Photoresist liquid spraying system that saves photoresist liquid

Abstract

A photoresist liquid spraying system that saves photoresist liquid includes: a liquid storage tank for storing and supplying photoresist liquid; a first filter for filtering impurities in the photoresist liquid; a buffer for removing microbubbles in the photoresist liquid and for buffering and supplying the photoresist liquid; the first filter is disposed between the liquid storage tank and the buffer; a photoresist liquid pump for transporting the photoresist liquid in the buffer to a user end; a return pipe connected to the buffer, the first end of the return pipe extending into the buffer and the second end connected to the front end of the first filter; a return pump installed in the return pipe; the return pipe and the return pump are used to draw the photoresist liquid in the buffer back to the front end of the first filter. The photoresist liquid spraying system can save photoresist liquid and save costs.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing, and in particular to a photoresist liquid spraying system that saves photoresist liquid. Background Art

[0002] Photoresist coating plays a crucial role in semiconductor manufacturing. For example, in etching processes, a photoresist layer acts as a mask for the thin film being etched, protecting the desired pattern from removal by the etching reaction. Similarly, in ion implantation, a photoresist layer also serves as a mask, limiting dopant delivery to targeted areas.

[0003] The photoresist spraying system primarily consists of a reservoir, a buffer, a photoresist pump, a filter, a control valve, and a nozzle. The photoresist liquid supplied from the reservoir first enters the buffer, where it is pumped out by the pump. After filtering through the filter, the control valve controls the flow rate of the liquid out of the nozzle. The liquid is then sprayed onto a chip (wafer) placed in a spin coater. The spin coater rotates the chip, applying centrifugal force to evenly coat the chip surface.

[0004] However, during the photoresist coating process, bubbles or impurities in the photoresist often cause poor coating and poor flatness on the chip. This will reduce the etching yield or reliability of the chip, and in severe cases, even cause the chip to be scrapped.

[0005] Therefore, filters need to be replaced regularly to ensure filtration quality.

[0006] Currently, filters are often replaced at a fixed frequency of every three months. When replacing filters, they need to go through a pre-wetting process with photoresist liquid flowing through them to discharge 500mL to 1000mL of photoresist liquid. Only then can the wetted filters be used normally.

[0007] However, during the pre-wetting process, air bubbles can form due to speed, pressure, or temperature. If coating is performed directly, this will inevitably affect the coating effect. Degassing after pre-wetting is time-consuming and increases the cost of photoresist fluid, making filter replacement a time-consuming and costly process. Summary of the Invention

[0008] The problem solved by the present invention is to provide a photoresist liquid spraying system that saves photoresist liquid, so that after pre-wetting the filter, the micro bubbles generated in the pre-wetting process are removed in the system, thereby preventing extra consumption of photoresist liquid and saving operation time.

[0009] To solve the above problems, the present invention provides a photoresist liquid spraying system that saves photoresist liquid, comprising: a liquid storage tank for storing and supplying photoresist liquid; a first filter for filtering impurities in the photoresist liquid; a buffer for removing microbubbles in the photoresist liquid and for buffering and supplying the photoresist liquid; the first filter is arranged between the liquid storage tank and the buffer; a photoresist liquid pump for transporting the photoresist liquid in the buffer to a use end; the buffer is connected to a backdraw tube, the first end of the backdraw tube extends into the interior of the buffer, and the second end is connected to the front end of the first filter; the backdraw tube is installed with a backdraw pump; the backdraw tube and the backdraw pump are used to draw the photoresist liquid in the buffer back to the front end of the first filter.

[0010] Optionally, the withdrawal pipe is equipped with at least one of a liquid valve and a withdrawal liquid sensor.

[0011] Optionally, the buffer is connected to an exhaust pipe; the exhaust pipe is installed with at least one of an exhaust valve and a gas sensor.

[0012] Optionally, the system further includes a second filter, which is connected in parallel with the first filter between the liquid storage tank and the buffer.

[0013] Optionally, the front ends of the first filter and the second filter are connected to the liquid storage tank through a first three-way valve, and the rear ends of the first filter and the second filter are connected to the buffer through a second three-way valve.

[0014] Optionally, a one-way control valve is provided between the front end of the first filter and the liquid storage tank; and the second end of the withdrawal pipe is connected between the one-way control valve and the buffer.

