JP2009130250A - Substrate treating apparatus, and treating liquid substituting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate treating apparatus capable of efficiently changing liquid reserved in a treating tank from a chemical to a pure water while suppressing the supply amount of the pure water, and to provide a treating liquid substituting method for the substrate treating apparatus. <P>SOLUTION: The substrate treating apparatus makes a circulation line circulate a treating liquid when a measured value of a specific resistance meter reaches a reference value r1 while supplying pure water through a pure water supply line and discharging treating liquid through a waste liquid line. Consequently, a chemical component remaining in the treating tank can be stirred through the circulation of the treating liquid to discharge the stirred chemical component to outside the treating tank. Therefore, while the supply amount of the pure water is suppressed, the treating liquid reserved in the treating tank can be efficiently changed from the chemical to the pure water. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a substrate processing apparatus for sequentially performing chemical treatment with a chemical solution and rinsing treatment with pure water in a treatment tank on a substrate such as a semiconductor substrate, a glass substrate for a liquid crystal display device, a glass substrate for a photomask, and the like. The present invention relates to a processing liquid replacement method in a substrate processing apparatus.

  In the substrate manufacturing process, a so-called one-bus type substrate processing apparatus is used that sequentially performs chemical treatment with a chemical solution and rinse treatment with pure water on a substrate in one treatment tank. One-bus system substrate processing equipment immerses the substrate in the chemical stored in the processing tank, and overflows the chemical from the top of the processing tank while supplying the chemical from the bottom of the processing tank. I do. In addition, the one-bath type substrate processing apparatus, when the chemical processing for a predetermined time is completed, supplies the pure water from the bottom of the processing tank and overflows the liquid from the top of the processing tank, thereby removing the liquid inside the processing tank from the chemical liquid The water is gradually replaced with pure water. And the rinse process by a pure water is performed with respect to a board | substrate inside the processing tank after substituted with a pure water.

  A conventional one-bus type substrate processing apparatus is disclosed in Patent Document 1, for example.

Japanese Patent No. 3530426

  As described above, in the conventional one-bus system substrate processing apparatus, when the liquid inside the processing tank is replaced with the chemical liquid from the chemical liquid, the supply of the pure water to the processing tank and the discharge of the chemical liquid from the processing tank are continued. Only by this, the chemical solution was replaced with pure water. For this reason, the replacement efficiency of the liquid in a processing tank is bad, and much time was required for replacement | exchange from a chemical | medical solution to a pure water. In addition, in order to replace the liquid in the treatment tank from the chemical solution to the pure water, a large amount of pure water has to be supplied to the treatment tank.

  In particular, various solid surfaces such as the surface of the substrate, the inner wall surface of the processing tank, and the surface of the lifter member are present inside the processing tank. In the vicinity of such a solid surface, the flow of the chemical solution is slower than in other regions due to the viscosity of the chemical solution, so that there is a problem that the chemical component tends to stay and the replacement with pure water is particularly difficult to proceed. In order to completely replace the liquid inside the treatment tank, including chemical components that stay near the solid surface, from chemical to pure water, supply pure water to the treatment tank over a considerable amount of time. And the discharge of the chemical solution from the treatment tank had to be continued.

  The present invention has been made in view of such circumstances, and is capable of efficiently replacing a liquid stored in a processing tank from a chemical solution to pure water while suppressing a supply amount of pure water. It is an object of the present invention to provide a processing liquid replacement method in an apparatus and a substrate processing apparatus.

  In order to solve the above-mentioned problem, the invention according to claim 1 is a substrate processing apparatus for sequentially performing chemical treatment with a chemical solution and rinsing treatment with pure water on a substrate in the treatment bath. Pure water supply means for supplying pure water; drainage means for discharging liquid from the treatment tank; circulation means for circulating the liquid recovered from the treatment tank and re-supplying the liquid to the treatment tank; and the treatment tank Measuring means for measuring the specific resistance value of the liquid stored inside, and control means for controlling the operation of the pure water supply means, the drainage means, and the circulation means, the control means, When the liquid stored in the treatment tank is replaced with chemical water from pure liquid, measurement by the measurement means is performed while pure water is supplied by the pure water supply means and liquid is discharged by the drainage means. When the value reaches the first reference value, Characterized in that to perform the circulation of the liquid by serial circulating means.

  The invention according to claim 2 is the substrate processing apparatus according to claim 1, wherein the first reference value is a value of 6 MΩ · cm or more and 8 MΩ · cm or less.

  The invention according to claim 3 is the substrate processing apparatus according to claim 1 or 2, wherein the control means starts the circulation of the liquid by the circulation means, and then the measured value by the measurement means is When the second reference value is reached, the circulation of the liquid by the circulation means is stopped.

  The invention according to claim 4 is the substrate processing apparatus according to claim 3, wherein the second reference value is a value of 4 MΩ · cm or more and 6 MΩ · cm or less.

  The invention according to claim 5 is the substrate processing apparatus according to claim 1, wherein the control means supplies the pure water when the liquid stored in the processing tank is replaced with chemical water from pure liquid. Supply of pure water by the means and discharge of liquid by the drainage means, and when the measurement value by the measurement means reaches a first reference value, supply of pure water by the pure water supply means and the drainage The liquid discharge by the means is stopped, the liquid circulation by the circulation means is executed, and when the measurement value by the measurement means reaches the second reference value, the liquid circulation by the circulation means is stopped and the pure The supply of pure water by the water supply means and the discharge of the liquid by the drainage means are executed again.

  The invention according to claim 6 is the substrate processing apparatus according to claim 5, wherein the second reference value is a value of 0 MΩ · cm to 2 MΩ · cm.

  The invention according to claim 7 is the substrate processing apparatus according to any one of claims 1 to 6, wherein the circulating means is higher than a flow rate of pure water supplied by the pure water supply means. A liquid is supplied to the treatment tank at a flow rate.

