JP7253895B2 - Substrate processing equipment - Google Patents

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 etching processing or cleaning processing, and more particularly to a configuration for measuring the concentration of the processing liquid.

2. Description of the Related Art A manufacturing process of a semiconductor device includes a process of subjecting a substrate such as a semiconductor wafer to an etching process or a cleaning process by immersing the substrate in a processing tank. Such processes are performed by a substrate processing apparatus including a plurality of processing baths. 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 constituent components of the processing liquid. Concentration controls are in place to keep it within the proper range.

Conventionally, in order to control the concentration of the processing liquid, the conductivity of the processing liquid supplied to the processing bath has been often measured. However, with the method of measuring the conductivity of the processing liquid before it is supplied to the processing tank, it is sometimes difficult to accurately measure the concentration of the processing liquid actually used for 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 substrate processing in the processing tank. In some cases, 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 processing liquid contains a chemical solution such as TMAH (tetramethylammonium hydroxide), air bubbles tend to be mixed in when the processing liquid flows or falls, and the above disadvantages tend to become more pronounced.

As described above, as a technique for measuring the concentration of the processing liquid discharged from the processing bath, there are a waste liquid bath 70 for receiving the chemical solution or pure water overflowing from the substrate processing bath 10 for processing the surface of the substrate B, and a waste liquid bath. A known technique is provided with a drainage container 72 for receiving a chemical solution or pure water discharged from 70, and a measurement unit 801 of a resistivity measuring device 80 is arranged in the drainage container 72 (Patent Document 1 reference.). In this technique, the chemical solution or pure water in the drainage tank 70 is discharged to the drainage container 72 through the discharge inclined plate 703 arranged in the drainage container 70 and the receiving inclined plate 723 arranged in the drainage container 72 . be done. A measurement unit 801 of the resistivity measuring device 80 is arranged in the drainage container 72, and a diluent supply unit 821 of the diluent supply pipe 82 is arranged in the vicinity of the measurement unit 801. When the chemical solution or pure water containing a high degree of chemical solution is discharged to 72 , the pure water is supplied from the diluent supply section 821 of the diluent supply pipe 82 toward the measuring section 801 of the resistivity measuring device 80 .

However, this technique is intended to detect the presence of chemicals in the rinse liquid, and is not suitable for measuring the concentration of processing liquids containing chemicals such as TMAH that tend to generate bubbles. .

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

SUMMARY OF THE INVENTION The present invention has been made in view of the circumstances described above, and an object of the present invention is to enable more accurate measurement of the conductivity of a processing liquid discharged from a processing bath in a substrate processing apparatus. It is to provide 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 processing liquid containing one or more chemical solutions,
a processing tank in which the processing liquid can be stored;
A liquid receiving portion for receiving the processing liquid overflowing from the processing tank, and an outlet spaced apart from the liquid receiving section by a predetermined distance, for storing at least part of the processing liquid overflowing from the processing tank. a butt portion;
a vat drain pipe connected to the outlet for draining the processing liquid stored in the vat;
a pipe trap structure provided in the vat drainage pipe, and configured to fill the vat drainage pipe with the processing liquid discharged from the vat portion;
a conductivity measuring device for measuring the conductivity of the processing liquid filling the vat drainage pipe by inserting a sensor into the pipe trap structure;
A substrate processing apparatus comprising:

That is, in the present invention, the processing liquid overflowing from the processing bath in the substrate processing apparatus is temporarily stored in the vat portion. The vat portion has a liquid receiving portion for receiving the processing liquid overflowing from the processing tank, and an outlet spaced apart from the liquid receiving portion by a predetermined distance. 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. Furthermore, the vat drain pipe is provided with a pipe trap structure that fills the vat drain pipe with the processing liquid discharged from the vat part, and the pipe trap structure has a sensor of the conductivity measuring device. Interpolated.