[0015] Optionally, a filtered liquid sensor is provided between the rear end of the first filter and the buffer.

[0016] Optionally, the rear end of the buffer also has a control valve.

[0017] Optionally, the rear end of the control valve further has a nozzle mechanism.

[0018] Optionally, a liquid supply sensor is provided between the buffer and the nozzle mechanism.

[0019] In one aspect of the technical solution of the present invention, a new photoresist liquid spraying system is provided, which can save photoresist liquid while preventing residual bubbles in the photoresist liquid. In addition, the system can pre-wet the filter in two different ways, making the system more flexible and having better performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of a photoresist liquid spraying system for saving photoresist liquid provided by an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of another photoresist liquid spraying system for saving photoresist liquid provided by another embodiment of the present invention. DETAILED DESCRIPTION

[0022] During the photoresist coating process, poor coverage and poor flatness can occur. One reason for these problems is that bubbles remain within the photoresist during the filter pre-wetting process, causing discontinuous coating of the photoresist on the chip (wafer) surface. However, avoiding these problems often results in waste of photoresist, which is an expensive material.

[0023] Therefore, the present invention provides a photoresist liquid spraying system that saves photoresist liquid to solve the above-mentioned shortcomings. For a clearer representation, the present invention will be described in detail below with reference to the accompanying drawings.

[0024] The embodiment of the present invention provides a photoresist liquid spraying system that saves photoresist liquid. Figure 1 , the system comprising:

[0025] Liquid storage tank 100, used for storing and supplying photoresist liquid (photoresist liquid Figure 1 not shown);

[0026] A first filter 110 is used to filter impurities in the photoresist liquid;

[0027] The buffer 120 is used to remove microbubbles in the photoresist liquid and to buffer and provide the photoresist liquid;

[0028] The first filter 110 is disposed between the liquid storage tank 100 and the buffer 120;

[0029] The photoresist liquid pump 130 is used to transport the photoresist liquid in the buffer 120 to the user end;

[0030] The buffer 120 is connected to a back-draw tube 160, the first end of which extends into the interior of the buffer 120, and the second end is connected to the front end of the first filter 110; the back-draw tube 160 is installed with a back-draw pump 161; the back-draw tube 160 and the back-draw pump 161 are used to draw the photoresist liquid in the buffer 120 back to the front end of the first filter 110.

[0031] In this embodiment, the liquid storage tank 100 itself is a photoresist liquid storage device. The photoresist liquid in the liquid storage tank 100 can be discharged by inputting (pressing) dry air or nitrogen into the liquid storage tank 100, thereby realizing the supply of photoresist liquid. The pipeline that can be used to input dry air or nitrogen is as follows: Figure 1This is shown as the leftmost pipe in the figure (this pipe is not labeled).

[0032] In this embodiment, the photoresist liquid filtered by the first filter 110 is typically supplied from the liquid reservoir 100 to the first filter 110. However, in some cases, the photoresist liquid may be withdrawn from the buffer 120 via the return pipe 160 to the first filter 110 for pre-wetting. For details, see the following sections.

[0033] In this embodiment, the microbubbles removed by the buffer 120 mostly come from the photoresist liquid input into the buffer 120 during the pre-wetting process of the first filter 110. Of course, during use, if microbubbles are generated from the first filter 110, they can also be removed in the buffer 120.

[0034] like Figure 1 As shown, in the system provided by this embodiment, the retraction pipe 160 is installed with a liquid valve 162. The liquid valve 162 is used to further control the retraction operation, so that the photoresist liquid is only retracted when the liquid valve 162 is open and the retraction pump 161 is working, thereby ensuring safe and reliable operation.

[0035] like Figure 1 As shown, in the system provided by this embodiment, the buffer 120 is connected to an exhaust pipe 170, which is used to discharge gas. The exhaust pipe 170 can be led out from above the buffer 120. The gas has a low density and escapes upward. The exhaust pipe 170 is connected to the top of the buffer 120 to facilitate gas discharge.

[0036] like Figure 1 As shown, exhaust pipe 170 is equipped with an exhaust valve 172 and a gas sensor 171. Exhaust valve 172 is used to control the opening and closing of exhaust pipe 170 and can also monitor gas flow rate. Gas sensor 171 is used to further confirm whether the corresponding system exhaust status is normal during the exhaust process of buffer 120.