  The invention according to claim 8 is the substrate processing apparatus according to any one of claims 1 to 7, further comprising an inert gas filling means for filling the processing space including the processing tank with an inert gas. It is characterized by providing.

  According to a ninth aspect of the present invention, in the substrate processing apparatus for sequentially performing a chemical treatment with a chemical solution and a rinsing treatment with pure water on a substrate in the treatment bath, the liquid stored in the treatment bath is removed from the chemical solution. A treatment liquid replacement method for substituting with pure water, the first step of discharging liquid from the treatment tank while supplying pure water to the treatment tank; and the liquid in the treatment tank by the first step When the specific resistance value reaches the first reference value, the liquid recovered from the treatment tank is circulated and re-supplied to the treatment tank, and the liquid in the treatment tank is obtained by the second process. And the third step of stopping the circulation of the liquid and discharging the liquid from the processing tank while supplying pure water to the processing tank. Features.

  According to the first to eighth aspects of the present invention, when the substrate processing apparatus replaces the liquid stored in the processing tank with the pure water from the chemical solution, the pure water supply means and the drain means are used. When the measured value by the measuring means reaches the first reference value while the liquid is discharged by the liquid, the liquid is circulated by the circulating means. For this reason, the chemical component remaining inside the treatment tank can be stirred by circulation of the liquid, and the stirred chemical solution component can be discharged to the outside of the treatment tank. Therefore, it is possible to efficiently replace the liquid stored in the processing tank from the chemical solution to the pure water while suppressing the supply amount of the pure water.

  In particular, according to the invention described in claim 2, the first reference value is a value of 6 MΩ · cm or more and 8 MΩ · cm or less. For this reason, the circulation of the liquid can be started at the time when the replacement from the chemical liquid to the pure water has appropriately proceeded.

  In particular, according to the invention described in claim 3, the substrate processing apparatus starts the circulation of the liquid by the circulation means, and then when the measurement value by the measurement means reaches the second reference value, the liquid treatment by the circulation means. Stop circulation. For this reason, it can suppress supplying the stirred chemical | medical solution component to a processing tank again.

  In particular, according to the invention described in claim 4, the second reference value is a value of 4 MΩ · cm or more and 6 MΩ · cm or less. For this reason, it is possible to sufficiently stir the chemical component remaining inside the processing tank while continuing the supply of pure water by the pure water supply means and the discharge of the liquid by the drainage means.

  In particular, according to the invention described in claim 5, when the control means replaces the liquid stored in the processing tank with the pure water from the chemical liquid, the control means uses the pure water supply and the drainage means. When the measured value by the measuring means reaches the first reference value, the supply of pure water by the pure water supplying means and the discharging of the liquid by the draining means are stopped and the liquid by the circulating means is discharged. When the circulation is executed and the measurement value by the measurement means reaches the second reference value, the circulation of the liquid by the circulation means is stopped and the supply of the pure water by the pure water supply means and the discharge of the liquid by the drainage means are performed again. Let it run. For this reason, the liquid stored in the inside of the processing tank can be efficiently replaced with pure water from the chemical solution while further suppressing the supply amount of pure water.

  In particular, according to the invention described in claim 6, the second reference value is a value of 0 MΩ · cm or more and 2 MΩ · cm or less. For this reason, in the state which stopped supply of the pure water by the pure water supply means, and discharge | emission of the liquid by the drainage means, the chemical | medical solution component which remains in the inside of a processing tank can fully be stirred.

  In particular, according to the invention described in claim 7, the circulation means supplies the liquid to the treatment tank at a flow rate higher than the flow rate of the pure water supplied by the pure water supply means. For this reason, the chemical | medical solution component which remains in the inside of a processing tank can be stirred more favorably.

  In particular, according to the invention described in claim 8, the substrate processing apparatus further includes an inert gas filling means for filling the processing space including the processing tank with an inert gas. For this reason, it can prevent that gas, such as a carbon dioxide, melt | dissolves in the liquid stored by the processing tank, and can change the specific resistance value of a liquid correctly according to the density | concentration of a chemical | medical solution component.

  According to the invention described in claim 9, the processing liquid replacement method includes a first step of discharging the liquid from the processing tank while supplying pure water to the processing tank, and a first step in the processing tank. When the specific resistance value of the liquid reaches the first reference value, the ratio of the liquid in the processing tank by the second process in which the liquid recovered from the processing tank is circulated and re-supplied to the processing tank is determined. When the resistance value reaches the second reference value, there is provided a third step of stopping the circulation of the liquid and discharging the liquid from the treatment tank while supplying pure water to the treatment tank. For this reason, the chemical component remaining inside the treatment tank can be stirred by circulation of the liquid, and the stirred chemical solution component can be discharged to the outside of the treatment tank. Therefore, it is possible to efficiently replace the liquid stored in the processing tank from the chemical solution to the pure water while suppressing the supply amount of the pure water.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

<1. Configuration of substrate processing apparatus>
FIG. 1 is a diagram showing a configuration of a substrate processing apparatus 1 according to an embodiment of the present invention. The substrate processing apparatus 1 is a so-called one-bus type substrate processing apparatus that sequentially performs etching processing with dilute hydrofluoric acid and rinsing processing with pure water on a substrate W in one processing tank 10. In this embodiment, dilute hydrofluoric acid is used as the “chemical solution”, and the etching process as the “chemical solution treatment” is performed with the dilute hydrofluoric acid. In the following description, dilute hydrofluoric acid, pure water, and liquids having intermediate concentrations thereof are collectively referred to as “treatment liquid”.

