A large-size wafer chemical cleaning liquid supply valve and supply method

Abstract

A large-size wafer chemical cleaning liquid supply valve and supply method are involved, and the supply valve comprises: a main cavity with an inverted L-shaped flow channel, an on-off valve seat combined on the main cavity, and a backwash valve seat combined under the main cavity. One end of the piston rod of the on-off valve seat is connected to a double-conical main valve head corresponding to the liquid supply inlet, and one end of the float of the backwash valve seat is connected to a self-balancing valve head, which has a sealing surface and a reverse cone surface corresponding to the backwash port; when the valve is opened, the inlet fluid pressure acts on the reverse cone surface to automatically close the backwash port; the dynamic reduction of the inlet fluid pressure causes the self-balancing valve head to float naturally on the horizontal part of the inverted L-shaped flow channel; when the valve is closed, the backwash fluid pressure acts on the sealing surface of the self-balancing valve head to automatically open the backwash port; during the chemical cleaning of large-size wafers, valve damage can be reduced and supply interruption can be avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of high-end equipment manufacturing applied to semiconductor wafer processing and manufacturing, and in particular to a large-size (twelve-inch or larger) wafer chemical cleaning liquid supply valve and supply method. Background Art

[0002] In wafer processing and manufacturing technology, the surface of the wafer must first be cleaned, such as removing photoresist residues or organic impurities on the surface of the wafer, which is conducive to the execution of subsequent semiconductor chip manufacturing processes. The size of traditional wafers is six inches or eight inches, and the chemical cleaning fluids used are SC-1 and SC-2. SC-1 is generally a mixture of ammonia and hydrogen peroxide, and the processing temperature is about 20°C; SC-2 is generally a mixture of hydrochloric acid and hydrogen peroxide, and the processing temperature is about 80°C. The next generation of production equipment is to process wafers of twelve inches or larger (hereinafter referred to as large wafers), and traditional chemical cleaning fluids will not be sufficient because they cannot evenly clean a larger wafer surface area in a short time. Therefore, SC-3 chemical cleaning fluids are currently developed, with two main ratios, namely a mixture of sulfuric acid and hydrogen peroxide and a mixture of sulfuric acid and water, with a processing temperature between 140 and 160°C. SC-4 chemical cleaning fluids with a processing temperature between 180 and 190°C are still being developed. With the significant increase in cleaning temperature and enhanced corrosiveness of large-size wafers, the existing supply valves will not last long and will often damage the valve body, leading to leakage and inability to effectively control the supply. Therefore, it is necessary to develop a suitable chemical cleaning liquid supply valve for large-size wafers.

[0003] At present, the chemical cleaning liquid supply valves used for normal-sized wafers have the following three structures: the first is a one-way valve structure, which controls the one-way flow of the fluid through a one-way valve to prevent backflow. If it is used for large sizes, the flow control is poor. When it is not in use, the inside of the valve body is easily corroded by the chemical cleaning liquid; the second is a double-piston structure, which uses two pistons to control the main channel and the backwash channel respectively, and the valve is switched on and off through the pressure difference; the third is an electromagnetic drive structure, which uses an electromagnetic valve to control the on and off of the fluid. It has the characteristics of fast response and precise control, but it loses its function when it is abnormally powered off or subjected to electromagnetic interference. The electromagnetic valve is easily damaged and has relatively poor durability. The most common is the use of a double-piston structure, which is a three-way non-return backwash valve.

[0004] Invention patent publication number CN117090974A discloses a cleaning liquid dispensing valve for 12-inch wafer semiconductor manufacturing, including a main valve body assembly and n liquid dispensing valve assemblies installed on the main valve body assembly, the main valve body of the main valve body assembly is provided with a liquid dispensing pipeline located in the axial center and opening to the right and a liquid inlet pipeline located on the left and vertically connected with the liquid dispensing pipeline; the main valve body is provided with n groups of liquid dispensing valve mounting holes on the liquid dispensing pipeline side, the liquid dispensing valve mounting hole group includes a liquid dispensing valve core groove opening upward, a second liquid dispensing pipeline located directly below the liquid dispensing valve core groove and connected with the liquid dispensing valve core groove, and a second liquid inlet pipeline located in front of the liquid dispensing valve core groove and connected with the liquid dispensing valve core groove, the second liquid inlet pipeline is connected with the middle and lower part of the liquid dispensing valve core groove from the front side; the second liquid dispensing pipeline is connected with the liquid dispensing pipeline downward. The first piston and the first diaphragm control the opening and closing of the main valve body, and the second piston and the second diaphragm of the liquid dispensing valve assembly control the opening and closing of the liquid dispensing valve. The related prior art has determined that the combination of a main valve body assembly and n liquid dispensing valve assemblies installed on the main valve body assembly can simultaneously realize ultrapure water delivery and liquid dispensing of multiple chemicals.

[0005] Invention patent publication number CN101295622A discloses a device and method for cleaning wafers, wherein the device for cleaning wafers comprises: a cleaning chamber for accommodating wafers to be cleaned; a gate for discharging the cleaning liquid in the cleaning chamber into a liquid storage tank; a liquid storage tank for accommodating the cleaning liquid discharged from the cleaning chamber; a first transmission pipeline connecting the cleaning chamber and a three-way valve; a second transmission pipeline connecting the liquid storage tank and the three-way valve; a third transmission pipeline connecting the three-way valve and a reflux pump; a fourth transmission pipeline connecting the reflux pump and a filter; a fifth transmission pipeline connecting the filter and the cleaning chamber; a three-way valve for controlling the opening or closing of a circulating cleaning line and a recycling line; a reflux pump for extracting the cleaning liquid in the cleaning chamber or the liquid storage tank and transmitting it to the filter; a filter for filtering the cleaning liquid transmitted by the reflux pump, effectively removing fine particles on the surface of the wafer and recycling the cleaning liquid. It can be determined that the three-way valve is introduced in the equipment of the device for cleaning wafers.

[0006] Invention patent publication number CN118049512A discloses a three-way non-return backwash valve, including a rectangular valve body, an inlet and an outlet are respectively provided at both ends of the valve body, a backwash port located between the inlet and the outlet is provided on the valve body, a flow slot is provided in the valve body, a liquid inlet slot is provided in the inlet, a liquid outlet slot is provided in the outlet, a flushing liquid slot is provided in the backwash port, an elastic opening and closing mechanism is provided on the valve body, and a flow control mechanism is also provided on the valve body, the flow control mechanism includes a piston cylinder, a piston, a flow control plug, a handle and a locking mechanism, one end of the handle is connected to the rod end of the piston through an eccentric pin, a curved groove is provided in the flow control plug, and the two ends of the curved groove are respectively a liquid inlet and a liquid outlet. The flow control mechanism of the device is arranged in the valve body, and the amount of liquid entering the valve body is controlled in the process of opening the inlet by the handle. In the related art, a flow control plug with a special hollow sleeve structure is used. During the equipment cleaning stage after the equipment is used, the piston is driven down by a handle, and the liquid outlet on the flow control plug is completely blocked by the inner wall of the liquid inlet tank. High-pressure cleaning liquid is introduced into the backwash port. The elastic opening and closing mechanism automatically opens the backwash port due to the pressure of the cleaning liquid, and the cleaning liquid enters the flow tank to clean the equipment. When a three-way non-return backwash valve with a similar structure is used for chemical cleaning of large-sized wafers, the durability of the valve will become worse because the flow control plug is not a solid structure and the chemical cleaning liquid is more corrosive and the cleaning temperature is also higher. It cannot overcome the intermittent or even interrupted flow of the chemical cleaning liquid caused by fluid pressure changes or abnormal power outages during the chemical cleaning process of large-sized wafers. When encountering an abnormal state in use that is not in the cleaning stage, if there is no external control means, the chemical cleaning liquid will remain in the valve.

[0007] Although the existing structure has met the cleaning needs of small and medium-sized wafers to a certain extent, there are still obvious deficiencies in the cleaning process of large-sized wafers. The first is the durability problem. Since the cleaning fluid of large-sized wafers is highly corrosive and has a high temperature, the existing supply valve is easily damaged, resulting in leakage and unstable supply. The second is the stability problem. The existing supply valve is prone to chemical cleaning fluid interruption when the fluid pressure changes or there is an abnormal power outage, which will not only affect the cleaning effect, but also cause damage to the wafer. Therefore, it is urgent to develop a supply valve suitable for chemical cleaning of large-sized wafers that can solve the above problems and ensure the stability and reliability of the cleaning process. Summary of the invention

[0008] The main purpose of the present invention is to provide a chemical cleaning liquid supply valve for large-size wafers. The main improvement is that it can reduce damage to the supply valve during chemical cleaning of large-size wafers and avoid supply interruption due to abnormalities during use, and realize the automatic opening of the backwash port when any condition is met when the fluid pressure of the chemical cleaning liquid is abnormally reduced when the valve is in the closed state of the on-off valve seat and the valve is in the open state.

[0009] The second main purpose of the present invention is to provide a method for supplying chemical cleaning liquid to large-size wafers, which can realize automatic adjustment of the supply valve to prevent flow interruption. Regardless of whether the first fluid pressure through the liquid supply inlet or the second fluid pressure through the backwash port is abnormal, or there is an abnormal power outage, the liquid supply outlet of the supply valve can always continue to discharge the fluid, which is beneficial to maintaining the durability of the supply valve and related semiconductor equipment and preventing wafer scrapping during chemical cleaning of large-size wafers.