[0037] It should be noted that, in other embodiments, the exhaust pipe 170 may be installed with a corresponding air extraction device (not shown), such as an air extraction pump, to achieve better exhaust effect.

[0038] like Figure 1 As shown, in this embodiment, a one-way control valve 111 is disposed between the front end of the first filter 110 and the liquid reservoir 100. The one-way control valve 111 is used to facilitate the supply of photoresist liquid from the liquid reservoir 100 to the first filter 110. When the one-way control valve 111 is open, the photoresist liquid can be injected (pressed) from the liquid reservoir 100 into the first filter 110. When the one-way control valve 111 is closed, the first filter 110 can be replaced, or the liquid reservoir 100 can be replaced (e.g., after the photoresist liquid is depleted).

[0039] At the same time, in this embodiment, the second end of the withdrawal tube 160 is connected between the one-way control valve 111 and the buffer 120. At this time, the one-way control valve 111 can also be used to prevent the withdrawn photoresist liquid conveyed by the withdrawal tube 160 from flowing back to the side of the liquid storage tank 100, thereby ensuring that the withdrawn photoresist liquid is fully input into the first filter 110, thereby fully being used to pre-wet the first filter 110 and simultaneously achieving re-filtration of this portion of the photoresist liquid. Please refer to the subsequent content of this embodiment for reference.

[0040] In this embodiment, a filtered liquid sensor 112 is provided between the rear end of the first filter 110 and the buffer 120. The filtered liquid sensor 112 can be used to detect whether the photoresist liquid filtered from the first filter 110 is normally input into the buffer 120.

[0041] like Figure 1 In this embodiment, the rear end of the buffer 120 further comprises a use control valve 140. The use control valve 140 is used to further control the flow of the photoresist liquid to the use end. Even when the photoresist liquid pump 130 stops delivering (pressurizing) the photoresist liquid, the closing operation of the use control valve 140 can further prevent the photoresist liquid from flowing to the use end (e.g., leaking).

[0042] like Figure 1 The rear end of the control valve 140 is further provided with a nozzle mechanism 150. The nozzle mechanism 150 controls the ejection flow rate and ejection state of the final photoresist liquid for use in the manufacture of semiconductor products (such as chips).

[0043] Depend on Figure 1 As can be seen from the system structure shown, when the photoresist liquid pump 130 delivers the photoresist liquid to the user end, it does so by pumping the photoresist liquid buffered in the buffer 120 to the nozzle mechanism 150 at the rear end. That is, the nozzle mechanism 150 is the structure corresponding to the user end.

[0044] The system provided in this embodiment can, during normal use, draw out (press out) the photoresist liquid in the liquid storage tank 100 in various ways and deliver it to the first filter 110 via a delivery pipe (not marked). The first filter 110 filters out impurities. The filtered photoresist liquid is then delivered to the buffer 120 via a rear delivery pipe (not marked). The buffer 120 is designed to prevent damage to the user end when the photoresist liquid in the liquid storage tank 100 is used up and no photoresist liquid is sprayed out (i.e., idling). The buffer 120 can also remove air during operation. Therefore, the microbubbles generated in the previous process can be removed by the buffer 120 and then delivered to the nozzle mechanism 150 for spraying.

[0045] The first filter 110 needs to be replaced after filtering the photoresist liquid for a period of time.

[0046] First filter 110 is typically replaced at a fixed frequency, approximately every three months. In practice, each filter may require different replacement scenarios (e.g., clogging) depending on factors such as the usage rate and viscosity of the photoresist fluid. To ensure a safe service life for the entire system, filter replacement is typically limited to a minimum of three months. However, abnormal conditions may necessitate even shorter filter replacement times.

[0047] Photoresist fluid is primarily composed of resin, emulsifier, and solvent mixed in varying proportions. Therefore, the viscosity of the fluid often varies depending on the ratio of these three components. Therefore, after replacing a filter, it must be passed through a filter and 500 to 1000 mL of the fluid must be drained to wet the filter. This process is called filter pre-wetting.