  As shown in FIG. 1, the substrate processing apparatus 1 mainly conveys a processing tank 10 for storing a processing liquid and a plurality of substrates (hereinafter simply referred to as “substrates”) W while holding up and down. A lifter 20, a processing liquid supply unit 30 for supplying a processing liquid to the processing tank 10, a processing liquid recovery unit 40 for recovering the processing liquid from the processing tank 10, and a chamber 50 for accommodating the processing tank 10 therein. A nitrogen gas supply unit 60 for supplying nitrogen gas into the chamber 50, and a control unit 70 for controlling the operation of each unit in the apparatus.

  The processing tank 10 is a storage container made of a chemical resistant material such as quartz. The processing tank 10 includes an inner tank 11 in which dilute hydrofluoric acid and pure water are sequentially stored and the substrate W is immersed therein, and an outer tank 12 formed on the outer peripheral portion of the inner tank 11. Further, a processing liquid discharge unit 13 that discharges the processing liquid toward the inside of the inner tank 11 is provided at the bottom of the inner tank 11. The treatment liquid discharge unit 13 has a pair of nozzle tubes 13a and 13b, and each nozzle tube 13a and 13b has a plurality of discharge ports (not shown). For this reason, the treatment liquid supplied to the nozzle tubes 13 a and 13 b is discharged from the plurality of discharge ports to the inner tank 11 and stored in the inner tank 11. Further, the processing liquid stored up to the upper part of the inner tank 11 overflows from the upper part of the inner tank 11 to the outer tank 12.

  A specific resistance meter 14 for measuring the specific resistance value of the processing liquid is installed inside the inner tank 11. The specific resistance meter 14 has a pair of metal electrodes, and measures the specific resistance value of the treatment liquid by measuring the electrical resistance between the metal electrodes. The specific resistance meter 14 measures the specific resistance value of the processing liquid stored in the processing tank 10 and transmits the acquired specific resistance value information to the control unit 70 during the processing liquid replacement process described later. To do. The specific resistance meter 14 may include a temperature sensor built in the metal electrode and transmit a converted value of the specific resistance value at a predetermined temperature to the control unit 70.

  The lifter 20 is a transport mechanism for transporting the substrate W up and down while holding the substrate W inside the chamber 50. The lifter 20 has three holding bars 21 extending in a direction perpendicular to the paper surface in FIG. 1, and each holding bar 21 has a plurality of holding grooves (not shown). The board | substrate W is hold | maintained in the standing attitude | position in parallel with each other on the three holding | maintenance rods 21 in the state which fitted the peripheral part to the holding groove. The lifter 20 is connected to the drive mechanism 22 conceptually shown in FIG. When the drive mechanism 22 is operated, the lifter 20 moves up and down, and the substrate W is transported between the immersion position (the state shown in FIG. 1) inside the processing tank 10 and the pulling position above the processing tank 10. .

  The processing liquid supply unit 30 is a piping system for supplying the processing liquid to the processing liquid discharge unit 13. As shown in FIG. 1, the treatment liquid supply unit 30 is configured by combining a hydrofluoric acid supply source 31, a pure water supply source 32, pipes 33 to 35, and on-off valves 36 to 38. The hydrofluoric acid supply source 31 and the pure water supply source 32 are connected to the pipe 35 via pipes 33 and 34, respectively, and on-off valves 36 and 37 are inserted in the middle of the paths of the pipes 33 and 34, respectively. Yes. Further, an on-off valve 38 is inserted in the middle of the path of the pipe 35, and the downstream side of the pipe 35 is branched into two and connected to the pair of nozzle pipes 13a and 13b, respectively.

  In such a treatment liquid supply unit 30, when the on-off valves 36 to 38 are opened, hydrofluoric acid from the hydrofluoric acid supply source 31 and pure water from the pure water supply source 32 pass through the pipes 33 and 34, respectively. 35 and mixed at a predetermined ratio in the pipe 35 to become dilute hydrofluoric acid. And the diluted hydrofluoric acid produced | generated in the piping 35 is supplied to the nozzle pipes 13a and 13b from the piping 35, and is discharged into the inside of the processing tank 10 from the several discharge port of the nozzle pipes 13a and 13b.

  Further, when the on-off valve 36 is closed and the on-off valves 37 and 38 are opened in the processing liquid supply unit 30, only pure water from the pure water supply source 32 passes through the pipe 34 and the pipe 35 to the nozzle pipes 13a and 13b. It is supplied and discharged into the processing tank 10 from a plurality of discharge ports of the nozzle tubes 13a and 13b.

  The processing liquid recovery unit 40 is a piping system for recovering the processing liquid from the outer tank 12 and discharging or circulating the recovered processing liquid. As shown in FIG. 1, the treatment liquid recovery unit 40 includes pipes 41 to 43, on-off valves 44 to 46, and a circulation pump 47. The upstream end of the pipe 41 is connected to the outer tub 12, and the downstream end of the pipe 41 is branched in two directions and connected to the pipe 42 and the pipe 43, respectively. An on-off valve 44 is connected in the course of the pipe 42, and the downstream side of the pipe 42 is connected to a drainage facility in the factory. Further, an on-off valve 45, a circulation pump 47, and an on-off valve 46 are inserted in order from the upstream side in the course of the pipe 43, and the downstream end of the pipe 43 is connected to the on-off valve 38 of the pipe 35. Is also connected to the downstream site.

  When the on-off valves 45 and 46 are closed and the on-off valve 44 is opened in such a processing liquid recovery unit 40, the processing liquid recovered from the outer tub 12 to the pipe 41 is discharged to the drainage facility through the pipe 42. Is done. In the processing liquid recovery unit 40, when the on-off valve 44 is closed and the on-off valves 45 and 46 are opened and the circulation pump 47 is operated, the processing liquid recovered from the outer tank 12 to the pipe 41 is transferred to the pipe 43, It is again supplied to the inner tank 11 via the pipe 35 and the processing liquid discharge part 13. That is, the piping 41, the piping 43, and the piping 35 constitute a circulation line that circulates the processing liquid in the processing tank 10.

