JP2005109166A - Method and device for treating substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and device for treating substrate by which a treating liquid left in a treating liquid pipeline can be prevented from being utilized for the next substrate treatment, and, in addition, the contamination of the outside of a cup caused by the treating liquid when the liquid leaks out from a nozzle and falls onto the outside of the cup can be prevented without increasing the consumption of the treating liquid. <P>SOLUTION: After the supply of a sulfuric acid and a hydrogen peroxide solution to a mixing valve 61 is stopped, a nitrogen gas is supplied to the valve 61 so as to eject the mixed solution of the sulfuric acid and the hydrogen peroxide solution staying in the valve 61 and the treating liquid pipeline 5 from the nozzle 3 as an SPM. The SPM ejected from the nozzle 3 is supplied to the surface of a wafer W and contributes to the peeling of a resist film on the surface of the wafer W. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method and apparatus for processing a substrate using a processing liquid. Substrates to be processed include, for example, semiconductor wafers, glass substrates for liquid crystal display devices, glass substrates for plasma displays, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, photomask substrates, and the like. .

  In the manufacturing process of a semiconductor device or a liquid crystal display device, a process using a processing liquid is performed on a substrate such as a semiconductor wafer or a glass substrate for a liquid crystal display panel. For example, in a single-wafer type substrate processing apparatus that processes substrates one by one, a spin chuck that rotates while holding the substrate horizontally, and a processing liquid nozzle that supplies a processing liquid to the surface of the substrate held by the spin chuck With the substrate being rotated by the spin chuck, the processing liquid is supplied to the entire surface of the substrate by supplying the processing liquid from the processing liquid nozzle to the surface of the rotating substrate, A treatment using a treatment liquid for the surface of the substrate is achieved.

  A processing liquid pipe is connected to the processing liquid nozzle, and the processing liquid is supplied from the processing liquid pipe. A treatment liquid valve for controlling the flow of the treatment liquid in the treatment liquid pipe is interposed in the middle of the treatment liquid pipe. When the processing liquid valve is opened, the processing liquid flows from the processing liquid pipe to the processing liquid nozzle, and the processing liquid is discharged from the processing liquid nozzle and supplied to the surface of the substrate. When the processing liquid valve is closed, the flow of the processing liquid in the processing liquid pipe is blocked, and the supply of the processing liquid from the processing liquid pipe to the processing liquid nozzle is stopped. Discharge is stopped.

  While the processing liquid valve is closed, no processing liquid flows into the processing liquid nozzle side of the processing liquid valve in the processing liquid piping, so that the processing liquid remains between the processing liquid valve and the tip of the processing liquid nozzle. It becomes a state. The treatment liquid remaining in the treatment liquid piping deteriorates with time. For example, SPM (sulfuric acid / hydrogen peroxide mixture) whose temperature is adjusted to a constant liquid temperature is used as a processing liquid for the process of removing the resist film that is no longer necessary from the surface of the substrate. If this SPM is left in a state where it remains in the processing liquid pipe, the chemical properties and liquid temperature of the SPM remaining in the processing liquid pipe deteriorate (decrease) over time. In addition, in the process of washing the surface of the substrate with pure water, if the pure water remains in the processing liquid piping, bacteria and other germs are generated in the pure water remaining in the processing liquid piping. There is a fear. When the deteriorated processing liquid is accumulated in the processing liquid piping, the processing liquid deteriorated in the processing liquid piping is supplied to the substrate through the processing liquid nozzle when the next substrate is processed. There is a risk of causing a defect (for example, uneven peeling of the resist film) or causing contamination of the substrate.

Therefore, in order to prevent the deteriorated processing liquid from being used for the processing of the next substrate, the processing liquid valve is opened before the processing liquid is supplied to the processing target substrate and remains in the processing liquid piping. A so-called pre-dispensing of a processing liquid is performed in which a deteriorated processing liquid is discharged from a processing liquid nozzle into a space where no substrate exists (see, for example, Patent Document 1).
Japanese Patent Application No. 9-57176

  The deteriorated processing liquid discharged from the processing liquid nozzle by pre-dispensing cannot be reused for processing the substrate, and must be discarded. For this reason, when pre-dispensing is performed, the consumption of the processing liquid increases, and as a result, a new problem arises that the running cost increases. In particular, when an expensive processing liquid such as SPM is used for substrate processing, the pre-dispensing significantly increases the running cost.

  Further, in a single wafer processing apparatus, a spin chuck is disposed in a cup for receiving a processing liquid, and when supplying the processing liquid to the substrate, the processing liquid nozzle is placed above the spin chuck. When the supply of the processing liquid is completed, the processing liquid nozzle is moved from the processing position to a standby position set outside the cup. In the apparatus having such a configuration, as another problem, when the processing liquid remains in the processing liquid pipe after the processing liquid valve is closed, the processing liquid nozzle is moved from the processing position to the standby position. There is also a problem that the processing liquid remaining in the pipe falls from the processing liquid nozzle to the outside of the cup and the outside of the cup is contaminated by the processing liquid.

SUMMARY OF THE INVENTION An object of the present invention is to provide a substrate processing method and a substrate processing apparatus that can omit pre-dispensing.
Another object of the present invention is to provide a substrate processing method and a substrate processing apparatus capable of preventing contamination outside the cup due to the processing liquid leaking from the nozzle and falling outside the cup.

  The invention described in claim 1 for achieving the above object includes a processing liquid discharging step of discharging a processing liquid for processing the substrate (W) from the nozzle (3), and at the end of the processing liquid discharging step. A process liquid extrusion step of supplying a gas to the process liquid pipe (5, 61) for supplying the process liquid to the nozzle and pushing out the process liquid in the process liquid pipe from the nozzle. A substrate processing method.

