Photoresist supply system and control method thereof, and gluing and developing equipment

Abstract

The invention provides a photoresist supply system, a control method of the photoresist supply system and gluing and developing equipment. The gluing developing equipment comprises a photoresist supply system, the photoresist supply system comprises a photoresist bottle, a photoresist liquid supply tank, a suction pump and a gluing nozzle which are sequentially connected through a photoresist pipeline, and the photoresist pipeline is provided with a filter between an outlet of the photoresist liquid supply tank and an inlet of the gluing nozzle; the nitrogen supply module comprises a nitrogen pipeline connected to the photoresist pipeline, and the nitrogen pipeline is used for conveying nitrogen to the photoresist pipeline so as to reduce the pressure difference between the two ends of the filter. Forward thrust is provided through nitrogen pressure output by the nitrogen pipeline, and is cooperated with negative pressure suction of the suction pump, so that the pressure difference between the two ends of the filter is reduced, and bubbles in the photoresist pipeline are reduced.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor manufacturing technology, specifically relating to a photoresist supply control system, control method, and photoresist coating and developing equipment. Background Technology

[0002] In semiconductor photolithography, the specific structure of the liquid supply section in a photoresist supply system with a suction pump is as follows: Figure 1 As shown, the photoresist bottle 1 is connected sequentially to the photoresist supply tank 2, which is then connected to the suction pump 4. The output of the suction pump 4 is connected to the coating nozzle 6 at the end. A manual valve 5 is installed between the suction pump 4 and the coating nozzle 6, and a filter 3 is installed between the photoresist supply tank 2 and the suction pump 4. The filter 3 is used to filter impurities in the photoresist to avoid coating defects caused by impurities. However, in actual operation, especially during the photoresist reload process, air bubbles are easily generated in the photoresist pipeline 7 of the existing photoresist supply system, which leads to wafer coating defects and seriously affects product yield. Summary of the Invention

[0003] The purpose of this invention is to provide a photoresist supply system and its control method, as well as a photoresist coating and developing equipment, which aims to reduce the generation of bubbles in the photoresist pipeline and improve wafer production yield.

[0004] To achieve the above objectives, the present invention provides a photoresist supply system, comprising:

[0005] A photoresist bottle, a photoresist supply tank, a suction pump, and a coating nozzle are sequentially connected via a photoresist pipeline. A filter is provided between the outlet of the photoresist supply tank and the inlet of the coating nozzle in the photoresist pipeline.

[0006] And a nitrogen supply module, the nitrogen supply module including a nitrogen pipeline connected to the photoresist pipeline, the nitrogen pipeline being used to supply nitrogen to the photoresist pipeline to reduce the pressure difference across the filter.

[0007] Optionally, the photoresist supply system further includes a data acquisition module and a closed-loop control module; the closed-loop control module is communicatively connected to the nitrogen supply module and the data acquisition module, respectively.

[0008] The acquisition module is used to acquire target parameters during the operation of the photoresist supply system; the target parameters include at least the pressure difference across the filter and the speed of the suction pump.

[0009] The closed-loop control module is used to generate a corresponding nitrogen pressure adjustment command according to the target parameters and preset conditions, and then adjust the nitrogen output pressure of the nitrogen supply module so that the pressure difference across the filter is within the safe range of the preset pressure difference threshold.

[0010] The preset conditions include at least a preset differential pressure threshold and a matching relationship between the pump speed and the nitrogen output pressure.

[0011] Optionally, the acquisition module includes a differential pressure sensor and a speed sensor; the differential pressure sensor is installed at both ends of the filter to acquire the pressure difference between the two ends of the filter; the speed sensor is integrated into the suction pump to acquire the speed of the suction pump.

[0012] Optionally, the target parameters also include nitrogen pipeline pressure and photoresist flow rate; the preset conditions also include preset nitrogen pipeline threshold and preset photoresist flow rate threshold; the closed-loop control module is further used to correct the nitrogen pressure adjustment command based on the deviation between the nitrogen pipeline pressure and the preset nitrogen pipeline pressure threshold, and the deviation between the photoresist flow rate and the preset photoresist flow rate threshold.

[0013] Optionally, the nitrogen supply module further includes:

[0014] A nitrogen source connected to the end of the nitrogen pipeline that is furthest from the photoresist pipeline;

[0015] And a regulating valve and an on / off control valve are sequentially installed on the nitrogen pipeline;

[0016] The regulating valve is used to adjust its own opening degree according to the nitrogen pressure regulation command, thereby regulating the nitrogen output pressure; the on / off control valve is used to control the on / off of the nitrogen pipeline.

