JP2013070103A - Substrate processing apparatus and substrate processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate processing apparatus and a substrate processing method for drying a substrate surface wet with a processing liquid by using a low surface tension solvent, in which the substrate surface is excellently dried with a little amount of the low surface tension solvent.SOLUTION: After rinsing processing is completed, a rotation speed of a substrate W is reduced from 600 rpm to 10 rpm to form a puddle-like DIW liquid film. Then, supply of DIW is continued just for 9 seconds and is then stopped to wait for a film thickness t1 of the paddle-like liquid film to be approximately uniform with the lapse of a prescribed time (0.5 second), and IPA is discharged toward a surface center part of a substrate surface Wf at a flow rate of 100 (mL/min) for instance. By the supply of the IPA, the DIW is replaced with the IPA at the surface center part of the surface W to form a replaced region SR. Further, after three seconds of IPA supply, the rotation speed of the substrate W is accelerated from 10 rpm to 300 rpm. Thus, the replaced region SR is caused to expand in a radial direction of the substrate W so that the entire substrate surface Wf is replaced with the low surface tension solvent.

Description

  The present invention relates to a substrate processing apparatus and a substrate processing method for supplying a processing liquid to a substrate surface, subjecting the substrate surface to a predetermined wet process, and then drying the substrate surface wet with the processing liquid. Substrates to be dried include semiconductor wafers, photomask glass substrates, liquid crystal display glass substrates, plasma display glass substrates, FED (Field Emission Display) substrates, optical disk substrates, and magnetic substrates. A disk substrate, a magneto-optical disk substrate, and the like are included.

  A number of drying methods have been proposed in the past to remove the rinse liquid adhering to the substrate surface after the chemical liquid treatment with the chemical liquid and the rinse treatment with pure water or the like. As one of them, a drying method using a liquid (low surface tension solvent) containing an organic solvent component such as IPA (isopropyl alcohol) whose surface tension is lower than that of pure water is known. As this drying method, for example, there is a drying method described in Patent Document 1. In a substrate processing apparatus that executes this drying method, hydrofluoric acid treatment is performed on a substrate surface, and then pure water is supplied to the substrate surface to perform a cleaning process (rinse process). Next, IPA is supplied to the surface of the substrate without interruption after the supply of pure water is stopped or while the pure water is being supplied. Thereby, IPA dissolves in pure water on the substrate surface, and the pure water is replaced by IPA. Thereafter, the substrate is rotated at a high speed to remove IPA from the substrate surface, and the substrate surface is dried.

  In the resist developing method described in Patent Document 2, the substrate surface is dried while reducing the amount of fine dust on the substrate surface as follows. First, after resist development, pure water is supplied to the substrate to perform pure water cleaning (rinsing treatment). Thereafter, the substrate is cleaned by supplying pure water (IPA aqueous solution) containing IPA of about 10% by volume to the substrate. Next, the substrate is spin-dried while rotating the substrate at a high speed.

Japanese Patent Laid-Open No. 9-38595 (FIG. 5) Japanese Patent Laid-Open No. 3-209715 (FIG. 1)

  By the way, in the above prior art, a rinsing process is performed by supplying a rinsing liquid to the substrate surface while rotating the substrate at a medium speed (for example, 300 rpm in Patent Document 1 and 500 rpm in Patent Document 2). In the replacement process following the rinse process, a large amount of a low surface tension solvent such as IPA or an IPA aqueous solution is supplied to the substrate surface while maintaining the rotation speed of the substrate to reduce the rinse liquid on the substrate in a short time. It is replaced with a surface tension solvent. Therefore, in the prior art, there is a problem that the amount of the low surface tension solvent used is relatively large and the running cost increases. Therefore, in order to reduce the amount of low surface tension solvent used, it has been studied to reduce the flow rate of the low surface tension solvent.