In addition, the alphanumeric characters in parentheses represent corresponding components in the embodiments described later. The same applies hereinafter.
According to the method of claim 1, gas is supplied into the processing liquid pipe at the end of the processing liquid discharge process, and the processing liquid in the processing liquid pipe is pushed out from the nozzle. There is no processing liquid remaining in the processing liquid piping. Therefore, even if pre-dispensing is not performed, the processing liquid deteriorated (processing capacity is reduced) is not supplied to the substrate.

  Further, as described in claim 2, by performing the process liquid extrusion step in a state where the gas discharged by pushing the process liquid in the process liquid pipe from the nozzle can hit the substrate to be processed, The processing liquid to be extruded can be supplied to the substrate. Therefore, unlike the pre-dispensing method, the processing liquid pushed out from the nozzle can contribute to the processing of the substrate, and waste of the processing liquid due to waste of the processing liquid can be eliminated. In addition, since the processing liquid pushed out from the nozzle is not deteriorated, even if the processing liquid pushed out from the nozzle is supplied to the substrate, there is no possibility of causing processing variations between the substrates and processing defects on the substrate.

According to a third aspect of the present invention, there is provided the substrate holding means (2) for holding the substrate to be processed by the gas discharged by pushing out the processing liquid in the processing liquid piping from the nozzle. 3. The substrate processing method according to claim 1, wherein the substrate processing method is performed in a state where the liquid can be supplied into a cup (4) provided surrounding the substrate.
According to this method, since the processing liquid pushed out from the nozzle is supplied into the cup, there is no possibility that the outside of the cup is contaminated by the processing liquid.

Therefore, in parallel with the processing liquid extrusion step, there is a case where a nozzle moving step for moving the nozzle from a processing position set above the substrate holding means to a standby position set outside the cup is further included. However, it is possible to prevent contamination due to the processing liquid leaking from the nozzle returned to the standby position and falling out of the cup.
In the invention according to claim 4, in the treatment liquid extrusion step, after the supply of the treatment liquid from the treatment liquid pipe to the nozzle is stopped, the treatment liquid in the treatment liquid pipe is pushed out from the nozzle, 4. The substrate processing method according to claim 1, wherein the substrate processing method is performed over a period until the gas supplied into the processing liquid pipe is discharged from the nozzle.

As in this method, the processing liquid extrusion process is performed until the gas supplied into the processing liquid pipe is discharged from the nozzle, so that the processing liquid in the processing liquid pipe is not left in the processing liquid pipe from the nozzle. Can be extruded.
The invention according to claim 5 includes a nozzle (3) for discharging a processing liquid for processing the substrate (W), a processing liquid pipe (5, 61) through which the processing liquid supplied to the nozzle flows, Gas supply means (64, 641, 613) for supplying gas into the processing liquid pipe, and after the supply of the processing liquid from the processing liquid pipe to the nozzle is stopped, the gas supply means is controlled to perform the processing. A substrate processing apparatus comprising gas supply control means (100) for supplying the gas into the liquid pipe.

  According to this configuration, after the supply of the processing liquid from the processing liquid pipe to the nozzle is stopped, the gas is supplied from the gas supply means into the processing liquid pipe. Thereby, the processing liquid staying in the processing liquid pipe can be pushed out from the nozzle, and the processing liquid can be prevented from being left in the processing liquid pipe. Therefore, even if pre-dispensing is not performed, the processing liquid deteriorated (processing capacity is reduced) is not supplied to the substrate.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a diagram schematically showing the configuration of a substrate processing apparatus according to an embodiment of the present invention. This substrate processing apparatus treats SPM (sulfuric acid / hydrogen peroxide mixture) on the surface (upper surface) of a silicon semiconductor wafer W (hereinafter simply referred to as “wafer W”), which is an example of a substrate. Is a single wafer type apparatus that performs a resist stripping process for stripping a resist film that is no longer needed from the surface of the wafer W. The wafer W is placed almost horizontally in a processing chamber 1 partitioned by a partition wall. A spin chuck 2 for holding and rotating, a nozzle 3 for supplying SPM to the surface of the wafer W held by the spin chuck 2, and a cup 4 for receiving SPM flowing down or scattered from the wafer W And.

The spin chuck 2 can hold the wafer W in a substantially horizontal posture, for example, by holding the wafer W with a plurality of holding members 21, and further rotates around a substantially vertical axis in that state. The held wafer W can be rotated while maintaining a substantially horizontal posture.
On the side of the spin chuck 2, a pivot shaft 31 is disposed substantially along the vertical direction, and the nozzle 3 is attached to the tip end of a nozzle arm 32 that extends substantially horizontally from the upper end of the pivot shaft 31. ing. The swivel shaft 31 is provided so as to be rotatable around its central axis. By rotating the swivel shaft 31, the nozzle 3 is disposed above the wafer W held by the spin chuck 2, or the outer side of the cup 4. It can be arranged at a standby position set to. Further, by reciprocating the swivel shaft 31 within a predetermined angle range, the nozzle arm 32 can be swung over the wafer W held by the spin chuck 2. The SPM supply position from the nozzle 3 can be scanned (moved) on the surface of the held wafer W.

Connected to the nozzle 3 is a tip of a treatment liquid pipe 5 made of PFA (perfluoro-alkylvinyl-ether-tetrafluoro-ethlene-copolymer) excellent in chemical resistance and heat resistance. The other end of the processing liquid pipe 5 extends outside the processing chamber 1 and is connected to a mixing valve 61 disposed in a fluid box 6 provided adjacent to the processing chamber 1.
The mixing valve 61 has three input ports: a sulfuric acid port 611, a hydrogen peroxide water port 612, and a nitrogen gas port 613. The sulfuric acid port 611, the hydrogen peroxide water port 612, and the nitrogen gas port 613 are each a sulfuric acid pipe 62 for supplying sulfuric acid whose temperature is adjusted to a constant temperature (for example, 80 ° C.) from a sulfuric acid supply source, A hydrogen peroxide water pipe 63 for supplying hydrogen peroxide water from a hydrogen peroxide water supply source and a nitrogen gas pipe 64 for supplying nitrogen gas from a nitrogen gas supply source are connected.