[0017] Optionally, the nitrogen supply module further includes a one-way valve disposed on the nitrogen pipeline, the one-way valve being used to prevent photoresist from flowing back into the nitrogen pipeline.

[0018] Optionally, the nitrogen pipeline is located between the outlet of the photoresist supply tank and the inlet of the suction pump, or the nitrogen pipeline is located between the outlet of the suction pump and the inlet of the coating nozzle.

[0019] Optionally, when the nitrogen pipeline is located between the outlet of the suction pump and the inlet of the coating nozzle, the photoresist pipeline is provided with a manual valve between the outlet of the suction pump and the inlet of the coating nozzle, and the nitrogen pipeline is located between the outlet of the suction pump and the inlet of the manual valve.

[0020] To achieve the above objectives, the present invention also provides a control method for a photoresist supply system, applied to the aforementioned photoresist supply system, comprising the following steps:

[0021] S1. Set preset conditions for the closed-loop control module;

[0022] S2. Acquire the target parameters of the photoresist supply system during operation through the acquisition module;

[0023] S3. The closed-loop control module generates a corresponding nitrogen pressure regulation command based on the target parameters and the preset conditions, and transmits the nitrogen pressure regulation command to the nitrogen supply module.

[0024] S4. The nitrogen supply module adjusts the nitrogen output pressure of the nitrogen pipeline according to the nitrogen pressure adjustment command, so that the pressure difference across the filter is within the safe range of the preset pressure difference threshold.

[0025] S5. The target parameters are continuously collected by the acquisition module and fed back to the closed-loop control module, and steps S3 to S4 are repeated.

[0026] Optionally, the target parameters may also include nitrogen pipeline pressure and photoresist flow rate; the preset conditions may also include preset nitrogen pipeline pressure threshold and preset photoresist flow rate threshold.

[0027] In step S3, the closed-loop control module further corrects the nitrogen pressure adjustment command based on the deviation between the nitrogen pipeline pressure and the preset nitrogen pipeline pressure threshold, and the deviation between the photoresist flow rate and the preset photoresist flow rate threshold.

[0028] Optionally, in step S5, the closed-loop control module further monitors the rate of change of the pump speed. When the rate of change of the pump speed exceeds a preset rate threshold, the matching relationship between the pump speed and the nitrogen output pressure is corrected.

[0029] Optionally, in step S3, the closed-loop control module determines the preset differential pressure threshold corresponding to the current photoresist viscosity and the matching relationship based on the externally input photoresist viscosity parameters; wherein, the preset conditions include preset differential pressure thresholds corresponding to various photoresist viscosities and the matching relationship.

[0030] To achieve the above objectives, the present invention also provides a photoresist coating and developing apparatus, including any of the photoresist supply systems described in the present invention.

[0031] Compared with the prior art, the photoresist supply system and control method of the present invention, as well as the photoresist coating and developing equipment, have at least the following advantages:

[0032] This invention provides a positive thrust to the photoresist fluid within the photoresist pipeline by adding a nitrogen line between the outlet of the photoresist supply tank and the inlet of the coating nozzle. Compared to existing technologies that rely solely on a suction pump to generate negative pressure to draw in photoresist, this invention, through the combined suction of the pump and the positive thrust of nitrogen, directly reduces the pressure difference across the filter during the replenishment process. This fundamentally reduces the generation of air bubbles within the photoresist pipeline, improving wafer coating quality and photolithography yield.

[0033] In a further improvement, this invention uses a data acquisition module to collect the pressure difference across the filter and the speed of the suction pump in real time. Then, a closed-loop control module adjusts the nitrogen output pressure of the nitrogen supply module according to the collected target parameters and preset conditions, achieving a precise match between the nitrogen pressure and the speed of the suction pump. This helps to continuously stabilize the pressure difference across the filter, further suppressing the generation of bubbles in the photoresist pipeline from the source and ensuring the quality of the photoresist supply.

[0034] Furthermore, by matching the pump speed with the nitrogen output pressure, this invention can achieve synchronous adjustment of nitrogen pressure as the pump speed changes, ultimately balancing the positive thrust of nitrogen and the negative pressure of the pump, further avoiding bubble formation caused by fluctuations in liquid supply resistance, and further improving the stability of liquid supply. Attached Figure Description

[0035] The accompanying drawings are provided to further illustrate the present application and form part of the specification. They are used together with the following detailed description to explain the present application, but do not constitute a limitation thereof. In the drawings:

[0036] Figure 1 This is a schematic diagram of the liquid supply pipeline in a photoresist supply system in the prior art;

[0037] Figure 2 This is a schematic diagram of the structure of a photoresist supply system provided according to an embodiment of the present invention.