  However, when the flow rate of the low surface tension solvent is reduced, the substitution to the low surface tension solvent proceeds only gradually, and the substrate surface may be partially dried by Marangoni convection. This will be briefly described with reference to FIG. At the initial stage when the supply of the low surface tension solvent such as IPA is started, the low surface tension solvent such as IPA is supplied to the center of the surface of the substrate W and replaced by the low surface tension solvent as shown in FIG. Region SR is formed. At this time, a part of the low surface tension solvent rebounds on the substrate surface Wf and scatters around the replacement region SR, or the evaporated low surface tension solvent component diffuses around the replacement region SR. May be mixed in the rinse liquid. In particular, in the prior art, as described above, since the rotation speed of the substrate W is maintained at a medium speed, the thickness of the liquid film is relatively thin. Therefore, the concentration of the low surface tension solvent increases in the liquid film portion MR mixed with the low surface tension solvent. As a result, as shown in FIG. 5B, Marangoni convection occurs in the mixed portion MR, and the substrate surface Wf. May be partially dried, resulting in problems such as the generation of watermarks.

  The present invention has been made in view of the above problems, and in a substrate processing apparatus and a substrate processing method for drying a substrate surface wetted with a processing solution using a low surface tension solvent such as IPA, the substrate surface with a small amount of low surface tension solvent. It aims at drying well.

  In order to achieve the above object, a substrate processing method according to the present invention includes a wet processing step of performing wet processing on a substrate surface using a processing liquid while rotating a substantially horizontal substrate at a first speed, A paddle forming step of reducing the rotation speed to the second speed to form a liquid film of the processing liquid on the substrate in a paddle shape, and a surface tension higher than that of the processing liquid while maintaining the rotation speed of the substrate below the second speed. A replacement region forming step of supplying a low low surface tension solvent to the center of the surface of the substrate to form a replacement region by the low surface tension solvent, and supplying a low surface tension solvent to the center of the surface to place the replacement region in the radial direction of the substrate And replacing the entire surface of the substrate with a low surface tension solvent, and a drying step of removing the low surface tension solvent from the substrate surface and drying the substrate surface after the replacement step. Treatment liquid on the surface It is characterized by being supplied.

  In addition, the substrate processing apparatus according to the present invention replaces the processing liquid on the substrate surface with a low surface tension solvent having a surface tension lower than that of the processing liquid after the wet processing on the substrate surface using the processing liquid, and then the low surface tension. In a substrate processing apparatus for removing a solvent from a substrate surface and drying the substrate surface, a substrate holding means for holding the substrate in a substantially horizontal posture, and a substrate rotation for rotating the substrate held by the substrate holding means about a predetermined rotation axis Means for supplying the low surface tension solvent to the central portion of the surface of the substrate held by the substrate holding means, and a control means for adjusting the rotation speed of the substrate by controlling the substrate rotating means. , While setting the rotational speed in the wet processing to the first speed, the rotational speed is reduced to the second speed before supplying the low surface tension solvent, and a liquid film of the processing liquid is formed in a paddle shape on the substrate and supplied. Means is the rotation speed of the substrate The low surface tension solvent is supplied to the replacement area after the low surface tension solvent is supplied at the second speed and the replacement area by the low surface tension solvent is formed at the center of the substrate surface. While the replacement area is enlarged in the radial direction of the substrate, the entire surface of the substrate is replaced with a low surface tension solvent, and the control means rotates the substrate at the second speed to form a liquid film of the processing liquid in a paddle shape. The processing liquid is supplied to the substrate surface.

  In the invention (substrate processing method and apparatus) configured as described above, the substrate in a substantially horizontal state is rotated at the first speed, and wet processing such as rinsing is performed on the substrate surface using a processing liquid. Is done. Thereafter, the rotation speed of the substrate is reduced to the second speed (<first speed), and a liquid film of the processing liquid is formed in a paddle shape on the substrate. In this state, a low surface tension solvent having a surface tension lower than that of the treatment liquid is supplied to the central portion of the surface of the substrate, thereby forming a replacement region of the low surface tension solvent at the central portion of the substrate surface (substitution region forming step). . Subsequently, the low surface tension solvent is further supplied to the center of the surface, the replacement region is expanded in the radial direction of the substrate, and the entire surface of the substrate is replaced with the low surface tension solvent (replacement step). Thereafter, the low surface tension solvent is removed from the substrate surface and the substrate surface is dried. In this way, the entire surface of the substrate is replaced with a low surface tension solvent while controlling the formation and expansion of the substitution region, so a large amount of the low surface tension solvent is supplied to the substrate surface, and the entire surface of the substrate is quickly removed. The amount of the low surface tension solvent used can be reduced as compared with the conventional technique of replacing the above.

