 1, the bottom of the multi-layer tapered tube 1 is provided with an arc of 110 degrees, a wafer 8 is provided below the multi-layer tapered tube 1, the multi-layer tapered tube 1 comprises an outer layer, the outer layer is sequentially covered with a middle layer and an inner layer, and the outer layer and the middle layer are respectively equipped with a pressure circulation pump; the outer layer is a feed layer 2, the feed layer 2 is provided with a feed port 21, the feed port 21 is connected to a liquid pressure circulation pump 22, a feed flow meter 23 is installed on the feed port 21, and a filtering and defoaming ball 4 is provided at the bottom of the feed layer 2, which is a spherical screen. There are needles on the surface of the filter and defoaming balls 4, the diameter of the filter and defoaming balls 4 is equal to the width of the feed layer 2, the bottom of the filter and defoaming balls 4 is connected with a discharge port 5, and a flow meter switch 6 is installed at the discharge port 5; the middle layer is an airflow layer 3, the airflow layer 3 is provided with an air inlet 31, the air inlet 31 is connected to a gas pressure circulation pump 32, and an air inlet flowmeter 33 is installed on the air inlet 31; the width of the feed layer 2 is greater than the width of the airflow layer 3; ultrasonic vibrators 7 are respectively installed on the inner walls on both sides of the inner layer, and the ultrasonic vibrator 7 includes an ultrasonic output part 71, and the ultrasonic output part 71 is in contact with the inner walls on both sides of the inner layer.

[0042] Example 3:

[0043] A device for improving the uniformity of photoresist coating comprises a multi-layer tapered tube 1, the bottom of the multi-layer tapered tube 1 is provided with a 120° arc, a wafer 8 is provided below the multi-layer tapered tube 1, the multi-layer tapered tube 1 comprises an outer layer, the outer layer is sequentially covered with a middle layer and an inner layer, and the outer layer and the middle layer are respectively equipped with a pressure circulation pump; the outer layer is a feed layer 2, the feed layer 2 is provided with a feed port 21, the feed port 21 is connected to a liquid pressure circulation pump 22, a feed flow meter 23 is installed on the feed port 21, and a filtering and defoaming ball 4 is provided at the bottom of the feed layer 2, which is a spherical screen. There are needles on the surface of the filter and defoaming balls 4, the diameter of the filter and defoaming balls 4 is equal to the width of the feed layer 2, the bottom of the filter and defoaming balls 4 is connected with a discharge port 5, and a flow meter switch 6 is installed at the discharge port 5; the middle layer is an airflow layer 3, the airflow layer 3 is provided with an air inlet 31, the air inlet 31 is connected to a gas pressure circulation pump 32, and an air inlet flowmeter 33 is installed on the air inlet 31; the width of the feed layer 2 is greater than the width of the airflow layer 3; ultrasonic vibrators 7 are respectively installed on the inner walls on both sides of the inner layer, and the ultrasonic vibrator 7 includes an ultrasonic output part 71, and the ultrasonic output part 71 is in contact with the inner walls on both sides of the inner layer.

[0044] Example 4:

[0045] A device for improving the uniformity of photoresist coating comprises a multi-layer tapered tube 1, the bottom of the multi-layer tapered tube 1 is provided with a 130° arc, a wafer 8 is provided below the multi-layer tapered tube 1, the multi-layer tapered tube 1 comprises an outer layer, the outer layer is sequentially covered with a middle layer and an inner layer, and the outer layer and the middle layer are respectively equipped with a pressure circulation pump; the outer layer is a feed layer 2, the feed layer 2 is provided with a feed port 21, the feed port 21 is connected to a liquid pressure circulation pump 22, a feed flow meter 23 is installed on the feed port 21, and a filtering and defoaming ball 4 is provided at the bottom of the feed layer 2, which is a spherical screen. There are needles on the surface of the filter and defoaming balls 4, the diameter of the filter and defoaming balls 4 is equal to the width of the feed layer 2, the bottom of the filter and defoaming balls 4 is connected with a discharge port 5, and a flow meter switch 6 is installed at the discharge port 5; the middle layer is an airflow layer 3, the airflow layer 3 is provided with an air inlet 31, the air inlet 31 is connected to a gas pressure circulation pump 32, and an air inlet flowmeter 33 is installed on the air inlet 31; the width of the feed layer 2 is greater than the width of the airflow layer 3; ultrasonic vibrators 7 are respectively installed on the inner walls on both sides of the inner layer, and the ultrasonic vibrator 7 includes an ultrasonic output part 71, and the ultrasonic output part 71 is in contact with the inner walls on both sides of the inner layer.

