JP2020072189A - Substrate processing apparatus - Google Patents

Abstract

To provide a technology capable of measuring conductivity of effluent, drained from a processing tank, more accurately in a substrate processing apparatus.SOLUTION: A substrate processing apparatus performing a predetermined process for a substrate by immersing the substrate into process liquid has a processing tank (7a) capable of pooling the process liquid, a vat part (61) having a liquid receiving part (62) for receiving the process liquid overflowing the processing tank, and an exhaust port (65) placed while spaced apart from the liquid receiving part by a prescribed interval, and pooling at least a part of the process liquid overflowing the processing tank, vat effluent piping (67) connected with the exhaust port, and exhausting the process liquid pooled in the vat part, a piping trap structure part (69) provided in the vat effluent piping, and bringing about a state where the vat effluent piping is filled with the process liquid exhausted from the vat part, and a conductivity measuring device (63) for measuring conductivity of the process liquid filling the vat effluent piping, by inserting a sensor into the piping trap structure part.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a substrate processing apparatus for immersing a substrate such as a semiconductor wafer in a processing liquid stored in a processing tank to perform an etching process or a cleaning process, and particularly to a configuration for measuring the concentration of the processing liquid.

  The manufacturing process of a semiconductor device includes a process of immersing a substrate such as a semiconductor wafer in a processing bath to subject the substrate to an etching process or a cleaning process. Such steps are executed by a substrate processing apparatus including a plurality of processing tanks. The concentration of the processing liquid in each processing tank of this substrate processing apparatus may change over time due to evaporation, decomposition, etc. of the components of the processing liquid. Concentration control is performed to maintain the concentration within an appropriate range.

  In order to control the concentration of the treatment liquid, conventionally, the conductivity of the treatment liquid supplied to the treatment tank has often been measured. However, in the method of measuring the conductivity of the processing liquid before being supplied to the processing tank, it may be difficult to accurately measure the concentration of the processing liquid actually used for the substrate processing in the processing tank. On the other hand, by measuring the conductivity of the processing liquid discharged from the processing tank, it is possible to measure the concentration of the processing liquid actually used for the substrate processing in the processing tank. There were cases where it was difficult to perform highly accurate measurement due to variations in the concentration of the treatment liquid and inclusion of air bubbles. In particular, when the treatment liquid contains a chemical liquid such as TMAH (tetramethylammonium hydroxide), bubbles tend to be mixed in when the treatment liquid flows or drops, and the above-mentioned inconvenience tends to be remarkable.

  As described above, as a technique for measuring the concentration of the processing liquid discharged from the processing bath, the drainage tank 70 for receiving the chemical liquid or the pure water overflowed from the substrate processing bath 10 for processing the surface of the substrate B, and the drainage tank A technique is known in which a drainage container 72 for receiving a chemical solution or pure water discharged from 70 is provided, and a measuring unit 801 of a resistivity measuring device 80 is disposed in the drainage container 72 (Patent Document 1). reference.). In this technique, the chemical liquid or pure water in the drainage tank 70 is discharged to the drainage container 72 via the drainage slope plate 703 arranged in the drainage tank 70 and the receiving slope plate 723 arranged in the drainage container 72. To be done. In the drainage container 72, the measuring unit 801 of the specific resistance measuring device 80 is arranged, and in the vicinity of the measuring unit 801, the diluting liquid supply unit 821 of the diluting liquid supply pipe 82 is installed in parallel, and When the chemical liquid or pure water having a high degree of mixing of the chemical liquid is discharged to 72, pure water is supplied from the diluting liquid supply unit 821 of the diluting liquid supply pipe 82 toward the measuring unit 801 of the resistivity measuring device 80.

  However, this technique is not suitable for measuring the concentration of a treatment liquid containing a chemical liquid such as TMAH, which easily generates bubbles, because it detects that the rinse liquid contains a chemical liquid. ..

JP-A-11-354483 JP, 2017-147369, A JP, 2016-72480, A Patent No. 4975790 JP, 2006-278466, A JP, 9-289158, A

  The present invention has been invented in view of the above situation, and an object thereof is to be able to more accurately measure the conductivity of a processing liquid discharged from a processing tank in a substrate processing apparatus. It is to provide the technology.

The present invention for solving the above problems is a substrate processing apparatus for performing a predetermined process on a substrate by immersing the substrate in a process liquid containing one or more chemical solutions,
A treatment tank capable of storing the treatment liquid;
It has a liquid receiving portion that receives the processing liquid that overflows from the processing tank, and an outlet that is arranged at a predetermined distance from the liquid receiving portion, and stores at least a part of the processing liquid that overflows from the processing tank. The butt part,
A vat drainage pipe connected to the discharge port, for discharging the processing liquid stored in the vat portion,
A pipe trap structure part provided in the vat drainage pipe, wherein the processing liquid discharged from the vat portion fills the vat drainage pipe,
By inserting the sensor in the pipe trap structure, a conductivity measuring device for measuring the conductivity of the treatment liquid that fills the vat drainage pipe,
And a substrate processing apparatus.

