JP3557581B2 - Liquid processing equipment - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a liquid processing apparatus for immersing a processing target such as a semiconductor wafer or a glass substrate for an LCD in a processing liquid for processing.
[0002]
[Prior art]
Generally, in a manufacturing process of a semiconductor manufacturing apparatus, an object to be processed (hereinafter, referred to as a wafer or the like) such as a semiconductor wafer or LCD glass is treated with a chemical solution such as ammonia water (NH4OH) or hydrofluoric acid (HF) or a rinsing solution. 2. Description of the Related Art A cleaning method in which a cleaning process is performed by sequentially immersing in a processing tank in which a processing liquid such as (for example, pure water) is stored is widely used.
[0003]
As this type of conventional cleaning processing apparatus, a processing liquid supply line that supplies a processing liquid to a processing tank, a chemical liquid supply line including a chemical liquid supply source and a chemical liquid supply unit such as a pump, a lower part of the processing tank, and a chemical liquid 2. Description of the Related Art There is known a structure formed by a liquid supply line connected to a supply source of a liquid for producing a treatment liquid, for example, pure water. According to this liquid processing apparatus, a processing liquid {for example, diluted hydrofluoric acid (DHF)} in which a chemical liquid (for example, HF) is mixed in a rinsing liquid (for example, pure water) is stored in a processing tank, and the processing liquid is stored in this processing liquid. By immersing the wafer or the like for a predetermined time, etching treatment, for example, removal of particles adhering to the wafer surface or removal of a chemically or physically adsorbed heavy metal such as Ni or Cr or a natural oxide film can be performed. After that, the wafer can be immersed in a rinsing liquid supplied into the processing tank to remove the chemical solution attached to the wafer surface.
[0004]
[Problems to be solved by the invention]
However, in this type of conventional liquid processing apparatus, the liquid supply line is configured to be connected to a lower part of the processing tank and a supply source of a liquid, such as pure water, which mixes with a chemical solution to generate a processing liquid. For example, when a device such as a valve provided in the liquid supply line breaks down for some reason, there is a possibility that the chemical solution in the treatment tank or the chemical solution on the chemical solution supply side may flow back to the pure water supply source side. . When the chemical liquid flows back to the pure water supply source side in this way, there is a problem that not only the subsequent processing cannot be performed but also the pure water cannot be used for another processing section.
[0005]
The present invention has been made in view of the above circumstances, and provides a liquid processing apparatus that prevents a processing liquid from flowing back to a liquid supply source side when equipment such as a valve in a liquid supply line breaks down. It is intended for that purpose.
[0006]
[Means for Solving the Problems]
To achieve the above objectives,The liquid processing apparatus of the present invention comprises:A processing tank for storing a processing liquid, a chemical liquid supply line having a chemical liquid supply source for supplying a chemical liquid to the processing tank, a supply source of a liquid mixed with the chemical liquid to generate the processing liquid, A liquid processing apparatus comprising: a supply source and a liquid supply line connected to a lower part of the processing tank;Higher than top edge ofWhile forming an upper detour to detour to the position, this upper detour,Through the buffer tankConnect the branch that opens to the atmosphereAnd a drain pipe is connected to the buffer tank., Characterized by (claims1).
[0008]
In the present invention,It is preferable to provide an open / close valve in the drain pipe (claim 2). Also,It is preferable to connect the branch path to the uppermost position of the upper detour or an appropriate position closer to the processing tank than the uppermost position.(Claim 3).
[0009]
With the above-described configuration, the equipment such as the valves in the liquid supply line should break down, and the processing liquid (including the chemical liquid and the chemical liquid on the side of the chemical liquid supply source) in the processing tank may be supplied to the liquid supply line. Even if the processing liquid flows back to the liquid supply source side, when the processing liquid flows through the upper detour, air flows into the upper detour from the atmosphere side, so that the processing liquid flows back to the liquid supply source side. Can be prevented. Therefore, loss such as interruption of subsequent processing can be reduced as much as possible, and the reliability of the apparatus can be improved, for example, by allowing pure water to be used in another processing section (claim). Item 13).
