JPH0666026U - Substrate processing liquid quantitative supply device - Google Patents

Abstract

(57) [Summary] [Purpose] To make it possible to inexpensively, accurately and cleanly supply a fixed amount of processing liquid without re-adjustment. [Structure] The substrate processing liquid quantitative supply device is a device for weighing and supplying a predetermined amount of substrate processing liquid to a substrate cleaning tank 6 for cleaning a wafer W. This apparatus includes a storage tank 1, an overflow pipe 2, a discharge detection sensor D1, and a processing liquid supply pipe 7. The storage tank 1 can store the substrate processing liquid.
The overflow pipe 2 has a discharge position set in accordance with a predetermined amount, and overflows and discharges a predetermined amount or more of the substrate processing liquid in the storage tank 1. The discharge detection sensor D1 detects that the overflow pipe 2 has discharged the substrate processing liquid. The processing liquid supply pipe 7 supplies the substrate processing liquid from the storage tank 1 to the substrate cleaning tank 6. An automatic on / off valve AV2 and a liquid flow detection sensor D2 are arranged in the processing liquid supply pipe 7.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a substrate processing liquid constant amount supply device, and more particularly to a substrate processing liquid constant amount supply device which weighs and supplies a predetermined amount of substrate processing liquid to a substrate processing tank for processing a substrate.

[0002]

[Prior art]

 For example, a substrate cleaning apparatus is used for cleaning a thin wafer such as a semiconductor wafer that has undergone processing steps such as etching and plating and a glass substrate for liquid crystal or photomask. This substrate cleaning apparatus is provided with a cleaning tank for immersing the substrate and a processing liquid quantitative supply device for supplying a plurality of processing liquids to the cleaning tank. The treatment liquid quantitative supply device is used to mix a plurality of treatment liquids (for example, sulfuric acid and hydrogen peroxide solution) at an appropriate ratio. That is, a predetermined amount of the processing liquid is weighed by the processing liquid quantitative supply device for each type of the processing liquid and supplied into the cleaning tank, and the mixing ratio thereof is made appropriate.

This processing liquid supply device has a storage tank disposed above the cleaning tank and a supply pipe having a relatively large diameter from the bottom of the storage tank to the cleaning tank. The processing liquid is supplied through the supply pipe. It is possible to supply the processing liquid to the cleaning tank at a higher speed than the supply by a pump by flowing it from the storage tank to the cleaning tank. An apparatus disclosed in Japanese Utility Model Application Laid-Open No. 3-39116 is an example of this type of processing liquid quantitative supply apparatus. This device is equipped with a storage tank having a supply pipe at the bottom for supplying the processing liquid to the cleaning tank, and a gas level sensor for measuring the liquid level in the storage tank. The gas level sensor has a gas pipe whose tip is arranged near the bottom of the storage tank, a regulator arranged in the middle of the gas pipe, and a pressure sensor arranged between the regulator and the tip of the gas pipe. is doing.

In this gas level sensor, for example, an inert nitrogen gas is regulated by a regulator, and bubbles of the regulated gas are ejected from the tip of the gas pipe. Then, the pressure sensor reads the pressure that fluctuates subtly according to the change in the head pressure caused by the distance from the tip of the gas pipe to the liquid level, and measures the liquid level. In order to detect a liquid level of about ± 1 mm with this gas level sensor, it is necessary to use a highly accurate pressure sensor, install multiple precise regulators, and accurately adjust the pressure of the supplied gas. .

In this processing liquid constant amount supply device, when the processing liquid is stored in the storage tank, the liquid level of the processing liquid is detected by the gas level sensor, and the processing liquid is processed when a predetermined amount of the processing liquid is stored. Stop supplying the fluid. Then, the supply pipe is opened and the treatment liquid is supplied from the supply pipe to the cleaning tank. Then, after a predetermined time, it is determined that the supply of the processing liquid is completed, and the supply pipe is closed. By providing a plurality of such storage tanks, a plurality of treatment liquids can be mixed to obtain a cleaning liquid having an appropriate mixing ratio.