As described above, in the present invention, since the processing liquid overflowing from the processing bath is temporarily stored in the vat portion, the concentration of the processing liquid whose 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. are spaced apart. Therefore, it is possible to prevent the air bubbles caught in the processing liquid in the liquid receiving portion from flowing into the vat drain pipe as they are discharged from the discharge port. Furthermore, since the vat drain pipe is provided with a pipe trap structure that fills the vat drain pipe with the processing liquid discharged from the vat portion, the sensor of the conductivity measuring device can more reliably detect the vat drain. It is immersed in the treatment 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 processing liquid contains chemicals such as TMAH, the presence of the activator makes the processing liquid more likely to entrain air bubbles (i.e., easily foam), and furthermore, gas such as hydrogen is generated due to a chemical reaction during substrate processing. Therefore, mixing of air bubbles in the processing liquid tends to become a problem. Therefore, if the present invention is applied to the case where the treatment liquid contains a chemical such as TMAH, it is possible to obtain a more remarkable effect.

Further, in the present invention, the processing baths include an inner bath in which the substrate is immersed and the predetermined processing is performed, and an outer bath in which the processing liquid overflowing from the inner bath is temporarily stored around the inner bath. and
A liquid receiving portion in the vat portion may receive the processing liquid overflowing from the outer tank.

According to this, after the substrate is subjected to a predetermined process in the inner tank of the processing tank, the processing solution is temporarily stored in the outer tank and further stored in the vat portion. Therefore, it is possible to more reliably equalize the concentration of the processing liquid.

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

That is, in the present invention, when the processing liquid is received from the processing tank into the vat section, the processing liquid overflowing from the processing tank flows obliquely into the vat section through the inflow section. Therefore, it is possible to suppress entrainment of air bubbles in the treatment liquid as compared with the case where the treatment liquid falls directly onto the vat portion from a high position. Also, the discharge port connected to the vat discharge pipe is arranged on the side opposite to the inflow direction of the treatment liquid flowing from the inflow part. Therefore, it is possible to prevent the air bubbles caught in the processing liquid from flowing into the discharge port as they are, and it is possible to secure time and distance leeway for the trapped air bubbles to be removed from the processing liquid in the vat portion. can. As a result, it is possible to more reliably prevent air bubbles from entering the treatment liquid flowing into the vat drain pipe.

Further, in the present invention, the vat portion is connected to a second discharge port disposed in the inflow direction of the treatment liquid flowing from the inflow portion with respect to the inflow portion, and the second discharge port is connected to the second discharge port. A second vat drain pipe for discharging the processing liquid stored in the vat portion may be further provided.

Here, in the present invention, the second vat drain pipe is not provided with a pipe trap structure and a conductivity measuring device. By providing this second vat drainage pipe, the amount of the processing liquid flowing into the vat drainage pipe out of the processing liquid overflowing from the processing tank can be adjusted to an appropriate amount, and the amount of the processing liquid stored in the vat portion can be controlled. A moderate amount can be maintained. Furthermore, in the present invention, as described above, the second outlet and the second vat drain pipe are arranged in the inflow direction of the processing liquid that flows obliquely from the inflow portion to the vat portion. Therefore, most of the air bubbles entrained by the inflow of the treatment liquid are discharged from the vat portion through the second outlet and the second vat drain pipe. As a result, it is possible to suppress the air bubbles caught by the inflow of the treatment liquid from flowing into the discharge port and the vat drainage pipe and affecting the conductivity measurement 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, air bubbles entrained in the processing liquid stored in the vat portion are more easily discharged from the second discharge port than from the discharge port. As a result, it is possible to more reliably prevent air bubbles entrained in the treatment liquid from flowing into the outlet and the vat drain pipe and affecting the conductivity measurement by the conductivity measuring device.

Further, in the present invention, the vat portion may have stirring means for stirring the processing liquid stored in the vat portion.