  That is, in the present invention, the processing liquid overflowing laterally from the processing tank in the substrate processing apparatus is temporarily stored in the butt portion. The butt portion has a liquid receiving portion that receives the processing liquid overflowing from the processing tank, and a discharge port that is arranged at a predetermined distance from the liquid receiving portion. Then, the conductivity of the processing liquid flowing through the vat drain pipe for discharging the processing liquid stored in the vat portion is measured. Further, the vat drainage pipe is provided with a pipe trap structure part for keeping the vat drainage pipe filled with the processing liquid discharged from the vat part, and in this pipe trap structure part, the sensor of the conductivity measuring device is provided. Interpolated.

  As described above, in the present invention, the processing liquid overflowing from the processing tank is temporarily stored in the butt portion, so that the concentration of the processing liquid of which conductivity is to be measured can be made uniform. Further, in the present invention, the conductivity of the processing liquid discharged from the discharge port of the vat portion is measured, but this discharge port is provided at a predetermined interval from the liquid receiving portion into which the processing liquid overflowing laterally from the processing tank flows in the vat portion. Spaced apart. Therefore, it is possible to prevent bubbles trapped in the processing liquid in the liquid receiving section from being discharged from the discharge port as they are and flowing into the vat drain pipe. Further, since the vat drainage pipe is provided with a pipe trap structure section that keeps the vat drainage pipe filled with the processing liquid discharged from the vat part, the sensor of the conductivity measuring device can more reliably detect the vat drainage liquid. It is immersed in the processing liquid in the pipe. As a result, it is possible to improve the accuracy of conductivity measurement by the conductivity measuring device.

  As a result, according to the present invention, it is possible to more accurately measure the conductivity of the processing liquid overflowing from the processing tank. When the treatment liquid contains a chemical such as TMAH, the presence of the activator makes it easier for the treatment liquid to entrap bubbles (that is, bubbles easily), and a gas such as hydrogen is generated by a chemical reaction during the substrate treatment. Since it is easy to do so, mixing of bubbles in the processing liquid is likely to be a problem. Therefore, when the present invention is applied to the case where the treatment liquid contains a drug such as TMAH, a more remarkable effect can be obtained.

Further, in the present invention, the treatment bath is an inner bath in which the substrate is immersed and the predetermined treatment is performed, and an outer bath which temporarily stores a processing liquid overflowing from the inner bath around the inner bath. Has and
The liquid receiving portion in the butt portion may receive the processing liquid that overflows further from the outer tank.

  According to this, after the substrate is subjected to the predetermined processing in the inner tank of the processing tank, the processing liquid is temporarily stored in the outer tank and further stored in the butt portion. Therefore, it is possible to more reliably make the concentration of the treatment liquid uniform.

  Further, in the present invention, the liquid receiving portion further includes an inflow portion that obliquely flows the processing liquid overflowing from the processing tank into the vat portion, and the discharge port is configured to inflow the inflow portion with respect to the inflow portion. It may be arranged on the side opposite to the inflow direction of the processing liquid flowing in from the section.

  That is, in the present invention, when the processing liquid is received from the processing tank to the vat portion, the processing liquid overflowing from the processing tank obliquely flows into the vat portion via the inflow portion. Therefore, as compared with the case where the processing liquid directly drops from the high position to the butt portion, it is possible to suppress the inclusion of bubbles in the processing liquid. Further, the discharge port connected to the vat drainage pipe is arranged on the opposite side to the inflow direction of the processing liquid flowing from the inflow portion. Therefore, it is possible to prevent the air bubbles entrapped when the processing liquid flows in as they are from flowing into the discharge port, and it is possible to secure a time and distance allowance for the entrained air bubbles to be removed from the processing liquid in the butt portion. it can. As a result, it is possible to more reliably suppress the inclusion of bubbles in the processing liquid flowing into the vat drainage pipe.

  Further, in the present invention, the butt portion is connected to the second outlet and the second outlet arranged in the inlet direction of the processing liquid flowing from the inlet with respect to the inlet. You may make it further have a 2nd vat drainage piping which discharges the process liquid stored in the vat part.

  Here, in the present invention, the second vat drainage pipe is not provided with the pipe trap structure and the conductivity measuring device. By providing this second vat drainage pipe, the amount of the treatment liquid flowing into the vat drainage pipe out of the treatment liquid overflowing from the treatment tank is adjusted to an appropriate amount, and the amount of the treatment liquid stored in the vat portion is adjusted. It is possible to maintain an appropriate amount. Furthermore, in the present invention, as described above, the second discharge port and the second vat drainage pipe are arranged in the inflow direction of the processing liquid that obliquely flows into the vat portion from the inflow portion. Therefore, most of the bubbles trapped due to the inflow of the processing liquid are discharged from the butt portion by the second discharge port and the second butt drainage pipe. As a result, it is possible to prevent the bubbles entrapped by the inflow of the processing liquid from flowing into the discharge port and the vat drain pipe and affecting the measurement of the conductivity by the conductivity measuring device.

  Further, in the present invention, in the butt portion, the discharge port may be arranged at a position lower than the second discharge port.

  According to this, the bubbles trapped in the treatment liquid stored in the butt portion are more likely to be discharged from the second outlet than the outlet. As a result, it is possible to more reliably prevent the bubbles entrapped in the treatment liquid from flowing into the discharge port and the vat drain pipe and affecting the measurement of conductivity by the conductivity measuring device.