[0038] Figure 3 This is a schematic diagram of the structure of a photoresist supply system provided by the present invention according to another embodiment.

[0039] Figure 4 This is a structural block diagram of a nitrogen supply module, a data acquisition module, and a closed-loop control module provided according to an embodiment of the present invention.

[0040] Figure 5 This is a flowchart of a control method for a photoresist supply system according to an embodiment of the present invention.

[0041] Figure 6 This is a schematic diagram of the structure of a nitrogen supply module provided by the present invention according to an embodiment.

[0042] [The annotations in the attached figures are explained below]:

[0043] 1-Photoresist bottle, 2-Photoresist supply tank, 3-Filter, 4-Suction pump, 5-Manual valve, 6-Coating nozzle, 7-Photoresist pipeline, 11-Nitrogen pipeline, 12-Nitrogen source, 13-Regulating valve, 14-On / off control valve, 15-Check valve, 110-Nitrogen supply module, 120-Acquisition module, 130-Closed-loop control module. Detailed Implementation

[0044] To make the technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Although exemplary implementation methods of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments described herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0045] The invention is described more specifically by way of example in the following paragraphs with reference to the accompanying drawings. The advantages and features of the invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and are only used to facilitate and clarify the illustration of the embodiments of the invention. It is understood that the terms "on," "above," and "over" in this invention should be interpreted in the broadest sense, such that "on" not only means "on" something without any intervening feature or layer (i.e., directly on something), but also includes "on" something with an intervening feature or layer. In the embodiments of the invention, the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be noted that the technical solutions described in the embodiments of the invention can be arbitrarily combined without conflict.

[0046] As described in the background section, current photoresist supply systems with suction pumps are prone to generating bubbles within the photoresist pipeline during actual operation, leading to wafer coating defects. Analysis reveals that the main cause of bubble formation is that the suction pump 4 exerts a strong suction force on the outlet or inlet side of the filter 3, resulting in a large negative pressure difference across the filter 3. This creates localized low-pressure areas within the photoresist pipeline 7, causing dissolved gases in the photoresist to precipitate and ultimately form bubbles. After these bubbles are generated, some redissolve in the photoresist, while others are transported to the coating nozzle 6 along with the photoresist. When photoresist containing bubbles is applied to the wafer surface, it forms various defects such as dots and lines, reducing the wafer product yield. Furthermore, the frequent generation of bubbles also affects the stability of the photoresist supply, indirectly shortening the lifespan of components such as filters and suction pumps, and increasing equipment maintenance costs.

[0047] To address the above problems, this invention provides an improved solution for a photoresist supply system with a suction pump. By directly installing a nitrogen pipeline on the photoresist pipeline, the pressure difference across the filter is reduced, thereby reducing the generation of air bubbles in the photoresist pipeline.

[0048] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer from the following description. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention. Many specific details are set forth in the following description to provide a thorough understanding of the present invention; however, the present invention may also be practiced in other ways different from those described herein, and therefore the present invention is not limited to the specific embodiments disclosed below.

[0049] Figure 2 This is a schematic diagram of the structure of a photoresist supply system provided in one embodiment of the present invention. Figure 3 This is a schematic diagram of a photoresist supply system provided in another embodiment of the present invention. Figure 2 and Figure 3 As shown, the photoresist supply system includes a photoresist bottle 1, a photoresist supply tank 2, a filter 3, a suction pump 4, a manual valve 5, and a coating nozzle 6, which are connected in sequence via photoresist tubing 7. Although the manual valve 5 is shown in the figure, this configuration can be optional. The manual valve 5 is typically used to control the on / off state of the photoresist tubing 7 and to regulate the supply flow rate.

[0050] It should be noted that the installation position of the filter 3 is not limited to between the outlet of the photoresist supply tank 2 and the inlet of the suction pump 4 as shown in the figure. In other cases, the filter 3 can also be set between the outlet of the suction pump 4 and the inlet of the coating nozzle 6. For example, the filter 3 can be set between the outlet of the suction pump 4 and the inlet of the manual valve 5, or between the outlet of the manual valve 5 and the inlet of the coating nozzle 6. The term "inlet" as used herein refers to the side where the photoresist (i.e., photoresist) flows in, and "outlet" refers to the side where the photoresist flows out. In other words, the photoresist pipeline 7 only needs to have a filter 3 between the outlet of the photoresist supply tank 2 and the inlet of the coating nozzle 6.

