JP2008244115A - Substrate processing device and substrate processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate processing device and a substrate processing method, which prevents residual process liquid from falling from a process liquid discharge opening provided at a central axis member by air flow generated in a gap space formed between a shielding member and a substrate top face. <P>SOLUTION: While a lower limit side 6a of a medial axis member 6 being arranged in an upper part position to a lower surface 5a of a shielding member 5, a mixed liquor discharge opening 62a is arranged in an upward evacuated position to the lower limit side 6a of the central axis member 6. On account of this, even when mixed liquor remains and sticks near the mixed liquor discharge opening 62a, an impact of the air flow generated in a gap space SP1 to the residual mixed liquor is reduced. The residual mixed liquor is thereby prevented from falling on a substrate front surface Wf from the mixed liquor discharge opening 62a during the time when a discharge of the mixed liquor from the mixed liquor discharge opening 62a stops. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a substrate processing apparatus and a substrate processing method for supplying a processing liquid to a substrate upper surface and subjecting the substrate upper surface to a predetermined wet process. The substrates to be wet processed include semiconductor wafers, glass substrates for photomasks, glass substrates for liquid crystal displays, glass substrates for plasma displays, FED (Field Emission Display) substrates, optical disk substrates, magnetic disk substrates, A magneto-optical disk substrate is included.

  Conventionally, as a substrate processing apparatus of this type, a processing liquid is supplied to a substrate while rotating the substrate while holding the substrate such as a semiconductor wafer in a substantially horizontal posture by a spin chuck (substrate holding means), and is predetermined with respect to the substrate. There is a substrate processing apparatus that performs the wet processing (see Patent Document 1).

  In this substrate processing apparatus, a disk-shaped blocking member is disposed to face the upper surface of a substrate held by a spin chuck. The blocking member is connected to the lower end of a rotary support cylinder formed hollow inside, and a cylindrical insertion shaft (center axis member) is inserted through the hollow portion of the rotary support cylinder. A processing liquid supply path serving as a path for processing liquid such as chemical liquid or pure water is formed on the insertion shaft, and a lower end (front end) facing the upper surface of the substrate of the processing liquid supply path is a processing liquid discharge port. . In addition, a gas supply path serving as a passage for a gas such as nitrogen gas is formed along the side of the processing liquid supply path on the insertion shaft, and the lower end of the gas supply path is a gas discharge port. Further, a space portion formed between the outer peripheral surface of the insertion shaft and the inner peripheral surface of the rotation support cylinder constitutes an outer gas supply path, and the lower end of the outer gas supply path becomes an annular outer gas discharge port. Yes. Then, after the chemical treatment and rinsing treatment of the substrate and before the spin drying treatment, the gas is directed from the gas discharge port and the outer gas discharge port to a space (gap space) formed between the blocking member and the upper surface of the substrate, respectively. Thus, water droplets remaining on the upper surface of the substrate are removed from the substrate.

JP 2004-146784 A (FIG. 1)

  However, in the above conventional apparatus, the following problems may occur while the wet process such as the chemical process or the rinse process is stopped. That is, in the above-described conventional apparatus, when the processing liquid remains at the tip of the processing liquid supply path (near the processing liquid discharge port), such processing liquid (hereinafter referred to as “residual processing liquid”) stops the wet processing. During this time, the gas may have dropped from the treatment liquid discharge port onto the upper surface of the substrate due to the influence of the air flow generated by the gas discharged from the gas discharge port and the outer gas discharge port toward the gap space. As a result, the residual processing liquid may adhere to the upper surface of the substrate and become a particle generation source and contaminate the substrate.

  The present invention has been made in view of the above problems, and the residual processing liquid falls from a processing liquid discharge port provided in the central shaft member by an air flow generated in a gap space formed between the blocking member and the upper surface of the substrate. An object of the present invention is to provide a substrate processing apparatus and a substrate processing method capable of preventing the above.

  The present invention is a substrate processing apparatus for supplying a processing liquid to the upper surface of the substrate while rotating the substrate and performing a predetermined wet process on the upper surface of the substrate. A substrate holding means for holding in a posture, a rotating means for rotating the substrate held by the substrate holding means, and arranged to extend above the center of the upper surface of the substrate held by the substrate holding means, and provided at the lower end side thereof A central shaft member capable of discharging the processing liquid from the processing liquid discharge port toward the center of the upper surface of the substrate, and an opposing surface facing the upper surface of the substrate so as to surround the central shaft member outside the central shaft member in the radial direction. A blocking member disposed away from the upper surface of the substrate while facing the upper surface of the substrate, and a gas supply means for supplying gas to a gap space formed between the facing surface of the blocking member and the upper surface of the substrate; Control the gas supply means Control means for supplying gas to the gap space while the discharge of the treatment liquid from the treatment liquid discharge port is stopped, and the lower end surface of the central shaft member is at the same height position as the opposing surface of the blocking member or The processing liquid discharge port is disposed at an upper position and is disposed at a position retracted upward with respect to the lower end surface of the central shaft member.

  The present invention also includes a substrate holding means for holding the substrate in a substantially horizontal position, a rotating means for rotating the substrate held by the substrate holding means, and an upper central portion of the substrate held by the substrate holding means. A central shaft member capable of discharging a processing liquid from a processing liquid discharge port provided on the lower end side thereof toward the center of the upper surface of the substrate, and surrounding the central shaft member radially outside the central shaft member And a gap member formed between the opposing surface of the blocking member and the upper surface of the substrate, and a blocking member that is spaced from the upper surface of the substrate while facing the upper surface of the substrate. A substrate processing method for supplying a processing liquid to the upper surface of the substrate while rotating the substrate and performing a predetermined wet process on the upper surface of the substrate using a substrate processing apparatus having a gas supply means for supplying gas to the substrate And achieve the above objective Therefore, the lower end surface of the central shaft member is disposed at the same height or an upper position with respect to the opposing surface of the blocking member, and the processing liquid discharge port is at a position retracted upward with respect to the lower end surface of the central shaft member. The gas supply means supplies gas to the gap space while the discharge of the processing liquid from the processing liquid discharge port is stopped.