  Further, in the present invention, the vat section may have a stirring means for stirring the treatment liquid stored in the vat section.

  The stirring means may be a stirring rod or a stirring plate that is provided inside the vat portion and that stirs the processing liquid by rotating. Further, it may be a vibration generator that applies vibration or ultrasonic waves to the treatment liquid stored in the butt portion. Further, it may be a resistor that complicatedly changes the flow of the processing liquid generated in the vat when the processing liquid flows from the inflow portion. As a result, the concentration of the treatment liquid stored in the butt portion can be made more reliable, and the accuracy of conductivity measurement by the conductivity measuring device can be improved.

  Further, in the present invention, the second vat drainage pipe may be provided with valve means capable of controlling the amount of the processing liquid discharged through the second vat drainage pipe.

  According to this, the valve means actively controls the amount of the processing liquid discharged through the second vat drainage pipe, so that the vat drainage pipe of the processing liquid that overflows from the processing tank can be more reliably supplied to the vat drainage pipe. It is possible to control the amount of the processing liquid that flows in to an appropriate amount and to maintain the amount of the processing liquid stored in the butt portion at an appropriate amount.

  Further, in the present invention, the pipe trap structure portion may be a portion provided in the vat drainage pipe and maintaining the vat drainage pipe substantially horizontal.

  In this way, by maintaining the vat drainage pipe substantially horizontal, it is possible to reduce the flow rate of the processing liquid flowing through the vat drainage pipe and to retain the processing liquid in the vat drainage pipe at this portion. .. Therefore, with a simpler structure, it is possible to fill the vat drainage pipe with the treatment liquid in the pipe trap structure portion. Further, at that time, if the sensor of the conductivity measuring device is placed in the vat drainage pipe from the lower side, more reliably, the entire surface of the sensor of the conductivity measuring device is treated in the vat drainage pipe. It can be brought into contact with the liquid, and it is possible to more reliably improve the measurement accuracy of the conductivity.

  Further, in the present invention, in the vat drainage pipe, on the downstream side of the pipe trap structure, a pipe rising part that is bent so that the vat drainage pipe is at a position higher than the pipe trap structure is provided. It may be provided.

  According to this, the treatment liquid can be retained in the pipe trap structure more reliably, and the vat drain pipe can be filled with the treatment liquid. Therefore, the entire surface of the sensor of the conductivity measuring device can be more surely brought into contact with the treatment liquid in the vat drainage pipe, and the conductivity measurement accuracy can be improved.

  Further, in the present invention, in the pipe trap structure, a branch pipe having a flow passage cross-sectional area smaller than that of the vat drainage pipe and extending downward is provided on the downstream side of the sensor of the conductivity measuring device. You may be allowed to.

  According to this, after the substrate processing is completed, the processing liquid remaining in the piping trap structure section can be discharged from the branch piping. Therefore, it is possible to suppress the occurrence of inconveniences such as the treatment liquid remaining in the pipe trap structure portion after the substrate treatment is finished and the sensor of the conductivity measuring device is corroded.

  The above-mentioned means for solving the problems can be appropriately combined and used.

  According to the present invention, in the substrate processing apparatus, it is possible to more accurately measure the conductivity of the processing liquid discharged from the processing bath.

1 is a perspective view showing a schematic configuration of a substrate processing apparatus according to a first embodiment. 3 is a functional block diagram of the substrate processing apparatus according to the first embodiment. FIG. 5 is a diagram showing a configuration related to control of a processing liquid in each processing tank in the processing unit of the substrate processing apparatus according to the first embodiment. FIG. 3 is a schematic diagram of a configuration related to concentration measurement of a processing liquid discharged from a processing tank of the substrate processing apparatus according to the first embodiment. FIG. FIG. 3 is a diagram showing a configuration around a bat portion according to the first embodiment. FIG. 3 is a plan view of the bat portion according to the first embodiment. FIG. 7 is a diagram showing a configuration around a bat portion according to a second embodiment. FIG. 7 is a diagram showing a configuration around a bat portion according to a third embodiment.

<Example 1>
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the following embodiment is one mode of the present invention and does not limit the technical scope of the present invention. FIG. 1 is a perspective view showing a schematic configuration of the substrate processing apparatus 1 according to the first embodiment. The substrate processing apparatus 1 mainly performs an etching process or a cleaning process (hereinafter, also simply referred to as “process”) on a substrate W. In the substrate processing apparatus 1, the buffer unit 2 for stocking the substrate W is arranged at one end in the longitudinal direction (that is, the right rear side in FIG. 1), and the buffer unit 2 has an outer wall side (that is, further right rear side in FIG. 1). On the side), a front panel (not shown) for operating the substrate processing apparatus 1 is provided. A substrate loading / unloading port 3 is provided on the opposite side of the buffer unit 2 from the front panel. Further, in the longitudinal direction of the substrate processing apparatus 1, from the opposite side of the buffer section 2 (that is, the left front side in FIG. 1), processing sections 5, 7 and 9 that perform processing on the substrate W are juxtaposed.