[0010] The main purpose of the present invention is achieved by the following technical solution, which provides a large-size wafer chemical cleaning liquid supply valve, comprising:

[0011] The main cavity has an inverted L-shaped flow channel, the bottom end of the inverted L-shaped flow channel is a liquid supply inlet, the side end of the inverted L-shaped flow channel is a liquid supply outlet, and a backwash port is formed on a part of the horizontal portion of the inverted L-shaped flow channel;

[0012] An on-off valve seat is combined with the upper part of the main cavity and aligned with the vertical part of the inverted L-shaped flow channel. One end of the piston rod of the on-off valve seat is connected with a double-conical main valve head, which is larger than the longitudinal flow channel diameter of the vertical part and is used to open and close the liquid supply inlet and the liquid supply outlet of the inverted L-shaped flow channel;

[0013] A backwash valve seat is combined with the lower part of the main cavity and aligned with the backwash port located at the horizontal part of the inverted L-shaped flow channel, one end of the float of the backwash valve seat is connected with a self-balancing valve head, which is larger than the diameter of the backwash port, and the self-balancing valve head has an inverted cone surface;

[0014] The backwash valve seat is configured to:

[0015] The first fluid pressure of the double-conical main valve head opening the inverted L-shaped flow channel acts on the reverse cone surface of the self-balancing valve head, which is sufficient to make the self-balancing valve head automatically close the backwash port;

[0016] When the first fluid pressure of the liquid supply inlet is dynamically reduced, the self-balancing valve head naturally floats in the horizontal portion of the inverted L-shaped flow channel, and the fluid is supplemented by the backwash port to stabilize the liquid supply;

[0017] When the double-conical main valve head closes the inverted L-shaped flow channel, the second fluid pressure from the backwash port acts on the sealing surface of the self-balancing valve head, which is sufficient to make the self-balancing valve head automatically open the backwash port.

[0018] The implementation principle of this basic structure example is that during the chemical cleaning liquid supply process, when the first fluid pressure at the liquid supply inlet is higher than the preset value, the self-balancing valve head can automatically close the backwash port to ensure that the liquid supply path is unobstructed, thereby ensuring a stable supply of chemical cleaning liquid. When the first fluid pressure at the liquid supply inlet is dynamically reduced, the self-balancing valve head will naturally float in the horizontal part of the inverted L-shaped flow channel, and the fluid will be replenished from the backwash port, thereby stabilizing the liquid supply and avoiding liquid supply interruption caused by pressure fluctuations, thereby improving the reliability and stability of the large-size wafer chemical cleaning system. In addition, when the double-conical main valve head closes the inverted L-shaped flow channel, the second fluid pressure at the backwash port can cause the self-balancing valve head to automatically open the backwash port, ensuring that liquid supply interruption can be prevented even when the valve is closed, further improving the safety of the large-size wafer chemical cleaning system. To sum up, the supply valve of the example of the present invention can maintain stable liquid supply performance under different working conditions, effectively reduce valve body damage, avoid interruption of chemical cleaning liquid supply due to abnormal conditions and reduce the possibility of chemical cleaning liquid remaining in the valve for a long time. It is suitable for large-size wafer chemical cleaning processes in highly corrosive and high-temperature environments.

[0019] In a preferred example, the present invention can be further configured as follows: the backwash valve seat includes a self-adjusting elastic mechanism to provide a second buoyancy force for the float, and the self-adjusting elastic mechanism can dynamically adjust the sealing pressure of the self-balancing valve head toward the backwash port as the second fluid pressure from the backwash port changes.

[0020] By adopting the preferred technical features of the above structure, the self-adjusting elastic mechanism can dynamically adjust the upward sealing pressure of the self-balancing valve head toward the backwash port synchronously according to the change in the downward second fluid pressure at the backwash port. This not only improves the sealing performance of the backwash port, ensuring that a good backwash port sealing effect can be maintained under working conditions where the second fluid pressure suddenly increases, but also effectively prevents the leakage of chemical cleaning liquid from the backwash port, and extends the service life of the delivery pipeline connected to the backwash port of the supply valve. When the pressure of the valve cleaning liquid fluctuates greatly, the sealing pressure is adaptively adjusted to maintain a stable supply state of the chemical cleaning liquid, thereby avoiding abnormal supply of the chemical cleaning liquid due to sudden changes in the pressure of the valve cleaning liquid.

[0021] In a preferred example, the present invention can be further configured as follows: the backwash valve seat includes: a self-propelled valve body, combined below the main cavity, to provide movable accommodation for the float; and a self-propelled elastic member, disposed in the self-propelled valve body, to provide a first buoyancy for the float.

[0022] By adopting the preferred technical features of the above structure, the self-driven elastic member can provide the first buoyancy of the floater, ensuring that when the first fluid pressure at the liquid supply inlet is dynamically reduced, the self-balancing valve head overcomes the second fluid pressure and naturally floats in the horizontal part of the inverted L-shaped flow channel, and the fluid is replenished from the backwash port, thereby stabilizing the liquid supply. This not only improves the reliability and stability of the supply valve, but also effectively avoids the problem of surges and intermittent flow fluctuations at the supply end caused by fluid pressure fluctuations of the chemical cleaning liquid.

[0023] In a preferred example, the present invention can be further configured as follows: the self-adjusting elastic mechanism includes a bypass pipe and a self-balancing flow channel pressure regulator arranged in the bypass pipe, the bypass pipe connects the delivery pipeline for connecting the backwash port and the inner space of the backwash valve seat, and the bypass pipe provides a second buoyancy force that can push the float to rise through the self-balancing flow channel pressure regulator.

[0024] By adopting the preferred technical features of the above structure, the self-adjusting elastic mechanism includes a bypass pipe and a self-balancing flow channel pressure regulator arranged in the bypass pipe. The bypass pipe connects the delivery pipeline for connecting the backwash port and the inner space of the backwash valve seat. The bypass pipe provides a second buoyancy that can push the floater to rise through the self-balancing flow channel pressure regulator. This connection structure can ensure that when the second fluid pressure of the backwash port changes, the self-balancing valve head can dynamically adjust the sealing pressure, thereby better adapting to different working environments and improving the reliability and durability of the valve. The effects are specifically manifested in the following aspects:

[0025] 1. Stable liquid supply: When the first fluid pressure at the liquid supply inlet is dynamically reduced, the self-balancing valve head can naturally float in the horizontal part of the inverted L-shaped flow channel, and the fluid is replenished from the backwash port to ensure the stability of the liquid supply;

[0026] 2. Automatic adjustment: The self-adjusting elastic mechanism can dynamically adjust the sealing pressure of the self-balancing valve head toward the backwash port through the bypass pipe and the self-balancing flow channel pressure regulator as the second fluid pressure of the backwash port changes, thereby maintaining good sealing performance;

[0027] 3. Reduce valve body damage: In the process of chemical cleaning of large-size wafers, it can reduce the wear and corrosion of the valve body and extend the service life of the valve;

[0028] 4. Dealing with abnormal situations: When the valve of the on-off valve seat is closed, the backwash fluid pressure acts on the sealing surface of the self-balancing valve head, automatically opening the backwash port to prevent fluid supply interruption caused by abnormal situations.

[0029] The present invention can be further configured in a preferred example as follows: the on-off valve seat comprises:

[0030] A separate drive valve body is combined above the main cavity to movably accommodate the piston disc of the piston rod; the piston rod has a sleeve portion located in the separate drive valve body and a rod portion passing through the separate drive valve body above the piston disc;

[0031] The sealing elastic member is located in the other-drive valve body and sleeved on the sleeve portion of the piston rod to provide elastic downward pressure for the piston rod.

[0032] By adopting the preferred technical features of the above structure, the piston rod of the on-off valve seat has a sleeve portion located in the other-drive valve body and a rod portion passing through the other-drive valve body above the piston disc, and the sealing elastic member is located in the other-drive valve body and sleeved on the sleeve portion of the piston rod, which can provide elastic downward pressure of the piston rod. This structure ensures that the lifting and lowering movement of the piston rod in the on-off valve seat can accurately control the on-off of the liquid supply inlet and the liquid supply outlet, and improves the sealing performance and reliability in the main cavity. Especially in the highly corrosive and high temperature environment of the chemical cleaning liquid, the elastic downward pressure provided by the sealing elastic member can effectively prevent leakage and extend the service life of the main cavity.

[0033] In a preferred example, the present invention can be further configured as follows: the on-off valve seat also includes: a driving handle, which is arranged above the externally driven valve body, and one end of the driving handle is eccentrically pivoted to connect the protruding end of the rod portion of the piston rod, and the driving handle has a first side horizontal plane and a second side horizontal plane. A first distance from the eccentric pivot point to the first side horizontal plane corresponds to the valve-on state of the on-off valve seat, and a second distance from the eccentric pivot point to the second side horizontal plane corresponds to the valve-off state of the on-off valve seat. The first distance is greater than the second distance, and the difference between the first distance and the second distance is greater than or equal to the lifting stroke of the piston rod.

[0034] By adopting the preferred technical features of the above structure and utilizing the specific structure of the driving handle, precise control of the on-off valve seat can be achieved, which is specifically manifested in the following aspects:

[0035] 1. One end of the driving handle is eccentrically pivoted to connect the protruding end of the rod of the piston rod, so that the driving handle can accurately control the height position of the piston rod under different horizontal postures, thereby realizing the switching of the on state and the off state of the supply valve;

[0036] 2. Since the first distance is greater than the second distance, and the difference between the first distance and the second distance is greater than or equal to the lifting stroke of the piston rod, the sealing elastic member absorbs the difference and collapses, ensuring that the driving handle can provide sufficient mechanical advantage when in different positions, and ensuring that the movement range of the piston rod meets the on-off requirements of the supply valve;

[0037] 3. This specific structure not only improves the response speed and accuracy of the supply valve, but also enhances the reliability and stability of the large-size wafer cleaning system, and reduces the risk of misoperation due to mechanical failure. Especially in the chemical cleaning process of large-size wafers, it can effectively avoid the problem of chemical cleaning liquid interruption caused by valve body damage or control failure, thereby ensuring the continuity and safety of the cleaning process.