[0048] Photoresist fluid is quite expensive for semiconductor manufacturing. During the filter pre-wetting process, microbubbles may naturally form as the filter surface is fully wetted. Alternatively, microbubbles may be generated due to the pre-wetting filtering speed, bending and turning of the delivery pipe during photoresist fluid delivery, and other factors during the photoresist fluid supply. If the filter is placed after the buffer according to a known system structure design, it will take time and photoresist fluid to pre-wet the filter after the filter is replaced. In addition, it will take time and excess photoresist fluid to remove the microbubbles generated during the pre-wetting process. Therefore, the photoresist fluid is wasted and the manufacturing cost increases.

[0049] In the system provided in this embodiment, after replacing the first filter 110 with a new one, when the first filter 110 is to be pre-wetted with the photoresist liquid, two methods can be used.

[0050] In the first method, the photoresist liquid can be drawn out from the liquid storage tank 100, and the photoresist liquid is first pre-wetted and impurities are removed in the first filter 110. Microbubbles generated by the photoresist liquid during the pre-wetting process will be discharged in the buffer 120 when the photoresist liquid leaves the first filter 110 and reaches the buffer 120 (without the need to use additional photoresist liquid for bubble removal after pre-wetting). Therefore, not only time is saved, but also the amount of photoresist liquid used can be saved (the photoresist liquid used in the pre-wetting process and the photoresist liquid used in the subsequent microbubble removal process are saved), thereby achieving the purpose of saving costs.

[0051] In the second method, the photoresist liquid can be withdrawn from the buffer 120 and this withdrawn photoresist liquid flows back to the first filter 110, thereby pre-wetting the first filter 110 and filtering out impurities from the photoresist liquid again. During this pre-wetting process, the microbubbles generated by the photoresist liquid will also be discharged from the buffer 120 when the photoresist liquid leaves the first filter 110 and returns to the buffer 120 (without the need to use additional photoresist liquid for bubble removal after pre-wetting). Therefore, this method also saves time and can also save the amount of photoresist liquid used (saving the photoresist liquid used in the pre-wetting process and the photoresist liquid used in the subsequent microbubble removal process), thereby achieving the purpose of saving costs.

[0052] According to the above two pre-wetting operation modes, the system provided in this embodiment has the following process when performing the pre-wetting operation in the first mode:

[0053] After the new first filter 110 is replaced with the delivery pipeline of the photoresist liquid spraying system, a pre-wetting operation is immediately performed. First, the photoresist liquid in the liquid storage tank 100 is drawn out and transported to the first filter 110 via the delivery pipe. The first filter 110 performs the pre-wetting operation and filters out impurities. The filtered photoresist liquid is then transported to the buffer 120 via the delivery pipe. The buffer 120 can remove air during operation. Therefore, the microbubbles generated during the filter pre-wetting process can be removed by the buffer 120 and then sent to the nozzle mechanism 150 for spraying. As a result, the microbubbles generated by the pre-wetting of the first filter 110 are blocked within the buffer 120 and do not affect the photoresist liquid coating.

[0054] When the second method is used, the following process occurs:

[0055] After the new first filter 110 is replaced with the delivery pipeline of the photoresist liquid spraying system, a pre-wetting operation is immediately performed. First, the one-way control valve 111 is closed, and the photoresist liquid is drawn from the buffer 120 back to the front end of the first filter 110 via the return pipe 160 and the return pump 161. The liquid is then transported through the delivery pipe to the first filter 110, where it is pre-wetted and impurities are filtered out. The filtered photoresist liquid is then transported to the buffer 120 via the delivery pipe. The buffer 120 can remove air during operation, so microbubbles generated during the filter pre-wetting process can be removed by the buffer 120 and then sent to the nozzle mechanism 150 for spraying. As a result, the microbubbles generated by the pre-wetting of the first filter 110 are blocked within the buffer 120 and do not affect the photoresist liquid coating.

[0056] It should be noted that this embodiment employs the second method for pre-wetting the first filter 110, which presupposes that there is sufficient photoresist liquid in the buffer 120. This "sufficient" implies two aspects: first, sufficient photoresist liquid in the buffer 120 to continuously supply the user end; second, sufficient photoresist liquid in the buffer 120 to simultaneously provide for the entire pre-wetting operation. Both requirements generally need to be met simultaneously.

[0057] In this embodiment, a corresponding liquid level sensor may be provided in the buffer 120 to determine whether the photoresist liquid in the buffer 120 is sufficient to meet the above two requirements.