[0010]
Also,The above branch path is opened to the atmosphere through a buffer tank, so that the processing liquid (including a chemical solution or the like) flowing backward through the liquid supply line, or from the branch path when the supply pressure of the liquid supply source at normal time is high. The effluent can be stored in the buffer tank and then drained if necessary.it can.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this embodiment, a case in which the liquid processing apparatus of the present invention is applied to a semiconductor wafer cleaning processing system will be described.
[0012]
FIG. 1 is a schematic plan view showing an example of a cleaning system to which a liquid processing apparatus according to the present invention is applied.
[0013]
The cleaning processing system includes a loading / unloading unit 2 for loading and unloading a container, for example, a carrier 1, which stores a semiconductor wafer W (hereinafter, referred to as a wafer W), which is a substrate to be processed, in a horizontal state; A processing unit 3 that performs a liquid process and a drying process with a cleaning liquid or the like, and an interface unit 4 that is located between the loading / unloading unit 2 and the processing unit 3 and that performs transfer of the wafer W, position adjustment, and posture change. Is configured.
[0014]
The carry-in / carry-out section 2 has a carrier carry-in section 5a and a carrier carry-out section 5b provided at one end of the cleaning processing system, and a wafer transfer section 6 is provided. In this case, a transfer mechanism (not shown) is provided between the carrier carry-in section 5a and the wafer transfer section 6 so that the carrier 1 is transferred from the carrier carry-in section 5a to the wafer transfer section 6 by the transfer mechanism. It is configured.
[0015]
In addition, a carrier lifter (not shown) is disposed in each of the carrier unloading section 5b and the wafer transfer section 6, and a carrier waiting section (not shown) provided above the loading / unloading section 2 with the empty carrier 1 by the carrier lifter. (Not shown) and receiving from a carrier standby unit. In this case, a carrier transfer robot (not shown) movable in the horizontal direction (X, Y direction) and the vertical direction (Z direction) is provided in the carrier standby unit, and the carrier transfer robot transfers the wafer. The empty carrier 1 conveyed from the section 6 is arranged and can be carried out to the carrier carrying-out section 5b. In addition, in the carrier waiting section, not only the empty carrier but also the carrier 1 in which the wafer W is stored can be made to stand by.
[0016]
The wafer transfer section 6 is open to the interface section 4, and a lid opening / closing device 7 is provided in the opening. The lid (not shown) of the carrier 1 is opened or closed by the lid opening / closing device 7. Therefore, the lid of the carrier 1 containing the unprocessed wafers W transferred to the wafer transfer unit 6 is removed by the lid opening / closing device 7 so that the wafers W in the carrier 1 can be unloaded, and all the wafers W have been unloaded. Thereafter, the lid can be closed again by the lid opening / closing device 7. Further, the lid of the empty carrier 1 transported from the carrier standby section to the wafer transfer section 6 is removed by the lid opening / closing device 7 so that the wafers W can be loaded into the carrier 1 and after all the wafers W have been loaded. Then, the lid can be closed again by the lid opening / closing device 7. A mapping sensor 8 for detecting the number of wafers W stored in the carrier 1 is provided near the opening of the wafer transfer section 6.
[0017]
The interface unit 4 includes a horizontal transfer unit such as a wafer transfer arm 9 for holding a plurality of, for example, 25 wafers W in a horizontal state and transferring the wafer W to and from the carrier 1 of the wafer transfer unit 6. A pitch changer (not shown) that holds, for example, 50 wafers W in a vertical state at predetermined intervals, and a plurality of, for example, 25 wafers W, are positioned between the wafer transfer arm 9 and the pitch changer. And vertical position, for example, a posture converting device, and a position detecting unit for detecting a notch (not shown) provided on the wafer W whose posture has been changed to the vertical state, for example, a notch aligner (not shown). Are arranged. The interface section 4 is provided with a transfer path 16 connected to the processing section 3, and a wafer transfer means such as a wafer transfer chuck 15 is movably disposed on the transfer path 1.