[0006]

[Problems to be solved by the device]

 In the above conventional configuration, since the nitrogen gas directly contacts the treatment liquid, when the nitrogen gas is contaminated with particles or the like, the treatment liquid may be contaminated with particles or the like. On the contrary, if the vapor generated from the treatment liquid is mixed in the nitrogen gas, the pressure sensor may be corroded over time. Also, if water is used instead of the treatment liquid at the time of shipment adjustment, it will be necessary to readjust the gas level sensor due to the difference in specific gravity between the treatment liquid and water. Furthermore, if the gas level sensor is to detect the liquid surface with high accuracy, it is necessary to detect the pressure with high accuracy and adjust the pressure with high accuracy, which requires an expensive pressure sensor or air regulator, which makes it possible to perform quantitative determination. The cost of the feeder is high.

On the other hand, in this type of processing liquid quantitative supply device, it is necessary to confirm whether or not all the liquid stored in the storage tank has been supplied to the cleaning tank. However, in the above-mentioned conventional configuration, when the liquid level becomes lower than the tip of the gas sensor, the liquid level cannot be detected, and it cannot be determined whether or not all the treatment liquid has been actually put into the cleaning tank. Therefore, there is a possibility that the next step may be started before the processing liquid is completely charged due to a failure of the valve arranged in the supply pipe.

An object of the present invention is to make it possible to supply the substrate processing liquid in a fixed amount in a clean, inexpensive, accurate and readjusted manner. Another object of the present invention is to ensure that the supply of the substrate processing liquid can be confirmed.

[0009]

[Means for Solving the Problems]

 The substrate processing liquid quantitative supply device according to the first invention is a device for weighing and supplying a predetermined amount of substrate processing liquid to a substrate processing bath for processing a substrate. This device comprises a storage tank, a discharge means, a discharge detection means, and a liquid supply means. The storage tank can store the substrate processing liquid. The discharging means has a discharging position set in accordance with a predetermined amount, and is for discharging the substrate processing liquid in the reservoir over a predetermined amount by causing it to overflow. The discharge detection means detects that the discharge means has discharged the substrate processing liquid. The liquid supply means supplies the substrate processing liquid from the storage tank to the substrate processing tank.

A substrate processing liquid quantitative supply device according to a second aspect comprises a reservoir, a liquid supply means, and a flow detection means. The liquid supply means has a pipe connected from the storage tank to the substrate processing bath, and an automatic on / off valve arranged in the middle of the pipe. The flow detecting means detects whether or not the substrate processing liquid is flowing through the pipe.

[0011]

[Action]

 In the substrate processing liquid quantitative supply device according to the first invention, when the substrate processing liquid is stored in the storage tank, a predetermined amount or more of the substrate processing liquid overflows and is discharged by the discharging means. When the discharge detection means detects that the discharge means has discharged the substrate processing liquid, the supply of the liquid to the storage tank is stopped. Subsequently, the liquid supply means supplies the substrate processing liquid from the storage tank to the substrate processing tank.

Here, the substrate processing liquid can be weighed by simply detecting the discharge of the substrate processing liquid from the discharging means, and the fixed amount can be accurately supplied. In the substrate processing liquid quantitative supply device according to the second aspect, the substrate processing liquid stored in the storage tank is supplied to the substrate processing tank by the liquid supply means. At this time, the flow detection means detects whether or not the substrate processing liquid is flowing through the pipe.

Here, at the start of supply, the flow detection means detects that the substrate processing liquid is flowing through the pipe. Then, when the processing liquid in the storage tank is used up, the flow detecting means detects that the substrate processing liquid is not flowing in the pipe. Therefore, it is possible to reliably confirm the supply from the storage tank.

[0014]

【Example】

 Referring to FIG. 1, a substrate processing liquid quantitative supply device according to an embodiment of the present invention has a plurality of storage tanks (only one is shown in the drawing) 1. The storage tank 1 has an overflow pipe 2 penetrating the bottom surface and protruding upward. The overflow pipe 2 is liquid-tightly attached to the bottom of the storage tank 1 by a through fitting 3. Therefore, the height position of the tip of the overflow pipe 2 can be adjusted in the vertical direction.