[0051] To address the issue of air bubbles easily forming within the photoresist pipeline 7, the photoresist supply system further includes a nitrogen supply module 110, such as... Figure 4 As shown.

[0052] like Figure 2 and Figure 3 As shown, the nitrogen supply module 110 includes a nitrogen pipeline 11 connected to the photoresist pipeline 7. This nitrogen pipeline 11 is used to supply nitrogen to the photoresist pipeline 7 (as indicated by the arrow), thereby reducing the pressure difference across the filter 3. The installation position of the nitrogen pipeline 11 can be flexibly adjusted according to the actual layout of the photoresist supply system, and various implementation methods can be adopted.

[0053] Specifically, in some embodiments, the nitrogen pipeline 11 is located between the outlet of the photoresist supply tank 2 and the inlet of the suction pump 4, such as... Figure 2 As shown. In other embodiments, the nitrogen line 11 is located between the outlet of the suction pump 4 and the inlet of the adhesive nozzle 6, as shown. Figure 3 As shown.

[0054] Figure 2 In this embodiment, the nitrogen pipeline 11 is located between the outlet of the photoresist supply tank 2 and the inlet of the filter 3. In other embodiments, the nitrogen pipeline 11 may also be located between the outlet of the filter 3 and the inlet of the suction pump 4.

[0055] Figure 3 In this embodiment, when the nitrogen pipeline 11 is located between the outlet of the suction pump 4 and the inlet of the coating nozzle 6, the photoresist pipeline 7 is equipped with a manual valve 5 between the outlet of the suction pump 4 and the inlet of the coating nozzle 6, and the nitrogen pipeline 11 is located between the outlet of the suction pump 4 and the inlet of the manual valve 5. In some other embodiments, the nitrogen pipeline 11 may also be located between the outlet of the manual valve 5 and the inlet of the coating nozzle 6.

[0056] Therefore, the specific installation position of the nitrogen line 11 on the photoresist line 7 is not critical. The key is that the nitrogen line 11 can provide positive thrust to the photoresist fluid in the photoresist line 7. This positive thrust, in conjunction with the negative pressure suction of the suction pump 4, reduces the pressure difference across the filter 3 during the replenishment process, thereby reducing the generation of bubbles in the photoresist line 7 and improving the wafer coating quality and photolithography yield. At the same time, it can reduce the pump's suction load and extend the service life of the pump and filter.

[0057] Specifically, in a photoresist supply system, replenishment and suction are crucial for photoresist delivery. Replenishment refers to the process of transferring photoresist from photoresist bottle 1 to photoresist supply tank 2 (i.e., buffer tank / intermediate tank, RSV tank). Suction refers to the process where, during system operation, suction pump 4 extracts photoresist from photoresist supply tank 2 and delivers it to the downstream coating station. In existing technology, photoresist supply tank 2 is basically under normal pressure, and the power for both replenishment and suction comes from the negative pressure suction of suction pump 4. During the replenishment stage, suction pump 4 starts to generate negative pressure, first drawing the photoresist from photoresist bottle 1 into photoresist supply tank 2; during the suction supply stage, suction pump 4 continues to suction under negative pressure, drawing the photoresist out of photoresist supply tank 2 and delivering it to the downstream station.

[0058] Taking the example of filter 3 installed between the outlet of photoresist supply tank 2 and the inlet of suction pump 4. During the replenishment stage, if the back pressure between photoresist supply tank 2 and suction pump 4 is less than the pipeline pressure loss, negative pressure may form inside and outside filter 3, causing bubbles in photoresist pipeline 7. Conversely, if the back pressure of suction pump 4 is greater than the pressure loss, bubbles are less likely to form in photoresist pipeline 7. Therefore, the core issue is the imbalance between back pressure and pressure loss during replenishment. When the back pressure is less than the pressure loss (including pipeline friction resistance, filter resistance, and local resistance), the pressure outside filter 3 is less than the pressure inside, creating a negative pressure environment. This negative pressure causes dissolved gases in photoresist pipeline 7 to precipitate out, allowing outside air to easily penetrate and form visible bubbles. Some of these bubbles dissolve in the photoresist and are released during coating, causing defects.