[0038] In a preferred example, the present invention can be further configured as follows: an L-shaped retaining wall is formed on the top of the externally driven valve body, and a limited rotation stop portion is formed on only one side of the pivotal end of the driving handle, and with the cooperation of the limited rotation stop portion and the L-shaped retaining wall, the horizontal rotation angle of the driving handle in a horizontal position is not greater than 60 degrees, and the horizontal rotation angle of the driving handle in an upright position is not greater than 120 degrees.

[0039] By adopting the preferred technical features of the above structure, the L-shaped retaining wall formed on the top of the other-drive valve body and the rotation-limiting stopper formed at one end of the driving handle cooperate with each other. If the driving handle is to be turned over, the maximum rotation angle of the driving handle in the horizontal position is limited to no more than 60 degrees, thereby ensuring the stability of the driving handle during the horizontal rotation process and preventing mechanical damage caused by excessive rotation. At the same time, the maximum rotation angle of the driving handle in the upright position does not exceed 180 degrees, ensuring the precise control of the driving handle in the upright position and improving the reliability and service life of the on-off valve seat. This not only improves the safety of operation, but also enhances the stability and reliability of the supply valve under different working conditions.

[0040] In a preferred example, the present invention may be further configured such that the driving handle has different horizontal postures in the valve-on state and the valve-off state of the on-off valve seat.

[0041] By adopting the preferred technical features of the above structure, the driving handle has different horizontal postures in the valve-on state and the valve-off state of the on-off valve seat, which ensures the precise position of the driving handle in different working states, thereby improving the reliability and stability of the on-off valve seat. Specifically, it is manifested in the following aspects:

[0042] 1. In the valve conduction state, the first side horizontal surface of the driving handle is flat against the top of the driving valve body in the first horizontal posture, ensuring the maximum opening of the on-off valve seat, so that the chemical cleaning liquid can flow smoothly without clogging;

[0043] 2. When the valve is closed, the horizontal surface of the second side of the driving handle is flat against the top of the driving valve body, ensuring that the on-off valve seat completely closes the chemical cleaning liquid at the liquid supply inlet, preventing leakage of the chemical cleaning liquid and protecting the safe operation of large-size wafer chemical cleaning equipment;

[0044] Therefore, this structural setting not only improves the service life of the valve body, but also reduces the system maintenance cost, and is suitable for high-precision control requirements in the chemical cleaning process of large-size wafers.

[0045] The second main purpose of the present invention is achieved by the following technical solution, which provides a method for supplying chemical cleaning liquid to large-size wafers, comprising:

[0046] S1. Provide a large-size wafer chemical cleaning liquid supply valve as described in the above basic structure example, wherein the inlet of the supply valve is connected to a delivery pipeline of the chemical cleaning liquid, the outlet of the supply valve is connected to a semiconductor wafer cleaning chamber, and the backwash port of the supply valve is connected to a delivery pipeline of the chamber cleaning liquid;

[0047] S2, in the valve conduction state of the on-off valve seat, when the first fluid pressure of the chemical cleaning liquid passing through the liquid supply inlet is higher than the lower threshold of the flow channel pressure, the self-balancing valve head automatically seals the backwash port; at this time, the valve conduction is normal use, and the chemical cleaning liquid flows out from the outlet;

[0048] S3, in the valve conduction state of the on-off valve seat, when the second fluid pressure of the cavity cleaning liquid passing through the backwashing port changes dynamically, the self-balancing valve head still automatically seals the backwashing port; therefore, under abnormal backwashing pressure, the valve conduction is still used normally, and the chemical cleaning liquid flows out of the outlet;

[0049] S4, in the valve conduction state of the on-off valve seat, when the first fluid pressure of the chemical cleaning liquid passing through the liquid supply inlet is dynamically reduced and is lower than the lower threshold of the flow channel pressure, the self-balancing valve head naturally floats in the horizontal part of the inverted L-shaped flow channel, and the cavity cleaning liquid is supplemented from the backwash port to stabilize the liquid supply; for example, when the conduction pressure is abnormally reduced due to power failure, the fluid is supplemented from the backwash port, and the valve conduction is still used normally to prevent the outlet from being cut off, and the chemical cleaning liquid and the cavity cleaning liquid flow out of the outlet;

[0050] S6. With the on-off valve seat in the valve-off state, when the double-conical main valve head closes the inverted L-shaped flow channel, the second fluid pressure of the cavity cleaning liquid passing through the backwash port is sufficient to cause the self-balancing valve head to automatically open the backwash port; therefore, when the valve is closed, the backwash port is automatically fully opened to prevent the outlet from being interrupted, and the outlet causes the cavity cleaning liquid to flow out.

[0051] The implementation principle of this basic method example is that the large-size wafer chemical cleaning liquid supply method described above can achieve the following technical effects:

[0052] 1. Ensure stable liquid supply: In the valve conduction state of the on-off valve seat, when the first fluid pressure at the liquid supply inlet is higher than the lower threshold of the flow channel pressure, the self-balancing valve head automatically seals the backwash port to ensure that the chemical cleaning liquid flows stably from the liquid supply outlet to the liquid supply outlet, avoiding the problem of unstable liquid supply at the liquid supply outlet due to leakage from the backwash port;

[0053] 2. Respond to changes in backwash pressure: Even when the valve is in the on-off state of the on-off valve seat, when the pressure of the second fluid of the cavity cleaning liquid passing through the backwash port changes dynamically, the self-balancing valve head can still automatically seal the backwash port. The second fluid pressure has a wide allowable range, ensuring that the liquid supply process is not affected, and improving the reliability and stability of the large-size wafer chemical cleaning system;

[0054] 3. Preventing interruption of liquid supply: When the first fluid pressure at the liquid supply inlet decreases dynamically and is lower than the lower threshold of the flow channel pressure, the self-balancing valve head will naturally float in the horizontal part of the inverted L-shaped flow channel, and the cavity cleaning liquid will be replenished from the backwash port, thereby stabilizing the liquid supply and avoiding the problem of liquid supply interruption caused by insufficient liquid supply pressure;

[0055] 4. Automatic backwashing: In the valve-off state of the on-off valve seat, when the double-cone main valve head closes the inverted L-shaped flow channel, the second fluid pressure of the cavity cleaning liquid passing through the backwash port is sufficient to make the self-balancing valve head automatically open the backwash port, ensuring the automatic opening of the backwash port when the valve is closed, preventing the chemical cleaning liquid from being retained in the valve and reducing the damage to the valve body;

[0056] In summary, this method significantly improves the durability and reliability of the chemical cleaning liquid supply valve for large-size wafers by optimizing the automatic control mechanism of the backwash port, ensuring the continuity and stability of the chemical cleaning process for large-size wafers.

[0057] The present invention can be further configured in a preferred example as follows: the on-off valve seat comprises:

[0058] A separate drive valve body is combined above the main cavity to movably accommodate the piston disc of the piston rod; the piston rod has a sleeve portion located in the separate drive valve body and a rod portion passing through the separate drive valve body above the piston disc;

[0059] A sealing elastic member, located in the other-drive valve body and sleeved on the sleeve portion of the piston rod to provide elastic downward pressure for the piston rod;

[0060] A driving handle is arranged above the separately driven valve body, one end of the driving handle is eccentrically pivotally connected to the protruding end of the rod portion of the piston rod, the driving handle has a first side horizontal plane and a second side horizontal plane, a first distance from the eccentric pivot point to the first side horizontal plane corresponds to the valve on state of the on-off valve seat, a second distance from the eccentric pivot point to the second side horizontal plane corresponds to the valve off state of the on-off valve seat, the first distance is greater than the second distance, and a difference between the first distance and the second distance is greater than or equal to the lifting stroke of the piston rod;

[0061] Wherein, an L-shaped retaining wall is formed on the top of the separately driven valve body, and a limited rotation stop portion is formed on only one side of the pivoted end of the driving handle. Under the cooperation of the limited rotation stop portion and the L-shaped retaining wall, the horizontal rotation angle of the driving handle in a horizontal position is not greater than 60 degrees, and the horizontal rotation angle of the driving handle in an upright position is not greater than 120 degrees;

[0062] The supply method further includes: an on-off switching step S5 between any one of step S2, step S3 and step S4 and step S6, comprising:

[0063] Changing the first horizontal posture of the driving handle from the first horizontal posture of the first side horizontal surface flat against the top of the other-driven valve body to an upright posture, so that the on-off valve seat is in a valve conduction state;

[0064] Rotate the driving handle in the upright position so that the end of the rotation limit stop portion originally adjacent to the L-shaped retaining wall changes to the other end adjacent to the L-shaped retaining wall, and the rotation angle of the driving handle in the upright position is between 60 degrees and 120 degrees;

[0065] The upright posture of the driving handle is changed from the upright posture to a second horizontal posture in which the horizontal surface of the second side is flat against the top of the other-drive valve body, so that the on-off valve seat is in the valve closing state.