The overflow pipe 2 has an inclined portion 4 that extends obliquely downward at an angle θ below the through fitting 3. A discharge detection sensor D1 using a capacitance sensor is arranged on the lower surface of the inclined portion 4. The discharge detection sensor D1 detects that the substrate processing liquid has overflowed into the overflow tube 2. Here, since the discharge detection sensor D1 is provided on the lower surface of the inclined portion 4, the substrate processing liquid overflowing into the overflow tube 2 can be reliably detected even if an inexpensive capacitance sensor is used. The lower end of the overflow pipe 2 is connected to a drainage treatment device (not shown).

A substrate processing liquid is supplied to the storage tank 1 from a supply pipe 5 in which an automatic on / off valve AV1 is arranged. A level sensor D3, which uses a capacitance sensor and detects a rough liquid level of the substrate processing liquid, is arranged on the side surface slightly below the liquid level of the storage tank 1. On the bottom surface of the storage tank 1, a processing solution supply pipe 7 composed of a relatively large-diameter piping system for flowing down and supplying the substrate processing solution to the substrate cleaning tank 6 and the processing solution are forcibly sent. Is connected to the replenishment pipe 8. The ends of these pipes 7 and 8 are connected to the substrate cleaning tank 6. An automatic on / off valve AV2 for turning on / off the supply of the treatment liquid is arranged in the middle of the treatment liquid supply pipe 7. In order to confirm that the supply of the substrate processing liquid from the storage tank 1 to the substrate cleaning tank 6 is completed between the automatic on / off valve AV2 and the substrate cleaning tank 6, a liquid flow detection sensor D2 including an optical sensor is arranged. Has been done. A pump P1 is arranged in the middle of the replenishment pipe 8. The pump P1 is for forcibly supplying a required amount of the substrate processing liquid to the substrate cleaning tank 6 when replenishing the fixed amount.

The substrate cleaning tank 6 stores a cleaning liquid obtained by mixing a predetermined amount of substrate processing liquid weighed in the plurality of storage tanks 1. A large number of wafers W accommodated in the cassette C can be immersed in the substrate cleaning tank 6. The cleaning liquid in the substrate cleaning tank 6 is circulated through the pump P2 and the filter 9. Further, this fixed quantity supply device has a control unit 10 composed of a microcomputer shown in FIG. An operation panel 11 and sensors D1 to D3 are connected to the control unit 10. Further, the control unit 10 is further connected to an automatic on / off valve AV1 drive unit 12, an automatic on / off valve AV2 drive unit 13, a pump P1 drive unit 14, a trouble display unit 15 for displaying a trouble, and other input / output units. ing.

Next, the operation of the constant quantity supply device configured as described above will be described according to the control flow charts of FIGS. 3 to 5. In step S1 of FIG. 3, initial setting is performed. Here, the timer value described later is set to a predetermined value. In step S2, weighing processing (described later) is performed. In this weighing process, the substrate processing liquid is supplied from the supply pipe 5 to the storage tank 1.

In step S3, it is determined whether or not a supply command has been issued. In step S4, it is determined whether or not a quantitative replenishment command has been issued. In step S5, other general processing is performed. When other processing is completed, the process returns to step S3. If it is determined in step S3 that the supply command has been issued, the process proceeds to step S6. In step S6, a supply process (described later) is performed. The supply process is a process in which the entire amount of the substrate processing liquid weighed in the storage tank 1 is supplied to the substrate cleaning tank 6. In step S7, the same weighing process as in step S2 is performed.

If it is determined in step S4 that the quantitative replenishment command has been issued, the process proceeds to step S8. In step S8, a fixed amount replenishment process (described later) is performed. The quantitative replenishment process is a process of supplying a small amount of the substrate processing liquid stored in the storage tank 1 to the substrate cleaning tank 6 in order to adjust the amount and concentration of the cleaning liquid in the substrate cleaning tank 6. In step S9, weighing processing is performed.

The weighing process of steps S2, S7 and S9 is shown in FIG. In step S11 of FIG. 4, the automatic on / off valve AV1 is opened. As a result, the substrate processing liquid is supplied from the supply pipe 5 to the storage tank 1. Succeedingly, in a step S12, it is determined whether or not the discharge detection sensor D1 is turned on. The sensor D1 is turned on when the substrate processing liquid is discharged from the overflow pipe 2 as described above. If it is determined that the sensor D1 is not turned on, the process proceeds to step S13. In step S13, it is determined whether the time T1 has elapsed. This time T1 is sufficient to store a predetermined amount of substrate processing liquid in the storage tank 1 after opening the valve AV1. While the time T1 has not elapsed, the process returns to step S12.