  The chamber 50 is a casing made of an airtight material. The interior of the chamber 50 is a processing space for processing the substrate W, and the processing tank 10 is disposed in the processing space. An opening 51 for loading or unloading the substrate W is formed in the upper portion of the chamber 50. The opening 51 is closed and opened by a sliding lid 52. When the opening 51 is opened, the substrate W can be loaded and unloaded through the opening 51. When the opening 51 is closed, the processing space inside the chamber 50 is isolated from the outside. It can be a sealed space. Note that the slide-type lid 50 is slid by the drive mechanism 53 conceptually shown in FIG.

  Above the processing tank 10 inside the chamber 50, a nitrogen gas discharge unit 54 that discharges nitrogen gas into the chamber 50 is disposed. The nitrogen gas discharge unit 54 has a pair of nozzle tubes 54a and 54b, and a plurality of discharge ports (not shown) are formed in the nozzle tubes 54a and 54b. For this reason, when nitrogen gas is supplied to the nozzle tubes 54 a and 54 b, the nitrogen gas is discharged from the plurality of discharge ports of the nozzle tubes 54 a and 54 b toward the inside of the chamber 50. Further, an exhaust pipe 55 is connected near the bottom of the chamber 50. An on-off valve 56 is inserted in the middle of the route of the pipe 55, and the downstream side of the pipe 55 is connected to an exhaust facility in the factory. Therefore, by opening the on-off valve 56, the gas inside the chamber 50 can be discharged to the exhaust equipment via the pipe 55.

  The nitrogen gas supply unit 60 is a piping system for supplying nitrogen gas, which is an inert gas, to the nitrogen gas discharge unit 54. As shown in FIG. 1, the nitrogen gas supply unit 60 includes a nitrogen gas supply source 61, a pipe 62, and an on-off valve 63. The upstream end of the pipe 62 is connected to a nitrogen gas supply source 61, and an open / close valve 63 is inserted in the middle of the path of the pipe 62. Further, the downstream side of the pipe 62 is branched into two and connected to the pair of nozzle pipes 54a and 54b. Therefore, when the on-off valve 63 is opened, nitrogen gas is supplied from the nitrogen gas supply source 61 through the pipe 62 to the pair of nozzle pipes 54a and 54b, and the inside of the chamber 50 is supplied from the plurality of discharge ports of the nozzle pipes 54a and 54b. Nitrogen gas is discharged.

  The control unit 70 is a computer device for controlling the operation of each unit of the substrate processing apparatus 1. The control unit 70 is electrically connected to the specific resistance meter 14, the drive mechanism 22, the open / close valves 36 to 38, the open / close valves 44 to 46, the circulation pump 47, the drive mechanism 53, the open / close valve 56, and the open / close valve 63. . The control unit 70 is connected to a storage unit 71 composed of a hard disk or a memory. The storage unit 71 stores a processing recipe 71a that defines the processing procedure of the substrate processing apparatus 1, and data such as reference values r1 to r4, ra, which will be described later. The control unit 70 includes a drive mechanism 22, on-off valves 36 to 38, on-off valves 44 to 46, a circulation pump based on the processing recipe 71 a, data such as reference values r 1 to r 4, ra, and measured values received from the resistivity meter 14. 47, the processing of the substrate W is advanced by operating the drive mechanism 53, the on-off valve 56, and the on-off valve 63.

<2. Operation of substrate processing apparatus>
Next, an operation when the substrate W is processed in the substrate processing apparatus 1 will be described. FIG. 2 is a flowchart showing the flow of processing in the substrate processing apparatus 1. 3 to 7 are views showing the state of the substrate processing apparatus 1 at each stage of processing. When processing the substrate W in the substrate processing apparatus 1, first, the on-off valves 37, 38, 44 are opened with the on-off valves 36, 45, 46 closed. As a result, pure water is supplied from the pure water supply source 32 to the processing liquid discharge unit 13 via the pipes 34 and 35, and the pure water is supplied from the processing liquid discharge unit 13 to the inside of the processing tank 10 as shown in FIG. Is discharged. The pure water discharged from the treatment liquid discharge unit 13 is gradually stored inside the inner tank 11 and eventually overflows from the upper part of the inner tank 11 to the outer tank 12 (step S1).

  Next, the substrate processing apparatus 1 operates the drive mechanism 53 to slide the lid portion 52 to open the opening 51 of the chamber 50. Then, the substrate W transported from another apparatus by a predetermined transport mechanism is carried into the chamber 50 through the opening 51. Inside the chamber 50, as shown in FIG. 4, the lifter 20 stands by above the processing tank 10, and the substrate W is placed on the three holding bars 21 of the lifter 20. When the loading of the substrate W is completed, the substrate processing apparatus 1 slides the lid portion 52 (see FIG. 3) again to close the opening portion 51 of the chamber 50.

  Thereafter, the substrate processing apparatus 1 operates the drive mechanism 22 to lower the lifter 20, and as shown in FIG. 5, the substrate W is immersed in pure water stored in the processing tank 10 (step S2). ). Further, the substrate processing apparatus 1 opens the opening / closing valve 63 to discharge nitrogen gas into the chamber 50 from the nitrogen gas discharge portion 54 and opens the opening / closing valve 56 to discharge gas from the chamber 50. The discharge of nitrogen gas and the exhaust from the chamber 50 are continuously performed in the subsequent processing. For this reason, the processing space inside the chamber 50 is always filled with nitrogen gas.