  A sulfuric acid valve 621 for switching supply / stop of sulfuric acid to the mixing valve 61 and a sulfuric acid flow meter 622 for detecting the flow rate of sulfuric acid flowing through the sulfuric acid pipe 62 are provided in the middle of the sulfuric acid pipe 62. It is inserted in this order from the upstream in the distribution direction. The sulfuric acid pipe 62 is connected to a sulfuric acid return path 65 at a branch point upstream of the sulfuric acid valve 621 in the flow direction of sulfuric acid. During the period when the sulfuric acid valve 621 is closed, the sulfuric acid pipe 62 is closed. The sulfuric acid flowing through the water passes through the sulfuric acid return path 65 and is returned to the sulfuric acid supply source. Thus, during the period in which the sulfuric acid valve 621 is closed, sulfuric acid whose temperature is adjusted to a constant temperature circulates in the sulfuric acid circulation path including the sulfuric acid supply source, the sulfuric acid pipe 62 and the sulfuric acid return path 65, and the sulfuric acid in the sulfuric acid pipe 62 Since sulfuric acid does not stagnate in the downstream portion of the valve 621, sulfuric acid whose temperature is adjusted to a constant temperature immediately after the opening of the sulfuric acid valve 621 can be supplied to the mixing valve 61.

  In the middle of the hydrogen peroxide solution pipe 63, a hydrogen peroxide solution valve 631 for switching supply / stop of the hydrogen peroxide solution to the mixing valve 61 and a hydrogen peroxide solution flowing through the hydrogen peroxide solution pipe 63 are provided. A hydrogen peroxide flow meter 632 for detecting the flow rate is interposed in this order from the upstream side in the flow direction of the hydrogen peroxide solution. In addition, a hydrogen peroxide solution return path 66 is branched and connected to the hydrogen peroxide solution pipe 63 at a branch point upstream of the hydrogen peroxide solution valve 631 with respect to the flow direction of the hydrogen peroxide solution. During the period when the hydrogen water valve 631 is closed, the hydrogen peroxide solution flowing through the hydrogen peroxide solution pipe 63 is returned to the hydrogen peroxide solution supply source through the hydrogen peroxide solution return path 66. Yes. As a result, during the period when the hydrogen peroxide solution valve 631 is closed, the hydrogen peroxide solution circulation path including the hydrogen peroxide solution supply source, the hydrogen peroxide solution pipe 63 and the hydrogen peroxide solution return channel 66 is passed through the hydrogen peroxide solution circulation path. The water circulates to prevent the hydrogen peroxide solution from staying in the downstream portion of the hydrogen peroxide solution valve 631 of the hydrogen peroxide solution pipe 63. In this embodiment, the temperature of the hydrogen peroxide solution is not adjusted, and the hydrogen peroxide solution at room temperature (about 25 ° C.) flows through the hydrogen peroxide solution pipe 63.

A nitrogen gas valve 641 for switching supply / stop of nitrogen gas to the mixing valve 61 is interposed in the middle of the nitrogen gas pipe 64.
When the sulfuric acid valve 621 and the hydrogen peroxide water valve 631 are opened, and when the sulfuric acid port 611 and the hydrogen peroxide water port 612 of the mixing valve 61 are opened, sulfuric acid and peroxidation from the sulfuric acid pipe 62 and the hydrogen peroxide water pipe 63, respectively. Hydrogen water flows into the mixing valve 61, and sulfuric acid and hydrogen peroxide water join together at the mixing valve 61, thereby creating a mixed solution of sulfuric acid and hydrogen peroxide water. The prepared mixed solution of sulfuric acid and hydrogen peroxide solution flows out from the mixing valve 61 to the processing liquid pipe 5 and flows through the processing liquid pipe 5 toward the nozzle 3.

  In the mixing valve 61, the sulfuric acid from the sulfuric acid pipe 62 and the hydrogen peroxide solution from the hydrogen peroxide water pipe 63 simply merge, and the mixed liquid flowing out from the mixing valve 61 to the treatment liquid pipe 5 is mixed with sulfuric acid. The SPM has not yet been sufficiently mixed with hydrogen peroxide. Therefore, the processing liquid pipe 5 is provided with a flow pipe 51 with stirring fins for stirring the mixed solution of sulfuric acid and hydrogen peroxide water flowing through the processing liquid pipe 5 to generate SPM.

The stirring fin-equipped flow pipe 51 includes a plurality of stirring fins each formed of a rectangular plate body in which a twist of about 180 degrees is added around the liquid flow direction in the pipe member, around the central axis of the pipe along the liquid flow direction. For example, a product name “MX Series: Inline Mixer” manufactured by Noritake Co., Limited Advance Electric Industry Co., Ltd. can be used. In the flow pipe 51 with stirring fins, the mixed solution of sulfuric acid and hydrogen peroxide solution is sufficiently stirred, whereby a chemical reaction between sulfuric acid and hydrogen peroxide solution (H ₂ SO ₄ + H ₂ O ₂ → H ₂ SO ₅ + H ₂ O) occurs, and SPM containing H ₂ SO ₅ having strong oxidizing power is generated. At that time, heat is generated due to a chemical reaction (reaction heat), and due to this heat generation, the liquid temperature of the SPM is a high temperature (for example, 80 ° C. or higher) at which the resist film formed on the surface of the wafer W can be satisfactorily peeled off. Until the temperature rises.