[0018]
On the other hand, the processing unit 3 includes a first processing unit 11 for removing particles and organic contaminants attached to the wafer W, a second processing unit 12 for removing metal contaminants attached to the wafer W, and a wafer. A cleaning / drying processing unit 13 and a chuck cleaning unit 14 for removing and drying a chemical oxide film attached to W are linearly arranged, and include first and second processing units 11 and 12 and a cleaning / drying processing unit. 13, a liquid processing apparatus according to the present invention is used. The wafer transfer chuck movable in the X, Y directions (horizontal direction), the Z direction (vertical direction), and the rotation direction (θ direction) is provided on a transfer path 16 provided at a position facing each of the units 11 to 14. 15 are provided. Further, at a position facing each of the units 11 to 14 on the opposite side of the transport path 16, a storage portion 17 for storing a chemical solution tank and piping devices is formed.
[0019]
Next, the liquid processing apparatus according to the present invention will be described.
[0020]
◎referenceEmbodiment
FIG. 2 shows a liquid processing apparatus according to the present invention.referenceIt is an outline sectional view showing an embodiment. The above-mentioned liquid processing apparatus stores a processing liquid such as a diluting liquid (DHF), which is a mixture of a chemical liquid such as hydrofluoric acid (HF) and a liquid such as pure water (hereinafter referred to simply as a processing liquid) or a rinsing liquid such as pure water. At the same time, a processing tank 20 for immersing an object to be processed, for example, a semiconductor wafer W (hereinafter, referred to as a wafer W), in a processing liquid or a rinsing liquid to clean the surface thereof, And a processing liquid supply line 30 for supplying a processing liquid or pure water to the apparatus.
[0021]
In this case, the processing tank 20 includes an inner tank 21 for storing the processing liquid and the pure water, and an outer tank 22 surrounding the upper end opening of the inner tank and receiving the processing liquid and the pure water overflowing from the inner tank 21. It is configured. Above the processing tank 20, a wafer boat 23 that receives or transfers a plurality of wafers W, for example, 50 wafers, between the wafer boat chuck 15 and the wafer transfer chuck 15 is provided so as to be able to move up and down. The plurality of wafers W, for example, 50 wafers W are configured to be immersed in the processing liquid or pure water stored in the inner tank 21 by lowering.
[0022]
On the other hand, the processing liquid supply line 30 includes a chemical liquid supply line 32 connected to a chemical liquid supply source such as an HF supply source 31 and a liquid supply line connected to a liquid such as a pure water supply source 33 (hereinafter referred to as a pure water supply source 33). 34 (hereinafter referred to as a pure water line 34). As described above, the processing liquid supply line 30 composed of the two systems of the chemical liquid supply line 32 and the pure water supply line 34 joins the chemical liquid supply line 32 and the pure water supply line 34, mixes the chemical liquid and the pure water, and processes the processing liquid. Is generated, the processing liquid can be supplied into the processing tank 20 from the branched processing liquid supply unit 24.
[0023]
In this case, the chemical solution supply line 32 has a fixed amount tank 35 for storing a predetermined amount of the chemical solution (HF) to be supplied into the processing tank 20, and a chemical solution supply for sending the chemical solution stored in the fixed amount tank 35 to the predetermined amount processing tank 20. A metering pump 36 is provided as a means, and the HF supply source 31 is connected between the metering tank 35 and the metering pump 36 via a switching valve 37. In this case, the case where the chemical solution supply means is formed by the metering pump 36 has been described. However, a pumping gas such as N2 gas is supplied into the metering tank 35 without using the metering pump 36, and the chemical solution (HF) is formed. You may make it supply in the processing tank 20.
[0024]
On the other hand, an upper detour 38 located above the level of the processing liquid L stored in the processing tank 20 is formed in a part of the pure water supply line. There is a branch point X at one location, and a branch path 39 that opens to the atmosphere is connected to the branch point X. In this case, a certain position (for example, a floor surface) is set as a reference horizontal plane F, and the height HA from the reference horizontal plane F to the upper end surface of the inner tank 21 of the processing tank 20 is the highest point of the upper detour 38 from the reference horizontal plane F. The height HB has a relationship of HA <HB. The branch path 39 that is open to the atmosphere is formed to be thinner than the pipe diameter of the upper detour 38, and a throttle 40 is interposed in the middle.
[0025]
A flow between the upper detour 38 and the processing liquid supply unit 24 for detecting the flow rate of pure water flowing in the pure water supply line 34 and transmitting the detection signal to the drive unit of the metering pump 36 A meter 41 and a switching valve 42 are provided. In addition, a check valve 43 is provided between the upper detour 38 and the pure water supply source 33 to flow only toward the processing tank 20 and prevent the liquid from flowing back to the pure water supply source 33.