[0059] Therefore, it is necessary to increase the back pressure between the photoresist supply tank 2 and the suction pump 4 to ensure that the back pressure is greater than the total pressure loss (the total pressure loss includes filter element resistance, pipeline friction resistance (pipe diameter, length, flow rate, etc.), and local resistance of the joints), such as being greater than 10% to 20% of the total pressure loss. Therefore, this invention adds a nitrogen pipeline 11 at the outlet of the photoresist supply tank 2, mainly to stabilize the pipeline pressure during the replenishment stage and prevent a sudden pressure drop that could create negative pressure. Specifically, during replenishment, nitrogen at a set pressure can be introduced first, and then the pump can be started to avoid sudden pressure changes. At this time, the positive thrust of nitrogen and the negative pressure of the pump are used to replenish the photoresist in the photoresist bottle 1 into the photoresist supply tank 2, and the pressure difference of the filter 3 is significantly reduced. After replenishment, the nitrogen pipeline 11 maintains continuous nitrogen pressure, and the photoresist is always subjected to the positive thrust of nitrogen. The suction pump 4 continues to pump, delivering the photoresist to the downstream coating nozzle 6. Preferably, the nitrogen line 11 is turned on before replenishing the liquid to purge the air in the line and further reduce the number of air bubbles in the photoresist line 7.

[0060] Furthermore, since the rotational speed of the suction pump 4 may dynamically change according to process requirements (such as replenishment and normal liquid supply), the suction force will change accordingly. If the nitrogen pressure is adjusted solely by the pressure difference, when the pump speed suddenly increases (the suction force increases), the pressure difference across the filter 3 will increase first, and then the nitrogen pressure adjustment will be triggered, resulting in a lag in adjustment. At the same time, it is impossible to predict changes in pump speed and adjust the nitrogen pressure in advance, which can easily lead to excessive pressure difference fluctuations, repeated bubble generation, and failure to completely solve the bubble problem.

[0061] To solve this technical problem, such as Figure 4 As shown, in some embodiments, the photoresist supply system further includes a data acquisition module 120 and a closed-loop control module 130; the closed-loop control module 130 is communicatively connected to the nitrogen supply module 110 and the data acquisition module 120, respectively.

[0062] The acquisition module 120 is used to acquire target parameters during the operation of the photoresist supply system. These target parameters are core operating parameters related to filter differential pressure stability, suction pump speed, and nitrogen pressure regulation. Therefore, the target parameters include at least the filter differential pressure and suction pump speed. Furthermore, the target parameters also include nitrogen pipeline pressure and photoresist flow rate. After the acquisition module 120 completes the acquisition, it transmits the target parameters to the closed-loop control module 130.

[0063] The closed-loop control module 130 (such as a PLC closed-loop controller) is used to generate corresponding nitrogen pressure adjustment commands based on target parameters and preset conditions, thereby adjusting the nitrogen output pressure of the nitrogen supply module 110 so that the pressure difference across the filter 3 is within a safe range of a preset pressure difference threshold. Simultaneously, the preset conditions include at least a preset pressure difference threshold and a matching relationship between the suction pump speed and the nitrogen output pressure.

[0064] In this way, the present invention can achieve closed-loop control of nitrogen pressure and suction pump speed, and dynamically match nitrogen pressure and suction pump speed, further suppressing the generation of bubbles in photoresist pipeline 7.

[0065] This means that by using the matching relationship between the suction pump speed and the nitrogen output pressure as the adjustment benchmark, and the pressure difference across the filter as the adjustment basis, the closed-loop control module 130, together with the acquisition module 120 and the nitrogen supply module 110, can achieve dynamic and precise adjustment of nitrogen pressure, ultimately stabilizing the filter pressure difference and suppressing photoresist bubbles.

[0066] In this embodiment, the closed-loop control module 130 pre-sets the matching relationship between the suction pump speed and the nitrogen output pressure, and sets the pressure difference threshold across the filter as the key to suppressing bubbles.

[0067] The acquisition module 120 acquires at least two core target parameters at a preset frequency: the real-time rotation speed of the suction pump, which reflects the system's liquid supply demand. The higher the rotation speed, the greater the liquid supply resistance and the stronger the required nitrogen forward thrust; and the real-time pressure difference across the filter, which reflects the current system operating status and is directly related to the generation of photoresist bubbles. Excessive pressure difference can easily lead to photoresist overflow and an increase in bubbles, while excessively low pressure difference can easily lead to poor liquid supply.

[0068] Then, the closed-loop control module 130 compares and analyzes the collected target parameters and generates appropriate nitrogen pressure adjustment commands based on the matching relationship. Specifically, firstly, based on the real-time rotational speed of the suction pump, the preset rotational speed and nitrogen pressure matching relationship is used to determine the nitrogen pressure reference value (initial adjustment target) under the current operating conditions; then, the collected real-time pressure difference of the filter is compared with the preset pressure difference threshold to determine the deviation, and the nitrogen pressure reference value is corrected based on the deviation. For example, if the filter pressure difference is greater than the preset pressure difference threshold, it indicates that the current nitrogen pressure is too high and the nitrogen output pressure needs to be reduced; conversely, it indicates that the nitrogen pressure is insufficient and the nitrogen output pressure needs to be increased.