  Subsequently, the substrate processing apparatus 1 opens the on-off valve 36 while maintaining the on-off valves 45, 46 in a closed state and the on-off valves 37, 38, 44 in an open state. Thus, hydrofluoric acid is supplied from the hydrofluoric acid supply source 31 through the pipe 33 to the pipe 35, and pure water is supplied from the pure water supply source 32 through the pipe 34 to the pipe 35. The hydrofluoric acid and pure water are mixed in the pipe 35 to become dilute hydrofluoric acid, and are discharged into the inner tank 11 through the treatment liquid discharge unit 13. By the discharge of the diluted hydrofluoric acid, the processing liquid stored in the processing tank 10 is gradually replaced from pure water to diluted hydrofluoric acid (step S3).

  Even after the replacement of pure water with dilute hydrofluoric acid is completed inside the treatment tank 10, the discharge of dilute hydrofluoric acid from the treatment liquid discharge unit 13 is continued, and as shown in FIG. It will be in the state immersed in the diluted hydrofluoric acid stored inside the tank 10. FIG. A liquid solution of dilute hydrofluoric acid flowing upward is formed around the substrate W, and the substrate W is subjected to an etching process using dilute hydrofluoric acid (step S4). In addition, until the rinse process mentioned later is completed, the board | substrate W remains immersed in the process liquid in the inside of the process tank 10 like FIG.

  When the etching process for a predetermined time is completed, the substrate processing apparatus 1 replaces the processing liquid inside the processing tank 10 with pure water again from dilute hydrofluoric acid (step S5). FIG. 8 is a flowchart showing a detailed operation flow of the substrate processing apparatus 1 when replacing dilute hydrofluoric acid with pure water. Hereinafter, the operation of the substrate processing apparatus 1 in step S5 will be described in detail with reference to the flowchart of FIG.

  When replacing the treatment liquid in the treatment tank 10 from dilute hydrofluoric acid with pure water, first, the on-off valve 36 is maintained while the on-off valves 45, 46 are kept closed and the on-off valves 37, 38, 44 are kept open. Close. Thereby, the supply of hydrofluoric acid from the hydrofluoric acid supply source 31 is stopped, and pure water is supplied from the pure water supply source 32 to the inside of the treatment tank 10 through the pipes 34 and 35 and the treatment liquid discharge unit 13, The processing liquid overflowed to the outer tub 12 is discharged to the drainage facility via the pipes 41 and 42 (step S511). That is, in the treatment tank 10 at this time, as shown in FIG. 9, a pure water supply line WL that supplies pure water to the treatment tank 10 and a drain line DL that discharges the treatment liquid from the treatment tank 10. Will be in communication. Then, due to the supply of pure water through the pure water supply line WL and the discharge of the processing liquid through the drainage line DL, the processing liquid stored in the processing tank 10 is gradually replaced with dilute hydrofluoric acid from pure water. Go.

  As the concentration of hydrofluoric acid component in the treatment liquid stored in the treatment tank 10 decreases, the specific resistance value of the treatment liquid gradually increases. For this reason, the measured value of the specific resistance meter 14 gradually increases as shown at times t1 to t2 in FIG. The control unit 70 of the substrate processing apparatus 1 receives the measurement value of the resistivity meter 14 and continuously monitors whether the measurement value has reached a preset reference value r1 (first reference value). (Step S512).

  The substrate processing apparatus 1 continues the supply of pure water through the pure water supply line WL and the discharge of the processing liquid through the drain line DL while the measured value of the resistivity meter 14 does not reach the reference value r1. It is desirable that the substrate processing apparatus 1 supplies pure water in an amount equal to or larger than the volume of the processing tank 10 to the inside of the processing tank 10 before starting the circulation of the processing liquid described later. The substrate processing apparatus 1 desirably sets the reference value r1 to a value of, for example, 6 MΩ · cm or more and 8 MΩ · cm or less. In this way, the replacement of the chemical liquid with pure water can be appropriately advanced before the start of the circulation of the processing liquid described later.

  Eventually, when the measured value of the resistivity meter 14 reaches the reference value r1, the substrate processing apparatus 1 maintains the open / close valves 37, 38, and 44 and the open / close valve 36 in a closed state while the open / close valves 45 and 46 are closed. And the circulation pump 47 is operated. Thereby, in addition to the pure water supply line WL and the drainage line DL, the treatment liquid circulation line CL is opened as shown in FIG. 10 (step S513).

  When the circulation line CL is opened, a part of the processing liquid collected in the pipe 41 flows into the pipe 43 and is supplied to the pipe 35 by the pressure of the circulation pump 47. Then, the processing liquid supplied to the pipe 35 is supplied again into the processing tank 10 through the processing liquid discharge unit 13. That is, the pure water supplied from the pure water supply source 32 and the processing liquid circulated through the circulation line CL flow into the processing liquid discharge unit 13 at this time. Accordingly, the processing liquid discharge unit 13 discharges the processing liquid at a higher flow rate than steps S511 to S512. The processing liquid discharged from the processing liquid discharge unit 13 also flows at a relatively high flow velocity in the vicinity of the solid surface such as the surface of the substrate W inside the processing tank 10, the surface of the lifter 20, and the inner wall of the inner tank 11, The hydrofluoric acid component remaining in the vicinity of these solid surfaces is stirred. In particular, the circulation pump 47 feeds the processing liquid at a pressure higher than the pure water supply pressure by the pure water supply source 32. For this reason, the hydrofluoric acid component remaining inside the treatment tank 10 can be stirred better.

  Due to the stirring of the hydrofluoric acid component, the measured value of the resistivity meter 14 slightly decreases as shown at times t2 to t3 in FIG. The control unit 70 of the substrate processing apparatus 1 receives the measurement value of the specific resistance meter 14 and continuously monitors whether or not the measurement value has decreased to a preset reference value r2 (second reference value). (Step S514). The substrate processing apparatus 1 continues to circulate the processing solution as long as the measured value of the resistivity meter 14 is higher than the reference value r2. The substrate processing apparatus 1 desirably sets the reference value r2 to a value of 4 MΩ · cm or more and 6 MΩ · cm or less, for example. In this way, the hydrofluoric acid component remaining inside the treatment tank 10 is sufficiently stirred while continuing the supply of pure water through the pure water supply line WL and the discharge of the treatment liquid through the drainage line DL. Can do.