[0026]
In the liquid processing apparatus configured as described above, by switching the switching valve 42 and driving the metering pump 36, a predetermined amount of pure water flows through the pure water supply line 34 toward the processing tank 20. A predetermined amount of the chemical flows from the fixed quantity tank 35 through the chemical supply line 32. Then, the liquid is merged (mixed) at the merging section, and a processing solution having a predetermined concentration is generated and supplied into the inner tank 21 of the processing tank 20. At this time, when pure water is flowing toward the treatment tank 20, a small amount of pure water normally flows out from the branch path 39 to the atmosphere side. However, since the pipe diameter is reduced and the throttle 40 is interposed, It becomes smaller than the flow rate flowing to the processing tank 20 side. In other words, the flow rate of the pure water to be drained is small. Thereafter, a plurality of, for example, 50 wafers W supported by the wafer boat 23 are immersed in the processing liquid L stored in the inner tank 21 of the processing tank 20 for a predetermined time, and particles and the like adhere to the surface of the wafer W. Is removed.
[0027]
When cleaning the wafer W as described above, if the supply pressure of the pure water supply source 33 drops for some reason, the check valve 43 may not function properly or the metering pump 36 may be stopped. When the flow meter 41 that can perform the processing fails, the processing liquid L in the processing tank 20 and the chemical liquid supplied by the metering pump 36 tend to flow back toward the pure water supply source 33 due to the weight of the processing liquid L in the processing tank 20. . When the backflow is attempted in this manner, not only the pure water in the pure water supply line 34 but also the chemical in the chemical supply line 32 and the chemical in the treatment tank 20 are mixed due to the siphon pipe phenomenon in the upper detour 38. The processing liquid L flows backward in the pure water supply line 34 and tends to flow toward the pure water supply source 33. However, at this time, air flows into the upper detour 38 located at a position higher than the upper end surface of the inner tank 21 in the upper detour 38 from the branch path 39 opened to the atmosphere. At this time, as shown in FIG. 3, in the pipe on the processing tank 20 side from the highest point of the upper detour 38, at least the highest level of the upper detour 38 from the same level as the level of the processing liquid L in the inner tank 21. An air-only region Y is formed up to a point height HB (in FIGS. 2 and 3, a case where the height HC of the branch point X is equal to the height HB of the highest point of the upper detour 38). Here, when the supply pressure of the pure water supply source 33 is further reduced, the air region Y is formed over a wider range from the highest point to the opposite side, that is, to the pure water supply source 33 side. Therefore, the height of the liquid level of the processing liquid L in the inner tank 21 and the pure water up to the air region Y in the upper detour 38 (the liquid in contact with the air region Y is pure water at first. However, if the chemical solution spreads over time, it can be said that the liquid is always the same height as the processing solution). Even if the metering pump 36 continues to send the chemical solution, this balance is always maintained. Even if the maximum height is reached, up to the height HA of the upper end surface of the inner tank 21, all the overflowing of the inner tank 21 flows to the outer tank 22. Further, the overflowed processing liquid L can be discharged from the outer tank 22 through a drain pipe (not shown).
[0028]
Therefore, in the pure water supply line 34, the backflow of the chemical liquid upstream of the height HA of the upper end surface of the inner tank 21, that is, toward the pure water supply source 33 is caused by the air region Y formed by the branch path 39 opened to the atmosphere. Can be prevented. Further, in the above configuration, the number of the branch point X and the branch path 39 is one, but the number is not limited to one and may be plural. The height of the branch point X is the highest point of the upper detour 38. The position of the branch point X is from the point equal to the height HA of the upper end face of the inner tank 21 to the pure water supply source 33 side beyond the highest point of the upper detour 38. In this configuration, the air region Y can be formed and the backflow of the chemical solution can be prevented. By preventing the backflow of the chemical solution in this way, it is possible to reduce the loss time such as interruption of the subsequent processing and to enable the pure water to be used in another processing section.