The stirring means may be a stirring rod or a stirring plate that is provided in the vat portion and rotates to stir the processing liquid. Further, it may be a vibration generator that applies vibrations or ultrasonic waves to the treatment liquid stored in the vat portion. Furthermore, it may be a resistor that intricately changes the flow of the processing liquid generated in the vat as the processing liquid flows in from the inflow portion. As a result, the concentration of the processing liquid stored in the vat portion can be made uniform more reliably, 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 have valve means capable of controlling the amount of the processing liquid discharged through the second vat drainage pipe.

According to this, by actively controlling the amount of the processing liquid discharged through the second vat drainage pipe by the valve means, the processing liquid overflowing from the processing tank can be more reliably discharged into the vat drainage pipe. It is possible to appropriately control the amount of the inflowing treatment liquid and maintain the appropriate amount of the treatment liquid stored in the vat portion.

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 horizontally.

By maintaining the vat drain pipe substantially horizontally in this manner, the flow velocity of the processing liquid flowing through the vat drain pipe can be reduced, and the processing liquid can be retained in the vat drain pipe at this portion. . Therefore, it is possible to fill the vat drain pipe with the treatment liquid in the pipe trap structure with a simpler structure. Also, at that time, if the sensor of the conductivity measuring device is inserted into the vat drainage pipe from below, the entire surface of the sensor of the conductivity measuring device can be more reliably treated in the vat drainage pipe. It can be brought into contact with the liquid, and it becomes possible to more reliably improve the measurement accuracy of the conductivity.

Further, in the present invention, the vat drainage pipe has, downstream of the pipe trap structure portion, a pipe ascending portion that is bent so that the vat drainage pipe is at a position higher than the pipe trap structure portion. may be provided.

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

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

According to this, after the substrate processing is completed, the processing liquid remaining in the pipe trap structure can be discharged from the branch pipe. Therefore, it is possible to prevent the processing liquid from remaining in the piping trap structure after the substrate processing is completed, and causing problems such as corroding the sensor of the conductivity measuring device.

It should be noted that the means for solving the problems described above can be used in combination as appropriate.

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

1 is a perspective view showing a schematic configuration of a substrate processing apparatus according to Example 1; FIG. 1 is a functional block diagram of a substrate processing apparatus according to Embodiment 1; FIG. 4 is a diagram showing a configuration related to control of processing liquid in each processing tank in the processing section of the substrate processing apparatus according to the first embodiment; FIG. 4 is a schematic diagram of a configuration related to concentration measurement of a processing liquid discharged from a processing bath of the substrate processing apparatus according to the first embodiment; FIG. FIG. 4 is a diagram showing a configuration around a butt portion according to Example 1; 4 is a plan view of the butt portion according to Example 1. FIG. FIG. 10 is a diagram showing a configuration around a butt portion according to Example 2; FIG. 11 is a diagram showing a configuration around a butt portion according to Example 3;

<Example 1>
BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the example shown below is one aspect 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 a substrate processing apparatus 1 according to a first embodiment. This substrate processing apparatus 1 mainly performs etching processing and cleaning processing (hereinafter also simply referred to as “processing”) on substrates W. As shown in FIG. In the substrate processing apparatus 1, a buffer section 2 for stocking substrates W is arranged at one end in the longitudinal direction (that is, the right rear side in FIG. 1), and the outer wall side of the buffer section 2 (that is, further right rear side in FIG. 1) is arranged. side) is provided with a front panel (not shown) for operating the substrate processing apparatus 1 . Further, a board loading/unloading port 3 is provided on the opposite side of the front panel in the buffer section 2 . Processing units 5, 7, and 9 for processing substrates W are arranged side by side from the opposite side of the buffer unit 2 in the longitudinal direction of the substrate processing apparatus 1 (that is, the front left side in FIG. 1).