[0066] By adopting the preferred technical features of the above method, the reliability and stability of the supply valve can be ensured by using the on-off valve seat design. The externally driven valve body is combined with the upper part of the main cavity to provide a movable accommodation for the piston disc of the piston rod, ensuring that the piston disc of the piston rod can be controllably lifted and lowered inside the valve body, thereby realizing the on-off function of the valve; the sealing elastic member is located in the externally driven valve body and is sleeved on the sleeve part of the piston rod, providing elastic downward pressure of the piston rod, ensuring that the piston rod can maintain the valve head sealing position in the valve off state without external interference, and preventing accidental leakage; the driving handle is arranged above the externally driven valve body, and one end of the eccentric pivot is connected to the protruding end of the rod of the piston rod; the design of the driving handle enables it to switch between different horizontal planes through simple upright and rotating operations to realize the on-off state conversion of the valve, which is specifically manifested as follows:

[0067] When the horizontal surface of the first side of the driving handle is flat against the top of the driving valve body, the valve is in the conducting state;

[0068] When the horizontal surface of the second side of the driving handle is flat against the top of the driving valve body, the valve is in the closed state;

[0069] The rotation angle of the driving handle in a horizontal position is no more than 60 degrees, and the rotation angle in an upright position is between 60 degrees and 120 degrees, ensuring that the rotation limit stop portion of the driving handle can cooperate with the L-shaped retaining wall to limit the maximum rotation angle of the driving handle and prevent misoperation;

[0070] The L-shaped retaining wall is also used to form a rotation-limiting retaining portion on only one side of the pivotal end of the driving handle, which cooperates with the L-shaped retaining wall to limit the horizontal rotation angle of the driving handle, ensuring that the horizontal rotation angle of the driving handle in a horizontal position is no more than 60 degrees, and the horizontal rotation angle of the driving handle in an upright position is no more than 120 degrees, further improving the operating accuracy and reliability of the valve;

[0071] The on-off switching step S5 in the supply method has the following technical performances:

[0072] 1. Change the first horizontal posture of the driving handle from the first horizontal posture in which the first side horizontal surface is flat against the top of the driving valve body to the vertical posture, so that the on-off valve seat is in the valve conduction state;

[0073] 2. Rotate the driving handle in the upright position so that the end of the rotation limit stop originally adjacent to the L-shaped retaining wall changes to the other end adjacent to the L-shaped retaining wall, and the rotation angle of the driving handle in the upright position is between 60 degrees and 120 degrees;

[0074] 3. Change the upright posture of the driving handle from the upright posture to the second horizontal posture with the horizontal surface of the second side flat against the top of the other driving valve body, so that the on-off valve seat is in the valve closing state;

[0075] By implementing the above-mentioned operations, the on-off valve seat can not only accurately control the on-off state of the valve, but also effectively prevent valve failure caused by accidental operation or mechanical failure, thereby ensuring a stable supply of chemical cleaning liquid, reducing damage to the supply valve, and avoiding supply interruption.

[0076] In summary, the technical solution of the structure or method of the present invention includes at least one of the following technical effects that contribute to the prior art:

[0077] 1. In the valve conduction state of the on-off valve seat, through the specific structural cooperation of the double-cone main valve head and the self-balancing valve head with a reverse cone surface, the opening and closing state of the backwash port can be automatically adjusted when the fluid pressure of the chemical cleaning liquid at the liquid supply inlet changes abnormally, thereby avoiding supply interruption at the liquid supply outlet and ensuring the continuity and stability of the cleaning process; when the fluid pressure of the valve cleaning liquid at the backwash port changes abnormally, the backwash port will not open and close suddenly, and the fluid pressure at the liquid supply outlet has relative stability;

[0078] 2. When the first fluid pressure of the chemical cleaning liquid is dynamically reduced in the on-off valve seat, the self-balancing valve head will float naturally, and the fluid will be replenished from the backwash port, thereby stabilizing the liquid supply, reducing the interruption of liquid supply caused by pressure fluctuations, and protecting large-size wafers from damage caused by abnormal cleaning parameters;

[0079] 3. When the valve of the on-off valve seat is closed, the self-balancing valve head automatically opens under the action of the second fluid pressure of the backwash port, ensuring that liquid can continue to be supplied even under abnormal conditions, improving the reliability and durability of the large-size wafer cleaning system. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] Figure 1 A three-dimensional assembly diagram of a large-sized wafer chemical cleaning liquid supply valve according to an embodiment of the present invention is shown;

[0081] Figure 2 A schematic diagram of the exploded decomposition of components of the large-sized wafer chemical cleaning liquid supply valve according to an embodiment of the present invention is shown;

[0082] Figure 3 A schematic diagram of the on-off valve seat of the chemical cleaning liquid supply valve for large-sized wafers in an embodiment of the present invention is shown (A is an exploded view, and B is an assembled view);

[0083] Figure 4 A schematic diagram showing the on-off valve seat of the large-size wafer chemical cleaning liquid supply valve in the embodiment of the present invention being combined with the main cavity;

[0084] Figure 5 A schematic diagram showing that the backwash valve seat of the large-size wafer chemical cleaning liquid supply valve is combined below the main chamber in an embodiment of the present invention;

[0085] Figure 6 A flow chart of a method for supplying chemical cleaning solution to a large-sized wafer according to an embodiment of the present invention is shown;

[0086] Figure 7 The chemical cleaning liquid supply valve for large-sized wafers in the embodiment of the present invention corresponds to Figure 6 Schematic diagram of the valve in the on state in step S2 (A is a top view, B is a cross-sectional view, corresponding to the first horizontal posture of the driving handle);

[0087] Figure 8 The chemical cleaning liquid supply valve for large-sized wafers in the embodiment of the present invention corresponds to Figure 6 Schematic diagram of the backwash port pressure change when the valve is in the on state in step S3 (A is a top view, B is a cross-sectional view);

[0088] Fig. 9 The chemical cleaning liquid supply valve for large-sized wafers in the embodiment of the present invention corresponds to Figure 6 Schematic diagram of the change in the pressure reduction of the liquid supply inlet when the valve is in the on state in step S4 (A is a top view, B is a cross-sectional view);

[0089] Fig.10 The chemical cleaning liquid supply valve for large-sized wafers in the embodiment of the present invention corresponds to Figure 6 Step S6: Schematic diagram of the self-balancing valve head automatically opening in the valve-off state (A is a top view, B is a cross-sectional view, corresponding to the second horizontal posture of the driving handle);

[0090] Fig.11 and Fig.12 The chemical cleaning liquid supply valve for large-sized wafers in the embodiment of the present invention corresponds to Figure 6 Schematic diagram of the on-off switching of the valve in step S5 (A is a top view, B is a cross-sectional view).

[0091] Reference numerals: 10, main cavity; 11, inverted L-shaped flow channel; 12, liquid supply inlet; 13, liquid supply outlet; 14, backwash port; 15, delivery pipeline; 20, on-off valve seat; 21, piston rod; 21a, rod portion; 21b, shaft hole; 21c, sleeve portion; 21d, piston disc; 21e, connecting portion; 22, double-conical main valve head; 23, other drive valve body; 24, tight elastic member; 25, L-shaped retaining wall; 26, pressure diaphragm; 3 0. Backwash valve seat; 31. Float; 32. Self-balancing valve head; 32a. Anti-conical surface; 33. Self-driven valve body; 34. Self-driven elastic member; 35. Self-adjusting elastic mechanism; 36. Bypass pipe; 37. Self-balancing flow channel pressure regulator; 40. Drive handle; 41. First side horizontal plane; 42. Second side horizontal plane; 43. Eccentric pivot joint; 45. Rotation limit stop; 51. First connecting member; 52. Second connecting member; 53. Pivot. DETAILED DESCRIPTION

[0092] 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 described embodiments are only part of the embodiments for understanding the inventive concept of the present invention, and cannot represent all the embodiments, nor are they interpreted as the only embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field on the premise of understanding the inventive concept of the present invention are within the scope of protection of the present invention.

[0093] It should be noted that if there are directional indications (such as up, down, left, right, front, back, etc.) involved in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship and movement of the components in a certain specific posture. If the specific posture changes, the directional indications will also change accordingly. In order to facilitate the understanding of the technical solution of the present invention, the large-size wafer chemical cleaning liquid supply valve of the present invention is further described and explained below, but it is not limited to the protection scope of the present invention.

[0094] See also Figures 1 to 6 The embodiment of the present invention first provides a large-size wafer chemical cleaning liquid supply valve, Figure 1 A three-dimensional assembly diagram showing a large-size wafer chemical cleaning liquid supply valve. Figure 2 The exploded decomposition diagram of the components is shown. The embodiment of the present invention provides a large-size wafer chemical cleaning liquid supply valve which mainly includes: a main cavity 10 , an on-off valve seat 20 and a backwash valve seat 30 . Figure 3 Schematic diagram of the on-off valve seat 20 (A is an exploded view, B is an assembled view), Figure 4 Schematic diagram of the on-off valve seat 20 combined with the main cavity 10, Figure 5 Schematic diagram of the backwash valve seat 30 combined with the bottom of the main chamber 10. The internal structure of the large-size wafer chemical cleaning liquid supply valve can be found in Figure 7 The function of the main cavity 10 is to provide an inverted L-shaped flow channel 11, connecting the liquid supply inlet 12 and the liquid supply outlet 13, and the chemical cleaning liquid is introduced from the liquid supply inlet 12 and discharged from the liquid supply outlet 13; the function of the on-off valve seat 20 is to provide a mechanical structure for shutting off the liquid supply inlet 12 and the liquid supply outlet 13; the function of the backwash valve seat 30 is to mechanically and automatically provide valve cleaning liquid that can clean the internal space of the inverted L-shaped flow channel 11. Chemical cleaning liquid is used to clean the surface of large-sized wafers, and generally has high temperature and high corrosiveness, such as SC-3 chemical cleaning liquid or SC-4 chemical cleaning liquid; valve cleaning liquid is used to clean the internal space of the main cavity 10 and the delivery pipeline connected to the main cavity 10, and is generally neutral deionized water.