  Eventually, when the measured value of the resistivity meter 14 decreases to the reference value r2, the substrate processing apparatus 1 maintains the open state of the open / close valves 37, 38, 44 and the closed state of the open / close valve 36, and the open / close valves 45, 46. Is closed and the circulation pump 47 is stopped. Thereby, the circulation line CL is closed, and the circulation of the processing liquid is stopped (step S515).

  When the circulation line CL is closed, the substrate processing apparatus 1 returns to the state of FIG. 9 again, and supplies pure water from the pure water supply line WL and discharges the processing liquid to the drain line DL. The hydrofluoric acid component stirred in steps S513 to S514 overflows from the upper part of the treatment tank 10 together with the treatment liquid, is collected into the pipe 41, and is discharged to the drainage facility in the factory via the pipes 41 and 42.

  The measured value of the resistivity meter 14 rises more steeply than at the time of steps S511 to S512, as shown at times t3 to t4 in FIG. The control unit 70 of the substrate processing apparatus 1 receives the measured value of the resistivity meter 14 and continuously monitors whether or not the measured value has increased to a preset reference value ra (step S516). Eventually, when the measured value of the resistivity meter 14 rises to the reference value ra, the substrate processing apparatus 1 finishes the replacement process in step S5, assuming that the replacement of the chemical solution with pure water is completed inside the processing tank 10. .

  In this way, the substrate processing apparatus 1 of the present embodiment performs the supply of pure water by the pure water supply line WL and the discharge of the processing liquid by the drain line DL, while the measured value of the resistivity meter 14 is the reference value. When r1 is reached, the processing liquid is circulated by the circulation line CL. For this reason, the chemical component remaining inside the treatment tank 10 can be stirred by circulation of the treatment liquid, and the stirred chemical solution component can be discharged to the outside of the treatment tank 10. Therefore, it is possible to efficiently replace the processing liquid stored in the processing tank 10 from chemical liquid to pure water while suppressing the supply amount of pure water.

  In particular, the substrate processing apparatus 1 according to the present embodiment performs a replacement operation from a chemical solution to pure water while filling the periphery of the processing tank 10 with nitrogen gas. For this reason, gas, such as a carbon dioxide, does not melt | dissolve in the processing liquid stored in the processing tank 10, and the specific resistance value of a processing liquid can be changed correctly according to the density | concentration of a hydrofluoric acid component.

  Returning to the flowchart of FIG. 2, when the replacement of hydrofluoric acid with pure water is completed in the processing tank 10, the substrate W immersed in the pure water undergoes a rinsing process with pure water (step S6). During the rinsing process, as shown in FIG. 6, the discharge of pure water from the processing liquid discharge unit 13 is continued. When the rinsing process for a predetermined time is completed, the substrate processing apparatus 1 operates the drive mechanism 22 to raise the lifter 20 as shown in FIG. 7, and the substrate W is made from the pure water stored in the processing tank 10. Is raised (step S7). Thereafter, the substrate processing apparatus 1 operates the drive mechanism 53 to slide the lid portion 52 to open the opening portion 51 of the chamber 50. Then, the substrate W is carried out of the chamber 50 by a predetermined transport mechanism, and a series of processes for the set of substrates W is completed.

<3. Other Embodiment of Replacement Operation from Dilute Hydrofluoric Acid to Pure Water>
In the above embodiment, the replacement operation from dilute hydrofluoric acid to pure water (step S5) is performed according to the procedure shown in the flowchart of FIG. 8, but instead, the procedure shown in the flowchart of FIG. A replacement operation from dilute hydrofluoric acid to pure water may be performed. Below, the replacement | exchange operation | movement from the diluted hydrofluoric acid to pure water in other embodiment is demonstrated, referring the flowchart of FIG.

  In the flowchart of FIG. 12, first, the substrate processing apparatus 1 closes the on-off valve 36 while maintaining the on-off valves 45, 46 closed and the on-off valves 37, 38, 44 open. Thereby, the supply of hydrofluoric acid from the hydrofluoric acid supply source 31 is stopped, and pure water is supplied from the pure water supply source 32 to the inside of the treatment tank 10 through the pipes 34 and 35 and the treatment liquid discharge unit 13, The processing liquid overflowed to the outer tub 12 is discharged to the drainage equipment via the pipes 41 and 42 (step S521). That is, in the treatment tank 10 at this time, as shown in FIG. 9, a pure water supply line WL that supplies pure water to the treatment tank 10 and a drain line DL that discharges the treatment liquid from the treatment tank 10. Will be in communication. Then, due to the supply of pure water through the pure water supply line WL and the discharge of the processing liquid through the drainage line DL, the processing liquid stored in the processing tank 10 is gradually replaced with dilute hydrofluoric acid from pure water. Go.

  As the concentration of hydrofluoric acid component in the treatment liquid stored in the treatment tank 10 decreases, the specific resistance value of the treatment liquid gradually increases. For this reason, the measured value of the specific resistance meter 14 gradually increases as shown at times t5 to t6 in FIG. The control unit 70 of the substrate processing apparatus 1 receives the measurement value of the resistivity meter 14 and continuously monitors whether or not the measurement value has reached a preset reference value r3 (first reference value). (Step S522).