  In the invention configured as described above, the gas is supplied to the gap space formed between the blocking member and the upper surface of the substrate while rotating the substrate, and an air current is generated in the gap space. The central shaft member is arranged so that the lower end surface of the central shaft member faces the gap space. For this reason, the lower end surface of the central shaft member may be affected by the airflow generated in the gap space. However, according to the present invention, the lower end surface of the central shaft member is disposed at the same height position or an upper position with respect to the opposing surface of the blocking member, and the processing liquid discharge port is located above the lower end surface of the central shaft member. Arranged in the retracted position. For this reason, even if the residual processing liquid is attached in the vicinity of the processing liquid discharge port, the influence of the airflow generated in the gap space on the residual processing liquid can be reduced. Therefore, it is possible to prevent the residual processing liquid from dropping from the processing liquid discharge port onto the upper surface of the substrate while the discharge of the processing liquid from the processing liquid discharge port is stopped.

  Here, when gas is supplied to the gap space through the outer gas supply path using the annular space sandwiched between the central shaft member and the blocking member as the outer gas supply path, the gas discharge formed at the tip of the central shaft member Whether the gas is supplied from the outlet to the gap space or the gas is supplied from both (outer gas supply path and gas discharge port), the influence of the air flow generated in the gap space is reduced to discharge the treatment liquid. It is possible to prevent the residual treatment liquid from dropping from the outlet.

  Further, a first liquid discharge port that discharges the first liquid toward the center of the upper surface of the substrate is formed in the central shaft member, and the second liquid having a lower surface tension than the first liquid is processed from the processing liquid discharge port. Alternatively, it may be discharged toward the center of the upper surface of the substrate. According to this configuration, two types of liquids, that is, the first liquid and the second liquid having a lower surface tension than the first liquid can be supplied to the central portion of the upper surface of the substrate while the gap space is a gas atmosphere. . Here, since the second liquid has a lower surface tension than the first liquid, the adhesion force to the central shaft member is small. For this reason, the second liquid is more likely to fall from the discharge port than the first liquid. In contrast, in the present invention, the processing liquid discharge port for discharging the second liquid is disposed at a position retracted upward with respect to the lower end surface of the central shaft member in which the first liquid discharge port is formed. Even when the second liquid having a surface tension lower than that of the one liquid remains attached in the vicinity of the discharge port, it is possible to effectively prevent the second liquid from falling.

  Further, it is preferable that the diameter of the treatment liquid discharge port is smaller than the diameter of the first liquid discharge port. Thereby, the fall of the 2nd liquid can be prevented more effectively compared with the case where the 2nd liquid is discharged from the processing liquid discharge port of the same diameter as the diameter formed for the 1st liquid discharge.

  Further, in the substrate processing apparatus in which the processing liquid discharge port is provided adjacent to the annular space sandwiched between the central shaft member and the blocking member, the central shaft member has an annular shape with the lower space located immediately below the processing liquid discharge port. You may comprise so that it may have the partition which isolate | separates space. According to this configuration, since the lower space located immediately below the processing liquid discharge port is separated from the annular space by the partition wall, the inflow of gas from the annular space to the lower space can be suppressed. For this reason, even when the residual processing liquid is attached in the vicinity of the processing liquid discharge port, the influence of the air flow on the residual processing liquid is suppressed to effectively prevent the residual processing liquid from dropping from the processing liquid discharge port. can do.

  According to the present invention, the lower end surface of the central shaft member is disposed at the same height position or an upper position with respect to the opposing surface of the blocking member, and the processing liquid discharge port is located above the lower end surface of the central shaft member. Since it is disposed at the retracted position, even if the residual processing liquid is attached in the vicinity of the processing liquid discharge port, the influence of the airflow generated in the gap space on the residual processing liquid can be reduced. For this reason, it is possible to prevent the residual processing liquid from dropping from the processing liquid discharge port onto the upper surface of the substrate while the discharge of the processing liquid from the processing liquid discharge port is stopped.

<First Embodiment>
FIG. 1 is a diagram showing a configuration of a substrate processing apparatus according to a first embodiment of the present invention. FIG. 2 is a block diagram showing a main control configuration of the substrate processing apparatus of FIG. This substrate processing apparatus is a single-wafer type substrate processing apparatus used for a cleaning process for removing unnecessary substances attached to the surface Wf of a substrate W such as a semiconductor wafer. More specifically, after the substrate surface Wf is subjected to a chemical treatment with a chemical solution such as hydrofluoric acid and a rinse treatment with a rinse solution such as pure water or DIW (deionized water), the substrate surface Wf wet with the rinse solution is obtained. It is a device for drying. In this embodiment, the substrate surface Wf means a pattern formation surface on which a device pattern is formed.

  The substrate processing apparatus includes a spin chuck 1 that rotates while holding the substrate W in a substantially horizontal posture with the substrate surface Wf facing upward, and a chemical solution toward the surface Wf of the substrate W held by the spin chuck 1. A chemical solution discharge nozzle 3 for discharging, and a blocking member 5 arranged in a position above the spin chuck 1 are provided.

  The spin chuck 1 has a rotation support shaft 11 connected to a rotation shaft of a chuck rotation mechanism 13 including a motor, and can rotate about a rotation axis J (vertical axis) by driving the chuck rotation mechanism 13. A disc-shaped spin base 15 is integrally connected to the upper end portion of the rotation spindle 11 by a fastening component such as a screw. Therefore, the spin base 15 rotates around the rotation axis J by driving the chuck rotation mechanism 13 in accordance with an operation command from the control unit 4 (corresponding to “control means” of the present invention) that controls the entire apparatus. Thus, in this embodiment, the chuck rotating mechanism 13 functions as the “rotating unit” of the present invention.

  Near the peripheral edge of the spin base 15, a plurality of chuck pins 17 for holding the peripheral edge of the substrate W are provided upright. Three or more chuck pins 17 may be provided to securely hold the circular substrate W, and are arranged at equiangular intervals along the peripheral edge of the spin base 15. Each of the chuck pins 17 includes a substrate support portion that supports the peripheral portion of the substrate W from below, and a substrate holding portion that holds the substrate W by pressing the outer peripheral end surface of the substrate W supported by the substrate support portion. Yes. Each chuck pin 17 is configured to be switchable between a pressing state in which the substrate holding portion presses the outer peripheral end surface of the substrate W and a released state in which the substrate holding portion is separated from the outer peripheral end surface of the substrate W.