[0095] See also Figure 7 , Figure 1 and Figure 2, an inverted L-shaped flow channel 11 is provided in the main cavity 10, the bottom end of the inverted L-shaped flow channel 11 is a liquid supply inlet 12, the side end of the inverted L-shaped flow channel 11 is a liquid supply outlet 13, and a backwash port 14 is formed on a part of the horizontal part of the inverted L-shaped flow channel 11. In this example, the main cavity 10 can be made of stainless steel, which has high corrosion resistance and wear resistance. A filter screen can be provided at the liquid supply inlet 12, and the filter screen can be made of stainless steel wire mesh, and the aperture size can be selected according to actual needs. A one-way valve (not shown) can be provided at the liquid supply outlet 13 aligned with the horizontal side end of the inverted L-shaped flow channel 11, and the one-way valve can be made of silicone material, which has good elasticity and sealing. The backwash port 14 formed on a part of the horizontal part of the inverted L-shaped flow channel 11 is one in the accompanying drawings, and the backwash port 14 can be set to multiple in different examples, and the spacing can be adjusted according to actual needs. A filter screen can also be provided at the backwash port 14 to prevent foreign matter from entering the flow channel.

[0096] See also Figure 7 , which can be compared Figure 1 , Figure 2 , Figure 3 and Figure 4 The on-off valve seat 20 is combined with the upper part of the main cavity 10 and is aligned with the vertical part of the inverted L-shaped flow channel 11 (such as Figure 4 and Figure 7 As shown in FIG. 1 ), one end of the piston rod 21 of the on-off valve seat 20 is connected to a double-conical main valve head 22, which is larger than the longitudinal flow channel diameter of the vertical portion and is used to connect and disconnect the liquid supply inlet 12 and the liquid supply outlet 13 of the inverted L-shaped flow channel 11. In this example, refer to Figure 3 The on-off valve seat 20 includes a piston rod 21 having a piston disc 21d, a valve body 23, a sealing elastic member 24 and a driving handle 40. For details, please refer to Figure 2 and Figure 4, a plurality of first connecting members 51 such as screws are used to pass through the corresponding connecting holes of the main cavity 10 and connect to the externally driven valve body 23, so as to connect the externally driven valve body 23 to the upper part of the main cavity 10, so as to provide a movable accommodation for the piston disc 21d of the piston rod 21. The piston rod 21 has a sleeve portion 21c located in the externally driven valve body 23 and a rod portion 21a passing through the externally driven valve body 23 above the piston disc 21d of the piston rod 21. The sealing elastic member 24 is located in the externally driven valve body 23 and sleeved on the sleeve portion 21c of the piston rod 21, so as to provide an elastic downward pressure on the piston rod 21. The driving handle 40 is arranged above the externally driven valve body 23, and one end of the driving handle 40 is eccentrically pivotally connected to the protruding end of the rod portion 21a of the piston rod 21. The driving handle 40 has a first side horizontal plane 41 and a second side horizontal plane 42. A first distance from the eccentric pivot point 43 to the first side horizontal plane 41 corresponds to the valve-on state of the on-off valve seat 20, and a second distance from the eccentric pivot point 43 to the second side horizontal plane 42 corresponds to the valve-off state of the on-off valve seat 20. The first distance is greater than the second distance, and the difference between the first distance and the second distance is greater than or equal to the lifting stroke of the piston rod 21.

[0097] See also Figure 7 , which can be compared Figure 1 , Figure 2 and Figure 5 The backwash valve seat 30 is combined with the lower part of the main cavity 10 and is aligned with the backwash port 14 (such as Figure 5 and Figure 7 As shown), one end of the float 31 of the backwash valve seat 30 is connected to a self-balancing valve head 32, which is larger than the diameter of the backwash port 14, and the self-balancing valve head 32 has a reverse cone surface 32a. In this example, the reverse cone surface 32a of the self-balancing valve head 32 has a backwash cone head inclination of 15 to 30°, so that the fluid pressure in the horizontal part of the inverted L-shaped flow channel 11 acts as an upward thrust on the self-balancing valve head 32. In this example, the backwash valve seat 30 also includes a float 31, a self-driven valve body 33, a self-driven elastic member 34 and a self-adjusting elastic mechanism 35. The self-driven valve body 33 is combined under the main cavity 10 to provide a movable accommodation for the float 31. For details, please refer to Figure 2 and Figure 5, a plurality of second connecting members 52 such as long screws are used to pass through the corresponding connecting holes of the main cavity 10 and connected to the self-driven valve body 33, so as to realize the connection between the backwash valve seat 30 and the main cavity 10. The self-driven elastic member 34 is arranged in the self-driven valve body 33 to provide the first buoyancy of the float 31; the backwash spring force of the self-driven elastic member 34 is converted into an upward push pressure of about 2 bar on the self-balancing valve head 32. In a more specific example, the self-adjusting elastic mechanism 35 includes a bypass pipe 36 and a self-balancing flow channel pressure regulator 37 arranged in the bypass pipe 36, the bypass pipe 36 connects the delivery pipeline 15 for connecting the backwash port 14 and the inner space of the backwash valve seat 30, and the bypass pipe 36 provides a second buoyancy that can push the float 31 to rise through the self-balancing flow channel pressure regulator 37, and the second buoyancy changes synchronously with the change of the liquid pressure of the valve cleaning liquid provided by the backwash port 14. In this example, the liquid pressure of the valve cleaning liquid provided by the backwash port 14 can be set to 3-4 bar, and the liquid pressure of the chemical cleaning liquid provided by the liquid supply inlet 12 can be set to 5-6 bar.

[0098] Wherein, the backwash valve seat 30 is configured as:

[0099] The first fluid pressure of the double-conical main valve head 22 opening the inverted L-shaped flow channel 11 acts on the reverse cone surface 32a of the self-balancing valve head 32, which is sufficient to make the self-balancing valve head 32 automatically close the backwash port 14 (such as Figure 7 , Figure 8 shown);

[0100] When the first fluid pressure of the liquid supply inlet 12 is dynamically reduced, the self-balancing valve head 32 naturally floats in the horizontal portion of the inverted L-shaped flow channel 11, and the backwash port 14 replenishes the fluid to stabilize the liquid supply (such as Fig. 9 shown);

[0101] When the double-conical main valve head 22 closes the inverted L-shaped flow channel 11, the second fluid pressure from the backwash port 14 acts on the sealing surface of the self-balancing valve head 32, which is sufficient to cause the self-balancing valve head 32 to automatically open the backwash port 14 (such as Fig.10 As shown). Therefore, the permissible range of the liquid pressure of the valve cleaning liquid provided by the backwash port 14 can be expanded to 2 to 6 bar.

[0102] The implementation principle of the present invention as exemplified above is that during the supply of chemical cleaning liquid, when the first fluid pressure of the liquid supply inlet 12 is higher than the preset value, the self-balancing valve head 32 can automatically close the backwash port 14 based on the pressure received by the reverse cone surface 32a, ensuring that the liquid supply path is unobstructed, thereby ensuring the stable supply of chemical cleaning liquid. When the first fluid pressure of the liquid supply inlet 12 is dynamically reduced, the self-balancing valve head 32 will naturally float in the horizontal part of the inverted L-shaped flow channel 11, and the fluid will be replenished by the backwash port 14, thereby stabilizing the liquid supply and avoiding the interruption of the liquid supply at the liquid supply outlet 13 due to pressure fluctuations, thereby improving the reliability and stability of the large-size wafer chemical cleaning system. In addition, when the double-conical main valve head 22 closes the inverted L-shaped flow channel 11, the second fluid pressure of the backwash port 14 can cause the self-balancing valve head 32 to automatically open the backwash port 14, ensuring that the liquid supply interruption can be prevented even in the valve off state, further improving the safety of the large-size wafer chemical cleaning system. In summary, the supply valve of the present invention can maintain stable liquid supply performance under different working conditions. When the fluid pressure of the liquid supply inlet 12 drops suddenly during the chemical cleaning process of large-size wafers and any condition of the valve closing stage is met, the self-balancing valve head 32 automatically opens the backwash port 14, effectively reducing the damage to the valve body, avoiding the interruption of the liquid supply of the chemical cleaning liquid at the liquid supply outlet 13 due to abnormal conditions, and reducing the possibility of the chemical cleaning liquid remaining in the inverted L-shaped flow channel 11 in the main cavity 10 for a long time. It is suitable for large-size wafer chemical cleaning processes in highly corrosive and high-temperature environments. The high-temperature environment means that the supply valve can be applied to both normal temperature 23°C and high temperature of about 190°C. For twelve-inch wafers, a cleaning device of a large-size wafer cleaning system has twelve to sixteen wafer cleaning chambers, and each wafer cleaning chamber can be configured with six to eight of the supply valves.

[0103] See also Figure 7 and Figure 8In this preferred example, the self-adjusting elastic mechanism 35 included in the backwash valve seat 30 provides the second buoyancy of the float 31. The difference between the second buoyancy and the first buoyancy is that the second buoyancy is a variable value, and the first buoyancy is a fixed value. The self-adjusting elastic mechanism 35 can dynamically adjust the second buoyancy as the second fluid pressure from the backwash port 14 changes, that is, dynamically change the sealing pressure of the self-balancing valve head 32 toward the backwash port 14 to dynamically counteract the change in the liquid pressure of the valve cleaning liquid provided by the backwash port 14. Therefore, the self-adjusting elastic mechanism 35 can dynamically adjust the upward sealing pressure of the self-balancing valve head 32 toward the backwash port 14 synchronously according to the change in the downward second fluid pressure at the backwash port 14. This not only improves the sealing performance of the backwash port 14, ensuring that the good sealing effect of the backwash port 14 can be maintained under the working condition of the sudden increase of the second fluid pressure, but also effectively prevents the leakage of the chemical cleaning liquid from the backwash port 14, and prolongs the service life of the delivery pipeline 15 connected to the backwash port 14 of the supply valve. When the pressure of the valve cleaning fluid fluctuates greatly, the sealing pressure is adaptively adjusted to maintain a stable supply state of the chemical cleaning fluid, thereby avoiding abnormal supply of the chemical cleaning fluid caused by a sudden change in the pressure of the valve cleaning fluid.