[0069] Finally, the closed-loop control module 130 transmits the corrected nitrogen pressure adjustment command to the nitrogen supply module 110, which directly adjusts the nitrogen output pressure of the nitrogen pipeline 11. After adjustment, the acquisition module 120 continuously acquires target parameters such as filter differential pressure and suction pump speed, and feeds them back to the closed-loop control module 130, repeating the above steps.

[0070] It should be understood that the closed-loop control module 130 and the acquisition module 120 form a bidirectional feedback regulation, that is, the closed-loop control module 130 will transmit the execution feedback signal of the adjustment command back to the acquisition module 120, triggering the acquisition module 120 to continuously acquire the real-time parameters after adjustment. The closed-loop control module 130 can realize the dynamic adjustment of nitrogen pressure through a built-in control algorithm, which is a conventional control logic that those skilled in the art should know how to implement. Specifically, in this embodiment of the invention, the control algorithm analyzes the parameter deviation, compares the actual parameter value with a preset threshold, and then generates a corresponding nitrogen pressure adjustment command.

[0071] Further research revealed that changes in the pressure difference across the filter are influenced not only by nitrogen pressure and pump speed, but also by photoresist viscosity, pipeline resistance, and filter size / clogging level. Adjusting the nitrogen pressure solely based on the pressure difference parameter cannot distinguish whether the pressure difference change is caused by pump speed variations or other factors, easily leading to erroneous adjustments. If only the nitrogen pressure is adjusted to stabilize the pressure difference without considering changes in photoresist flow rate, over-adjustment of the nitrogen pressure may result in excessive photoresist flow, while under-adjustment may lead to insufficient photoresist supply. Both of these factors can negatively impact wafer coating quality.

[0072] Therefore, in some embodiments, the target parameters also include nitrogen pipeline pressure and photoresist flow rate; the preset conditions also include preset nitrogen pipeline threshold and preset photoresist flow rate threshold. Based on this, the closed-loop control module 130 is also used to correct the nitrogen pressure adjustment command according to the deviation between the nitrogen pipeline pressure and the preset nitrogen pipeline pressure threshold, and the deviation between the photoresist flow rate and the preset photoresist flow rate threshold. At this time, the pressure difference across the filter serves as the core trigger signal for nitrogen pressure adjustment; when the actual pressure difference deviates from the preset pressure difference threshold, the closed-loop control module 130 is triggered to start adjustment, and then, combined with parameters such as pump speed, photoresist flow rate, and nitrogen pipeline pressure, the nitrogen pressure adjustment amount is accurately determined, thereby improving the accuracy of nitrogen pressure adjustment.

[0073] In some embodiments, the acquisition module 120 includes a differential pressure sensor and a speed sensor; the differential pressure sensor is installed at both ends of the filter 3 to directly acquire the pressure difference across the filter; the speed sensor is integrated into the suction pump 4 to directly acquire the pump speed. Preferably, the suction pump 4 has its own speed sensor, thereby simplifying configuration and reducing costs.

[0074] Figure 6 This is a schematic diagram of the nitrogen supply module in an embodiment of the present invention. Figure 6As shown, in some embodiments, the nitrogen supply module 110 further includes: a nitrogen source 12 connected to the end of the nitrogen pipeline 11 away from the photoresist pipeline 7; the nitrogen source 12 can be a nitrogen cylinder or a nitrogen supply device already provided at the plant end; and a regulating valve 13 and an on / off control valve 14 sequentially arranged on the nitrogen pipeline 11. The regulating valve 13 is used to adjust its opening degree according to a nitrogen pressure regulation command, thereby regulating the nitrogen output pressure; the on / off control valve 14 is used to control the on / off state of the nitrogen pipeline 11. Both the regulating valve 13 and the on / off control valve 14 can be pneumatic valves or solenoid valves.

[0075] Schematic illustration: The regulating valve 13 is an electromagnetic proportional valve. The regulating valve 13 is preferably located near the photoresist pipeline 7 to facilitate rapid pressure transmission.

[0076] Schematic illustration: The on / off control valve 14 is a shut-off valve, such as a manual shut-off valve or a solenoid shut-off valve. The on / off control valve 14 is preferably located near the connection point between the nitrogen line 11 and the photoresist line 7.