  When the substrate W is delivered to the spin base 15, the plurality of chuck pins 17 are released, and when the substrate W is cleaned, the plurality of chuck pins 17 are pressed. To do. By setting the pressed state, the plurality of chuck pins 17 can grip the peripheral edge of the substrate W and hold the substrate W in a substantially horizontal posture at a predetermined interval from the spin base 15. As a result, the substrate W is held with the front surface (pattern forming surface) Wf facing upward and the back surface Wb facing downward. Thus, in this embodiment, the chuck pin 17 functions as the “substrate holding means” of the present invention. The substrate holding means is not limited to the chuck pins 17, and a vacuum chuck that holds the substrate W by sucking the substrate back surface Wb may be used.

  The chemical liquid discharge nozzle 3 is connected to a chemical liquid supply unit 21 and can supply a chemical liquid such as hydrofluoric acid or BHF (buffered hydrofluoric acid) from the chemical liquid supply unit 21 to the chemical liquid discharge nozzle 3. For this reason, when the chemical solution is pumped from the chemical solution supply unit 21 toward the chemical solution discharge nozzle 3 in accordance with a control command from the control unit 4, the chemical solution is discharged from the chemical solution discharge nozzle 3. Further, a nozzle moving mechanism 33 is connected to the chemical solution discharge nozzle 3, and the chemical solution discharge nozzle 3 is moved to the center of rotation of the substrate W by driving the nozzle moving mechanism 33 in accordance with an operation command from the control unit 4. It can be reciprocated between the upper discharge position and the standby position retracted to the side from the discharge position.

  The blocking member 5 includes a plate-like member 50 and a rotation support shaft 51 that supports the plate-like member 50 and has a hollow interior. The plate-like member 50 is a disk-like member having an opening at the center, and is spaced apart from the surface Wf of the substrate W held by the spin chuck 1. The plate-like member 50 has a lower surface (bottom surface) 5a that is a substrate-facing surface that faces the substrate surface Wf substantially in parallel, and the planar size of the plate-like member 50 is equal to or larger than the diameter of the substrate W. The plate-like member 50 is attached substantially horizontally to the lower end portion of the rotation support shaft 51 having a substantially cylindrical shape, and the rotation support shaft 51 is held rotatably about the rotation axis J by an arm 52 extending in the horizontal direction.

  A central shaft member 6 is inserted into the hollow portion of the blocking member 5 and is disposed so as to extend upward from the center of the surface of the substrate W (the center of the upper surface) held by the spin chuck 1. That is, the blocking member 5 is disposed so that the lower surface 5a faces the substrate surface Wf so as to surround the central shaft member 6 on the outer side in the radial direction of the central shaft member 6. A bearing (not shown) is interposed between the outer peripheral surface of the central shaft member 6 and the inner peripheral surface of the rotation support shaft 51. The arm 52 is connected to a blocking member rotating mechanism 53 and a blocking member lifting mechanism 54.

  The blocking member rotating mechanism 53 rotates the blocking member 5 around the rotation axis J in response to an operation command from the control unit 4. The blocking member rotating mechanism 53 is configured to rotate the blocking member 5 in the same rotational direction as the substrate W and at substantially the same rotational speed in accordance with the rotation of the substrate W held on the spin chuck 1.

  Further, the blocking member lifting mechanism 54 causes the blocking member 5 and the central shaft member 6 to be integrally disposed close to and opposed to the spin base 15 according to an operation command from the control unit 4, or to be separated from each other. It is possible. Specifically, the control unit 4 operates the blocking member raising / lowering mechanism 54 so that when the substrate W is carried into and out of the substrate processing apparatus, the blocking member 5 and the center are located at a separated position above the spin chuck 1. The shaft member 6 is raised. On the other hand, when a predetermined process is performed on the substrate W, the substrate W is cut off to a predetermined proximity position (position shown in FIG. 1) set very close to the surface Wf of the substrate W held by the spin chuck 1. The member 5 and the central shaft member 6 are lowered.

  FIG. 3 is a cross-sectional view showing a main part of the substrate processing apparatus of FIG. 4 is a cross-sectional view (cross-sectional view) taken along the line A-A ′ of FIG. The central shaft member 6 has a circular cross section. This is because the gap between the central shaft member 6 (non-rotating side member) and the rotation support shaft 51 (rotating side member) is made uniform over the entire circumference, and the center is obtained by introducing a seal gas into the gap. A gap between the shaft member 6 and the rotation support shaft 51 is sealed from the outside. Three fluid supply passages are formed in the central shaft member 6 so as to extend in the vertical axis direction. That is, a rinsing liquid supply path 61 serving as a passage for a rinsing liquid (corresponding to the “first liquid” of the present invention), a mixture in which a rinsing liquid and an organic solvent component that dissolves in the rinsing liquid and lowers surface tension A mixed liquid supply path 62 serving as a path for liquid (corresponding to the “second liquid” of the present invention) and a gas supply path 63 serving as a path for an inert gas such as nitrogen gas are formed in the central shaft member 6. The rinse liquid supply path 61, the mixed liquid supply path 62, and the gas supply path 63 insert tubes 611, 621, 631 made of PFA (perfluoroalkyl vinyl ether copolymer) in the axial direction inside the cylindrical outer tube 64. Each tube 611, 621, 631 is fixed by press-fitting a plug member 65 made of PTFE (polytetrafluoroethylene) into the lower end side (tip end side) of the outer tube 64. Yes.

  The lower ends of the rinse liquid supply path 61, the mixed liquid supply path 62, and the gas supply path 63 are respectively the rinse liquid discharge port 61a (corresponding to the “first liquid discharge port” of the present invention) and the mixed liquid discharge port 62a (the main liquid discharge port). The gas discharge port 63a and the surface Wf of the substrate W held by the spin chuck 1 are opposed to each other. Here, the rinse liquid discharge port 61 a and the gas discharge port 63 a are disposed on the lower end surface 6 a of the central shaft member 6, while the mixed liquid discharge port 62 a is retracted upward with respect to the lower end surface 6 a of the central shaft member 6. Is arranged. Specifically, a part of the lower end side of the central shaft member 6 (a lower part of the mixed liquid supply passage 62) is integrally cut out radially inward, so that the mixed liquid discharge port 62a faces upward. It is arranged at a position recessed in a step shape. And as a result of notching a part of lower end of the outer tube | pipe 64, the liquid mixture discharge port 62a is arrange | positioned adjacent to annular space SP2 pinched | interposed into the center shaft member 6 and the interruption | blocking member 5. FIG. That is, the lower space SP3 located immediately below the mixed liquid discharge port 62a is integrally coupled to the annular space SP2. Thus, in this embodiment, the mixed solution discharge port 62a is disposed at a position retracted upward with respect to the lower end surface 6a of the central shaft member 6 by integrally cutting off the lower end side of the central shaft member 6. Therefore, it is excellent in workability.