When the time T1 has elapsed in step S13, the sensor D1 is not turned on even though the substrate processing liquid should have already been stored in a predetermined amount. Therefore, the trouble of the sensor D1 or the automatic on / off valve It is determined that the trouble is AV1 and the trouble display section 15 is displayed to that effect to stop the processing. If it is determined in step S12 that the sensor D1 is turned on, the timer for time T2 is started and the process proceeds to step S14. In step S14, the process waits for the time T2 to elapse. This time T2 is for confirming the ON operation of the sensor D1, and the ON state of the sensor D1 is confirmed in step S12 until the time T2 elapses.

When it is determined that the time T2 has elapsed in step S14, the process proceeds to step S15. In step S15, the automatic on / off valve AV1 is closed. As a result, the substrate processing liquid is accurately weighed in the storage tank 1. In step S16, the process waits for the lapse of time T3. This time T3 is for checking whether the sensor D1 or the automatic on / off valve AV1 is abnormal, and is a time sufficient for the substrate processing liquid not to overflow into the overflow pipe 2.

In step S17, it is determined whether the sensor D1 is still on. If the sensor D1 is still on, it is considered that the automatic on / off valve AV1 and the sensor D1 are abnormal. Therefore, the trouble display section 15 is displayed to that effect and the processing is stopped. If the determination in step S17 is no, the weighing process is ended as it is.

Here, by detecting that the substrate processing liquid is discharged to the overflow pipe 2, it is possible to easily and accurately weigh a predetermined amount without readjustment. Moreover, the substrate processing liquid can be weighed inexpensively and cleanly. The supply process of step S6 of FIG. 3 is shown in FIG. In step S21 of FIG. 5, the automatic on / off valve AV2 is opened. Then, in step S22, it is determined whether or not the sensor D2 is turned on. If it is determined that the sensor D2 is not turned on, the process proceeds to step S23. In step S23, the elapse of time T4 is waited for. This time T4 is sufficient for the substrate processing liquid to reach the sensor D2 from the bottom surface of the storage tank 1 after opening the valve AV2. While the time T4 has not elapsed, the process returns to step S22. If the sensor D2 is not turned on even after the elapse of the time T4, it is considered that there is an abnormality in the sensor D2 or the abnormality in the automatic on / off valve AV2. Therefore, the trouble display section 15 is displayed to that effect. Stop processing.

When it is determined that the sensor D2 is turned on in step S22, the timer for time T5 is started, and the process proceeds to step S23. In step S23, the elapse of time T5 is waited for. This time T5 is a time for confirming the ON operation of the sensor D2, and is, for example, about 1 second. In step S24, it is determined whether the sensor D2 is turned off. If it is determined that the sensor D2 is not turned off, the process proceeds to step S25. In step S25, the elapse of time T6 is waited for. This time T6 is sufficient for supplying a predetermined amount of the substrate processing liquid from the storage tank 1 to the substrate cleaning tank 6. If the time T6 has not elapsed, the process returns to step S24. If the sensor D2 has not been turned off even after the time T6 has passed, it is considered that there is an abnormality in the sensor D2 or the abnormality in the automatic on / off valve AV2. To stop.

When it is determined that the sensor D2 is off, the process proceeds to step S26. In step S26, the elapse of time T7 is awaited. This time T7 is a time for confirming the OFF operation of the sensor D2. If it is determined that the sensor D2 is off during the time T7, it can be determined that the total amount of the substrate processing liquid stored in the storage tank 1 has been put into the substrate cleaning tank 6, so after the automatic on / off valve AV2 is closed in step S27. , Ends processing and returns to the main routine.

Here, since the sensor D2 for detecting whether or not the substrate processing liquid is flowing is disposed in the processing liquid supply pipe 7, the substrate processing liquid from the storage tank 1 to the substrate cleaning tank 6 is You can surely check the supply. In particular, as shown in FIG. 1, when the sensor D2 is arranged on the substrate cleaning tank 6 side of the automatic on / off valve AV2, a failure of the automatic on / off valve AV2 can also be detected.