  Each processing section 5, 7 and 9 has two processing tanks 5a and 5b, 7a and 7b, 9a and 9b, respectively. Further, in the substrate processing apparatus 1, a plurality of substrates W are moved only between the processing tanks of the processing units 5, 7, and 9 (that is, with respect to the direction and range of the short arrow in FIG. 1). The sub-transport mechanism 43 is provided. The sub-transport mechanism 43 moves the plurality of substrates W up and down in order to immerse the plurality of substrates W in the processing baths 5a and 5b, 7a and 7b, 9a and 9b or to pull them up from these processing baths. .. Each sub-transport mechanism 43 is provided with lifters 11, 13, and 15 for holding a plurality of substrates W. Further, in the substrate processing apparatus 1, in order to receive a plurality of substrates W and convey them to each of the processing units 5, 7 and 9, the range of the receiving place of each processing unit and the substrate in the arrangement direction of each processing unit. A main transport mechanism 17 capable of transporting the substrate W inside (that is, in the direction and range of the long arrow in FIG. 1) is provided.

  The main transport mechanism 17 has two movable arms 17a. These arms 17a are provided with a plurality of grooves (not shown) for mounting the substrate W, and in the state shown in FIG. 1, each substrate W is in an upright posture (the normal line of the main surface of the substrate is horizontal). Hold it in a posture along the direction). Further, the two arms 17a of the main transport mechanism 17 swing from the "V" shape to the inverted "V" shape when viewed from the diagonally lower right direction in FIG. Open up. By this operation, the substrate W can be transferred between the main transport mechanism 17 and the lifters 11, 13 and 15.

  FIG. 2 shows a functional block diagram of the substrate processing apparatus 1. The main transport mechanism 17, the sub transport mechanism 43, and the processing units 5, 7, and 9 described above are collectively controlled by the control unit 55. The hardware configuration of the control unit 55 is similar to that of a general computer. That is, the control unit 55 stores a CPU that performs various arithmetic processes, a ROM that is a read-only memory that stores a basic program, a RAM that is a readable / writable memory that stores various information, and a control application and data. It is equipped with a magnetic disk and the like. In the present embodiment, the CPU of the control unit 55 executes a predetermined program so that the substrate W is transferred to the processing units 5, 7, and 9 and the substrate W is processed according to the program. Control each part. The above program is stored in the storage unit 57.

  FIG. 3 is a diagram showing a configuration relating to control of the processing liquid in each of the processing tanks 5 a, 7 a, 9 a in the processing units 5, 7, 9 of the substrate processing apparatus 1. In FIG. 3, the processing tank 7a among the processing tanks 5a, 7a, 9a in the processing units 5, 7, 9 will be described as an example. The same or similar control as the control for the processing liquid in the processing tank 7a described below is also applied to the other processing tanks 5a and 9a.

  Here, in the manufacturing process of the semiconductor wafer, for example, a single crystal ingot of silicon or the like is sliced in the rod axis direction, and the obtained product is sequentially subjected to treatments such as chamfering, lapping, etching treatment and polishing. .. As a result, multiple layers, structures and circuits of different materials are formed on the surface of the substrate. The etching process of the substrate W performed in the processing bath 7a is performed, for example, for the purpose of removing the metal or the like remaining on the substrate W, and is performed by immersing the substrate W in the processing liquid for a predetermined time.

In FIG. 3, a treatment liquid containing TMAH (tetramethylammonium hydroxide), hydrofluoric acid (HF), and pure water (DIW) is used. However, the treatment liquid is not limited to this, and sulfuric acid (H ₂ SO ₄ ), acetic acid (CH ₃ COOH), nitric acid (HNO ₃ ), hydrochloric acid (HCL), ammonia water (NH ₃ Water), hydrogen peroxide water (H ₂ O ₂ ), an organic acid (for example, citric acid (C (OH) (CH ₂ COOH) ₂ COOH), oxalic acid ((COOH) ₂ ), etc.), a surfactant (Surfactant), a corrosion inhibitor (Corrosion Inhibitor), It may contain an organic solvent (Organic Solvent), carbonated water (CO ₂ Water), ozone water (Ozon Water), or the like.

  In FIG. 3, the processing tank 7a has a double tank structure composed of an inner tank 50a for immersing the substrate W in the processing liquid and an outer tank 50b for collecting the processing liquid overflowing from the upper portion of the inner tank 50a. ing. The inner tank 50a is a box-shaped member having a rectangular shape in a plan view, which is formed of quartz or a fluororesin material having excellent corrosion resistance to the treatment liquid. The outer tank 50b is made of the same material as the inner tank 50a, and is provided so as to surround the outer peripheral upper end portion of the inner tank 50a.

  Further, as described above, the processing bath 7a is provided with the lifter 13 for immersing the substrate W in the stored processing liquid. The lifter 13 collectively holds a plurality of (for example, 50) substrates W arranged in parallel in a standing posture by three holding bars. The lifter 13 is provided so as to be movable in the up, down, left, and right directions by the sub-transport mechanism 43, and has a processing position (position in FIG. 3) in which a plurality of substrates W to be held are immersed in the processing liquid in the inner tank 50a. It is possible to move up and down with respect to the delivery position where the processing liquid is pulled up and move it to the adjacent processing tank 7b.