[0058] As can be seen from the second filter pre-wetting method described above, in this embodiment, the first filter 110 can be pre-wetted by the photoresist liquid in the buffer 120 , and the buffer 120 can be used to remove microbubbles generated during the pre-wetting process of the first filter 110 .

[0059] The second filter pre-wetting method has an advantage: at this time, the pre-wetting operation may not involve the liquid storage tank 100, so the liquid storage tank 100 can be replaced during this operation time window.

[0060] The second filter pre-wetting method described above has another advantage: the photoresist liquid used for the pre-wetting operation is the photoresist liquid filtered in the final stage of the old first filter 110, and the filtration quality of this portion of the photoresist liquid is likely to be unsatisfactory. Therefore, by using the backflow method for the pre-wetting operation in this embodiment, this portion of the photoresist liquid can also be filtered again at the same time, thereby better ensuring that impurities in the photoresist liquid are effectively filtered.

[0061] Another embodiment of the present invention provides another photoresist liquid spraying system that saves photoresist liquid. Figure 2 , the system comprising:

[0062] Liquid storage tank 200, used for storing and supplying photoresist liquid (photoresist liquid in Figure 2 not shown);

[0063] A first filter 210 is used to filter impurities in the photoresist liquid;

[0064] The buffer 220 is used to remove microbubbles in the photoresist liquid and to buffer and provide the photoresist liquid;

[0065] The first filter 210 is disposed between the liquid storage tank 200 and the buffer 220;

[0066] The photoresist liquid pump 230 is used to transport the photoresist liquid in the buffer 220 to the user end;

[0067] The buffer 220 is connected to a backflow tube 260, the first end of which extends into the interior of the buffer 220 and the second end is connected to the front end of the first filter 210; the backflow tube 260 is installed with a backflow pump 261; the backflow tube 260 and the backflow pump 261 are used to draw the photoresist liquid in the buffer 220 back to the front end of the first filter 210.

[0068] like Figure 2 As shown, in the system provided by this embodiment, the buffer 220 is connected to the exhaust pipe 270, and the exhaust pipe 270 is installed with an exhaust valve 272 and a gas sensor 271.

[0069] like Figure 2 As shown, in this embodiment, a one-way control valve 211 is provided between the front end of the first filter 210 and the liquid storage tank 200 . The second end of the backflow pipe 260 is connected between the one-way control valve 211 and the buffer 220 .

[0070] In this embodiment, a filtered liquid sensor 212 is provided between the rear end of the first filter 210 and the buffer 220 .

[0071] like Figure 2 In this embodiment, the rear end of the buffer 220 also has a control valve 240.

[0072] like Figure 2 The rear end of the control valve 240 is further provided with a nozzle mechanism 250. The nozzle mechanism 250 controls the ejection flow rate and ejection state of the final photoresist liquid for use in the manufacture of semiconductor products (such as chips).

[0073] Depend on Figure 2 As can be seen from the system structure shown, when the photoresist liquid pump 230 delivers the photoresist liquid to the user end, it does so by pumping the photoresist liquid buffered in the buffer 220 to the nozzle mechanism 250 at the rear end, that is, the nozzle mechanism 250 is the structure corresponding to the user end.

[0074] The above structure of the system provided in this embodiment is basically the same as the corresponding structure of the aforementioned embodiment. Therefore, the properties, characteristics, advantages, working status, working principle and possible changes of the above structure can refer to the corresponding contents of the aforementioned embodiment.

[0075] Unlike the previous embodiment, in this embodiment, the withdrawal tube 260 is equipped with a withdrawal liquid sensor 263 in addition to the liquid valve 262. The withdrawal liquid sensor 263 can be used to monitor whether the corresponding photoresist liquid is being withdrawn normally during the subsequent filter pre-wetting operation using the withdrawn photoresist liquid, further ensuring the safety and reliability of the second filter pre-wetting method described above.

[0076] Different from the above-mentioned embodiment, this embodiment further includes a second filter 2100 , which is connected in parallel with the first filter 210 between the liquid storage tank 200 and the buffer 220 .

[0077] refer to Figure 2 It can be seen that the second filter 2100 is also located at the rear end of the one-way control valve 211. The rear end of the second filter 2100 is also connected to the filtered liquid sensor 212, that is, the filtered liquid sensor 212 is set at the common rear end of the first filter 210 and the second filter 2100.