Each treatment section 5, 7 and 9 has two treatment 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 in the processing sections 5, 7 and 9 (that is, in the directions and ranges indicated by the short arrows in FIG. 1). A sub-transport mechanism 43 is provided for this purpose. 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 lift them out of these processing baths. . Each sub-transport mechanism 43 is provided with lifters 11, 13 and 15 for holding a plurality of substrates W. As shown in FIG. Further, in the substrate processing apparatus 1, in order to receive a plurality of substrates W and transport them to each of the processing units 5, 7 and 9, the range of each processing unit and substrate receiving place is arranged in the direction in which the processing units are arranged. A main transport mechanism 17 capable of transporting the substrate W within (ie, 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 placing the substrates W. In the state shown in FIG. direction). Further, the two arms 17a of the main transport mechanism 17 swing from a "V" shape to an inverted "V" shape when viewed from the lower right direction in FIG. open the 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. As shown in FIG. The main transport mechanism 17 , sub-transport mechanism 43 , and processing units 5 , 7 , and 9 described above are collectively controlled by a 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 processing, a ROM that is a read-only memory that stores basic programs, a RAM that is a readable/writable memory that stores various information, and a control application and data. Equipped with a magnetic disk or the like to store. In this embodiment, the CPU of the control unit 55 executes a predetermined program to transport the wafer W to each of the processing units 5, 7, and 9, and to process the wafer W 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 related to control of the processing liquid in each of the processing tanks 5a, 7a, and 9a in the processing units 5, 7, and 9 of the substrate processing apparatus 1. As shown in FIG. In FIG. 3, of the processing tanks 5a, 7a, and 9a in the processing units 5, 7, and 9, the processing tank 7a will be described as an example. The same or similar control as the control for the processing liquid in the processing tank 7a below is also applied to the other processing tanks 5a and 9a.

Here, in the manufacturing process of a semiconductor wafer, for example, a single crystal ingot of silicon or the like is sliced in the direction of its rod axis, and the obtained ingot is sequentially subjected to processes such as chamfering, lapping, etching, and polishing. . As a result, multiple layers, structures, and circuits of different materials are formed on the substrate surface. The etching process of the substrate W performed in the processing bath 7a is performed for the purpose of removing metals and the like remaining on the substrate W, for example, and is performed by immersing the substrate W in the processing liquid for a predetermined period of 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 ), organic acids (such as citric acid (C(OH)(CH ₂ COOH) ₂ COOH), oxalic acid ((COOH) ₂ ), etc.), surfactants, corrosion inhibitors, An organic solvent (Organic Solvent), carbonated water (CO ₂ Water), ozone water (Ozon Water), and the like may be included.

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 part of the inner tank 50a. ing. The inner tank 50a is a box-shaped member that is rectangular in plan view and made of quartz or a fluororesin material having excellent corrosion resistance to the processing 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 of the inner tank 50a.

The processing bath 7a is also provided with the lifter 13 for immersing the substrate W in the stored processing liquid, as described above. The lifter 13 collectively holds a plurality of (for example, 50) substrates W arranged in parallel in an upright posture with three holding bars. The lifter 13 is provided so as to be movable in the vertical and horizontal directions by the sub-transport mechanism 43, and has a processing position (position in FIG. 3) where the 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 to and from the delivery position where it is pulled up from the processing liquid, and to move it to the adjacent processing bath 7b.

The substrate processing apparatus 1 also includes a circulation line 20 for circulating the processing liquid to the processing bath 7a. The circulation line 20 is a piping route for filtering and heating the processing liquid discharged from the processing tank 7a and for pumping it back to the processing tank 7a. It is configured by connecting the flow path. Moreover, the drainage line 30 branches off from the circulation line 20, and when the processing liquid is drained without being returned to the processing bath 7a, the drainage switching valve 26 and the drainage valve 27 are opened and closed. Thus, the treatment liquid discharged from the outer tank 50b is discarded as it is through the liquid discharge line 30. As shown in FIG.