  The substrate processing apparatus 1 continues the supply of pure water through the pure water supply line WL and the discharge of the processing liquid through the drain line DL while the measured value of the resistivity meter 14 does not reach the reference value r3. It is desirable that the substrate processing apparatus 1 supplies pure water in an amount equal to or larger than the volume of the processing tank 10 to the inside of the processing tank 10 before starting the circulation of the processing liquid described later. Further, the substrate processing apparatus 1 desirably sets the reference value r3 to a value of, for example, 6 MΩ · cm or more and 8 MΩ · cm or less. In this way, the replacement of the chemical liquid with pure water can be appropriately advanced before the start of the circulation of the processing liquid described later.

  Eventually, when the measured value of the resistivity meter 14 reaches the reference value r3, the substrate processing apparatus 1 closes the on-off valves 37, 38, and 44 and maintains the on-off valves 45, 46 while maintaining the on-off valve 36 in the closed state. And the circulation pump 47 is operated. Thereby, the supply of pure water through the pure water supply line WL and the discharge of the processing liquid through the drainage line DL are stopped, and the processing liquid circulation line CL is opened as shown in FIG. 13 (step S523). ).

  When the circulation line CL is opened, the processing liquid collected in the pipe 41 flows into the pipe 43 and is supplied to the pipe 35 by the pressure of the circulation pump 47. Then, the processing liquid supplied to the pipe 35 is supplied again into the processing tank 10 through the processing liquid discharge unit 13. The circulation pump 47 feeds the processing liquid at a pressure higher than the pure water supply pressure by the pure water supply source 32. For this reason, the processing liquid is discharged at a higher flow rate than in steps S521 to S522. The processing liquid discharged from the processing liquid discharge unit 13 also flows at a relatively high flow velocity in the vicinity of the solid surface such as the surface of the substrate W inside the processing tank 10, the surface of the lifter 20, and the inner wall of the inner tank 11, The hydrofluoric acid component remaining in the vicinity of these solid surfaces is stirred.

  Due to the stirring of the hydrofluoric acid component, the measured value of the resistivity meter 14 decreases as shown at times t6 to t7 in FIG. The control unit 70 of the substrate processing apparatus 1 receives the measured value of the resistivity meter 14 and continuously monitors whether the measured value has decreased to a preset reference value r4 (second reference value). (Step S524). The substrate processing apparatus 1 continues to circulate the processing solution as long as the measured value of the resistivity meter 14 is higher than the reference value r4. The substrate processing apparatus 1 desirably sets the reference value r4 to a value of, for example, 0 MΩ · cm or more and 2 MΩ · cm or less. In this way, the hydrofluoric acid component remaining inside the treatment tank 10 is sufficiently stirred in a state where the supply of pure water by the pure water supply line WL and the discharge of the treatment liquid by the drain line DL are stopped. be able to.

  Eventually, when the measured value of the resistivity meter 14 decreases to the reference value r4, the substrate processing apparatus 1 closes the on-off valves 45, 46 and maintains the on-off valves 37, 38, 44 while maintaining the on-off valve 36 in the closed state. Is opened and the circulation pump 47 is stopped. As a result, the circulation line CL is closed and the circulation of the treatment liquid is stopped. As shown in FIG. 9, the supply of the pure water from the pure water supply line WL and the supply of the treatment liquid to the drain line DL are performed. The discharge is resumed (step S525). The hydrofluoric acid component stirred in steps S523 to S524 overflows from the upper part of the treatment tank 10 together with the treatment liquid, is collected into the pipe 41, and is discharged to the drainage facility in the factory via the pipes 41 and 42.

  As shown at times t7 to t8 in FIG. 14, the measured value of the specific resistance meter 14 rises more steeply than at the time of steps S521 to S522. The control unit 70 of the substrate processing apparatus 1 receives the measurement value of the specific resistance meter 14 and continuously monitors whether or not the measurement value has increased to a preset reference value ra (step S526). Eventually, when the measured value of the resistivity meter 14 rises to the reference value ra, the substrate processing apparatus 1 finishes the replacement process in step S5, assuming that the replacement of the chemical solution with pure water is completed inside the processing tank 10. .

  In the present embodiment, when pure water is supplied through the pure water supply line WL and the treatment liquid is discharged through the drainage line DL in this way, the measured value of the resistivity meter 14 reaches the reference value r3. The supply of pure water by the water supply line WL and the discharge of the processing liquid by the drain line DL are stopped, and the processing liquid is circulated by the circulation line CL. When the measured value of the specific resistance meter 14 reaches the reference value r4, the circulation of the treatment liquid through the circulation line CL is stopped, and the supply of pure water through the pure water supply line WL and the discharge of the treatment liquid through the drainage line DL are stopped. To resume. For this reason, the chemical component remaining inside the treatment tank 10 can be stirred by circulation of the treatment liquid, and the stirred chemical solution component can be discharged to the outside of the treatment tank 10. Therefore, it is possible to efficiently replace the processing liquid stored in the processing tank 10 from chemical liquid to pure water while suppressing the supply amount of pure water.

  In the previous embodiment, when the processing liquid is circulated by the circulation line CL, the pure water supply by the pure water supply line WL and the discharge of the processing liquid by the drain line DL are continued. In the embodiment, when the processing liquid is circulated by the circulation line CL, the supply of pure water by the pure water supply line WL and the discharge of the processing liquid by the drain line DL are stopped. For this reason, the previous embodiment (the processing procedure of FIG. 8) is more advantageous when it is desired to further reduce the replacement time of the processing liquid. However, when it is desired to further reduce the supply amount of pure water, The embodiment (the processing procedure in FIG. 12) is more advantageous.

<4. Modification>
As mentioned above, although main embodiment of this invention was described, this invention is not limited to said example. For example, in each of the above embodiments, the circulation line CL is opened only once in a series of liquid replacement operations. However, the opening and closing of the circulation line CL may be repeated a plurality of times. If it does in this way, the stirring effect of the hydrofluoric acid component in the inside of processing tank 10 can be improved more.