  As described above, the mixed liquid discharge port 62a is disposed at an upper position with respect to the lower end surface 6a of the central shaft member 6 so as to be in the vicinity of the mixed liquid discharge port 62a (the lower end portion of the mixed liquid supply path 62). Even when the mixed liquid remains adhered (hereinafter, the mixed liquid remaining in this manner is referred to as “residual mixed liquid”), it is formed between the lower surface 5a of the blocking member 5 and the substrate surface Wf. The influence of the airflow generated in the gap space SP1 can be reduced. Thereby, it is possible to prevent the residual mixed liquid from falling from the mixed liquid discharge port 62a. In order to avoid the influence of the airflow generated in the gap space SP1 on the residual mixed liquid, the distance L1 from the gas discharge port 63a (the lower end surface 6a of the central shaft member 6) to the mixed liquid discharge port 62a in the vertical axis direction is 10 mm. It is preferable to set the above.

  The annular space SP2 forms an outer gas supply path 66, and the lower end of the outer gas supply path 66 is an annular outer gas discharge port 66a. That is, the outer gas is disposed radially outward with respect to the rinse liquid discharge port 61a, the mixed liquid discharge port 62a, and the gas discharge port 63a, and so as to surround the rinse liquid discharge port 61a, the mixed liquid discharge port 62a, and the gas discharge port 63a. A discharge port 66a is provided. The opening area of the outer gas discharge port 66a is much larger than the opening area of the gas discharge port 63a. For this reason, nitrogen gas having a different flow rate and flow velocity can be discharged from the two types of gas discharge ports. For example, (1) In order to keep the atmosphere around the substrate surface Wf in an inert gas atmosphere, it is desirable to supply nitrogen gas at a relatively large flow rate and low speed so as not to blow off the liquid on the substrate surface Wf. On the other hand, (2) when the mixed liquid layer formed by the mixed liquid formed on the substrate surface Wf is removed from the substrate surface Wf as described later, a relatively small flow rate and high speed are provided at the center of the surface of the substrate W. It is desirable to supply nitrogen gas. Therefore, in the case of (1) above, nitrogen gas is mainly discharged from the outer gas discharge port 66a, and in the case of (2), nitrogen gas is mainly discharged from the gas discharge port 63a to Nitrogen gas can be supplied toward the substrate surface Wf at an appropriate flow rate and flow rate according to the use of the gas.

  The lower end surface 6 a of the central shaft member 6 is disposed at an upper position with respect to the lower surface 5 a of the blocking member 5. According to such a configuration, the influence of the airflow generated in the gap space SP1 can be further effectively reduced, and it is effective for preventing the remaining mixed liquid from dropping from the mixed liquid discharge port 62a. In addition, the nitrogen gas discharged from the gas discharge port 63a can be diffused until the nitrogen gas reaches the substrate surface Wf, and the flow rate of the nitrogen gas can be reduced to some extent. That is, if the flow rate of the nitrogen gas from the gas discharge port 63a is too high, the liquid mixture layer on the substrate surface Wf may be discharged from the substrate W by interfering with the nitrogen gas from the outer gas discharge port 66a. It becomes difficult. As a result, droplets remain on the substrate surface Wf. On the other hand, according to the above configuration, the flow rate of the nitrogen gas from the gas discharge port 63a is relaxed, and the liquid mixture layer of the liquid mixture on the substrate surface Wf can be reliably discharged from the substrate W.

  In this embodiment, the diameter of the central shaft member 6 is formed to be about 16 mm, and the diameters of the rinse liquid discharge port 61a, the mixed liquid discharge port 62a, and the gas discharge port 63a are 4 mm, 2-3 mm, and 4 mm, respectively. Has been. Thus, in this embodiment, the diameter of the mixed liquid discharge port 62a is smaller than the diameter of the rinse liquid discharge port 61a. Thereby, compared with the case where a liquid mixture is discharged from the liquid mixture discharge port having the same diameter as that for rinsing liquid discharge, it is possible to more effectively prevent the liquid mixture from dropping. In addition, it is possible to suppress an increase in the discharge rate of the rinsing liquid from the rinsing liquid discharge port as compared with the case where the rinsing liquid is discharged from the rinsing liquid discharge port having the same diameter as that formed for discharging the mixed liquid. it can. This prevents the rinse liquid (DIW), which is an electrical insulator, from colliding with the substrate surface Wf at a relatively high speed, and suppresses the supply site to which the rinse liquid is directly supplied from being oxidized by charging. Can do.

  In this embodiment, the rinse liquid discharge port 61 a is provided at a position shifted radially outward from the central axis of the blocking member 5, that is, the rotation axis J of the substrate W. Thereby, it is avoided that the rinse liquid discharged from the rinse liquid discharge port 61a is concentrated and supplied to one point of the substrate surface Wf (the rotation center of the substrate W). As a result, charged portions on the substrate surface Wf can be dispersed, and oxidation due to charging of the substrate W can be reduced. On the other hand, if the rinse liquid discharge port 61a is too far from the rotation axis J, it is difficult to make the rinse liquid reach the rotation center of the substrate W. Therefore, in this embodiment, the distance L2 from the rotation axis J in the horizontal direction to the rinse liquid discharge port 61a (discharge port center) is set to about 4 mm. Here, the upper limit of the distance L2 at which the rinse liquid (DIW) can be supplied to the rotation center on the substrate surface Wf is 20 mm under the following conditions.

Flow rate of DIW: 2L / min
Substrate rotation speed: 1500rpm
The state of the substrate surface: the center of the surface is a hydrophobic surface Also, as for the upper limit value of the distance from the rotation axis J to the mixed liquid discharge port 62a (discharge port center), as long as the substrate rotation speed is set to 1500 rpm, the rotation axis described above This is basically the same as the upper limit value (20 mm) of the distance L2 from J to the rinse liquid discharge port 61a (discharge port center). Furthermore, the horizontal position of the mixed liquid discharge port 62a is disposed at a position where the discharged mixed liquid is prevented from contacting the central shaft member 6 (embedding member 65).