A circulation pump 21, a temperature controller 22, a filter 23, and a densitometer 24 are provided along the route of the circulation line 20 from the upstream side, in addition to the valves. The circulation pump 21 sucks the processing liquid from the outer tank 50b through the circulation line 20 and pumps 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. The processing tank 7a is also provided with a heater (not shown), and the processing liquid stored in the processing tank 7a is heated so as to maintain a predetermined processing temperature. The filter 23 is a filtration filter for removing foreign substances in the processing liquid flowing through the circulation line 20 .

Also, the densitometer 24 measures the electrical conductivity of the treatment liquid collected in the inner tank 50a through the circulation line 20. As shown in FIG. The concentration of the processing liquid in the processing tank 7a is controlled so that the conductivity value measured by the concentration meter 24 becomes the optimum value. The control unit 55 controls the concentration of the processing solution in the processing tank 7a. More specifically, the control unit 55 performs processing related to replacement control of all 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, regardless of whether or not the substrate W is immersed in the processing liquid stored in the processing bath 7a, the circulation pump 21 always pressure-feeds the processing liquid at a constant flow rate. The processing liquid returned to the processing bath 7a by the circulation line 20 is supplied from the bottom of the inner bath 50a. As a result, the processing liquid is caused to flow upward from the bottom 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 flowing into the outer bath 50b is sent from the outer bath 50b through the circulation line 20 to the circulation pump 21, and then pressure-fed back to the processing bath 7a, thereby continuing the circulation process.

In addition to the above, the substrate processing apparatus 1 is equipped 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 a TMAH supply source 41a, chemical lines 42a and 42b connecting the HF supply source 41b and the processing tank 7a, a pure water supply source 46, and a pure water supply source 46 and the processing tank 7a. and a pure water line 47 .

When the processing liquid is generated for the first time, a high supply speed is required, so the processing liquid is introduced from a thick pipe toward the inner tank 50a. You may do so. A flow meter 44a capable of measuring the flow rate of TMAH and a flow meter 44b capable of measuring the flow rate of HF are provided in the chemical lines 42a and 42b, respectively. 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 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. In addition, the aforementioned control unit 55 controls the replenishment valves 45a and 45b and the deionized water replenishment valve 49 based on the measurement result of the densitometer 51, and adjusts the concentration of the processing liquid in the processing bath 7a to the optimum concentration for processing. control so that

However, when only the concentration of the processing liquid before it is introduced into the processing tank 7a is measured, the influence of variations in the concentration of the processing liquid in the processing tank 7a cannot be fully reflected, and the concentration of the processing liquid cannot necessarily be measured. It was not possible to measure with high precision. As a result, it may be difficult to sufficiently improve the accuracy of concentration control of the processing solution in the processing bath 7a. In contrast, in this embodiment, the concentration of the processing liquid discharged from the processing tank 7a is measured using a conductivity meter. When measuring the concentration of the treatment liquid discharged from the treatment tank 7a using this conductivity meter, air bubbles in the treatment liquid to be measured should be removed, and the fluctuation of the concentration of the treatment liquid should be suppressed as much as possible. To make it uniform, it is necessary that the sensor of the conductivity meter (described later) is surely immersed in the processing liquid and that the entire sensor surface is in contact with the processing liquid.