  Here, there is a possibility that a low surface tension solvent is mixed around the substitution area when the substitution area is formed, and Marangoni convection may occur. However, since the rotation speed of the substrate is controlled as described above, the Marangoni convection Occurrence is suppressed. That is, in the present invention, in order to form a paddle-like liquid film while rotating the substrate, the centrifugal force acting on the treatment liquid is made smaller than the surface tension acting between the treatment liquid and the substrate surface. The second speed (including zero) is set. Therefore, by maintaining the rotation speed of the substrate below the second speed, the liquid film on the substrate surface becomes thicker than in the wet process. Then, since the replacement region is formed in that state, even if the low surface tension solvent is mixed around the replacement region, the liquid film is thicker than in the prior art, and Marangoni convection is generated at the mixing position. Is suppressed. As a result, the problem that the substrate surface is partially dried is effectively prevented.

  In the replacement process, the replacement region expands in the radial direction of the substrate, and the distance from the supply position of the low surface tension solvent (the central portion of the substrate surface) to the processing liquid on the substrate increases. Is less likely to be mixed around the replacement area. Therefore, in the replacement step, the rotation speed of the substrate may be set to a rotation speed higher than the second speed, which increases the centrifugal force acting on the processing liquid and the low surface tension solvent on the substrate. The time required for replacement with the surface tension solvent is shortened. Further, as the rotational speed increases, the liquid film becomes thinner, and the amount of low surface tension solvent used to cover the entire substrate surface can be reduced.

  The rotational speed of the substrate may be accelerated with the passage of time, which is suitable for shortening the processing time and reducing the amount of low surface tension solvent used. For example, the rotational speed can be accelerated in multiple stages. In addition, the acceleration at the time of accelerating the rotation speed may be configured to increase as the rotation speed increases.

  In addition, as a “low surface tension solvent” used in the present invention, a 100% organic solvent component or a mixed solution thereof with pure water can be used. Moreover, it may replace with the solvent containing an organic solvent component as a low surface tension solvent, and may use the solvent which essentially contains surfactant. Here, an alcohol-based organic solvent can be used as the “organic solvent component”. As the alcohol-based organic solvent, isopropyl alcohol, ethyl alcohol, or methyl alcohol can be used from the viewpoints of safety, cost, and the like, and isopropyl alcohol (IPA) is particularly preferable.

  According to the present invention, a low surface tension solvent is supplied to the central portion of the surface of the substrate while the rotational speed of the substrate is maintained at the second speed or less to form a replacement region, and then the replacement region is expanded in the radial direction of the substrate. Thus, the entire surface of the substrate is replaced with a low surface tension solvent. Therefore, the liquid film of the treatment liquid can be replaced with the liquid film of the low surface tension solvent without using the low surface tension solvent wastefully. In addition, it is possible to reliably prevent a portion of the substrate surface from being exposed to dryness by Marangoni convection during the entire formation of a liquid film of a low surface tension solvent on the substrate surface. Therefore, the substrate surface can be satisfactorily dried with a small amount of low surface tension solvent.