  On the other hand, the distance from the rotation axis J to the gas discharge port 63a (discharge port center) is not particularly limited as long as nitrogen gas can be discharged toward the gap space SP1. However, from the viewpoint of blowing nitrogen gas to the mixed liquid layer and discharging the mixed liquid layer from the substrate W, the gas discharge port 63a is preferably provided on the rotation axis J or in the vicinity thereof.

  Returning to FIG. 1 and FIG. 2, the description will be continued. The upper end of the rinsing liquid supply path 61 is connected to a DIW supply unit 22 configured by a factory utility or the like, and DIW can be discharged as a rinsing liquid from the rinsing liquid discharge port 61a in accordance with an operation command from the control unit 4 It has become.

  The upper end portion of the mixed liquid supply path 62 is connected to the mixed liquid supply unit 23. The mixed liquid supply unit 23 includes a cabinet part (not shown) for generating a mixed liquid (organic solvent component + DIW), and the mixed liquid generated in the cabinet part can be pumped to the mixed liquid supply path 62. ing. As the organic solvent component, a substance that dissolves in DIW (surface tension: 72 mN / m) and lowers the surface tension, for example, isopropyl alcohol (surface tension: 21 to 23 mN / m) is used. The organic solvent component is not limited to isopropyl alcohol (IPA), and various organic solvent components such as ethyl alcohol and methyl alcohol may be used. In this embodiment, the volume percentage of IPA in the liquid mixture (hereinafter referred to as “IPA concentration”) is set to a predetermined value within the range of 50% or less, for example, the IPA concentration is 10% to 15%. ing. By setting the IPA concentration in this way, it is possible to effectively reduce the surface tension of the liquid mixture while suppressing the consumption of IPA.

  The upper ends of the gas supply path 63 and the outer gas supply path 66 are respectively connected to the gas supply unit 24, and from the gas supply unit 24 to the gas supply path 63 and the outer gas supply path 66 according to the operation command of the control unit 4. Nitrogen gas can be pumped individually. Thereby, nitrogen gas can be independently supplied from the gas discharge port 63a and the outer gas discharge port 66a toward the gap space SP1. Thus, in this embodiment, the gas supply unit 24 functions as the “gas supply means” of the present invention.

  Next, the operation of the substrate processing apparatus configured as described above will be described in detail with reference to FIGS. FIG. 5 is a flowchart showing the operation of the substrate processing apparatus of FIG. FIG. 6 is a timing chart showing the operation of the substrate processing apparatus of FIG. FIG. 7 is a schematic diagram showing the operation of the substrate processing apparatus of FIG. When an unprocessed substrate W is carried into the substrate processing apparatus by a substrate transfer means (not shown) (step S1), the control unit 4 controls each part of the apparatus to perform a cleaning process (chemical solution processing + (Rinse process + replacement process + pre-drying process + drying process). Here, a fine pattern made of, for example, poly-Si is formed on the substrate surface Wf. Therefore, in this embodiment, the substrate W is carried into the apparatus with the substrate surface Wf facing upward and is held by the spin chuck 1. The blocking member 5 and the central shaft member 6 are located above the spin chuck 1 to prevent interference with the substrate W.

  First, chemical processing is performed on the substrate W. That is, the chemical solution discharge nozzle 3 is moved to the discharge position, and the substrate W held by the spin chuck 1 is rotated at a predetermined rotation speed (for example, 500 rpm) by driving the chuck rotation mechanism 13 (step S2). Then, when hydrofluoric acid is supplied as a chemical solution from the chemical solution discharge nozzle 3 to the substrate surface Wf, the hydrofluoric acid is spread by centrifugal force, and the entire substrate surface Wf is subjected to the chemical treatment with hydrofluoric acid (step S3; chemical solution treatment step).

  When this chemical processing is completed, the chemical discharge nozzle 3 is moved to the standby position. Then, a rinsing process is performed on the substrate W. That is, the rinsing liquid (DIW) is discharged from the rinsing liquid discharge port 61a of the central shaft member 6 located at the separation position. Simultaneously with the discharge of the rinse liquid, the blocking member 5 and the central shaft member 6 are integrally lowered toward the proximity position and positioned at the proximity position. As described above, the substrate surface Wf is kept wet by supplying the rinse liquid to the substrate surface Wf immediately after the chemical treatment. This is due to the following reason. That is, when the hydrofluoric acid is shaken off from the substrate W after the chemical treatment, the substrate surface Wf starts to dry. As a result, the substrate surface Wf may be partially dried, and spots or the like may occur on the substrate surface Wf. Therefore, in order to prevent such partial drying of the substrate surface Wf, it is important to keep the substrate surface Wf wet.

  Further, nitrogen gas is discharged from the gas discharge port 63a and the outer gas discharge port 66a. Here, nitrogen gas is mainly discharged from the outer gas discharge port 66a. That is, a relatively high flow rate of nitrogen gas is discharged from the outer gas discharge port 66a, while the flow rate balance of nitrogen gas discharged from both the discharge ports is such that the flow rate of nitrogen gas discharged from the gas discharge port 63a is very small. Adjust.

  The rinsing liquid supplied from the rinsing liquid discharge port 61a to the substrate surface Wf is spread by the centrifugal force accompanying the rotation of the substrate W, and the entire substrate surface Wf is rinsed (step S4; rinsing step). That is, the hydrofluoric acid remaining on the substrate surface Wf is washed away by the rinse liquid and removed from the substrate surface Wf. Further, the nitrogen gas is supplied to the gap space SP1, whereby the ambient atmosphere around the substrate surface Wf is kept in a low oxygen concentration atmosphere. For this reason, the raise of the dissolved oxygen concentration of a rinse liquid can be suppressed. Note that the rotation speed of the substrate W during the rinsing process is set to, for example, 100 to 1000 rpm.