[0104] See also Figure 7 and Figure 8 In a more specific example, the self-adjusting elastic mechanism 35 includes a bypass pipe 36 and a self-balancing flow channel pressure regulator 37 disposed in the bypass pipe 36. The bypass pipe 36 connects the delivery pipeline 15 for connecting the backwash port 14 and the inner space of the backwash valve seat 30. The bypass pipe 36 provides a second buoyancy force that can push the float 31 to rise through the self-balancing flow channel pressure regulator 37. This connection structure can ensure that when the second fluid pressure of the backwash port 14 changes, the self-balancing valve head 32 can dynamically adjust the sealing pressure, so as to better adapt to different working environments and improve the reliability and durability of the valve. The self-balancing flow channel pressure regulator 37 is specifically a regulating valve with good regulating accuracy and stability. The regulating valve can be adjusted manually or electrically or pneumatically. The regulating range of the regulating valve is selected according to actual needs to ensure that the second buoyancy of the float 31 can adapt to different fluid pressure changes.

[0105] See also Fig. 9In this preferred example, when the first fluid pressure at the liquid supply inlet 12 is dynamically reduced, the self-driven elastic member 34 can provide the first buoyancy of the float 31, but the total buoyancy of the self-balancing valve head 32 cannot be stable within the set range. This is because the first fluid pressure will act on the reverse cone 32a of the self-balancing valve head 32 to generate a third buoyancy. The self-balancing valve head 32 overcomes the second fluid pressure from the backwash port 14 and naturally floats in the horizontal part of the inverted L-shaped flow channel 11, and the fluid is replenished by the backwash port 14, thereby stabilizing the liquid supply. Since the self-balancing valve head 32 naturally floats longitudinally in the fluid in the horizontal part of the inverted L-shaped flow channel 11, the gravity of the self-balancing valve head 32 does not need to be considered based on the fluid density. This not only improves the reliability and stability of the supply valve, but also effectively avoids the problems of surges and intermittent flow fluctuations at the supply end caused by fluid pressure fluctuations of the chemical cleaning liquid.

[0106] See also Figure 2 and Figure 3 In the specific structure of the on-off valve seat 20, the piston rod 21 has a connecting portion 21e, a piston disc 21d, a sleeve portion 21c and a rod portion 21a in sequence from the lower connecting end to the upper protruding end. The connecting portion 21e is used to connect the double-conical main valve head 22. The piston disc 21d is used for guiding the piston rod 21 to slide in the other-driven valve body 23. The diameter of the sleeve portion 21c is larger than the diameter of the rod portion 21a and the connecting portion 21e. The diameter of the sleeve portion 21c is smaller than the diameter of the piston disc 21d. The sleeve portion 21c and the other-driven valve body 23 can be used in conjunction with each other to provide a space for accommodating the sealing elastic member 24. The rod portion 21a can protrude from the top of the other-driven valve body 23 to combine with a driving component, such as a driving handle 40. The sealing elastic member 24 is located in the other-driven valve body 23 and is sleeved on the sleeve portion 21c of the piston rod 21 to provide elastic downward pressure on the piston rod 21. That is, the portion of the piston rod 21 of the on-off valve seat 20 above the piston plate 21d is the sleeve portion 21c located in the externally driven valve body 23 and the rod portion 21a passing through the externally driven valve body 23. Figure 3As shown, an axial hole 21b is provided on the rod portion 21a, and a pivot 53 is provided through the eccentric pivot point 43 of the driving handle 40 and the axial hole 21b of the rod portion 21a of the piston rod 21, so that the posture adjustment of the driving handle 40 can change the lifting position of the piston rod 21. This structure ensures that the lifting and lowering movement of the piston rod 21 in the on-off valve seat 20 can accurately control the opening and closing between the liquid supply inlet 12 and the liquid supply outlet 13, and the double-conical main valve head 22 is conducive to improving the sealing performance and reliability in the main cavity 10, and the durability of the supply valve is improved. In the highly corrosive and high temperature environment of the chemical cleaning liquid, the elastic downward pressure provided by the sealing elastic member 24 can effectively prevent leakage and extend the service life of the main cavity 10. In addition, the on-off valve seat 20 may further include a diaphragm 26, which is disposed between the externally driven valve body 23 and the main cavity 10, and is used to press the first ring portion connected to the periphery of the double-conical main valve head 22, the first ring portion is pressed between the main cavity 10 and the externally driven valve body 23, and a first soft diaphragm portion that is not completely pressed is formed between the first ring portion and the valve head portion of the double-conical main valve head 22. The provision of the diaphragm 26 will facilitate the assembly of the on-off valve seat 20. In a valve head-like structure, the self-balancing valve head 32 has a second ring portion connected to the periphery, the second ring portion is pressed between the main cavity 10 and the self-driven valve body 33, and a second soft diaphragm portion that is not completely pressed is formed between the second ring portion and the valve head portion of the self-balancing valve head 32.

[0107] See also Figure 1 , Figure 2 and Figure 3 In a more specific structure of the on-off valve seat 20, the on-off valve seat 20 further includes a driving handle 40 for controlling the flow channel switch, the driving handle 40 is arranged above the other-drive valve body 23, one end of the driving handle 40 is eccentrically pivotally connected to the protruding end of the rod portion 21a of the piston rod 21, the driving handle 40 has a first side horizontal surface 41 and a second side horizontal surface 42, and a first distance from the eccentric pivot point 43 to the first side horizontal surface 41 corresponds to the valve conduction state of the on-off valve seat 20 (such as Figure 1 and Figure 7 As shown in FIG. 1 ), the second distance from the eccentric pivot point 43 to the second side horizontal plane 42 corresponds to the valve closing state of the on-off valve seat 20 (as shown in FIG. 1 ). Fig.10As shown in the figure), the first distance is greater than the second distance, and the difference between the first distance and the second distance is greater than or equal to the lifting stroke of the piston rod 21. Since the eccentric pivot at one end of the driving handle 40 is connected to the protruding end of the rod portion 21a of the piston rod 21, the driving handle 40 can accurately control the height position of the piston rod 21 under different horizontal postures by utilizing the difference between the first distance and the second distance, thereby realizing the switching of the on state and the off state of the supply valve. Since the first distance is greater than the second distance, and the difference between the first distance and the second distance is greater than or equal to the lifting stroke of the piston rod 21, the sealing elastic member 24 absorbs the difference and collapses, ensuring that the driving handle 40 can provide sufficient mechanical advantage when in different positions, ensuring that the movement range of the piston rod 21 meets the on-off requirements of the supply valve, thereby retaining the wear and tear durability space of the double-conical main valve head 22. The specific structure described above not only improves the response speed and accuracy of the supply valve, but also enhances the reliability and stability of the large-size wafer cleaning system, and reduces the risk of misoperation due to mechanical failure. Especially in the chemical cleaning process of large-size wafers, it can effectively avoid the problem of chemical cleaning liquid flow interruption caused by valve body damage or control failure, thereby ensuring the continuity and safety of the cleaning process.

[0108] See also Figure 1 and Figure 2 In this preferred example, an L-shaped retaining wall 25 is formed on the top of the other-drive valve body 23, and a limited rotation stop portion 45 is formed on only one side of the pivot end of the drive handle 40, so as to expand the width of the drive handle 40 at the eccentric pivot end and interfere with the horizontal rotation of the drive handle 40. More specifically, under the cooperation of the limited rotation stop portion 45 and the L-shaped retaining wall 25, the horizontal rotation angle of the drive handle 40 in the horizontal posture is not greater than 60 degrees (such as Figure 1 As shown in FIG. 1 ), the horizontal rotation angle of the driving handle 40 in the upright position is not greater than 120 degrees (as shown in FIG. Fig.11 and Fig.12 As shown). By using the L-shaped retaining wall 25 formed on the top of the other-drive valve body 23 and the rotation-limiting stopper 45 formed at one end of the driving handle 40 to cooperate with each other, if the driving handle 40 is to be turned over, the maximum rotation angle of the driving handle 40 in the horizontal position is limited to no more than 60 degrees, thereby ensuring the stability of the driving handle 40 during the horizontal rotation process and preventing mechanical damage caused by excessive rotation. At the same time, the maximum rotation angle of the driving handle 40 in the upright position does not exceed 180 degrees, thereby ensuring the precise control of the driving handle 40 in the upright position and improving the reliability and service life of the on-off valve seat 20. This not only improves the safety of operation, but also enhances the stability and reliability of the supply valve under different working conditions.

[0109] See also Figure 7 and Fig.10In this preferred example, the driving handle 40 has different horizontal postures in the valve-on state and the valve-off state of the on-off valve seat 20. By using the driving handle 40 having different horizontal postures in the valve-on state and the valve-off state of the on-off valve seat 20, the precise position of the driving handle 40 in different working states is ensured, thereby improving the reliability and stability of the on-off valve seat 20.

[0110] When the valve is in the on state, a portion of the first side horizontal surface 41 of the driving handle 40 is flat against the top of the other driving valve body 23 to form a first horizontal posture (such as Figure 7 As shown), the maximum opening of the on-off valve seat 20 is ensured, so that the chemical cleaning liquid can flow smoothly without clogging; when the valve is closed, the second side horizontal surface 42 of the driving handle 40 is flat against the top of the driving valve body 23, ensuring that the on-off valve seat 20 is completely closed to the chemical cleaning liquid at the liquid supply inlet 12, preventing leakage of the chemical cleaning liquid and protecting the safe operation of the large-size wafer chemical cleaning equipment; therefore, this structural setting not only improves the service life of the valve body, but also reduces the system maintenance cost, and is suitable for the high-precision control requirements in the chemical cleaning process of large-size wafers.