  The flow pipe 51 with stirring fins is provided in the processing chamber 1 by being attached to the nozzle arm 32. More specifically, as shown in FIG. 2, the mounting base 511 is fixed to the upper surface of the nozzle arm 32, and the flow fin 51 with a stirring fin is lower on the downstream side in the fluid flow direction than on the upstream side. It is attached to the mounting base 511 in a state of being inclined as described above. A bracket 321 is fixed to the tip of the nozzle arm 32, and the nozzle 3 is attached to the bracket 321. The nozzle 3 is a tubular straight nozzle bent in a square shape, and is attached in a state in which the discharge port at the tip is directed vertically downward, and is located at the upstream end of the fluid flow direction (SPM flow direction) of the nozzle 3. The pipe length L between the part and the end on the downstream side in the fluid flow direction of the flow pipe 51 with stirring fin is designed to be, for example, about 50 to 100 mm.

Thereby, high temperature SPM produced | generated with the flow pipe 51 with a stirring fin is supplied to the nozzle 3, without the liquid temperature falling. Therefore, high-temperature SPM can be supplied to the wafer W held on the spin chuck 2, and it can be peeled off and removed without leaving an unnecessary resist film from the surface of the wafer W.
Referring again to FIG. 1, a PFA exhaust pipe 71 for exhausting the atmosphere in the cup 4 and a waste liquid such as SPM received by the cup 4 (used for processing the wafer W) are provided on the bottom surface of the cup 4. And a waste liquid pipe 72 made of PFA for discharging the processing liquid to be discarded after being disposed.

  At the front end of the waste liquid pipe 72, a high concentration waste liquid introduction pipe 73 made of PFA for guiding the waste liquid flowing through the waste liquid pipe 72 to the dilution tank 8 provided in the fluid box 6 and the waste liquid pipe 72 flow. A general waste liquid introduction pipe 74 for leading the waste liquid to a gas-liquid separation tank 9 provided below the processing chamber 1 is branched and connected. At the branch point between the high-concentration waste liquid introduction pipe 73 and the general waste liquid introduction pipe 74, the introduction destination of the waste liquid flowing through the waste liquid pipe 72 is the high-concentration waste liquid introduction pipe 73 (dilution tank 8) and the general waste liquid introduction pipe 74. A waste liquid switching valve 75 for switching to (gas-liquid separation tank 9) is interposed.

  The dilution tank 8 is formed in a considerably smaller size than the gas-liquid separation tank 9 using PFA material. Cooling water for diluting and cooling the waste liquid (high concentration waste liquid) introduced from the high concentration waste liquid introduction pipe 73 is supplied to the dilution tank 8 via the dilution tank cooling water valve 81 and the dilution tank cooling water pipe 82. Are being supplied. The dilution tank cooling water valve 81 is a valve with a slow leak function, and when the dilution tank cooling water valve 81 is opened, the dilution tank cooling water pipe 82 cools the dilution tank 8 at a predetermined large flow rate. Even when water is supplied and the dilution tank cooling water valve 81 is closed, the dilution tank cooling water pipe 82 cools the dilution tank 8 at a predetermined minute flow rate (a flow rate smaller than the predetermined high flow rate). Water is supplied.

  A dilution waste liquid overflow pipe 83 is inserted through the bottom surface of the dilution tank 8. One end of the diluted waste liquid overflow pipe 83 is opened at a predetermined height in the dilution tank 8, and the other end of the waste liquid overflow pipe 83 is, for example, a waste liquid utility line of a factory in which the substrate processing apparatus is installed. It is connected to the. Thereby, the liquid can be stored in the dilution tank 8 up to the height of the one end of the diluted waste liquid overflow pipe 83 (the above-mentioned predetermined height), and the liquid flowing into the diluted waste liquid overflow pipe 83 beyond the height can be stored in the waste liquid utility. Can be discharged to the line.

  The gas-liquid separation tank 9 is formed in substantially the same size as the processing chamber 1 in plan view. In addition to the introduction of the waste liquid (low concentration waste liquid) from the general waste liquid introduction pipe 74, the gas-liquid separation tank 9 is introduced with an atmosphere exhausted from the cup 4 through the exhaust pipe 71. Further, in the gas / liquid separation tank 9, cooling water for diluting and cooling the waste liquid introduced from the general waste liquid introduction pipe 74 is supplied to the gas / liquid separation tank cooling water valve 91 and the gas / liquid separation tank cooling water pipe 92. It comes to be supplied through. The gas-liquid separation tank cooling water valve 91 is a valve with a slow leak function, and when the gas-liquid separation tank cooling water valve 91 is opened, the gas-liquid separation tank 92 is connected to the gas-liquid separation tank cooling water pipe 92. 9 is supplied to the gas-liquid separation tank 9 from the gas-liquid separation tank cooling water pipe 92 even when the gas-liquid separation tank cooling water valve 91 is closed. Cooling water is supplied at a flow rate (a flow rate smaller than the predetermined large flow rate).

  A general waste liquid overflow pipe 93 is inserted into the bottom surface of the gas-liquid separation tank 9. One end of the general waste liquid overflow pipe 93 is opened at a predetermined height in the gas-liquid separation tank 9, and the other end of the general waste liquid overflow pipe 93 is connected to, for example, a factory where the substrate processing apparatus is installed. It is connected to the waste liquid utility line. Thereby, the liquid can be stored in the gas-liquid separation tank 9 up to the height of the one end of the general waste liquid overflow pipe 93 (the above-mentioned predetermined height), and the liquid flowing into the general waste liquid overflow pipe 93 beyond the height can be stored. It can be discharged to the waste liquid utility line.