FIG. 4 shows a schematic diagram of a configuration related to concentration measurement of the processing liquid discharged from the processing bath 7a in the substrate processing apparatus 1. As shown in FIG. In this embodiment, the outer tank 50b of the processing tank 7a is provided with a discharge inclined plate 60 as an inflow part. The treatment liquid in the outer tank 50 b preferentially overflows from the inclined discharge plate 60 and flows into the vat portion 61 . In the vat portion 61, entrainment of air bubbles in the treatment liquid and variations in concentration are suppressed. Then, the processing liquid flows into the measurement discharge passage 67 as a vat drain pipe and is discharged from the vat portion 61 . The measurement discharge path 67 is provided with a conductivity meter 63 as a conductivity measuring device, which measures the conductivity of the treatment liquid passing through the measurement discharge path 67 . The processing liquid after the conductivity is measured is basically discarded, but it may be circulated and returned to the processing 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 butt portion 61 and related structures. As can be seen from FIG. 5, the inclined discharge plate 60 is arranged near the center of the vat portion 61 in the horizontal direction so that the processing liquid flows obliquely. In the butt portion 61, an elliptical region 62 indicated by broken lines 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 the end of the butt portion 61 in the inflow direction of the processing liquid flowing from the discharge slope plate 60 . The processing liquid discharged from the sub-discharge port 77 passes through the sub-discharge path 79 and is discharged. On the other hand, a measurement outlet 65 corresponding to the outlet in this embodiment is arranged at the end of the butt portion 61 opposite to the inflow direction of the treatment liquid flowing from the outlet inclined plate 60 . The processing liquid discharged from the measurement discharge port 65 passes through the measurement discharge passage 67 and is discharged. This measurement discharge passage 67 has a horizontal portion 69 corresponding to a piping trap structure part in the middle. A conductivity meter 63 is provided on the horizontal portion 69 .

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

6 is a plan view of the butt portion 61. FIG. As shown in FIG. 6, in this embodiment, the sub-discharge port 77 and the measurement discharge port 65 are arranged diagonally on the butt portion 61 with the oval region 62 serving as the liquid receiving portion interposed therebetween. Therefore, even if the processing liquid flowing into the vat portion 61 from the discharge inclined plate 60 entrains air bubbles in the oval area 62 which is the liquid receiving portion, most of the air bubbles flow toward the sub-discharge port 77 and flow toward the sub-discharge port 77 . It is discharged from outlet 77 . On the other hand, since the treatment liquid flows into the measurement outlet 65 after having flowed a relatively long distance in the vat portion 61 , air bubbles caught in the treatment liquid in the oval area 62 flow into the measurement outlet 65 . can be suppressed from being discharged from In addition, since the treatment liquid flowing into the measurement outlet 65 is sufficiently stirred in the vat portion 61, variations in the concentration of the treatment liquid flowing into the measurement outlet 65 are reduced, and the concentration of the treatment liquid is reduced. It is possible to make the concentration of the processing liquid to be measured more uniform.

In this embodiment, the conductivity of the processing liquid after substrate processing is measured. Therefore, even if a sensor made of metal is used as the sensor of the conductivity meter 63, the metal component of the sensor may affect the substrate. It is possible to prevent the state of the process from being affected. In this embodiment, the length of the vat portion 61 (lengthwise dimension in FIG. 6) is 260 mm when the flow rate of the processing liquid overflowing from the processing bath 7a is about 60 L/min. The width (transverse dimension in FIG. 4) may be about 210 mm and the depth may be about 65 mm.

By setting the capacity of the vat portion 61 to this level, it is possible to sufficiently reduce variations in concentration of the treatment liquid measured by the conductivity meter 63 . Also, the height from the bottom surface of the butt portion 61 to the tip of the discharge slope plate 60 may be 100 mm or less. By limiting the height from the bottom surface of the vat portion 61 to the tip of the discharge inclined plate 60 to this extent, it is possible to suppress entrainment of air bubbles when the treatment liquid flows into the vat portion 61 . Further, when the dimensions of the butt portion 61 are set as described above, the liquid receiving portion and the measurement discharge port 65 are separated from each other by about 130 mm in this embodiment. This distance of 130 mm corresponds to the predetermined distance in this embodiment.