  The substrate processing apparatus 1 also includes a circulation line 20 that circulates the processing liquid in the processing bath 7a. The circulation line 20 is a pipe path for filtering and heating the processing liquid discharged from the processing tank 7a and pumping it back to the processing tank 7a again. Specifically, the circulation line 20 connects the outer tank 50b and the inner tank 50a of the processing tank 7a. It is configured by connecting flow paths. Further, since the drainage line 30 branches off from the circulation line 20 and the treatment liquid is drained without returning to the treatment tank 7a, the drainage switching valve 26 and the drainage valve 27 are opened and closed. Thus, the processing liquid discharged from the outer tank 50b is directly discarded through the drain line 30.

In the middle of the route of the circulation line 20, a circulation pump 21, a temperature controller 22, a filter 23, and a concentration meter 24 are provided from the upstream side other than the valves. The circulation pump 21 sucks the processing liquid from the outer tank 50b through the circulation line 20 and pressure-feeds it toward the inner tank 50a. The temperature controller 22 reheats the processing liquid flowing through the circulation line 20 to a predetermined processing temperature. A heater (not shown) is also provided in the processing tank 7a, and the processing liquid stored in the processing tank 7a is also heated so as to maintain a predetermined processing temperature. The filter 23 is a filtration filter for removing foreign matter in the treatment liquid flowing through the circulation line 20.

  Further, the densitometer 24 measures the conductivity of the treatment liquid collected in the inner tank 50a by the circulation line 20. The concentration of the treatment liquid in the treatment tank 7a is controlled so that the conductivity value measured by the densitometer 24 becomes an optimum value. The processing for controlling the concentration of the processing liquid in the processing tank 7a is performed by the controller 55. More specifically, the control unit 55 performs processing related to total liquid exchange control of the processing liquid in the processing tank, feedback control of the concentration of the processing liquid, and the like.

  Next, the operation of the substrate processing apparatus 1 having the above configuration will be described in more detail. First, the circulation pump 21 constantly pumps the processing liquid at a constant flow rate regardless of whether the substrate W is immersed in the processing liquid stored in the processing tank 7a. The processing liquid recirculated to the processing tank 7a by the circulation line 20 is supplied from the bottom of the inner tank 50a. As a result, an upflow of the processing liquid flowing upward from the bottom is generated inside the inner tank 50a. The processing liquid supplied from the bottom eventually overflows from the upper end of the inner tank 50a and flows into the outer tank 50b. The processing liquid that has flowed into the outer tank 50b is sent from the outer tank 50b to the circulation pump 21 through the circulation line 20, and then pressure-fed back to the processing tank 7a again to continue the circulation process.

  In addition to the above, the substrate processing apparatus 1 is provided with a concentration control device 40 for controlling the concentration of the processing liquid in the processing bath 7a. The concentration control device 40 connects the TMAH supply source 41a, the chemical liquid lines 42a and 42b connecting the HF supply source 41b and the processing tank 7a, the pure water supply source 46, and the pure water supply source 46 and the processing tank 7a. It has a pure water line 47.

  When the treatment liquid is first generated, the supply speed is required, so the treatment liquid is fed from the thick pipe toward the inner tank 50a, but when the treatment liquid is replenished, it is replenished toward the outer tank 50b. You may do it. A flowmeter 44a capable of measuring the flow rate of TMAH and a flowmeter 44b capable of measuring the flow rate of HF are respectively provided in the chemical liquid lines 42a and 42b. Further, a replenishment valve 45a capable of adjusting the flow rate of TMAH and a replenishment valve 45b capable of adjusting the flow rate of HF are respectively provided. On the other hand, the pure water line 47 is provided with a pure water flow meter 48 for measuring the flow rate of pure water passing through the pure water line 47 and a pure water replenishment valve 49 for adjusting the flow rate of pure water. Further, the control unit 55 controls the replenishment valves 45a and 45b and the pure water replenishment valve 49 based on the measurement result of the densitometer 51 so that the concentration of the treatment liquid in the treatment tank 7a becomes the optimum concentration for the treatment. Control to be.

  However, when only the concentration of the treatment liquid before being added to the treatment tank 7a is measured, it is not possible to sufficiently reflect the influence of the concentration variation of the treatment liquid in the treatment tank 7a, and it is not always necessary to measure the concentration of the treatment liquid. It was not possible to measure with high accuracy. As a result, it may be difficult to sufficiently enhance the accuracy of the concentration control of the treatment liquid in the treatment tank 7a. On the other hand, in the present embodiment, the concentration of the processing liquid discharged from the processing tank 7a was measured using a conductivity meter. Then, when measuring the concentration of the treatment liquid discharged from the treatment tank 7a using this conductivity meter, it is necessary to remove bubbles in the treatment liquid related to the measurement, and to suppress concentration variation of the treatment liquid as much as possible. It is necessary that the sensor be made uniform and that the sensor (described later) of the conductivity meter is surely immersed in the treatment liquid so that the entire sensor surface is in contact with the treatment liquid.