[0077] In some embodiments, the nitrogen supply module 110 further includes a one-way valve 15 disposed on the nitrogen pipeline 11, the one-way valve 15 being used to prevent photoresist from flowing back into the nitrogen pipeline 11.

[0078] Indicatively, from the nitrogen source 12 to the photoresist pipeline 7, an on / off control valve 14, a regulating valve 13, and a check valve 15 are sequentially installed.

[0079] The control method of the photoresist supply system in the embodiments of the present invention will be further described next.

[0080] Figure 5 This is a flowchart illustrating the control method of the photoresist supply system in an embodiment of the present invention. Figure 5 As shown, the control method of the photoresist supply system includes the following steps:

[0081] S1. Set preset conditions for the closed-loop control module 130;

[0082] S2. Collect the target parameters of the photoresist supply system during operation through the acquisition module 120;

[0083] S3. The closed-loop control module 130 generates a corresponding nitrogen pressure regulation command based on the target parameters and preset conditions, and transmits the nitrogen pressure regulation command to the nitrogen supply module; 110

[0084] S4. The nitrogen supply module 110 adjusts the nitrogen output pressure of the nitrogen pipeline 11 according to the nitrogen pressure adjustment command, so that the pressure difference across the filter 3 is within the safe range of the preset pressure difference threshold.

[0085] S5. The target parameters are continuously collected by the acquisition module 120 and fed back to the closed-loop control module 130, and steps S3 to S4 are repeated.

[0086] In some embodiments, the target parameters further include nitrogen pipeline pressure and photoresist flow rate; the preset conditions further include preset nitrogen pipeline pressure threshold and preset photoresist flow rate threshold; wherein in step S3, the nitrogen pressure adjustment command is further corrected by the closed-loop control module 130 based on the deviation between the nitrogen pipeline pressure and the preset nitrogen pipeline pressure threshold and the deviation between the photoresist flow rate and the preset photoresist flow rate threshold.

[0087] In some embodiments, in step S5, the closed-loop control module 130 further monitors the rate of change of the suction pump speed. When the rate of change of the suction pump speed exceeds a preset rate threshold, the matching relationship between the suction pump speed and the nitrogen output pressure is corrected. This method can further improve the adjustment accuracy of the nitrogen pressure.

[0088] In some embodiments, considering the influence of photoresist viscosity, in step S3, the closed-loop control module 130 determines the preset differential pressure threshold corresponding to the current photoresist viscosity and the matching relationship based on the externally input photoresist viscosity parameters. The preset conditions include preset differential pressure thresholds and matching relationships corresponding to various photoresist viscosities. That is, each photoresist is assigned a corresponding preset differential pressure threshold and a matching relationship between nitrogen pressure and pump speed. This allows the preset conditions to be switched according to the photoresist viscosity to adapt to different photoresist coating requirements.

[0089] Furthermore, embodiments of the present invention also provide a photoresist coating and developing apparatus, which includes the photoresist supply system provided in embodiments of the present invention.

[0090] Since the photoresist coating and developing equipment provided by this invention and the photoresist supply system provided by this invention belong to the same inventive concept, the photoresist coating and developing equipment provided by this invention has all the advantages of the photoresist supply system provided by this invention. Therefore, the beneficial effects of the photoresist coating and developing equipment provided by this invention will not be described in detail here.

[0091] Finally, it should be noted that the closed-loop control module 130 described above can be implemented using existing control devices (such as PLC controllers, PID controllers, etc.) or control software. Those skilled in the art can understand its specific control implementation method based on the disclosure of this invention and common knowledge in the field, so it will not be elaborated here.

[0092] While the present invention has been disclosed above, it is not limited thereto. Those skilled in the art can make various modifications and variations to the present invention without departing from its spirit and scope. Therefore, if such modifications and variations fall within the scope of the present invention and its equivalents, the present invention also intends to include such modifications and variations.

Claims

1. A photoresist supply system, characterized in that, include: A photoresist bottle, a photoresist supply tank, a suction pump, and a coating nozzle are sequentially connected via a photoresist pipeline. A filter is provided between the outlet of the photoresist supply tank and the inlet of the coating nozzle in the photoresist pipeline. And a nitrogen supply module, the nitrogen supply module including a nitrogen pipeline connected to the photoresist pipeline, the nitrogen pipeline being used to supply nitrogen to the photoresist pipeline to reduce the pressure difference across the filter.