  Further, an exhaust suction pipe 94 for sucking and discharging the atmosphere in the gas-liquid separation tank 9 is inserted into the bottom surface of the gas-liquid separation tank 9. One end of the exhaust suction pipe 94 is opened at a position higher than one end of the general waste liquid overflow pipe 93 in the gas-liquid separation tank 9, and the other end of the exhaust suction pipe 94 is a negative pressure source that is always driven ( (Not shown). As a result, the gas-liquid separation tank 9 is always kept at a negative pressure, the atmosphere in the cup 4 is sucked into the gas-liquid separation tank 9 through the exhaust pipe 71, and further exhausted from the gas-liquid separation tank 9 through the exhaust suction pipe 94. can do. Further, since the atmosphere in the gas-liquid separation tank 9 is always exhausted, the atmosphere containing the liquid vapor stored in the gas-liquid separation tank 9 is connected to the general waste liquid introduction pipe 74 and the waste liquid pipe 72 or the exhaust pipe 71. There is no risk of flowing into the cup 4 (backflow).

Further, a dilution waste liquid temperature sensor 84 for detecting the liquid temperature of the liquid stored in the dilution tank 8 is provided in the dilution tank 8, and the gas-liquid separation tank 9 is provided in the gas-liquid separation tank 9. 9 is provided with a general waste liquid temperature sensor 95 for detecting the liquid temperature of the liquid stored in the liquid.
FIG. 3 is a block diagram showing an electrical configuration of the substrate processing apparatus. The substrate processing apparatus further includes a control device 100 configured to include a microcomputer.

  Detection signals from various sensors such as the diluted waste liquid temperature sensor 84 and the general waste liquid temperature sensor 95 are input to the control device 100. Further, the control device 100 includes a chuck driving mechanism 22 for inputting a rotational driving force to the spin chuck 2, an arm driving mechanism 33 for inputting a swing driving force of the nozzle arm 32 to the turning shaft 31, and a mixing valve 61. A sulfuric acid valve 621, a hydrogen peroxide water valve 631, a nitrogen gas valve 641, a waste liquid switching valve 75, a dilution tank cooling water valve 81, a gas-liquid separation tank cooling water valve 91, and the like are connected as control targets.

  The control device 100 controls the chuck driving mechanism 22, the arm driving mechanism 33, and the waste liquid switching valve 75 based on input signals from various sensors according to a program created in advance, and each port 611 of the mixing valve 61. To 613, the sulfuric acid valve 621, the hydrogen peroxide valve 631, the nitrogen gas valve 641, the cooling water valve 81 for the dilution tank, and the cooling water valve 91 for the gas-liquid separation tank are controlled. Thus, the SPM is discharged from the nozzle 3 to remove the resist film formed on the surface of the wafer W, and pure water is supplied to the surface of the wafer W after the resist film is peeled off by the SPM. Each process included in the resist stripping process is performed, such as a rinse process in which SPM adhering to W is washed away with pure water, and a spin dry process in which the wafer W after the rinse process is rotated at high speed to be dried.

  FIG. 4 is a flowchart for explaining the SPM discharge process. The wafer W to be processed is carried in by a transfer robot (not shown) and delivered from the transfer robot to the spin chuck 2. When the wafer W is held on the spin chuck 2, the wafer W is rotated by the spin chuck 2 at a predetermined rotation speed (step S1). Further, the nozzle arm 32 is turned, and the nozzle 3 is disposed above the wafer W held on the spin chuck 2 from a standby position set outside the cup 4 (step S2).

Subsequently, the sulfuric acid port 611 and the hydrogen peroxide solution port 612 of the mixing valve 61 are opened, and the sulfuric acid valve 621 and the hydrogen peroxide solution valve 631 are opened (step S3). Sulfuric acid and hydrogen peroxide water that flow into the mixing valve 61 from the sulfuric acid pipe 62 and the hydrogen peroxide water pipe 63 are combined at the mixing valve 61 to form a mixed liquid of sulfuric acid and hydrogen peroxide water, and the treatment liquid pipe 5. Flowing. Then, by sufficiently stirring when passing through the flow pipe 51 with stirring fins, it is supplied to the nozzle 3 as a high-temperature SPM containing H ₂ SO ₅ having strong oxidizing power, and is supplied from the nozzle 3 to the spin chuck 2. Is supplied to the surface of the wafer W being rotated.

On the other hand, the swing of the nozzle arm 32 is started (step S4), and the nozzle arm 32 is repeatedly swung within a predetermined angle range. As the nozzle arm 32 swings, the supply position on the surface of the wafer W to which the high-temperature SPM from the nozzle 3 is guided follows an arc-shaped locus within the range from the rotation center of the wafer W to the peripheral edge of the wafer W. It is scanned repeatedly while drawing. Further, the SPM supplied to the surface of the wafer W receives centrifugal force due to the rotation of the wafer W, and flows while spreading on the surface of the wafer W from the supply position toward the periphery of the wafer W. As a result, the SPM uniformly spreads over the entire surface of the wafer W, and the resist film formed on the surface of the wafer W is peeled off by the strong oxidizing power of H ₂ SO ₅ contained in the SPM.

  When a predetermined SPM supply time has elapsed since the sulfuric acid port 611 and the hydrogen peroxide water port 612, the sulfuric acid valve 621, and the hydrogen peroxide water valve 631 of the mixing valve 61 are opened (YES in step S5), the sulfuric acid of the mixing valve 61 While the port 611 and the hydrogen peroxide solution port 612 are closed, the sulfuric acid valve 621 and the hydrogen peroxide solution valve 631 are closed (step S6), and the supply of sulfuric acid and hydrogen peroxide solution to the mixing valve 61 is stopped. . In response to the stop of the supply of sulfuric acid and hydrogen peroxide solution to the mixing valve 61, the flow of the mixed solution of sulfuric acid and hydrogen peroxide solution in the processing solution pipe 5 is stopped. The mixed solution of sulfuric acid and hydrogen peroxide water stays in the mixing valve 61 and the treatment liquid pipe 5.