  Further, when performing the above-described rinsing process and the later-described replacement process and drying process, the blocking member 5 is rotated in the same rotational direction as the substrate W and at substantially the same rotational speed. Thereby, it is possible to prevent a relative rotational speed difference from occurring between the lower surface 5a of the blocking member 5 and the substrate surface Wf, and to suppress the occurrence of an entangled air current in the gap space SP1. For this reason, it is possible to prevent the mist-like rinse liquid and the mixed liquid from entering the gap space SP1 and adhering to the substrate surface Wf. Further, by rotating the blocking member 5, it is possible to shake off the rinsing liquid and the mixed liquid adhering to the lower surface 5a and prevent the rinsing liquid and the mixed liquid from staying on the lower surface 5a.

  When the rinsing process for a predetermined time is completed, the replacement process is executed. That is, the control unit 4 stops the discharge of the rinse liquid from the rinse liquid discharge port 61a and sets the rotation speed of the substrate W to 500 to 1000 rpm. Subsequently, the liquid mixture (IPA + DIW) is discharged from the liquid mixture discharge port 62a. Here, in the mixed liquid supply unit 23, a mixed liquid whose IPA concentration is adjusted to, for example, 10% to 15% is generated in advance, and the mixed liquid is discharged from the mixed liquid discharge port 62a toward the substrate surface Wf. Is done. The liquid mixture supplied to the substrate surface Wf flows due to centrifugal force acting on the liquid mixture, and the liquid mixture enters the gaps in the fine pattern formed on the substrate surface Wf. Thereby, the rinse liquid (DIW) adhering to the space | interval of a fine pattern is substituted by a liquid mixture (step S5; substitution process).

  Subsequently, in this embodiment, the following drying pretreatment process is executed to discharge the liquid mixture on the substrate surface Wf from the substrate W (step S6). First, the control unit 4 stops the rotation of the substrate W or sets the rotation speed of the substrate W to 100 rpm or less while discharging the mixed solution from the mixed solution discharge port 62a. Thus, by supplying the mixed liquid to the substrate surface Wf while the substrate W is stationary or rotated at a relatively low speed, the mixed liquid layer 41 by the paddle-shaped mixed liquid is formed as shown in FIG. It is formed on the entire substrate surface Wf. By forming such a paddle-like mixed liquid layer 41 on the substrate surface Wf (paddle treatment), it is possible to suppress particle adhesion to the substrate surface Wf. Next, the supply of the mixed liquid is stopped and nitrogen gas is blown from the gas discharge port 63a toward the center of the surface of the substrate W. That is, the flow rate balance of nitrogen gas discharged from both discharge ports is adjusted so that the flow rate of nitrogen gas discharged from the gas discharge port 63a is relatively higher than the flow rate of nitrogen gas discharged from the outer gas discharge port 66a. . Then, as shown in FIG. 7B, the liquid mixture at the center of the liquid mixture layer 41 is pushed away outward in the radial direction of the substrate W by the nitrogen gas blown from the gas discharge port 63a to the substrate surface Wf. A hole 42 is formed at the center of 41 and the surface portion is dried. Then, by continuously blowing nitrogen gas to the center of the surface of the substrate W, as shown in FIG. 7 (c), the holes 42 formed earlier are formed in the edge direction of the substrate W (the left-right direction in the figure). ) And the liquid mixture on the center side of the liquid mixture layer 41 is gradually pushed from the center side to the substrate edge side, and the drying region expands. Thereby, the liquid mixture adhering to the center part of the surface of the substrate W can be removed without leaving the liquid mixture in the center part of the surface of the substrate W.

  By performing the drying pretreatment process as described above, the liquid mixture remains in the form of droplets at the center of the surface of the substrate W during the drying process (spin drying) described later, and becomes a streak-like particle. It is possible to prevent the watermark from being formed. That is, when the substrate W is rotated to remove the mixed solution adhering to the substrate surface Wf and dry (spin dry), the centrifugal force acting on the mixed solution is higher in the mixed solution located at the center of the surface of the substrate W. It is small and is dried from the edge of the surface of the substrate W. At this time, a droplet remains from the center of the surface of the substrate W to the periphery thereof, and the droplet may run in the direction of the edge of the substrate W, and a watermark may be formed on the movement trace of the droplet. . On the other hand, according to this embodiment, by forming the hole 42 in the center of the paddle-like mixed liquid layer 41 previously formed on the substrate surface Wf before the drying step, the hole 42 is enlarged. Since the liquid mixture located at the center of the surface of the substrate W is excluded, the generation of the watermark can be reliably prevented.

  Here, after the supply of the mixed liquid is stopped, the mixed liquid sometimes remains in the vicinity of the mixed liquid discharge port 62a (the lower end of the mixed liquid supply path 62). Then, when the mixed solution (residual mixed solution) adhered in this way is affected by the air flow generated in the gap space SP1, the residual mixed solution may fall onto the substrate surface Wf. In particular, since the liquid mixture has a low surface tension with respect to DIW, the adhesive force to the central shaft member 6 is small, and the liquid mixture is more likely to drop from the discharge port than DIW due to the influence of airflow. Yes. However, in this embodiment, the lower end surface 6a of the central shaft member 6 is disposed above the lower surface 5a of the blocking member 5, and the mixed liquid discharge port 62a is disposed above the lower end surface 6a of the central shaft member 6. It is arranged at the position retracted. For this reason, it is difficult to be influenced by the air flow generated in the gap space SP1, and the fall of the remaining mixed liquid from the mixed liquid discharge port 62a can be prevented.

  Thus, when the drying pretreatment process is completed, the control unit 4 increases the rotation speed of the chuck rotation mechanism 13 to rotate the substrate W at a high speed (for example, 2000 to 3000 rpm). Thereby, the liquid mixture adhering to the substrate surface Wf is shaken off, and a drying process (spin drying) of the substrate W is executed (step S7; drying process). At this time, since the mixed solution has entered the gap between the patterns, the pattern collapse can be prevented. Further, since the gap space SP1 is filled with nitrogen gas, the drying time is shortened and the elution of the oxidizable substance to the liquid component (mixed liquid) adhering to the substrate W is reduced to suppress the generation of the watermark. be able to. In addition, even when the mixed liquid remains in the vicinity of the mixed liquid discharge port 62a, the residual mixed liquid is less affected by the air current generated in the gap space SP1, and the mixed liquid is dried during the drying process. It is possible to prevent the residual mixed liquid from falling from the discharge port 62a. In particular, when the residual mixed liquid falls on the substrate surface area (dry area) after drying, it causes generation of particles, but such contamination of the substrate surface Wf can be prevented.