[0046] The working method of the utility model is further described below:

[0047] The photoresist is added to the feed layer 2 from the feed port 21, and the photoresist circulates in the feed layer 2 in a counterclockwise direction. The gas is passed into the air flow layer 3, and the gas circulates in the air flow layer 3 in a clockwise direction. By circulating the photoresist and the gas in opposite directions in the feed layer 2 and the air flow layer 3 respectively, an effective countercurrent effect is formed. The countercurrent helps the photoresist to fully accept the ultrasonic vibration, promotes the dispersion of the photoresist, and can also reduce the influence of the heat generated during the ultrasonic treatment on the properties of the photoresist, thereby reducing the unevenness in the coating process. Then the ultrasonic vibrator 7 is started to perform ultrasonic treatment, which further refines the photoresist, and the ultrasound is transmitted in the gas medium in the form of longitudinal waves. The propagation is perpendicular to the flow direction of the photoresist, and the vibration generated disperses the photoresist into small droplets of photoresist, obtaining small droplets of photoresist, which quickly acts on the photoresist in the form of longitudinal waves, so that it forms more uniform and fine particles, further improving the uniformity of the coating; the small droplets of photoresist flow through the filter defoaming ball 4, which can effectively deal with bubbles in the photoresist, pierce the bubbles with the needle, reduce the uneven distribution of the solution, and make the film thickness more uniform during spin coating; by adjusting the flow meter switch 6, the small droplets of photoresist drip from the discharge port 5 onto the wafer 8, and adjusting the flow meter switch 6 can accurately control the flow of the photoresist, further optimizing the coating quality, and performing spin coating;

[0048] Preferably, the gas is an inert gas, which can avoid chemical reaction between the gas and the photoresist, thereby maintaining the chemical stability of the photoresist; the gas flow rate is 5~10 mL / min, which can ensure that the gas forms a stable circulation in the air flow layer 3, while avoiding excessive flow causing excessive disturbance to the photoresist; the frequency of ultrasonic treatment is 25 kHz~35 kHz, and the time is 20~40 min, which can generate sufficient energy to refine the photoresist particles, help to more effectively eliminate bubbles in the photoresist, and the reduction of bubbles can further improve the flatness and accuracy of the coating.

[0049] The working principle of the utility model is further described below:

[0050] like Figure 3 As shown, this is a schematic diagram of the principle of using ultrasound to act on photoresist in a device for improving the uniformity of photoresist coating according to the present invention. The photoresist flows in the opposite direction to the gas, and the ultrasound is transmitted to the photoresist in the form of longitudinal waves, which is perpendicular to the direction of the photoresist flow. The ultrasonic vibration caused by this wave can more fully disperse large droplets into small droplets. The reverse gas flow can cool the heat generated by the ultrasonic vibration that affects the performance of the photoresist. The photoresist is then subjected to secondary treatment by filtering and defoaming balls 4. The needles and filter screen on the filtering and defoaming balls 4 can eliminate bubbles in the photoresist and make the coating film thickness uniform.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for improving the uniformity of photoresist coating, characterized in that: The multilayer conical tube (1) comprises a wafer (8) disposed below the multilayer conical tube (1), the multilayer conical tube (1) comprising an outer layer, the outer layer being sequentially covered with a middle layer and an inner layer, and the outer layer and the middle layer being respectively provided with a pressure circulation pump; The outer layer is a feed layer (2), the feed layer (2) is provided with a feed port (21), a feed flow meter (23) is installed on the feed port (21), a filter defoaming ball (4) is provided at the bottom of the feed layer (2), the bottom of the filter defoaming ball (4) is connected to a discharge port (5), and a flow meter switch (6) is installed at the discharge port (5); The middle layer is an airflow layer (3), the airflow layer (3) is provided with an air inlet (31), and an air inlet flow meter (33) is installed on the air inlet (31); Ultrasonic vibrators (7) are respectively installed on the inner walls on both sides of the inner layer.

2. The device for improving photoresist coating uniformity according to claim 1, characterized in that: The width of the feed layer (2) is greater than the width of the airflow layer (3).

3. The device for improving photoresist coating uniformity according to claim 1, wherein: The bottom of the multi-layered conical tube (1) is provided with a curvature.

4. The device for improving photoresist coating uniformity according to claim 3, wherein: The arc is 110°~130°.

5. The device for improving photoresist coating uniformity according to claim 1, wherein: The filtering and defoaming balls (4) are spherical screens.

6. The device for improving photoresist coating uniformity according to claim 5, characterized in that: The surface of the spherical screen is provided with needles.

7. The device for improving photoresist coating uniformity according to claim 1, characterized in that: The diameter of the filtering and defoaming balls (4) is equal to the width of the feed layer (2).

8. The device for improving photoresist coating uniformity according to claim 1, characterized in that: The ultrasonic vibrator (7) comprises an ultrasonic output portion (71), and the ultrasonic output portion (71) is in contact with the inner walls on both sides of the inner layer.

9. The device for improving photoresist coating uniformity according to claim 1, characterized in that: The feed port (21) is connected to a liquid pressure circulation pump (22).

10. The device for improving photoresist coating uniformity according to claim 1, characterized in that: The air inlet (31) is connected to a gas pressure circulation pump (32).

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