FIG. 6 shows quantitative replenishment in step S8 of FIG. In step S31 of FIG. 6, the pump P1 is turned on. In step S32, it is determined whether time T8 has elapsed. This time T8 is the time required to accurately supply the substrate processing liquid required for quantitative replenishment to the substrate cleaning tank 6 by the pump P1. If the time T8 has elapsed, the process moves to step S33. In step S33, the pump P1 is turned off. As a result, a fixed amount of the substrate processing liquid is supplied from the storage tank 1 to the substrate cleaning tank 6. By this operation, the amount and concentration of the liquid in the substrate cleaning tank 6 can be adjusted.

When the sensor D3 shown in FIG. 1 is turned off during the quantitative replenishment, the process proceeds to step S21 shown in FIG. 5 and the automatic on / off valve AV1 is opened, so that step S9 shown in FIG. Alternatively, the weighing process may be started in advance. In this case, the position of the sensor D3 needs to be adjusted in advance so that the pump P1 stops before the liquid level of the substrate processing liquid rises to the upper end of the overflow pipe 2.

[Other Embodiments] (a) Instead of providing the overflow pipe 2 in the storage tank 1, an overflow tank adjacent to the storage tank and a sensor for detecting the discharge of the processing liquid to the overflow tank are provided. It may be provided. Between the overflow tank and the storage tank, for example, a vertically adjustable weir may be provided so that the height of the liquid surface can be adjusted. (B) The overflow pipe 2 may be arranged diagonally instead of vertically. In this case, the inclined portion 4 becomes unnecessary.

[0032]

[Effect of device]

 In the substrate processing liquid quantitative supply device according to the first invention, the substrate processing liquid is weighed by detecting that the substrate processing liquid has been discharged from the liquid discharging means, so that the processing liquid is inexpensive, accurate, and clean. Can be weighed. In addition, there is no need to use an expensive gas level sensor, there is no problem of sensor corrosion, and weighing can be performed without readjustment even if there is a change in specific gravity or atmospheric pressure.

In the substrate processing liquid quantitative supply device according to the second aspect of the present invention, since the flow detecting means is provided in the pipe connected from the storage tank to the substrate processing tank, the supply of the processing liquid from the storage tank to the substrate processing tank is provided. Can be surely confirmed.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of a substrate processing liquid quantitative supply device according to an embodiment of the present invention.

FIG. 2 is a block diagram of its control system.

FIG. 3 is a control flowchart thereof.

FIG. 4 is a control flowchart thereof.

FIG. 5 is a control flowchart thereof.

FIG. 6 is a control flowchart thereof.

[Explanation of symbols]

 1 Storage Tank 2 Overflow Pipe 6 Substrate Cleaning Tank 7 Processing Liquid Supply Pipe W Wafer AV1, AV2 Automatic On / Off Valve D1 Discharge Detection Sensor D2 Liquid Flow Detection Sensor

Claims (2)

[Scope of utility model registration request] 1. A substrate processing liquid quantitative supply device for weighing and supplying a predetermined amount of substrate processing liquid to a substrate processing tank for processing a substrate, the storage tank capable of storing the substrate processing liquid, and the predetermined amount. A discharge position is set in accordance with the above, and discharge means for overflowing and discharging the substrate processing liquid of the predetermined amount or more in the storage tank, and detecting that the discharging means has discharged the substrate processing liquid A substrate processing liquid quantitative supply device, comprising: an ejection detection unit; and a liquid supply unit that supplies the substrate processing liquid from the storage tank to the substrate processing tank. 2. A substrate processing liquid quantitative supply device for weighing and supplying a predetermined amount of substrate processing liquid to a substrate processing tank for processing a substrate, comprising: a reservoir tank capable of storing the predetermined amount of substrate processing liquid. A pipe connected from the storage tank to the substrate processing bath, a liquid supply means having an automatic on / off valve arranged in the middle of the pipe, and the pipe disposed in the pipe, the substrate processing liquid in the pipe. A substrate processing solution quantitative supply device, comprising: a flow detection means for detecting whether or not the liquid is in circulation.