  When the drying process of the substrate W is completed, the control unit 4 controls the chuck rotating mechanism 13 to stop the rotation of the substrate W (step S8). Thereafter, the substrate transfer means carries the processed substrate W out of the apparatus, and a series of cleaning processes for one substrate W is completed (step S9).

  As described above, according to this embodiment, an air flow caused by nitrogen gas is generated in the gap space SP1, but the lower end surface 6a of the central shaft member 6 is disposed at an upper position with respect to the lower surface 5a of the blocking member 5. The liquid mixture discharge port 62 a is disposed at a position retracted upward with respect to the lower end surface 6 a of the central shaft member 6. For this reason, even when the residual mixed liquid is attached in the vicinity of the mixed liquid discharge port 62a, the influence of the airflow generated in the gap space SP1 on the residual mixed liquid can be reduced. For this reason, it is possible to prevent the residual mixed liquid from dropping from the mixed liquid discharge port 62a to the substrate surface Wf while the discharge of the mixed liquid from the mixed liquid discharge port 62a is stopped.

  Further, according to this embodiment, two kinds of liquids, that is, a rinsing liquid (DIW) and a mixed liquid having a surface tension lower than that of the rinsing liquid, are provided in the central portion of the surface of the substrate W while the gap space SP1 is an inert gas atmosphere. Supply is possible. For this reason, when the rinsing liquid is replaced with the mixed liquid, the dissolution of oxygen from the ambient atmosphere around the substrate surface Wf into the mixed liquid can be reduced, and the occurrence of a watermark on the substrate surface Wf can be reliably prevented. Here, since the liquid mixture has a lower surface tension than the rinsing liquid, the adhesion to the central shaft member 6 is small. For this reason, the liquid mixture is in a state of being easily dropped from the discharge port as compared with the rinse liquid. On the other hand, in this embodiment, the liquid mixture discharge port 62a for discharging the liquid mixture is disposed at a position retracted upward with respect to the lower end surface 6a of the central shaft member 6 where the rinse liquid discharge port 61a is formed. Therefore, even when a mixed liquid having a lower surface tension than the rinse liquid remains and adheres in the vicinity of the discharge port, it is possible to effectively prevent the mixed liquid from falling.

Second Embodiment
FIG. 8 is a cross-sectional view showing the main part of the substrate processing apparatus according to the second embodiment of the present invention. 9 is a cross-sectional view (cross-sectional view) taken along the line BB ′ of FIG. The substrate processing apparatus according to the second embodiment is greatly different from the first embodiment in that the lower space SP3 located immediately below the mixed solution discharge port 62a is sandwiched between the central shaft member 6 and the blocking member 5 by the partition wall 641. This is a point separated from the annular space SP2. Since other configurations and operations are the same as those in the first embodiment, the same reference numerals are given here, and descriptions thereof are omitted.

  In this embodiment, the outer tube 64A extends to the lower end surface 6a of the central shaft member 6 over the entire circumference, and the lower space SP3 is separated from the annular space SP2 by a partition wall 641 constituting a part of the outer tube 64A. That is, the lower space SP3 is surrounded by the partition wall 641 and the plug member 65. According to this configuration, the inflow of the nitrogen gas from the annular space SP2 to the lower space SP3 is suppressed while the mixed liquid discharge port 62a is disposed at a position retracted upward with respect to the lower end surface 6a of the central shaft member 6. be able to. For this reason, even if it is a case where the residual liquid mixture has adhered to the vicinity of the liquid mixture discharge port 62a, the influence of the airflow with respect to a residual liquid mixture can further be reduced. Therefore, it is possible to effectively prevent the residual mixed liquid from dropping onto the substrate surface Wf from the mixed liquid discharge port 62a.

<Others>
The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in the above embodiment, DIW is used as the “first liquid” of the present invention, but carbonated water, hydrogen water, dilute ammonia (for example, about 1 ppm), dilute hydrochloric acid, or the like may be used. In the above embodiment, the mixed liquid (organic solvent component + DIW) is used as the “second liquid” of the present invention. However, a liquid containing 100% organic solvent component or surfactant may be used.

  In the above embodiment, the central shaft member 6 is formed with two liquid discharge ports, that is, a liquid discharge port that discharges the first liquid and a liquid discharge port that discharges the second liquid. The number is arbitrary. For example, the liquid discharge port may be formed only at a position retracted upward with respect to the lower end surface 6 a of the central shaft member 6 without forming the liquid discharge port on the lower end surface 6 a of the central shaft member 6. Further, two liquid discharge ports may be provided at a position retracted upward with respect to the lower end surface 6 a of the central shaft member 6. Specifically, another mixed liquid discharge port may be additionally provided at a position opposite to the mixed liquid discharge port 62a around the rotation axis J. According to this configuration, the opening area of the total (two) outlets formed in the central shaft member 6 is increased while the diameter of each outlet of the liquid mixture is reduced to prevent the liquid mixture from dropping. can do. As a result, the supply amount of the mixed liquid per unit time can be increased. Therefore, when forming the mixed liquid layer on the substrate surface Wf, the mixed liquid layer can be formed in a relatively short time, and the throughput of the apparatus can be improved.

  Moreover, in the said embodiment, although the liquid discharge port (1st liquid discharge port) which discharges a 1st liquid is formed in the lower end surface 6a of the center shaft member 6, a 1st liquid discharge port is also centered as needed. You may form in the position retracted | saved upward with respect to the lower end surface 6a of the shaft member 6. FIG.

  In the above embodiment, the liquid mixture is discharged from the liquid mixture discharge port 62a (corresponding to the “treatment liquid discharge port” of the present invention) toward the substrate surface Wf to perform the replacement process, and from the liquid mixture discharge port 62a. While the discharge of the mixed liquid is stopped, the mixed liquid is prevented from falling from the mixed liquid discharge port 62a. However, the present invention is not limited to this. For example, when the rinse liquid discharge port is provided at a position retracted upward with respect to the lower end surface 6a of the central shaft member 6, and the rinse liquid is discharged from the rinse liquid discharge port toward the substrate surface Wf to execute the rinse process In this case, it is possible to prevent the rinse liquid from dropping from the rinse liquid discharge port while the discharge of the rinse liquid from the rinse liquid discharge port is stopped. In this case, the rinse liquid discharge port corresponds to the “treatment liquid discharge port” of the present invention. In short, when a predetermined wet process is performed by the processing liquid discharged from the processing liquid discharge port, the processing liquid drops from the processing liquid discharge port while the discharge of the processing liquid from the processing liquid discharge port is stopped. Can be prevented.