  After the supply of sulfuric acid and hydrogen peroxide water to the mixing valve 61 is stopped, the nitrogen gas port 613 of the mixing valve 61 is opened and the nitrogen gas valve 641 is opened (step S7), and the nitrogen gas pipe 64 is connected to the mixing valve 61. Nitrogen gas is supplied. Nitrogen gas supplied to the mixing valve 61 flows from the mixing valve 61 to the processing liquid pipe 5, and the mixed liquid of sulfuric acid and hydrogen peroxide water staying in the mixing valve 61 and the processing liquid pipe 5 is changed to the nozzle 3. Pump towards Thus, the mixed solution of sulfuric acid and hydrogen peroxide solution flowing in the processing solution pipe 5 becomes a high-temperature SPM by passing through the flow pipe 51 with stirring fins, and the nozzle arm 32 reciprocally swings above the wafer W. It is discharged from the nozzle 3 at the tip.

  The supply of nitrogen gas to the mixing valve 61 stays in the predetermined gas pressure feed time (the time until the nitrogen gas supplied to the mixing valve 641 is discharged from the nozzle 3, that is, the mixing valve 61 and the processing liquid pipe 5. When it is performed for a sufficient time to discharge all the mixed liquid from the nozzle 3 (YES in step S8), the nitrogen gas port 613 and the nitrogen gas valve 641 of the mixing valve 61 are closed (step S9). Then, the nozzle arm 32 is turned, and the nozzle 3 is returned to the standby position set outside the cup 4 from above the wafer W (step S10).

  As described above, after the supply of sulfuric acid and hydrogen peroxide water to the mixing valve 61 is stopped, the nitrogen gas is supplied to the mixing valve 61 and the sulfuric acid and hydrogen peroxide remaining in the mixing valve 61 and the processing liquid pipe 5 are retained. The mixed liquid of water becomes SPM and is pushed out from the nozzle 3. As a result, the mixed solution of sulfuric acid and hydrogen peroxide water is not left in the mixing valve 61 and the processing solution pipe 5 without being left. Therefore, unlike the conventional substrate processing apparatus, even if pre-dispensing is not performed, the deteriorated SPM (processing capacity decreases) is not supplied to the wafer W. Further, since SPM having a substantially constant processing capability can be supplied to the wafer W throughout the entire period of the SPM discharge process, there is no possibility of causing processing variations between the wafers W or processing defects of the wafers W.

Further, since the SPM pushed out from the nozzle 3 is supplied to the surface of the wafer W and contributes to the removal of the resist film on the surface of the wafer W, unlike the pre-dispensing method, the expensive SPM may be wasted. Absent.
Furthermore, when the nozzle 3 is returned from the upper side of the wafer W to the standby position set outside the cup 4, a mixed solution or SPM of sulfuric acid and hydrogen peroxide solution is mixed into the mixing valve 61, the processing solution pipe 5 and the nozzle 3. Does not remain, and SPM does not leak from the nozzle 3 during the movement of the nozzle 3. Therefore, there is no possibility that the outside of the cup 4 is contaminated by the SPM.

  From the viewpoint of preventing contamination outside the cup 4, the SPM pushed out from the nozzle 3 by the nitrogen gas may not be supplied to the surface of the wafer W. For example, the nozzle 3 may be disposed outside the cup 4 from above the wafer W. During the return to the standby position set to, while the nozzle 3 is present at a position where the SPM discharged from the nozzle 3 is received in the cup 4, nitrogen gas is supplied to the mixing valve 61. Also good.

  FIG. 5 is a flowchart for explaining processing of the waste liquid generated during the SPM discharge process. The dilution tank cooling water valve 81 is a valve with a slow leak function, and while the dilution tank cooling water valve 81 is closed, a predetermined minute amount of cooling water is supplied from the dilution tank cooling water pipe 82 to the dilution tank 8. Since it is supplied at a flow rate, at the start of the SPM discharge process, a liquid containing almost only cooling water is stored in the dilution tank 8 to a predetermined height.

When the SPM discharge process is started, the waste liquid switching valve 75 is controlled, and the introduction destination of the waste liquid flowing through the waste liquid pipe 72 is switched to the dilution tank 8 (step T1). Also, the dilution tank cooling water valve 81 is opened (step T2), and cooling water is supplied from the dilution tank cooling water pipe 82 to the dilution tank 8 at a predetermined large flow rate.
In the SPM discharge process, high-temperature SPM is supplied to the wafer W, and SPM that flows down or scatters from the wafer W is received by the cup 4, so that the waste liquid flowing from the cup 4 into the high-concentration waste liquid introduction pipe 73 through the waste liquid pipe 72 is This is a high-concentration waste liquid (a waste liquid containing a high concentration of SPM) consisting only of substantially high-temperature SPM. Therefore, in the SPM discharge process, the high-concentration waste liquid is introduced into the dilution tank 8 from the high-concentration waste liquid introduction pipe 73, and the introduced high-concentration waste liquid is mixed into the liquid (cooling water) stored in the dilution tank 8. Will be. Further, the coolant stored in the dilution tank 8 is mixed with the cooling water supplied from the dilution tank cooling water pipe 82 to the dilution tank 8 at a large flow rate. Thereby, the high concentration waste liquid introduced into the dilution tank 8 is diluted and cooled by the liquid stored in the dilution tank 8 and the cooling water supplied from the dilution tank cooling water pipe 82. When the fully diluted and cooled waste liquid (mixed liquid of high-concentration waste liquid and a large amount of cooling water) exceeds the upper end of the diluted waste liquid overflow pipe 83 protruding into the dilution tank 8, the diluted waste liquid overflow pipe 83 enters the diluted waste liquid overflow pipe 83. It flows in and is discharged to the waste liquid utility line.