FIG. 4 shows a schematic diagram of a configuration related to the concentration measurement of the processing liquid discharged from the processing bath 7a in the substrate processing apparatus 1. In this embodiment, the outer tank 50b of the processing tank 7a is provided with a discharge inclined plate 60 as an inflow portion. The processing liquid in the outer tank 50b preferentially overflows from the discharge inclined plate 60 and flows into the vat portion 61. In the butt portion 61, the inclusion of bubbles in the treatment liquid and the concentration variation are suppressed. Then, the treatment liquid flows into the measurement discharge passage 67 as the vat drain pipe and is discharged from the vat portion 61. The measuring discharge path 67 is provided with a conductivity meter 63 as a conductivity measuring device, and the conductivity of the treatment liquid passing through the measuring discharge path 67 is measured. The treatment liquid after the conductivity is measured is basically discarded, but it may be circulated and returned to the treatment tank 7a again.

  Next, the configuration around the butt portion 61 in this embodiment will be described in more detail with reference to FIG. FIG. 5 is a cross-sectional view of the butt portion 61 and related configurations. As can be seen from FIG. 5, the discharge inclined plate 60 is arranged near the central portion of the butt portion 61 in the horizontal direction so that the treatment liquid obliquely flows in. In the butt portion 61, an oval region 62 indicated by a broken line as a portion where the processing liquid discharged from the discharge inclined plate 60 falls corresponds to the liquid receiving portion in this embodiment.

  A sub discharge port 77 corresponding to a second discharge port is arranged at an end portion of the butt portion 61 in the inflow direction of the processing liquid flowing from the discharge inclined plate 60. The processing liquid discharged from the sub discharge port 77 passes through the sub discharge passage 79 and is discharged. On the other hand, at the end of the butt portion 61 opposite to the inflow direction of the processing liquid flowing in from the discharge inclined plate 60, a measurement discharge port 65 corresponding to the discharge port in this embodiment is arranged. The processing liquid discharged from the measurement discharge port 65 passes through the measurement discharge passage 67 and is discharged. The discharge path 67 for measurement has a horizontal part 69 corresponding to a pipe trap structure part in the middle. The horizontal portion 69 is provided with the conductivity meter 63.

  In this embodiment, as described above, the measurement discharge path 67 has the horizontal portion 69, and the horizontal portion 69 is provided with the conductivity meter 63. Therefore, the flow velocity of the processing liquid that has fallen freely from the measurement discharge port 65 of the butt portion 61 is reduced in this portion, and compared with the case where the conductivity meter 63 is provided in the vertical portion of the measurement discharge passage 67, It is possible to make the state in which the treatment liquid fills the measurement discharge passage 67 more reliably. Therefore, the entire surface of the sensor (not shown) of the conductivity meter 63, which is inserted in the measurement discharge path 67, can be brought into contact with the treatment liquid. As a result, it is possible to improve the measurement accuracy of the conductivity (that is, concentration) of the processing liquid by the conductivity meter 63.

  FIG. 6 is a plan view of the butt portion 61. As shown in FIG. 6, in the present embodiment, the sub discharge port 77 and the measurement discharge port 65 are arranged diagonally to the butt portion 61 with the oval region 62, which is the liquid receiving portion, interposed therebetween. Therefore, even if the treatment liquid that has flowed into the butt portion 61 from the discharge inclined plate 60 entrains bubbles in the oval region 62 that is the liquid receiving portion, most of the bubbles flow toward the sub discharge port 77. It is discharged from the outlet 77. On the other hand, since the treatment liquid after flowing a relatively long distance in the butt portion 61 flows into the measurement discharge port 65, the bubbles trapped in the treatment liquid in the oval region 62 are discharged into the measurement discharge port 65. Can be suppressed. Further, since the treatment liquid flowing into the measurement discharge port 65 is arranged to be sufficiently agitated in the vat portion 61, the concentration variation of the treatment liquid flowing into the measurement discharge port 65 is reduced, and the concentration It is possible to make the measured concentration of the treatment liquid more uniform.

  In this example, since the conductivity is measured with respect to the processing liquid after the substrate processing, even if a metal sensor is used as the sensor of the conductivity meter 63, the substrate may be It is possible to prevent the processing state from being affected. Further, in the present embodiment, the dimension of the butt portion 61 is, for example, when the flow rate of the processing liquid overflowing from the processing tank 7a is about 60 L / min, the length (longitudinal dimension in FIG. 6) is 260 mm, The width (widthwise dimension in FIG. 4) may be about 210 mm and the depth may be about 65 mm.

By setting the capacity of the butt portion 61 to this level, there is a possibility that the concentration variation of the treatment liquid measured by the conductivity meter 63 can be sufficiently reduced. Further, the height from the bottom surface of the butt portion 61 to the tip of the discharge inclined plate 60 may be 100 mm or less. By suppressing the height from the bottom surface of the butt portion 61 to the tip of the discharge inclined plate 60 to this extent, it is possible to suppress the entrainment of bubbles when the processing liquid flows into the bat portion 61. Further, when the dimensions of the butt portion 61 are set as described above, the liquid receiving portion and the measurement outlet 65 are separated by about 130 mm in this embodiment. This distance of 130 mm corresponds to the predetermined distance in this embodiment.