It is a figure showing one embodiment of a substrate processing device concerning this invention. It is a block diagram which shows the main control structures of the substrate processing apparatus of FIG. It is a longitudinal cross-sectional view which shows the principal part of the interruption | blocking member with which the substrate processing apparatus of FIG. 1 was equipped. FIG. 4 is a cross-sectional view (cross-sectional view) taken along the line A-A ′ of FIG. 3. 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 a schematic diagram which shows operation | movement of the substrate processing apparatus of FIG. It is a timing chart which shows the substrate processing method concerning a comparative example. It is a figure which shows the particle distribution on the board | substrate surface processed by the comparative example and the Example. It is a schematic diagram which shows operation | movement of the conventional substrate processing apparatus.

FIG. 1 is a view showing an embodiment of a substrate processing apparatus according to 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 adhering to a surface Wf of a substrate W such as a semiconductor wafer. More specifically, the substrate surface Wf is treated with a chemical solution such as hydrofluoric acid and pure water or DIW (deionized water: deionized water).
This is an apparatus for drying the substrate surface Wf wetted with the rinsing liquid after rinsing with a rinsing liquid such as water). In this embodiment, the substrate surface Wf means a pattern formation surface on which a device pattern made of poly-Si or the like 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 9 arranged at 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. The rotating support shaft 11 and the chuck rotating mechanism 13 are accommodated in a cylindrical casing 2. 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 that controls the entire apparatus. Thus, in this embodiment, the chuck rotating mechanism 13 functions as the “substrate rotating means” of the present invention. Further, the control unit 4 controls the chuck rotation mechanism 13 to adjust the rotation speed.

  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 supported with its 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 supports 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 source via a chemical valve 31. For this reason, when the chemical liquid valve 31 is opened and closed based on the control command from the control unit 4, the chemical liquid is pumped from the chemical liquid supply source toward the chemical liquid discharge nozzle 3, and the chemical liquid is discharged from the chemical liquid discharge nozzle 3. Note that hydrofluoric acid or BHF (buffered hydrofluoric acid) or the like is used as the chemical solution. Further, a nozzle moving mechanism 33 (FIG. 2) is connected to the chemical liquid discharge nozzle 3, and the chemical liquid discharge nozzle 3 is moved to the substrate W by driving the nozzle moving mechanism 33 in accordance with an operation command from the control unit 4. Can be reciprocated between the discharge position above the rotation center and the standby position retracted to the side from the discharge position.

  The blocking member 9 includes a plate-like member 90, a rotation support shaft 91 that is hollow inside, and supports the plate-like member 90, and an insertion shaft 95 that is inserted through the hollow portion of the rotation support shaft 91. ing. The plate-like member 90 is a disk-like member having an opening at the center, and is disposed to face the surface Wf of the substrate W held by the spin chuck 1. The plate-like member 90 has a lower surface (bottom surface) 90 a that is a substrate facing surface that faces the substrate surface Wf substantially in parallel, and the planar size of the plate member 90 is equal to or larger than the diameter of the substrate W. The plate-like member 90 is attached substantially horizontally to the lower end portion of the rotation support shaft 91 having a substantially cylindrical shape, and the rotation support shaft 91 is rotatable about a rotation axis J passing through the center of the substrate W by an arm 92 extending in the horizontal direction. Is retained. A bearing (not shown) is interposed between the outer peripheral surface of the insertion shaft 95 and the inner peripheral surface of the rotation support shaft 91. A blocking member rotating mechanism 93 and a blocking member lifting mechanism 94 are connected to the arm 92.

  The blocking member rotation mechanism 93 rotates the rotation support shaft 91 around the rotation axis J in response to an operation command from the control unit 4. When the rotation support shaft 91 is rotated, the plate member 90 rotates integrally with the rotation support shaft 91. The blocking member rotating mechanism 93 is configured to rotate the plate-like member 90 (lower surface 90a) 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 by the spin chuck 1. Yes.

  Further, the blocking member elevating mechanism 94 can make the blocking member 9 close to and opposite to the spin base 15 according to an operation command from the control unit 4, or can be separated from the spin base 15. Specifically, the control unit 4 operates the blocking member elevating mechanism 94 to raise the blocking member 9 to a separation position above the spin chuck 1 when the substrate processing apparatus carries the substrate W in and out. Let On the other hand, when a predetermined process is performed on the substrate W, the substrate W is cut off to a predetermined facing 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 9 is lowered. In this embodiment, after the rinsing process is started, the blocking member 9 is lowered from the separated position to the facing position, and is continuously positioned until the drying process is completed.