  When the SPM discharge process is completed (YES in step T3), the waste liquid switching valve 75 is controlled, and the introduction destination of the waste liquid flowing through the waste liquid pipe 72 is switched to the gas-liquid separation tank 9 (step T4). Further, after the end of the SPM discharge process, whether or not the temperature detected by the diluted waste liquid temperature sensor 84 (the liquid temperature of the liquid stored in the dilution tank 8) has dropped below a predetermined supply stop temperature (for example, 40 ° C.). Are repeatedly examined (step T5). When the temperature detected by the diluted waste liquid temperature sensor 84 falls below the supply stop temperature, the dilution tank cooling water valve 81 is closed (step T6), and thereafter the dilution is performed until the SPM discharge process is performed again. Cooling water is supplied from the tank cooling water pipe 82 to the dilution tank 8 at a minute flow rate.

  In this way, the high concentration waste liquid discharged from the cup 4 during the SPM discharge process is sufficiently diluted and cooled in the dilution tank 8 to become a fully diluted and cooled waste liquid. It is discharged through the diluted waste liquid overflow pipe 83. In the conventional substrate processing apparatus, it is necessary to add an aspirator unit to dilute and cool the high concentration waste liquid of SPM, but in this substrate processing apparatus, the sufficiently diluted and cooled waste liquid is diluted with the dilution tank 8. Therefore, such an aspirator unit is unnecessary, and the initial cost and footprint can be reduced accordingly.

  The temperature detected by the diluted waste liquid temperature sensor 84 is always monitored, and when the temperature detected by the diluted waste liquid temperature sensor 84 reaches the first temperature (for example, 40 ° C.), the dilution tank cooling water valve 81 is opened. It is preferable to cool the waste liquid by pouring a large amount of cooling water into the dilution tank 8. Furthermore, in the unlikely event that the temperature is not sufficiently lowered due to a malfunction in the supply system related to the cooling water pipe 82 (in the event of an abnormality), the temperature detected by the diluted waste liquid temperature sensor 84 is higher than the first temperature. When the temperature exceeds a high second temperature (for example, 80 ° C.), it is preferable to immediately stop the operation of the substrate processing apparatus. By doing so, it is possible to reliably prevent the waste liquid that has not been sufficiently diluted and cooled for some reason from being discharged from the dilution tank 8, and the safety of the substrate processing apparatus can be further enhanced.

  FIG. 6 is a flowchart for explaining processing of waste liquid generated after the rinsing step. The gas-liquid separation tank cooling water valve 91 is a valve with a slow leak function, and the gas-liquid separation tank 92 is also connected to the gas-liquid separation tank cooling water pipe 92 while the gas-liquid separation tank cooling water valve 91 is closed. Since the cooling water is supplied to 9 at a predetermined minute flow rate, at the start of the rinsing process, a liquid containing almost only cooling water is stored in the gas-liquid separation tank 9 to a predetermined height.

  When the SPM discharge process is completed and the rinsing process is started subsequently, the waste liquid switching valve 75 is controlled, and the introduction destination of the waste liquid flowing through the waste liquid pipe 72 is switched to the gas-liquid separation tank 9 (step) E1). Further, the gas-liquid separation tank cooling water valve 91 is opened (step E2), and the cooling water is supplied from the gas-liquid separation tank cooling water pipe 92 to the gas-liquid separation tank 9 at a predetermined large flow rate.

  In the rinsing process, pure water is supplied to the wafer W, and pure water from which the SPM adhering to the wafer W has been washed off is received by the cup 4, so that it flows from the cup 4 into the general waste liquid introduction pipe 74 through the waste liquid pipe 72. The waste liquid is a low-concentration waste liquid composed of pure water containing a small amount of SPM. Therefore, in the rinsing step, the low concentration waste liquid is introduced into the gas-liquid separation tank 9 from the general waste liquid introduction pipe 74, and the introduced low-concentration waste liquid is converted into the liquid (cooling water) stored in the gas-liquid separation tank 9. It will be mixed. Further, the coolant stored in the gas-liquid separation tank 9 is mixed with cooling water supplied from the gas-liquid separation tank cooling water pipe 92 to the gas-liquid separation tank 9 at a large flow rate. Thereby, the low concentration waste liquid introduced into the gas-liquid separation tank 9 is further diluted with the liquid stored in the gas-liquid separation tank 9 and the cooling water newly supplied from the cooling water pipe 92 for the gas-liquid separation tank. The Then, when the diluted waste liquid exceeds the upper end of the general waste liquid overflow pipe 93 protruding into the gas-liquid separation tank 9, it flows into the general waste liquid overflow pipe 93 and is discharged to the waste liquid utility line.

  After completion of the rinsing process, whether or not the temperature detected by the general waste liquid temperature sensor 95 (the liquid temperature of the liquid stored in the gas-liquid separation tank 9) has dropped below a predetermined supply stop temperature (for example, 40 ° C.). It is repeatedly examined (step E3). When the temperature detected by the general waste liquid temperature sensor 95 falls below the supply stop temperature, the gas-liquid separation tank cooling water valve 91 is closed (step E4), and thereafter, until the rinsing process is performed again. Cooling water is supplied from the gas-liquid separation tank cooling water pipe 92 to the gas-liquid separation tank 9 at a minute flow rate.

  As described above, the waste liquid introduced into the gas-liquid separation tank 9 is a low-concentration waste liquid discharged from the cup 4 after the rinsing process and contains almost no SPM. The separation tank 9 may not be made of a PFA material having excellent chemical resistance and heat resistance. Thereby, compared with the conventional apparatus which employ | adopted the gas-liquid separation tank made from PFA, the cost of an apparatus can be reduced significantly.