2. The photoresist supply system according to claim 1, characterized in that, It also includes a data acquisition module and a closed-loop control module; the closed-loop control module is communicatively connected to the nitrogen supply module and the data acquisition module, respectively. The acquisition module is used to acquire target parameters during the operation of the photoresist supply system; the target parameters include at least the pressure difference across the filter and the speed of the suction pump. The closed-loop control module is used to generate a corresponding nitrogen pressure adjustment command according to the target parameters and preset conditions, and then adjust the nitrogen output pressure of the nitrogen supply module so that the pressure difference across the filter is within the safe range of the preset pressure difference threshold. The preset conditions include at least a preset differential pressure threshold and a matching relationship between the pump speed and the nitrogen output pressure.

3. The photoresist supply system according to claim 2, characterized in that, The acquisition module includes a differential pressure sensor and a speed sensor; the differential pressure sensor is installed at both ends of the filter to acquire the pressure difference between the two ends of the filter; the speed sensor is integrated into the suction pump to acquire the speed of the suction pump.

4. The photoresist supply system according to claim 2, characterized in that, The target parameters also include nitrogen pipeline pressure and photoresist flow rate; the preset conditions also include preset nitrogen pipeline threshold and preset photoresist flow rate threshold. The closed-loop control module is also used to correct the nitrogen pressure adjustment command based on the deviation between the nitrogen pipeline pressure and the preset nitrogen pipeline pressure threshold, and the deviation between the photoresist flow rate and the preset photoresist flow rate threshold.

5. The photoresist supply system according to claim 1 or 2, characterized in that, The nitrogen supply module also includes: A nitrogen source connected to the end of the nitrogen pipeline that is furthest from the photoresist pipeline; And a regulating valve and an on / off control valve are sequentially installed on the nitrogen pipeline; The regulating valve is used to adjust its own opening degree according to the nitrogen pressure regulation command, thereby regulating the nitrogen output pressure; the on / off control valve is used to control the on / off of the nitrogen pipeline.

6. The photoresist supply system according to claim 5, characterized in that, The nitrogen supply module further includes a one-way valve disposed on the nitrogen pipeline, the one-way valve being used to prevent photoresist from flowing back into the nitrogen pipeline.

7. The photoresist supply system according to claim 1 or 2, characterized in that, The nitrogen pipeline is located between the outlet of the photoresist supply tank and the inlet of the suction pump, or the nitrogen pipeline is located between the outlet of the suction pump and the inlet of the coating nozzle.

8. The photoresist supply system according to claim 7, characterized in that, When the nitrogen pipeline is located between the outlet of the suction pump and the inlet of the coating nozzle, the photoresist pipeline is equipped with a manual valve between the outlet of the suction pump and the inlet of the coating nozzle, and the nitrogen pipeline is located between the outlet of the suction pump and the inlet of the manual valve.

9. A control method for a photoresist supply system, applied to the photoresist supply system of claim 2, characterized in that, Includes the following steps: S1. Set preset conditions for the closed-loop control module; S2. Acquire the target parameters of the photoresist supply system during operation through the acquisition module; S3. The closed-loop control module generates a corresponding nitrogen pressure regulation command based on the target parameters and the preset conditions, and transmits the nitrogen pressure regulation command to the nitrogen supply module. S4. The nitrogen supply module adjusts the nitrogen output pressure of the nitrogen pipeline according to the nitrogen pressure adjustment command, so that the pressure difference across the filter is within the safe range of the preset pressure difference threshold. S5. The target parameters are continuously collected by the acquisition module and fed back to the closed-loop control module, and steps S3 to S4 are repeated.

10. The control method for the photoresist supply system according to claim 9, characterized in that, The target parameters also include nitrogen pipeline pressure and photoresist flow rate; the preset conditions also include preset nitrogen pipeline pressure threshold and preset photoresist flow rate threshold. In step S3, the closed-loop control module further corrects the nitrogen pressure adjustment command based on the deviation between the nitrogen pipeline pressure and the preset nitrogen pipeline pressure threshold, and the deviation between the photoresist flow rate and the preset photoresist flow rate threshold.

11. The control method for the photoresist supply system according to claim 9, characterized in that, In step S5, the closed-loop control module further monitors the rate of change of the pump speed. When the rate of change of the pump speed exceeds a preset rate threshold, the matching relationship between the pump speed and the nitrogen output pressure is corrected.

12. The control method for the photoresist supply system according to claim 9, characterized in that, In step S3, the closed-loop control module determines the preset differential pressure threshold and the matching relationship corresponding to the current photoresist viscosity based on the externally input photoresist viscosity parameters; wherein the preset conditions include preset differential pressure thresholds and the matching relationships corresponding to various photoresist viscosities.

13. A coating and developing apparatus, characterized in that, Includes the photoresist supply system as described in any one of claims 1-8.

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