[0111] In this example, if Figure 7 As shown, corresponding to the valve conduction state of the on-off valve seat 20, the first horizontal posture of the driving handle 40 is to point the extended end of the driving handle 40 toward the liquid supply outlet 13, and the vertical projection area of ​​the driving handle 40 overlaps in the main cavity 10; Fig.10 As shown, corresponding to the valve-off state of the on-off valve seat 20, the second horizontal posture of the driving handle 40 is to direct the extended end of the driving handle 40 in a direction perpendicular to the lead-out direction of the liquid supply outlet 13, and the vertical projection area of ​​the driving handle 40 exceeds the main cavity 10. Therefore, it is easy to judge whether the supply valve is in the valve-on state or the valve-off state according to the first horizontal posture and the second horizontal posture of the driving handle 40.

[0112] The embodiment of the present invention also provides a method for supplying chemical cleaning liquid to a large-sized wafer, such as Figure 6 The process shown includes steps S1 to S5 described below.

[0113] Step S1: Comparison Figure 1 and Figure 7 , providing a large-size wafer chemical cleaning liquid supply valve as described in the above basic structure example, the inlet of the supply valve is connected to the chemical cleaning liquid delivery pipeline 15, the outlet of the supply valve is connected to the semiconductor wafer cleaning chamber, and the backwash port 14 of the supply valve is connected to the chamber cleaning liquid delivery pipeline 15;

[0114] Step S2: Recheck Figure 7, in the valve conduction state of the on-off valve seat 20, when the first fluid pressure of the chemical cleaning liquid passing through the liquid supply inlet 12 is higher than the lower threshold of the flow channel pressure, the self-balancing valve head 32 automatically seals the backwash port 14; at this time, the valve conduction is normal use, and the chemical cleaning liquid flows out from the outlet;

[0115] Step S3: Comparison Figure 8 , in the valve conduction state of the on-off valve seat 20, when the second fluid pressure of the cavity cleaning liquid passing through the backwashing port 14 changes dynamically, the self-balancing valve head 32 still automatically seals the backwashing port 14; therefore, under abnormal backwashing pressure, the valve conduction is still used normally, and the chemical cleaning liquid flows out of the outlet;

[0116] Step S4: Comparison Fig. 9 , in the valve conduction state of the on-off valve seat 20, when the first fluid pressure of the chemical cleaning liquid passing through the liquid supply inlet 12 is dynamically reduced and is lower than the lower threshold of the flow channel pressure, the self-balancing valve head 32 naturally floats in the horizontal part of the inverted L-shaped flow channel 11, and the cavity cleaning liquid is supplemented by the backwashing port 14 to stabilize the liquid supply; for example, when the conduction pressure is abnormally reduced due to power failure, the fluid is supplemented by the backwashing port 14, and the valve conduction is still used normally to prevent the outlet from being cut off, and the chemical cleaning liquid and the cavity cleaning liquid flow out of the outlet;

[0117] Step S6: Comparison Fig.10 When the on-off valve seat 20 is in the valve-off state, when the double-conical main valve head 22 blocks the inverted L-shaped flow channel 11, the second fluid pressure of the cavity cleaning liquid passing through the backwash port 14 is sufficient to cause the self-balancing valve head 32 to automatically open the backwash port 14; therefore, when the valve is closed, the backwash port 14 is automatically fully opened to prevent the outlet from being interrupted, and the outlet flows out the cavity cleaning liquid.

[0118] The implementation principle of the above method example is that the above large-size wafer chemical cleaning liquid supply method can achieve the following technical effects:

[0119] 1. Ensure stable liquid supply: In the valve conduction state of the on-off valve seat 20, when the first fluid pressure of the liquid supply inlet 12 is higher than the lower threshold of the flow channel pressure (higher than the lower limit of the liquid pressure setting of the valve cleaning liquid, for example, greater than 3 bar), the self-balancing valve head 32 automatically seals the backwashing port 14 to ensure that the chemical cleaning liquid flows stably from the liquid supply outlet 13 to the liquid supply outlet 13, avoiding the problem of unstable liquid supply at the liquid supply outlet 13 due to leakage of the backwashing port 14;

[0120] 2. Dealing with backwash pressure changes: Even in the valve conduction state of the on-off valve seat 20, when the second fluid pressure of the cavity cleaning liquid passing through the backwash port 14 changes dynamically (for example, greater than the upper limit of the liquid pressure setting of the valve cleaning liquid, such as greater than 4 bar, specifically 5 bar), the self-balancing valve head 32 can still automatically seal the backwash port 14, and the second fluid pressure has a wide allowable range, ensuring that the liquid supply process is not affected, thereby improving the reliability and stability of the large-size wafer chemical cleaning system;

[0121] 3. Preventing interruption of liquid supply: When the first fluid pressure at the liquid supply inlet 12 decreases dynamically and is lower than the lower threshold of the flow channel pressure (lower than the lower limit of the liquid pressure setting of the valve cleaning liquid, for example, less than 3 bar, specifically 2 bar), the self-balancing valve head 32 will naturally float in the horizontal part of the inverted L-shaped flow channel 11, and the cavity cleaning liquid will be replenished by the backwash port 14, thereby stabilizing the liquid supply, avoiding the problem of liquid supply interruption caused by insufficient liquid supply pressure at the liquid supply inlet 12, and eliminating the hidden danger of equipment failure caused by abnormal power outage;

[0122] 4. Automatic backwashing: In the valve-off state of the on-off valve seat 20, when the double-cone main valve head 22 closes the L-shaped flow channel 11, the second fluid pressure of the cavity cleaning liquid passing through the backwash port 14 is sufficient to make the self-balancing valve head 32 automatically open the backwash port 14, ensuring the automatic opening of the backwash port 14 when the valve is closed, preventing the chemical cleaning liquid from being retained in the valve, and reducing the damage to the valve body;

[0123] In summary, the method significantly improves the durability and reliability of the chemical cleaning liquid supply valve for large-size wafers by optimizing the automatic control mechanism of the backwash port 14, thereby ensuring the continuity and stability of the chemical cleaning process for large-size wafers.

[0124] In this preferred example, because the top of the other-drive valve body 23 is formed with an L-shaped retaining wall 25, the driving handle 40 forms a limited rotation stop portion 45 on only one side of the pivoted end. Under the cooperation of the limited rotation stop portion 45 and the L-shaped retaining wall 25, the horizontal rotation angle of the driving handle 40 in a horizontal position is not greater than 60 degrees, and the horizontal rotation angle of the driving handle 40 in an upright position is not greater than 120 degrees; the supply method further includes: an on-off switching step S5 between any one of step S2, step S3 and step S4 and step S6, including: referring to Fig.11 , changing the first horizontal posture of the driving handle 40 from the first horizontal posture of the first side horizontal surface 41 flat against the top of the other-driving valve body 23 to the upright posture, so that the on-off valve seat 20 is in the valve conduction state; refer to Fig.12, the driving handle 40 in the upright position is rotated so that the end of the rotation limit stopper 45 originally adjacent to the L-shaped retaining wall 25 is changed to the other end adjacent to the L-shaped retaining wall 25. The rotation angle of the driving handle 40 in the upright position is between 60 degrees and 120 degrees; refer to Fig.10 , changing the upright posture of the driving handle 40 from the upright posture to a second horizontal posture with its second side horizontal surface 42 flat against the top of the other-drive valve body 23, so that the on-off valve seat 20 is in the valve closing state.

[0125] In summary, the design of the on-off valve seat 20 can ensure the reliability and stability of the supply valve. The externally driven valve body 23 is combined with the upper part of the main cavity 10 to provide a movable accommodation for the piston disc 21d of the piston rod 21, ensuring the controllable lifting and lowering movement of the piston disc 21d of the piston rod 21 inside the valve body of the externally driven valve body 23, thereby realizing the on-off function of the valve; the sealing elastic member 24 is located in the externally driven valve body 23 and is sleeved on the sleeve 21c of the piston rod 21, providing elastic downward pressure of the piston rod 21, ensuring that the piston rod 21 can maintain the valve head sealing position in the valve closing state without external interference, and preventing accidental leakage; the driving handle 40 is arranged above the externally driven valve body 23, and one end of the eccentric pivot is connected to the protruding end of the rod portion 21a of the piston rod 21; the design of the driving handle 40 enables it to switch between different horizontal planes through simple upright and rotating operations to realize the on-off state conversion of the valve, which is specifically manifested as follows:

[0126] When the first side horizontal surface 41 of the driving handle 40 is flat against the top of the driving valve body 23, the valve is in the conducting state (eg, Figure 7 shown);

[0127] When the second side horizontal surface 42 of the driving handle 40 is flat against the top of the driving valve body 23, the valve is in the closed state (eg, Fig.10 shown);

[0128] The rotation angle of the driving handle 40 in a horizontal position is not greater than 60 degrees, and the rotation angle in an upright position is between 60 degrees and 120 degrees, ensuring that the rotation limit stopper 45 of the driving handle 40 can cooperate with the L-shaped retaining wall 25 to limit the maximum rotation angle of the driving handle 40 and prevent misoperation;

[0129] The L-shaped retaining wall 25 is also used to form a rotation limiting stopper 45 at only one side of one end of the driving handle 40, which cooperates with the L-shaped retaining wall 25 to limit the horizontal rotation angle of the driving handle 40, ensuring that the horizontal rotation angle of the driving handle 40 in a horizontal posture is not greater than 60 degrees, and the horizontal rotation angle of the driving handle 40 in an upright posture is not greater than 120 degrees, thereby further improving the operating accuracy and reliability of the valve;

[0130] The on-off switching step S5 in the supply method has the following technical performances:

[0131] 1. Change the first horizontal posture of the driving handle 40 from the first horizontal posture in which the first side horizontal surface 41 is flat against the top of the driving valve body 23 to the upright posture, so that the on-off valve seat 20 is in the valve conduction state;

[0132] 2. Rotate the driving handle 40 in the upright position so that the end of the rotation limit stopper 45 originally adjacent to the L-shaped retaining wall 25 changes to the other end adjacent to the L-shaped retaining wall 25. The rotation angle of the driving handle 40 in the upright position is between 60 degrees and 120 degrees;

[0133] 3. Change the upright posture of the driving handle 40 from the upright posture to the second horizontal posture with its second side horizontal surface 42 flat against the top of the other driving valve body 23, so that the on-off valve seat 20 is in the valve closing state; the above-mentioned implementation operations are not only convenient in steps (pull the driving handle 40 up and rotate it 90 degrees in the upright posture, and then press down on the back side), but also simple in overall on-off switching structure. The on-off valve seat 20 can not only accurately control the on-off state of the valve, but also effectively prevent valve failure caused by accidental operation or mechanical failure, thereby ensuring the stable supply of chemical cleaning liquid, reducing damage to the supply valve, and avoiding supply interruption. Therefore, the driving handle 40 can realize the on-off operation of the supply valve at a limited rotation angle (specifically, a 90-degree rotation of the driving handle 40 in the upright posture) to prevent accidental touch and misoperation, which is conducive to improving the durability of the supply valve.