  Note that low-concentration waste liquid discharged from the cup 4 after the rinsing step may be introduced into the dilution tank 8 and discharged from the dilution tank 8 through the dilution waste liquid overflow pipe 83. For this purpose, the dilution tank 8 is used. Needs to be formed in the same size as the gas-liquid separation tank 9. When the PFA-made dilution tank 8 becomes large, the initial cost of the apparatus increases significantly. Therefore, it can be said that it is desirable to introduce the low-concentration waste liquid discharged from the cup 4 after the rinse process into the dilution tank 8 as well. Absent.

  In this embodiment, the liquid is stored in the gas-liquid separation tank 9, and the waste liquid introduced into the gas-liquid separation tank 9 becomes the waste liquid further diluted in the gas-liquid separation tank 9. It is discharged from the tank 9 through a general waste liquid overflow pipe 93. Thereby, even if the high concentration waste liquid of SPM flows into the gas-liquid separation tank 9, the high concentration waste liquid can be sufficiently diluted and cooled and discharged.

  Further, the temperature detected by the general waste liquid temperature sensor 95 is constantly monitored, and when the temperature detected by the general waste liquid temperature sensor 95 reaches the first temperature (for example, 40 ° C.), the cooling water valve 91 for the gas-liquid separation tank is set. It is preferable to reduce the temperature of the waste liquid by opening a large amount of cooling water into the gas-liquid separation tank 9 after the opening. Furthermore, in the unlikely event that the temperature is not sufficiently lowered due to a malfunction in the supply system related to the cooling water pipe 92 (in the event of an abnormality), the temperature detected by the general waste liquid temperature sensor 95 is higher than the first temperature. When the temperature exceeds a high second temperature (for example, 80 ° C.), the operation of the substrate processing apparatus may be immediately stopped. By doing so, it is possible to reliably prevent the waste liquid that has not been sufficiently diluted and cooled for some reason from being discharged from the gas-liquid separation tank 9, and the safety of the substrate processing apparatus can be further enhanced. .

  As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form. For example, as the spin chuck 2, the lower surface of the wafer W is vacuum-sucked to hold the wafer W in a substantially horizontal posture, and in this state, the wafer W is held by rotating around a substantially vertical axis. A vacuum chucking type (vacuum chuck) that can rotate the shaft may be employed.

Further, the resist stripping process for stripping the resist film that is no longer necessary from the surface of the wafer W is taken as an example. Other types of substrates such as glass substrates for photomasks, glass substrates for photomasks, and substrates for magnetic / optical disks may be used.
Further, the processing for the substrate may be processing other than resist stripping processing, and the processing liquid used for the processing is not limited to SPM, but a mixed liquid other than SPM generated by a chemical reaction of two or more processing liquids. It may be. The liquid mixture generated by the chemical reaction of two or more kinds of treatment liquids cannot be recovered and reused once discharged from the nozzle 3. Therefore, when such a mixed solution is used as a processing solution, the mixed solution staying in the processing solution pipe 5 or the like is pushed out with nitrogen gas, and the mixed solution is supplied to the substrate to contribute to the processing. As a result, the effect that the waste of the mixed liquid (processing liquid) can be reduced is remarkably exhibited. In addition, DIW (deionized pure water) and functional water such as ozone water, ionic water, carbonated water and magnetic water are not easily reused because they are easily deteriorated even if they are single liquids. Even when the liquid is used as the processing liquid, the effect that the waste of the processing liquid can be reduced is remarkably exhibited. Furthermore, a temperature adjusting liquid whose temperature is adjusted to a certain temperature suitable for processing may be used as the processing liquid.

  In addition, various design changes can be made within the scope of matters described in the claims.

1 is a diagram schematically showing a configuration of a substrate processing apparatus according to an embodiment of the present invention. It is a figure for demonstrating the attachment state of a flow pipe with a stirring fin. It is a block diagram which shows the electric constitution of the said substrate processing apparatus. It is a flowchart for demonstrating a SPM discharge process. It is a flowchart for demonstrating the process of the waste liquid produced at the time of a SPM discharge process. It is a flowchart for demonstrating the process of the waste liquid produced after the rinse process.

Explanation of symbols

2 Spin chuck 3 Nozzle 4 Cup 5 Treatment liquid piping 61 Mixing valve 64 Nitrogen gas piping 100 Controller 613 Nitrogen gas port 641 Nitrogen gas valve W Wafer

Claims (5)

A processing liquid discharge step for discharging a processing liquid for processing the substrate from the nozzle;
A treatment liquid extrusion step of supplying gas to the treatment liquid pipe for supplying the treatment liquid to the nozzle and pushing out the treatment liquid in the treatment liquid pipe from the nozzle at the end of the treatment liquid discharge process; A substrate processing method.   2. The substrate processing method according to claim 1, wherein the processing liquid extruding step is performed in a state in which a gas discharged by extruding the processing liquid in the processing liquid piping from the nozzle can hit a substrate to be processed.   In the processing liquid extrusion step, the gas discharged by pushing out the processing liquid in the processing liquid pipe from the nozzle is supplied into a cup provided surrounding a substrate holding means for holding a substrate to be processed. The substrate processing method according to claim 1, wherein the substrate processing method is performed in a state where the substrate is obtained.   In the treatment liquid extrusion step, after the supply of the treatment liquid from the treatment liquid pipe to the nozzle is stopped, the treatment liquid in the treatment liquid pipe is pushed out from the nozzle and supplied into the treatment liquid pipe. 4. The substrate processing method according to claim 1, wherein the gas is discharged over a period until the gas is discharged from the nozzle. A nozzle for discharging a processing liquid for processing the substrate;
A processing liquid pipe through which the processing liquid supplied to the nozzle flows;
A gas supply means for supplying gas into the processing liquid pipe;
Gas supply control means for controlling the gas supply means to supply the gas into the treatment liquid pipe after supply of the treatment liquid from the treatment liquid pipe to the nozzle is stopped. Substrate processing equipment.

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