[0078] To cooperate with the use of the above-mentioned second filter 2100, in this embodiment, the front ends of the first filter 210 and the second filter 2100 are connected to the liquid storage tank 200 through a first three-way valve 281, and the rear ends of the first filter 210 and the second filter 2100 are connected to the buffer 220 through a second three-way valve 282.

[0079] By providing the second filter 2100, the first three-way valve 281, and the second three-way valve 282, this embodiment allows for faster and more timely filter replacement. Specifically, simply by coordinating the first and second three-way valves 281, 282 and switching the corresponding delivery pipelines, the second filter 2100 can be quickly replaced with a new first filter 210, or vice versa.

[0080] As can be seen from the above, in this embodiment, the first filter 210 and the second filter 2100 are equal. During initial use, if both filters are new, you can choose to use either filter first. Later, when one filter needs to be replaced after use, the corresponding delivery pipeline can be switched using the first three-way valve 281 and the second three-way valve 282. After switching, the new spare filter is put into use, and the filter that needs to be replaced can be promptly replaced and kept in reserve. This method makes corresponding filter replacement faster and more convenient.

[0081] Different from the above embodiment, in this embodiment, a liquid supply sensor 290 is provided between the buffer 220 and the nozzle mechanism 250. The liquid sensor 290 can be used to further monitor the supply of photoresist liquid from the buffer 220 to the user end.

[0082] In this embodiment, the liquid sensor 290 is located between the photoresist liquid pump 230 and the use control valve 240. In other embodiments, the liquid sensor can have more optional locations and only needs to be located between the buffer and the nozzle mechanism.

[0083] It should be noted that the liquid sensors in the various embodiments of the present invention can further be sensors with flow sensing and monitoring functions, that is, liquid flow sensors; accordingly, the gas sensors in the various embodiments of the present invention can also be gas sensors with gas flow sensing and monitoring functions; accordingly, the (control) valves in the various embodiments of the present invention can further be control valves with gas or liquid flow control functions.

[0084] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A photoresist liquid spraying system for saving photoresist liquid, characterized in that: include: Liquid storage tank, used for storing and supplying photoresist liquid; A first filter, used for filtering impurities in the photoresist liquid; A buffer, used to remove microbubbles in the photoresist liquid, and to buffer and supply the photoresist liquid; The first filter is arranged between the liquid storage tank and the buffer; A photoresist liquid pump, used for delivering the photoresist liquid in the buffer to a use end; The buffer is connected to a suction pipe, the first end of which extends into the interior of the buffer and the second end is connected to the front end of the first filter; the suction pipe is installed with a suction pump; the suction pipe and the suction pump are used to draw the photoresist liquid in the buffer back to the front end of the first filter; The withdrawal pipe is equipped with at least one of a liquid valve and a withdrawal liquid sensor; The buffer is connected to an exhaust pipe; the exhaust pipe is equipped with at least one of an exhaust valve and a gas sensor; the exhaust pipe is also equipped with an exhaust device; The device further comprises a second filter, which is connected in parallel with the first filter between the liquid storage tank and the buffer.

2. The photoresist liquid spraying system for saving photoresist liquid according to claim 1, characterized in that: The front ends of the first filter and the second filter are connected to the liquid storage tank through a first three-way valve, and the rear ends of the first filter and the second filter are connected to the buffer through a second three-way valve.

3. The photoresist liquid spraying system for saving photoresist liquid as claimed in claim 2, characterized in that: A one-way control valve is provided between the front end of the first filter and the liquid storage tank; the second end of the back-drawing pipe is connected between the one-way control valve and the buffer.

4. The photoresist liquid spraying system for saving photoresist liquid according to claim 1 or 3, characterized in that: A filtered liquid sensor is provided between the rear end of the first filter and the buffer.

5. The photoresist liquid spraying system for saving photoresist liquid as claimed in claim 4, characterized in that: The rear end of the buffer is also provided with a control valve.

6. The photoresist liquid spraying system for saving photoresist liquid as claimed in claim 5, characterized in that: The rear end of the control valve is further provided with a nozzle mechanism.

7. The photoresist liquid spraying system for saving photoresist liquid according to claim 6, characterized in that: A liquid supply sensor is also provided between the buffer and the nozzle mechanism.

Images