  In the above embodiment, dilute hydrofluoric acid and pure water are discharged from the common nozzle tubes 13a and 13b. However, a dilute hydrofluoric acid nozzle tube and a deionized water nozzle tube are disposed inside the processing tank 10. May be provided separately, and each supply line may also be provided separately.

  In the above embodiment, the liquid replacement operation control is performed while monitoring the measurement value of the specific resistance meter 14. However, the time until the specific resistance value of the treatment liquid reaches the reference values r1 to r4, ra. The liquid replacement operation control may be performed based on the time determined by the experiment or the like in advance.

  In each of the above embodiments, dilute hydrofluoric acid is used as the chemical solution, but the chemical solution of the present invention is not limited to dilute hydrofluoric acid, and SC-1 solution, SC-2 solution, phosphoric acid, Other chemicals such as CARO acid may be used.

  The present invention can be applied not only to a substrate processing apparatus for processing a semiconductor substrate but also to a substrate processing apparatus for processing various substrates such as a glass substrate for a liquid crystal display device and a glass substrate for a photomask. it can.

It is the figure which showed the structure of the substrate processing apparatus. It is the flowchart which showed the flow of the process in a substrate processing apparatus. It is the figure which showed the state of the substrate processing apparatus in the middle of a process. It is the figure which showed the state of the substrate processing apparatus in the middle of a process. It is the figure which showed the state of the substrate processing apparatus in the middle of a process. It is the figure which showed the state of the substrate processing apparatus in the middle of a process. It is the figure which showed the state of the substrate processing apparatus in the middle of a process. It is the flowchart which showed the flow of the detailed operation | movement at the time of substitution to dilute hydrofluoric acid to pure water. It is the figure which showed the state of the supply-drain system of the substrate processing apparatus in the middle of a process. It is the figure which showed the state of the supply-drain system of the substrate processing apparatus in the middle of a process. It is the figure which showed the example of the change of the measured value of a specific resistance meter. It is the flowchart which showed the flow of the detailed operation | movement at the time of substitution to dilute hydrofluoric acid to pure water. It is the figure which showed the state of the supply-drain system of the substrate processing apparatus in the middle of a process. It is the figure which showed the example of the change of the measured value of a specific resistance meter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate processing apparatus 10 Processing tank 13 Processing liquid discharge part 14 Resistivity meter 20 Lifter 30 Processing liquid supply part 40 Processing liquid collection | recovery part 47 Circulation pump 50 Chamber 54 Nitrogen gas discharge part 60 Nitrogen gas supply part 70 Control part 71 Storage part W Substrate WL Pure water supply line DL Drain line CL Circulation line r1 to r4 Reference value

Claims (9)

A substrate processing apparatus for sequentially performing chemical treatment with a chemical solution and rinse treatment with pure water on a substrate in a treatment tank,
Pure water supply means for supplying pure water to the treatment tank;
Drainage means for draining the liquid from the treatment tank;
A circulation means for circulating the liquid recovered from the treatment tank and re-supplying the liquid to the treatment tank;
Measuring means for measuring the specific resistance value of the liquid stored in the treatment tank;
Control means for controlling operations of the pure water supply means, the drainage means, and the circulation means;
With
The control means, when replacing the liquid stored in the processing tank from chemical liquid to pure water, while performing the supply of pure water by the pure water supply means and the discharge of the liquid by the drainage means, The substrate processing apparatus, wherein when the measured value by the measuring means reaches a first reference value, the liquid is circulated by the circulating means. The substrate processing apparatus according to claim 1,
The substrate processing apparatus, wherein the first reference value is a value of 6 MΩ · cm to 8 MΩ · cm. The substrate processing apparatus according to claim 1 or 2, wherein
The control means stops the circulation of the liquid by the circulation means when the measurement value by the measurement means reaches a second reference value after starting the circulation of the liquid by the circulation means. Processing equipment. The substrate processing apparatus according to claim 3, wherein
The substrate processing apparatus, wherein the second reference value is a value of 4 MΩ · cm to 6 MΩ · cm. The substrate processing apparatus according to claim 1,
The control means, when replacing the liquid stored in the processing tank from chemical liquid to pure water, performs the supply of pure water by the pure water supply means and the discharge of the liquid by the drainage means, When the measurement value by the measurement means reaches the first reference value, the supply of pure water by the pure water supply means and the discharge of the liquid by the drainage means are stopped and the circulation of the liquid by the circulation means is executed. When the measurement value by the measurement means reaches the second reference value, the circulation of the liquid by the circulation means is stopped and the supply of pure water by the pure water supply means and the discharge of the liquid by the drainage means are executed again. A substrate processing apparatus. The substrate processing apparatus according to claim 5,
The substrate processing apparatus, wherein the second reference value is a value of 0 MΩ · cm to 2 MΩ · cm. A substrate processing apparatus according to any one of claims 1 to 6,
The substrate processing apparatus, wherein the circulation unit supplies the liquid to the processing tank at a flow rate higher than a flow rate of pure water supplied by the pure water supply unit. A substrate processing apparatus according to any one of claims 1 to 7,
A substrate processing apparatus, further comprising an inert gas filling means for filling a processing space including the processing tank with an inert gas. In a substrate processing apparatus for sequentially performing chemical processing with a chemical and rinsing with pure water on a substrate in a processing tank, processing liquid replacement for replacing the liquid stored in the processing tank with chemical from pure water A method,
A first step of discharging liquid from the treatment tank while supplying pure water to the treatment tank;
When the specific resistance value of the liquid in the processing tank reaches the first reference value by the first process, the second process circulates the liquid recovered from the processing tank and re-supplys it to the processing tank; ,
When the specific resistance value of the liquid in the processing tank reaches the second reference value by the second step, the liquid circulation is stopped, and the liquid is supplied from the processing tank while supplying pure water to the processing tank. A third step of discharging;
A treatment liquid replacement method comprising:

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