[0029]
In addition, by stopping the operation of the metering pump 36 due to the failure of the flow meter 41, it is possible to prevent the backflow from the metering pump 36. However, the chemical liquid is stored due to the presence of the processing liquid L stored in the processing tank 20. Cannot be completely prevented from flowing back to the pure water supply source 33 side. Therefore, by providing the above-described upper detour 38 and the branch path 39 open to the atmosphere in the pure water supply line 34, it is possible to prevent the chemical liquid from flowing back to the pure water supply source 33 side.
[0030]
◎firstEmbodiment
FIG. 4 shows a liquid processing apparatus according to the present invention.firstIt is an outline sectional view showing an embodiment.
[0031]
firstIn the embodiment, when the supply pressure of the pure water supply source 33 is sufficiently high and the pure water flows to the treatment tank 20 side, the pure water flowing out of the branch path 39 is allowed to be temporarily stored and then drained. It is. That is, as shown in FIG. 4, a buffer tank 45 having an atmosphere opening portion 44 is connected to a branch path 39 connected to the upper detour 38, and a lower end of the buffer tank 45 is connected to the lower end of the buffer tank 45 via an open / close valve 46. This is the case where the drain pipe 47 is connected. In addition,firstIn the embodiment, other parts are as described above.referenceSince the configuration is the same as that of the embodiment, the same portions are denoted by the same reference numerals, and description thereof will be omitted.
[0032]
referenceIn the embodiment, the branch path 39 has a narrow pipe diameter and is provided with the throttle 40. Therefore, when the pure water flows to the processing tank 20 side, the flow rate is usually smaller than the flow rate to the processing tank 20 side. Although it becomes smaller, some pure water flows out of the branch path 39 to the atmosphere side. That is, the pure water is drained from the branch path 39. However, if the outlet of the branch path 39 is provided in a place where the pure water cannot be directly discharged or a place where the drainage can be discharged is far away, if the upper detour 38 is piped to that point, the pipe diameter becomes larger. Because of the large size, it takes a lot of space and the piping is complicated, making assembly and maintenance difficult. If piping is performed to a place where the branch path 39 can be drained instead of the upper bypass path 38, the branch path 39 becomes very long, and even if the liquid starts to flow backward, the air immediately enters the upper bypass path 38 and does not come. In this case, there is a possibility that a part of the processing liquid (or the chemical liquid) flows into the pure water supply source 33 side during a time lag from the start of the backflow to the formation of the air region Y in the pipe.
[0033]
Therefore,firstAs in the embodiment, a branch path 39 of an appropriate length is connected to the buffer tank 45, an atmosphere opening part 44 is provided at the upper part of the buffer tank 45, and a drain pipe 47 is provided at the lower part via an opening / closing valve 46. By connecting the pipe and connecting the outlet of the drain pipe 47 to a place where the liquid can be drained, the pure water that has passed through the branch path 39 when the pure water is flowing toward the processing tank 20 is usually buffered once. 45. At this time, the air corresponding to the amount of pure water that has flowed in from the atmosphere opening portion 44 flows out of the buffer tank 45. After storing the stored pure water for a predetermined amount or for a predetermined time, the pure water is drained through a drain pipe 47 to a place where the liquid can be drained (for example, a drain line of pure water). Therefore, the drainage of the branch passage 39 and the drainage of the drainage pipe 47 can be completely independently performed, so that the piping of the drainage pipe 47 can be used freely.
[0034]
Here, the position (height) of the buffer tank 45 can be set arbitrarily. However, the length of the branch path 39 is set at a position such that a part of the processing liquid does not flow into the pure water supply source 33 due to the time lag. Is preferred. In addition, the pure water is stored in the buffer tank 45 for a predetermined amount or for a predetermined time, but the open / close valve 46 may always be opened to continuously discharge the pure water. In order to reuse the drained pure water, the outlet of the drain pipe 47 is connected to a processing unit or a supply line that requires another pure water. A pump or the like may be interposed).