[0134] The embodiments of this specific implementation method are all preferred embodiments for facilitating the understanding or implementation of the technical solutions of the present invention, and are not intended to limit the protection scope of the present invention. All equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A chemical cleaning liquid supply valve for large-sized wafers, characterized in that: include: The main cavity has an inverted L-shaped flow channel, the bottom end of the inverted L-shaped flow channel is a liquid supply inlet, the side end of the inverted L-shaped flow channel is a liquid supply outlet, and a backwash port is formed on a part of the horizontal portion of the inverted L-shaped flow channel; The on-off valve seat is combined with the upper part of the main cavity and aligned with the vertical part of the inverted L-shaped flow channel. The double-conical main valve head connected to one end of the piston rod of the on-off valve seat is larger than the longitudinal flow channel diameter of the vertical part, and is used to open and close the liquid supply inlet and the liquid supply outlet of the inverted L-shaped flow channel; A backwash valve seat is combined with the lower part of the main cavity and is aligned with the backwash port located at the horizontal part of the inverted L-shaped flow channel. The self-balancing valve head connected to one end of the float of the backwash valve seat is larger than the diameter of the backwash port, and the self-balancing valve head has an inverted cone surface. The backwash valve seat is configured to: The first fluid pressure of the double-conical main valve head opening the inverted L-shaped flow channel acts on the reverse cone surface of the self-balancing valve head, which is sufficient to make the self-balancing valve head automatically close the backwash port; When the first fluid pressure of the liquid supply inlet is dynamically reduced, the self-balancing valve head naturally floats in the horizontal portion of the inverted L-shaped flow channel, and the fluid is supplemented by the backwash port to stabilize the liquid supply; When the double-conical main valve head closes the inverted L-shaped flow channel, the second fluid pressure from the backwash port acts on the sealing surface of the self-balancing valve head, which is sufficient to make the self-balancing valve head automatically open the backwash port; The on-off valve seat comprises: A separate drive valve body is combined above the main cavity to movably accommodate the piston disc of the piston rod; the piston rod has a sleeve portion located in the separate drive valve body and a rod portion passing through the separate drive valve body above the piston disc; A sealing elastic member, located in the other-drive valve body and sleeved on the sleeve portion of the piston rod to provide elastic downward pressure for the piston rod; The on-off valve seat also includes: a driving handle, which is arranged above the externally driven valve body, and one end of the driving handle is eccentrically pivoted to connect the protruding end of the rod portion of the piston rod, and the driving handle has a first side horizontal plane and a second side horizontal plane. A first distance from the eccentric pivot point to the first side horizontal plane corresponds to the valve-on state of the on-off valve seat, and a second distance from the eccentric pivot point to the second side horizontal plane corresponds to the valve-off state of the on-off valve seat. The first distance is greater than the second distance, and the difference between the first distance and the second distance is greater than or equal to the lifting stroke of the piston rod.

2. The large-size wafer chemical cleaning liquid supply valve according to claim 1, characterized in that: The backwash valve seat includes a self-adjusting elastic mechanism to provide a second buoyancy of the floater. The self-adjusting elastic mechanism can dynamically adjust the sealing pressure of the self-balancing valve head toward the backwash port as the second fluid pressure from the backwash port changes.

3. The large-size wafer chemical cleaning liquid supply valve according to claim 2, characterized in that: The backwash valve seat comprises: A self-driving valve body is combined below the main cavity to accommodate the float in a movable manner; The self-driving elastic member is arranged in the self-driving valve body to provide a first buoyancy force for the floater.

4. The large-size wafer chemical cleaning liquid supply valve according to claim 3, characterized in that: The self-adjusting elastic mechanism includes a bypass pipe and a self-balancing flow channel pressure regulator arranged in the bypass pipe. The bypass pipe connects the delivery pipeline for connecting the backwash port and the inner space of the backwash valve seat. The bypass pipe provides a second buoyancy force that can push the float to rise through the self-balancing flow channel pressure regulator.

5. The large-size wafer chemical cleaning liquid supply valve according to claim 1, characterized in that: An L-shaped retaining wall is formed on the top of the externally driven valve body, and a limited rotation stop portion is formed on only one side of the pivotal end of the driving handle. With the cooperation of the limited rotation stop portion and the L-shaped retaining wall, the horizontal rotation angle of the driving handle in a horizontal position is not greater than 60 degrees, and the horizontal rotation angle of the driving handle in an upright position is not greater than 120 degrees.

6. The large-size wafer chemical cleaning liquid supply valve according to claim 5, characterized in that: The driving handle has different horizontal postures in the valve-on state and the valve-off state of the on-off valve seat.

7. A method for supplying chemical cleaning liquid to large-size wafers, characterized in that: Includes steps: S1. Provide a large-size wafer chemical cleaning liquid supply valve as described in claim 1, wherein the inlet of the supply valve is connected to a delivery pipeline of the chemical cleaning liquid, the outlet of the supply valve is connected to a semiconductor wafer cleaning chamber, and the backwash port of the supply valve is connected to a delivery pipeline of the chamber cleaning liquid; S2, in the valve conduction state of the on-off valve seat, when the first fluid pressure of the chemical cleaning liquid passing through the liquid supply inlet is higher than the lower limit threshold of the flow channel pressure, the self-balancing valve head automatically seals the backwash port; S3, in the valve conduction state of the on-off valve seat, when the second fluid pressure of the cavity cleaning liquid passing through the backwash port changes dynamically, the self-balancing valve head still automatically seals the backwash port; S4, in the valve conduction state of the on-off valve seat, when the first fluid pressure of the chemical cleaning liquid passing through the liquid supply inlet is dynamically reduced and is lower than the lower limit threshold of the flow channel pressure, the self-balancing valve head naturally floats in the horizontal part of the inverted L-shaped flow channel, and the cavity cleaning liquid is supplemented by the backwash port to stabilize the liquid supply; S6, with the on-off valve seat in the valve-off state, when the double-cone main valve head closes the inverted L-shaped flow channel, the second fluid pressure of the cavity cleaning liquid passing through the backwash port is sufficient to cause the self-balancing valve head to automatically open the backwash port; Wherein, the on-off valve seat comprises: A separate drive valve body is combined above the main cavity to movably accommodate the piston disc of the piston rod; the piston rod has a sleeve portion located in the separate drive valve body and a rod portion passing through the separate drive valve body above the piston disc; A sealing elastic member, located in the other-drive valve body and sleeved on the sleeve portion of the piston rod to provide elastic downward pressure for the piston rod; A driving handle is arranged above the externally driven valve body, one end of the driving handle is eccentrically pivoted to the protruding end of the rod portion of the piston rod, the driving handle has a first side horizontal plane and a second side horizontal plane, a first distance from the eccentric pivot point to the first side horizontal plane corresponds to the valve-on state of the on-off valve seat, a second distance from the eccentric pivot point to the second side horizontal plane corresponds to the valve-off state of the on-off valve seat, the first distance is greater than the second distance, and the difference between the first distance and the second distance is greater than or equal to the lifting stroke of the piston rod.

8. The method for supplying chemical cleaning liquid to large-size wafers according to claim 7, characterized in that: An L-shaped retaining wall is formed on the top of the externally driven valve body, and a limited rotation stop portion is formed on only one side of the pivotal end of the driving handle. With the cooperation of the limited rotation stop portion and the L-shaped retaining wall, the horizontal rotation angle of the driving handle in a horizontal position is not greater than 60 degrees, and the horizontal rotation angle of the driving handle in an upright position is not greater than 120 degrees.

9. The method for supplying chemical cleaning liquid to large-size wafers according to claim 8, characterized in that: The supply method further includes: an on-off switching step S5 between any one of step S2, step S3 and step S4 and step S6, comprising: Changing the first horizontal posture of the driving handle from the first horizontal posture of the first side horizontal surface flat against the top of the other-driven valve body to an upright posture, so that the on-off valve seat is in a valve conduction state; Rotate the driving handle in the upright position so that the end of the rotation limit stop portion originally adjacent to the L-shaped retaining wall changes to the other end adjacent to the L-shaped retaining wall, and the rotation angle of the driving handle in the upright position is between 60 degrees and 120 degrees; The upright posture of the driving handle is changed from the upright posture to a second horizontal posture in which the horizontal surface of the second side is flat against the top of the other-drive valve body, so that the on-off valve seat is in the valve closing state.

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