<Example 2>
Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, a pipe trap structure is realized by a configuration different from that of the first embodiment, and the entire surface of the sensor (not shown) of the conductivity meter 63 inserted in the measurement discharge passage 67 has the treatment liquid. To be in contact with. Further, it is possible to actively control the amount of the processing liquid flowing into the measurement outlet 65. Further, by positively stirring the treatment liquid in the vat portion 61, it is possible to make the concentration uniform.

  FIG. 7 is a cross-sectional view of the butt portion 61 and related configurations. In FIG. 7, the arrangement of the discharge inclined plate 60, the sub discharge port 77, and the measurement discharge port 65 is the same as that in the first embodiment, and thus the description thereof is omitted. In this embodiment, the measurement discharge passage 67 does not have the horizontal portion 69, and the conductivity meter 63 is provided in the portion where the measurement discharge passage 67 is formed vertically. Instead, in the measurement discharge passage 67, in the region 70 on the downstream side of the conductivity meter 63, the pipe diameter is reduced so that the flow passage area is reduced. Therefore, in the region 68 on the upstream side of the region 70 where the pipe diameter is reduced in the measurement discharge passage 67, the treatment liquid is retained and fills the measurement discharge passage 67. As a result, the entire surface of the sensor of the conductivity meter 63 can be brought into contact with the treatment liquid more reliably. Here, the region 68 immediately upstream of the region 70 where the pipe diameter is reduced in the measurement discharge passage 67 corresponds to the pipe trap structure portion in the present embodiment.

  Further, in this embodiment, a flow rate control valve 78 is provided in the sub discharge passage 79. That is, by controlling the opening degree of the flow rate control valve 78, it is possible to appropriately control the amount of the processing liquid stored in the butt portion 61. Here, if the amount of the treatment liquid stored in the butt portion 61 is too small, the concentration variation of the treatment liquid becomes large. On the other hand, if the amount is too large, the response of the measured value by the conductivity meter 63 to the change in the concentration of the processing liquid used for the substrate processing becomes slow.

  Therefore, by appropriately controlling the opening degree of the flow rate control valve 78, the amount of the processing liquid stored in the butt portion 61 is appropriately managed, and the accuracy of the concentration measurement of the processing liquid and the response speed are in a desired state. Can be adjusted to. The control of the opening degree of the flow rate control valve 78 may be performed by the control unit 55 by feedback control that converges the liquid surface height of the butt portion 61 to a target value, or by selecting another control method. I don't care. Moreover, you may control manually.

  Further, when the flow rate of the processing liquid overflowing laterally from the processing tank 7a is about 60 L / min, the length of the butt portion 61 (the lengthwise dimension in FIG. 6) is 260 mm and the width (FIG. 6) is as described above. When the short-side dimension in () is 210 mm and the depth is about 65 mm, the flow rate control valve 78 may be controlled so that the liquid surface height is about 30 mm from the bottom surface of the butt portion 61. By setting the volume of the butt portion 61 to the above-mentioned level and setting the liquid level height to about 30 mm, it is possible to sufficiently reduce the concentration variation of the treatment liquid measured by the conductivity meter 63 and to flow into the bat portion 61. It is possible to secure a sufficiently fast response time (about 120 seconds) with respect to the stepwise change in the concentration of the treatment liquid.

  Further, in the present embodiment, a fan 72 for stirring the processing liquid is provided in the vat portion 61. By rotating the fan 72, it is possible to more reliably suppress the concentration variation of the processing liquid flowing from the measurement outlet 65 into the measurement outlet 67. As a result, it is possible to further improve the accuracy of the concentration measurement by the conductivity meter 63.

<Example 3>
Next, a third embodiment of the present invention will be described with reference to FIG. In the present embodiment, the entire surface of the sensor of the conductivity meter 63, which is inserted in the measurement discharge path 67, is provided by providing the horizontal portion 69 described in the first embodiment with an additional configuration. The state of contacting the treatment liquid more reliably.

  FIG. 8 is a cross-sectional view of the butt portion 61 and related configurations in this embodiment. In this embodiment, the arrangement of the discharge inclined plate 60, the sub discharge port 77, and the measurement discharge port 65 is the same as that in the first embodiment, and therefore the description thereof is omitted. In the present embodiment, a bent portion 75 corresponding to a pipe rising portion is provided downstream of the conductivity meter 63 in the horizontal portion 69, and the measurement discharge path 67 is bent to be higher than the horizontal portion 69. did. As a result, it is possible to temporarily prevent the processing liquid from flowing from the horizontal portion 69 to the downstream side. Therefore, in the horizontal portion 69, it is possible to more reliably bring the processing liquid into the measurement discharge passage 67. You can Therefore, the entire surface of the sensor (not shown) of the conductivity meter 63, which is inserted in the measurement discharge path 67, can be brought into contact with the treatment liquid more reliably. As a result, it is possible to improve the measurement accuracy of the conductivity (that is, the concentration) of the processing liquid by the conductivity meter 63.