[0035]
In the liquid processing apparatus configured as described above, when the supply pressure of the pure water supply source 33 decreases for some reason, the check valve 43 does not function properly or the metering pump 36 can be stopped. When the flow meter 41 breaks down, the processing liquid L in the processing tank 20 and the chemical supplied by the metering pump 36 tend to flow back toward the pure water supply source 33 due to the weight of the processing liquid L in the processing tank 20. When the backflow is attempted in this manner, not only the pure water in the pure water supply line 34 but also the chemical in the chemical supply line 32 and the chemical in the treatment tank 20 are mixed due to the siphon pipe phenomenon in the upper detour 38. The processing liquid L flows backward in the pure water supply line 34 and tends to flow toward the pure water supply source 33. However, at this time, air flows from the atmosphere opening portion 44 through the buffer tank 45 and the branch path 39 into the upper detour 38 located at a position higher than the upper end surface of the inner tank 21 in the upper detour 38. At this time, the pure water stored in the buffer tank 45 is prevented from flowing into the branch path 39, that is, the pure water level is always lower than the connection between the buffer tank 45 and the branch path 39. Next, the on-off valve 46 must be opened to drain the liquid.
[0036]
After this,Reference embodimentSimilarly, in the pipe on the processing tank 20 side from the highest point of the upper detour 38, at least the height HB of the highest point of the upper detour 38 from the same level as the level of the processing liquid L in the inner tank 21. FIG. 4 shows a case where the height HC of the branch point X is equal to the height HB of the highest point of the upper detour 38). Here, when the supply pressure of the pure water supply source 33 is further reduced, the air region Y is formed over a wider range from the highest point to the opposite side, that is, to the pure water supply source 33 side. Therefore, the height of the liquid level of the processing liquid L in the inner tank 21 and the pure water up to the air region Y in the upper detour 38 (the liquid in contact with the air region is pure water at first. However, if the chemical solution spreads over time, it can be said that the liquid is always the same height as the processing solution). Even if the metering pump 36 continues to send the chemical solution, this balance is always maintained. Even if the maximum height is reached, up to the height HA of the upper end surface of the inner tank 21, all the overflowing of the inner tank 21 flows to the outer tank 22. Further, the overflowed processing liquid L can be discharged from the outer tank 22 through a drain passage (not shown).
[0037]
Accordingly, in the pure water supply line 34, the air region Y formed by the branch path 39 that is open to the atmosphere allows the chemical solution to flow upstream of the height HA of the upper end surface of the inner tank 21, that is, toward the pure water supply source 33. Backflow can be prevented. Further, in the above configuration, the number of the branch points X and the number of the branch paths 39 are one, but the number is not limited to one and may be plural. Further, the position of the branch point X may be in a range from a point equal to the height HA of the upper end surface of the inner tank 21 to the pure water supply source 33 side beyond the highest point of the upper detour 38. Even with the configuration, the air region Y can be formed to prevent the backflow of the chemical solution. By preventing the backflow of the chemical solution in this way, it is possible to reduce the loss time such as interruption of the subsequent processing and to enable the pure water to be used in another processing section.
[0038]
◎secondEmbodiment
FIG. 5 shows a liquid processing apparatus according to the present invention.secondFIG. 6 is a schematic sectional view showing an embodiment.secondIt is an outline sectional view showing an important section of an embodiment.
[0039]
secondThe embodiment is described above.firstThis is a case where the branch point X is located at a point lower than the height HA of the upper end surface of the inner tank 21 in the embodiment. That is, as shown in FIG. 6, the height HC of the branch point X, which is a connection part of the branch path 39 connected to the upper detour 38 (part of the pure water supply line 34), and the height HC of the upper end surface of the inner tank 21. The height HA has a relationship of HA> HC. The relationship between the height HB of the highest point of the upper detour 38 and the upper end surface HA of the inner tank 21 is as described above.Reference and firstAs in the embodiment, HA <HB. Other parts arefirstSince the configuration is the same as that of the embodiment, the same portions are denoted by the same reference numerals, and description thereof will be omitted.