  In the above embodiment, the lower end surface 6 a of the central shaft member 6 is disposed above the lower surface 5 a of the blocking member 5, but the lower end surface 6 a of the central shaft member 6 is the same as the lower surface 5 a of the blocking member 5. You may comprise so that it may arrange | position in a height position. Even in this configuration, as long as the processing liquid discharge port is disposed at a position retracted upward with respect to the lower end surface of the central shaft member, the influence of the air flow generated in the gap space SP1 is reduced, and the processing liquid discharge port It is possible to prevent (residual processing liquid) from falling.

  The present invention relates to a semiconductor wafer, a glass substrate for photomask, a glass substrate for liquid crystal display, a glass substrate for plasma display, a substrate for FED (Field Emission Display), a substrate for optical disk, a substrate for magnetic disk, a substrate for magneto-optical disk, etc. The present invention can be applied to a substrate processing apparatus and a substrate processing method in which a processing liquid is supplied to the entire substrate including the substrate and a predetermined wet process is performed on the substrate.

It is a figure which shows the structure of the substrate processing apparatus concerning 1st Embodiment of this invention. It is a block diagram which shows the main control structures of the substrate processing apparatus of FIG. It is sectional drawing which shows the principal part of the substrate processing apparatus of FIG. FIG. 4 is a cross-sectional view taken along line A-A ′ of FIG. 3. It is a flowchart which shows operation | movement of the substrate processing apparatus of FIG. 2 is a timing chart showing the operation of the substrate processing apparatus of FIG. 1. It is a schematic diagram which shows operation | movement of the substrate processing apparatus of FIG. It is sectional drawing which shows the principal part of the substrate processing apparatus concerning 2nd Embodiment of this invention. FIG. 9 is a sectional view taken along line B-B ′ in FIG. 8.

Explanation of symbols

4. Control unit (control means)
5 ... Blocking member 5a ... Bottom surface (of the blocking member) (opposing surface)
6 ... Center shaft member 6a ... Lower end surface (of the center shaft member) 13 ... Chuck rotating mechanism (rotating means)
17 ... chuck pin (substrate holding means)
24 ... Gas supply unit (gas supply means)
61a: Rinse liquid discharge port (first liquid discharge port)
62a: Mixed liquid discharge port (treatment liquid discharge port)
63a ... Gas outlet 66 ... Outside gas supply path 641 ... Partition wall SP1 ... Gap space SP2 ... Ring space SP3 ... Down space W ... Substrate

Claims (7)

In a substrate processing apparatus for supplying a processing liquid to the upper surface of the substrate while rotating the substrate and performing a predetermined wet process on the upper surface of the substrate,
Substrate holding means for holding the substrate in a substantially horizontal posture;
Rotating means for rotating the substrate held by the substrate holding means;
Arranged so as to extend above the center of the upper surface of the substrate held by the substrate holding means, the processing liquid can be discharged from the processing liquid discharge port provided on the lower end side toward the center of the upper surface of the substrate. A central shaft member;
A blocking member having a facing surface facing the top surface of the substrate so as to surround the central shaft member at a radially outer side of the central shaft member, and being spaced apart from the top surface of the substrate while facing the facing surface to the top surface of the substrate When,
Gas supply means for supplying gas to a gap space formed between the opposing surface of the blocking member and the upper surface of the substrate;
Control means for controlling the gas supply means to supply the gas to the gap space while stopping the discharge of the processing liquid from the processing liquid discharge port,
The lower end surface of the central shaft member is disposed at the same height or an upper position with respect to the opposing surface of the blocking member, and the treatment liquid discharge port is retracted upward with respect to the lower end surface of the central shaft member. A substrate processing apparatus, wherein the substrate processing apparatus is disposed at the position.   2. The substrate processing according to claim 1, wherein the gas supply means supplies the gas to the gap space through the outer gas supply path with an annular space sandwiched between the central shaft member and the blocking member as an outer gas supply path. apparatus.   The substrate processing apparatus according to claim 1, wherein the gas supply unit supplies the gas to the gap space from a gas discharge port formed on a lower end surface of the central shaft member. A first liquid discharge port that discharges the first liquid toward the center of the upper surface of the substrate is formed on the lower end surface of the central shaft member,
4. The substrate processing apparatus according to claim 1, wherein a second liquid having a lower surface tension than the first liquid is discharged from the processing liquid discharge port toward the center of the upper surface of the substrate as the processing liquid. 5.   The substrate processing apparatus according to claim 4, wherein a diameter of the processing liquid discharge port is smaller than a diameter of the first liquid discharge port. The substrate processing apparatus according to claim 1, wherein the processing liquid discharge port is provided adjacent to an annular space sandwiched between the central shaft member and the blocking member.
The substrate processing apparatus, wherein the central shaft member includes a partition that separates a lower space located immediately below the processing liquid discharge port and the annular space. A substrate holding means for holding the substrate in a substantially horizontal posture, a rotating means for rotating the substrate held by the substrate holding means, and extending above the center of the upper surface of the substrate held by the substrate holding means. A central shaft member that is disposed and capable of discharging a processing liquid from a processing liquid discharge port provided on the lower end side thereof toward the center of the upper surface of the substrate, and surrounds the central shaft member on a radially outer side of the central shaft member And having a facing surface facing the top surface of the substrate, the shielding member being spaced apart from the top surface of the substrate with the facing surface facing the top surface of the substrate, and between the facing surface of the shielding member and the top surface of the substrate A substrate processing apparatus including a gas supply unit configured to supply a gas to a gap space formed in the substrate, and supplying a processing liquid to the upper surface of the substrate while rotating the substrate, and supplying a predetermined amount to the upper surface of the substrate. Wet treatment A plate processing method,
The lower end surface of the central shaft member is disposed at the same height or an upper position with respect to the opposing surface of the blocking member, and the treatment liquid discharge port is retracted upward with respect to the lower end surface of the central shaft member. The substrate processing method is characterized in that the gas is supplied to the gap space by the gas supply means while the discharge of the processing liquid from the processing liquid discharge port is stopped.

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