  Further, as shown in FIG. 8, in the present embodiment, the flow passage cross-sectional area between the horizontal portion 69 and the bent portion 75 is smaller than that of the measurement discharge passage 67, and corresponds to a branch pipe extending downward. A branch path 73 is provided. The branch path 73 can prevent the processing liquid from remaining in the horizontal portion 69 after the substrate processing is completed. As a result, it is possible to suppress the inconvenience such as the corrosion of the sensor of the conductivity meter 63 due to the processing liquid accumulated in the horizontal portion 69.

  Further, in the present embodiment, a recirculation passage 71 for recirculating the treatment liquid from the horizontal portion 69 of the measurement discharge passage 67 to the butt portion 61 is provided. As a result, when the flow rate of the processing liquid in the horizontal portion 69 decreases, a part of the processing liquid flowing in from the measurement outlet 65 can be returned to the vat portion 61, and the processing liquid in the vat portion 61 can be discharged. It becomes possible to promote stirring. Further, even when bubbles are mixed in the treatment liquid flowing from the measurement outlet 65, it is possible to reduce the bubbles in the treatment liquid by separating the bubbles from the treatment liquid via the reflux passage 71. Is.

  In addition to the above-described example, the pipe trap structure in the present invention has a shape in which a measurement discharge path 67 extends from the measurement discharge port 65 in a vertical downward direction, and then the measurement discharge path 67 is U-shaped. A bent shape may be formed so as to be bent in a letter shape so as to extend vertically upward, and further bent in an inverted U shape and extend vertically downward again. In this case, the conductivity meter 63 may be provided at the portion where the measurement discharge path 67 is bent in the U shape.

DESCRIPTION OF SYMBOLS 1 ... Substrate processing apparatus 2 ... Buffer part 3 ... Substrate carry-in / out port 5, 7, 9 ... Processing parts 5a, 5b, 7a, 7b, 9a, 9b ... Processing tanks 11, 13, 15 ... Lifter 17 ... Main transport mechanism 20 ... Circulation lines 24, 47, 63 ... Conductivity meter 43 ... Sub transport mechanism 50a ... Inner tank 50b ... Outer tank 55 ... .. Control unit 57 ... Storage unit 60 ... Discharge inclined plate 61 ... Butt portion 65 ... Measurement discharge port 67 ... Measurement discharge path 69 ... Horizontal portion 71 ... Reflux Path 72 ... Fan 73 ... Branch path 75 ... Bend 77 ... Sub discharge port 78 ... Flow control valve 79 ... Sub discharge path

Claims (10)

A substrate processing apparatus for performing a predetermined process on a substrate by immersing the substrate in a process liquid containing one or more chemicals,
A treatment tank capable of storing the treatment liquid;
It has a liquid receiving portion that receives the processing liquid that overflows from the processing tank, and an outlet that is arranged at a predetermined distance from the liquid receiving portion, and stores at least a part of the processing liquid that overflows from the processing tank. The butt part,
A vat drainage pipe connected to the discharge port, for discharging the processing liquid stored in the vat portion,
A pipe trap structure part provided in the vat drainage pipe, wherein the processing liquid discharged from the vat portion fills the vat drainage pipe,
By inserting the sensor in the pipe trap structure, a conductivity measuring device for measuring the conductivity of the treatment liquid that fills the vat drainage pipe,
A substrate processing apparatus comprising: The processing tank has an inner tank in which the substrate is immersed and the predetermined processing is performed, and an outer tank for temporarily storing a processing liquid overflowing from the inner tank around the inner tank,
The substrate processing apparatus according to claim 1, wherein the liquid receiving portion of the butt portion receives the processing liquid that overflows further from the outer tank. The liquid receiving part further comprises an inflow part for obliquely inflowing the processing liquid overflowing from the processing tank into the vat part,
The substrate processing apparatus according to claim 1, wherein the discharge port is arranged on the side opposite to the inflow direction of the processing liquid flowing from the inflow section with respect to the inflow section.   The butt part is connected to the second discharge port, which is arranged in the inflow direction of the processing liquid flowing from the inflow part with respect to the inflow part, and the process stored in the butt part. 4. The substrate processing apparatus according to claim 3, further comprising a second vat drainage pipe for draining the liquid.   The substrate processing apparatus according to claim 4, wherein, in the butt portion, the discharge port is arranged at a position lower than the second discharge port.   The substrate processing apparatus according to any one of claims 1 to 5, wherein the butt section has a stirring means for stirring the processing liquid stored in the bat section.   6. The substrate processing apparatus according to claim 4, wherein the second vat drainage pipe has valve means capable of controlling the amount of the processing liquid drained by the second vat drainage pipe. ..   The substrate according to any one of claims 1 to 7, wherein the pipe trap structure portion is provided in the vat drainage pipe and is a part that maintains the vat drainage pipe substantially horizontal. Processing equipment.   In the vat drainage pipe, on the downstream side of the pipe trap structure, there is provided a pipe rising part that is bent so that the vat drainage pipe is at a position higher than the pipe trap structure. The substrate processing apparatus according to claim 8. In the pipe trap structure part, a branch pipe having a flow passage cross-sectional area smaller than that of the vat drainage pipe and extending downward is provided on the downstream side of the sensor of the conductivity measuring device. The substrate processing apparatus according to claim 9.

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