<Example 2>
Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, the 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 is covered with the processing liquid. be in contact with Also, the amount of processing liquid flowing into the measurement outlet 65 can be actively controlled. Furthermore, 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 butt portion 61 and related components. In FIG. 7, the arrangement of the inclined discharge plate 60, the sub-discharge port 77, and the measurement discharge port 65 is the same as that of the first embodiment, so the description thereof is omitted. In this embodiment, the measuring discharge passage 67 does not have a horizontal portion 69, and the conductivity meter 63 is provided in a portion where the measuring discharge passage 67 is formed vertically. Instead, the diameter of the measuring discharge channel 67 is reduced in a region 70 downstream of the conductivity meter 63 so as to reduce the flow area. Therefore, in the region 68 on the upstream side of the region 70 where the pipe diameter is reduced in the measurement discharge channel 67 , the processing liquid stays and fills the measurement discharge channel 67 . As a result, the entire surface of the sensor of the conductivity meter 63 can more reliably come into contact with the processing liquid. Here, a 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 this embodiment.

Further, in this embodiment, the sub-discharge path 79 is provided with a flow control valve 78 . That is, by controlling the opening degree of the flow control valve 78, it is possible to appropriately control the amount of the processing liquid stored in the vat portion 61. FIG. Here, if the amount of the processing liquid stored in the vat portion 61 is too small, variations in concentration of the processing liquid will increase. Also, if it is too large, the response of the measured value by the conductivity meter 63 to changes in the concentration of the processing liquid used for substrate processing will be slow.

Therefore, by appropriately controlling the opening degree of the flow control valve 78, the amount of the processing liquid stored in the vat portion 61 can be appropriately managed, and the accuracy of the concentration measurement of the processing liquid and the response speed can be adjusted to the desired state. can be adjusted to The control of the degree of opening of the flow control valve 78 may be performed by the control section 55 through feedback control for converging the liquid level height of the vat section 61 to a target value, or by selecting another control method. I don't mind. Also, it may be controlled manually.

The flow rate of the processing liquid overflowing from the processing tank 7a is about 60 L/min, and the dimensions of the butt portion 61 are 260 mm in length (longitudinal dimension in FIG. 6) and 260 mm in width (in FIG. 6). ) is about 210 mm and the depth is about 65 mm, the flow rate control valve 78 may be controlled so that the liquid level is about 30 mm from the bottom of the vat portion 61 . By setting the capacity of the vat portion 61 to the above range and the liquid level height to be about 30 mm, it is possible to sufficiently reduce variations in the concentration of the treatment liquid measured by the conductivity meter 63, and the amount of liquid flowing into the vat portion 61 is reduced. It is possible to secure a sufficiently fast response time (about 120 sec) to a stepwise change in concentration of the processing liquid.

In this embodiment, the vat portion 61 is provided with a fan 72 for agitating the treatment liquid. By rotating the fan 72 , it is possible to more reliably suppress variations in concentration of the processing liquid flowing from the measurement outlet 65 into the measurement outlet 67 . As a result, the accuracy of concentration measurement by the conductivity meter 63 can be further improved.

<Example 3>
Next, a third embodiment of the present invention will be described with reference to FIG. In this embodiment, the horizontal portion 69 described in Embodiment 1 is further provided with an additional structure, so that the entire surface of the sensor of the conductivity meter 63 inserted in the measurement discharge passage 67 is A state in which contact with the processing liquid is ensured.

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

In addition, as shown in FIG. 8, in this embodiment, between the horizontal portion 69 and the curved portion 75, the channel cross-sectional area is smaller than that of the measurement discharge channel 67, and corresponds to a branch pipe extending downward. A fork 73 is provided. This branch path 73 can prevent the processing liquid from staying in the horizontal portion 69 after the substrate processing is finished. As a result, problems such as corrosion of the sensor of the conductivity meter 63 due to the processing liquid remaining in the horizontal portion 69 can be suppressed.