[0040]
In the liquid processing apparatus configured as described above, when the supply pressure of the pure water supply source 33 decreases for some reason, the check valve 43 may not function properly or the metering pump 36 may be stopped. If the possible flow meter 41 fails, the processing liquid L in the processing tank 20 and the chemical supplied by the metering pump 36 tend to flow back to the pure water supply source 33 due to the weight of the processing liquid L in the processing tank 20. However, at this time, air flows from the atmosphere opening portion 44 through the buffer tank 45 and the branch path 39 from a branch point X located at a position lower than the upper end surface of the inner tank 21 in the upper detour 38. When the air starts to flow in, the liquid level of the upper detour 38 becomes equal to the liquid level of the processing liquid L in the inner tank 21 at that time. However, at the time when the liquid level of the processing liquid L is higher than the height HC of the branch passage X, pure water located above the branch passage X in the upper detour 38 rapidly flows through the branch passage 39. As a result, it flows out to the buffer tank 45. Finally, as shown in FIG. 6, the height of the liquid surface becomes the height HC of the branch point X in the piping on the processing tank 20 side and on the processing tank 20 side from the highest point of the upper detour 38. Keep the balance at height. In the meantime, even if a chemical solution is sent from the metering pump 36 through the chemical solution supply line 32, the same amount of the liquid continues to be discharged from the branch path 39 to the buffer tank 45, and the height of the liquid surface balance does not change. However, since the concentration of the chemical solution gradually increases, even if pure water is initially discharged from the branch passage 39, the treatment liquid having a high chemical concentration gradually flows into the buffer tank through the branch passage 39. Therefore, the drainage pipe 47 connected to the buffer tank 45 must be connected to a place where the liquid can be drained, for example, to a drainage line for the chemical solution coming out of the processing tank 20 to drain the liquid. Therefore, since pure water or treatment liquid always flows through the buffer tank 45, it is better to always drain the liquid with the open / close valve 46 kept open.
[0041]
With such a configuration, an air region Y is formed from at least the height HC of the branch point X to the height HB of the highest point of the upper detour 38, and the chemical region (or the processing solution) is supplied to the water supply source 33 side. Backflow can be prevented. By preventing the backflow of the chemical solution in this way, it is possible to reduce a loss time such as interruption of the subsequent processing and to enable the pure water to be used in another processing unit.
[0042]
In the above description, it is assumed that HA <HB. However, even if HA> HB, if the relationship of HB> HC is established, the air region Y is formed in the same manner as described above, so that backflow is prevented. be able to.
[0043]
◎ Other embodiments
(1) In the above embodiment, two systems, a chemical solution supply line 32 and a pure water supply line 34 forming the treatment solution supply line 30, are connected to the lower part of the treatment tank 20, and the chemical solution and the pure water are mixed and treated. Although the case where the liquid is generated and then supplied into the processing tank 20 has been described, it is not always necessary to connect both the chemical liquid supply line 31 and the pure water supply line 34 to the lower part of the processing tank 20, and at least the pure water supply line As long as the chemical liquid supply line 32 is connected to the lower part of the processing tank 20 and the chemical liquid supply line 32 is piped above the processing tank 20, the chemical liquid is supplied from above the processing tank 20. Good.
[0044]
(2) In the above embodiment, the processing liquid supply line 30 is formed of two systems, the chemical liquid supply line 32 and the pure water supply line 34, and is connected to the lower part of the processing tank 20, or the pure water supply line 32 is connected to the lower part of the processing tank 20, and the case where two systems of the chemical liquid supply line 32 and the pure water supply line 34 are provided, such as a case where the chemical liquid supply line 32 is piped above the processing tank 20, has been described. It is also possible to form the processing liquid supply line 30 in one system.
[0045]
That is, as shown in FIG.Second referenceAs in the embodiment, the processing liquid supply line 30 is formed by only the pure water supply line 34 that connects the supply source 33 of the rinsing liquid such as pure water and the processing liquid supply unit 24 as the processing liquid, and the processing liquid supply line An upper detour 38 is formed in a part of 30 to detour to a position above the level of the rinsing liquid (pure water) L stored in the processing tank 20, and the upper detour 38 is open to the atmosphere. The branch path 39 may be connected.
[0046]
In addition,Second referenceIn the embodiment, other parts are as described above.referenceEmbodiment orsecondSince the configuration is the same as that of the embodiment, the same portions are denoted by the same reference numerals, and description thereof will be omitted.
[0047]
With the above configuration, a rinsing liquid (pure water) can be supplied into the processing tank 20 to remove a chemical solution, particles, and the like attached to the surface of the wafer W.
[0048]
However, when rinsing the wafer W as described above, if the supply pressure of the pure water supply source 33 decreases for some reason, the check valve 43 does not function properly, or the flow meter 41 When a failure occurs, as described above, the processing liquid (rinse liquid) L containing particles and the like subjected to the rinsing processing in the processing tank 20 tends to flow back to the pure water supply source 33 side. At this time, the processing liquid (rinse liquid) L containing particles and the like flows backward to the pure water supply source 33 by providing the above-described detour 38 and the branch path 39 open to the atmosphere in the pure water supply line 34. Can be prevented.
[0049]
(3) In the above embodiment, the case where the liquid processing apparatus according to the present invention is applied to the second processing unit 12 has been described. However, the liquid processing apparatus is also applied to the first processing unit 11 and the cleaning / drying processing unit 13. Of course, you can.
[0050]
(4) In the above embodiment, the case where the liquid processing apparatus according to the present invention is applied to a semiconductor wafer cleaning processing system has been described. However, it is needless to say that the liquid processing apparatus can be applied to LCD glass substrates other than semiconductor wafers. .
[0051]
【The invention's effect】
As described above, according to the present invention, since the configuration is as described above, the following effects can be obtained.
[0052]
(1)The inventionAccording to the above, in the unlikely event that equipment such as valves in the liquid supply line breaks down, the processing liquid (including the chemical liquid and the chemical liquid at the chemical liquid supply source side) in the processing tank is supplied through the liquid supply line. Even if the processing liquid flows back to the source side, when the processing liquid flows through the upper detour, air flows into the upper detour from the atmosphere side, thereby preventing the processing liquid from flowing back to the liquid supply source side. . Therefore, loss such as interruption of subsequent processing can be reduced as much as possible, and the reliability of the apparatus can be improved, for example, by allowing the liquid (pure water) to be used for another processing section. it can.
[0053]
(2)Also,The processing liquid flowing backward in the liquid supply line, or the liquid flowing out of the branch path when the supply pressure of the liquid supply source in a normal state is high, can be stored in the buffer tank, and then drained as necessary. Therefore, in addition to the above (1), it is possible to sufficiently manage the processing liquid (including a chemical solution or the like) that has flowed back, and to improve safety.
[Brief description of the drawings]
FIG. 1 is a schematic plan view of a cleaning system to which a liquid processing apparatus according to the present invention is applied.
FIG. 2 shows a liquid processing apparatus according to the present invention.referenceIt is an outline sectional view showing an embodiment.
FIG. 3referenceIt is an outline sectional view showing an important section of an embodiment.
FIG. 4 shows a liquid processing apparatus according to the present invention.firstIt is an outline sectional view showing an embodiment.
FIG. 5 shows a liquid processing apparatus according to the present invention.secondIt is an outline sectional view showing an embodiment.
FIG. 6secondIt is an outline sectional view showing an important section of an embodiment.
FIG. 7 shows a liquid processing apparatus according to the present invention.Second referenceIt is an outline sectional view showing an embodiment.
[Explanation of symbols]
W Semiconductor wafer (workpiece)
20 treatment tank
30 Treatment liquid supply line
31 HF supply source (chemical solution supply source)
32 Chemical supply line
33 Pure water supply source (liquid supply source)
34 Pure water supply line (liquid supply line)
36 Metering pump (chemical solution supply means)
38 Upper detour
39 fork
41 Flow meter
42 Switching valve
44 Open to atmosphere
45 buffer tank
47 Drain pipe

Claims (3)

A processing tank for storing a processing liquid, a chemical liquid supply line having a chemical liquid supply source for supplying a chemical liquid to the processing tank, a supply source of a liquid mixed with the chemical liquid to generate the processing liquid, A liquid processing apparatus comprising a supply source and a liquid supply line connected to a lower part of the processing tank,
Part of the liquid supply line, while forming an upper detour to detour to a position higher than the upper end surface of the processing tank , connected to the upper detour, a branch path that opens to the atmosphere via a buffer tank , And a drainage pipe connected to the buffer tank . The liquid processing apparatus according to claim 1,
A liquid processing apparatus, wherein an open / close valve is interposed in the drain pipe. The liquid processing apparatus according to claim 1, wherein
A liquid processing apparatus, wherein a branch path is connected to an uppermost position of the upper detour or an appropriate position closer to the processing tank than the uppermost position.

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