Further, in this embodiment, a return path 71 is provided for returning the treatment liquid from the horizontal portion 69 of the measurement discharge path 67 to the vat portion 61 . As a result, when the flow rate of the processing liquid in the horizontal portion 69 decreases, part of the processing liquid that has flowed in from the measurement outlet 65 can be returned to the vat portion 61 . It becomes possible to promote stirring. Also, even if bubbles are mixed in the processing liquid flowing from the measurement outlet 65, the bubbles in the processing liquid can be reduced by separating the bubbles from the processing liquid via the return path 71. is.

In addition to the above example, the pipe trap structure according to the present invention may have a shape in which the measurement discharge passage 67 once extends vertically downward from the measurement discharge port 65, and then the measurement discharge passage 67 extends in a U direction. It may be bent in a letter shape to extend vertically upward, and further bent in an inverted U shape to 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.

REFERENCE SIGNS LIST 1 substrate processing apparatus 2 buffer unit 3 substrate loading/unloading ports 5, 7, 9 processing units 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 section 57 Storage section 60 Slanted discharge plate 61 Butt section 65 Measurement discharge port 67 Measurement discharge path 69 Horizontal section 71 Reflux Path 72...Fan 73...Branch path 75...Bending portion 77...Sub-discharge port 78...Flow control valve 79...Sub-discharge path

Claims (9)

A substrate processing apparatus for performing a predetermined process on a substrate by immersing the substrate in a processing liquid containing one or more chemical solutions,
a processing tank in which the processing liquid can be stored;
A liquid receiving portion for receiving the processing liquid overflowing from the processing tank, and an outlet spaced apart from the liquid receiving section by a predetermined distance, for storing at least part of the processing liquid overflowing from the processing tank. a butt portion;
a vat drain pipe connected to the outlet for draining the processing liquid stored in the vat;
a pipe trap structure provided in the vat drainage pipe, and configured to fill the vat drainage pipe with the processing liquid discharged from the vat portion;
a conductivity measuring device for measuring the conductivity of the processing liquid filling the vat drainage pipe by inserting a sensor into the pipe trap structure;
with
The liquid receiving part further includes an inflow part for obliquely inflowing the treatment liquid overflowing from the treatment tank into the vat part,
The substrate processing apparatus according to claim 1, wherein the discharge port is disposed on the side opposite to the inflow direction of the processing liquid flowing from the inflow portion with respect to the inflow portion. The processing bath has an inner bath in which the substrate is immersed and the predetermined processing is performed, and an outer bath in which the processing liquid overflowing from the inner bath is temporarily stored around the inner bath,
2. The substrate processing apparatus according to claim 1, wherein said liquid receiving portion in said vat portion receives the processing liquid overflowing from said outer tank. The vat portion includes a second outlet disposed in the inflow direction of the processing liquid flowing from the inflow portion, and a processing liquid stored in the vat portion connected to the second outlet. 2. The substrate processing apparatus according to claim 1, further comprising a second vat drainage pipe for discharging the liquid. 4. The substrate processing apparatus according to claim 3, wherein said discharge port is arranged at a position lower than said second discharge port in said vat portion. 5. The substrate processing apparatus according to any one of claims 1 to 4, wherein said vat section has stirring means for stirring the processing liquid stored in said vat section. 5. The substrate processing apparatus according to claim 3, wherein the second vat drainage pipe has valve means capable of controlling the amount of the processing liquid discharged by the second vat drainage pipe. . 7. The substrate according to any one of claims 1 to 6, wherein the pipe trap structure portion is provided in the vat drainage pipe and is a portion that maintains the vat drainage pipe substantially horizontally. processing equipment. The vat drain pipe is provided with a pipe ascending portion that is bent so that the vat drain pipe is positioned higher than the pipe trap structure on the downstream side of the pipe trap structure. The substrate processing apparatus according to claim 7. A branch pipe extending downward and having a flow passage cross-sectional area smaller than that of the vat drainage pipe is provided downstream of the sensor of the conductivity measuring device in the pipe trap structure. The substrate processing apparatus according to claim 8.

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