  FIG. 3 is a longitudinal sectional view showing the main part of the blocking member provided in the substrate processing apparatus of FIG. 4 is a cross-sectional view (cross-sectional view) taken along the line A-A ′ of FIG. An insertion shaft 95 inserted in the hollow portion of the rotation support shaft 91 has a circular cross section. This is to make the gaps between the insertion shaft 95 (non-rotating side member) and the rotation support shaft 91 (rotating side member) uniform over the entire circumference. The gap between the insertion shaft 95 and the rotation support shaft 91 is sealed from the outside. Three fluid supply paths are formed in the insertion shaft 95 so as to extend in the vertical axis direction. That is, a rinse liquid supply path 96 serving as a rinse liquid path, a solvent supply path 97 serving as a path for a low surface tension solvent having an organic solvent component that dissolves in the rinse liquid and lowers the surface tension, and an inert gas such as nitrogen gas A gas supply path 98 serving as a passage is formed in the insertion shaft 95. The rinsing liquid supply path 96, the solvent supply path 97, and the gas supply path 98 are respectively connected to an interpolating shaft 95 made of PTFE (polytetrafluoroethylene) with PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer resin). Tetrafluoroethylene and perfluoroalkylvinylether) tubes 96b, 97b, 98b are inserted in the axial direction.

  Then, the lower ends of the rinse liquid supply path 96, the solvent supply path 97, and the gas supply path 98 become the rinse liquid discharge port 96a, the solvent discharge port 97a, and the gas discharge port 98a, respectively, of the substrate W held on the spin chuck 1. Opposite the surface Wf. In this embodiment, the diameter of the insertion shaft is 18 to 20 mm. Moreover, the diameters of the rinse liquid discharge port 96a, the solvent discharge port 97a, and the gas discharge port 98a are formed to 4 mm, 1 to 2 mm, and 4 mm, respectively. Thus, in this embodiment, the diameter of the solvent discharge port 97a is smaller than the diameter of the rinse liquid discharge port 96a. Thereby, the trouble shown below can be prevented. That is, the surface tension of the low surface tension solvent is lower than that of the rinse liquid (DIW). For this reason, when low surface tension solvent is discharged from the solvent discharge port having the same diameter as that for rinsing liquid discharge, the low surface tension solvent is discharged from the solvent discharge port after the discharge of the low surface tension solvent is stopped. There is a risk of falling. On the other hand, when the rinse liquid is discharged from the rinse liquid discharge port having the same diameter as that formed for solvent discharge, the discharge speed of the rinse liquid is increased. As a result, the rinse liquid (DIW), which is an electrical insulator, may collide with the substrate surface Wf at a relatively high speed, so that the supply portion of the substrate surface Wf to which the rinse liquid is directly supplied may be charged and oxidized. is there. In contrast, in this embodiment, the discharge port for the low surface tension solvent and the rinse liquid are provided separately, and the diameter of the solvent discharge port 97a is smaller than the diameter of the rinse liquid discharge port 96a. For this reason, it is possible to prevent the low surface tension solvent from dropping from the solvent discharge port, to suppress an increase in the discharge speed of the rinse liquid from the rinse liquid discharge port, and to suppress oxidation due to charging of the substrate surface Wf. it can.

  In this embodiment, the rinse liquid discharge port 96a is provided at a position shifted radially outward from the central axis of the blocking member 9, 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 96a is concentrated and supplied to one point (the rotation center W0 of the substrate W) of the substrate surface Wf. 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 96a is too far from the rotation axis J, it is difficult to make the rinse liquid reach the rotation center W0 on the substrate surface Wf. Therefore, in this embodiment, the distance L from the rotation axis J in the horizontal direction to the rinse liquid discharge port 96a (discharge port center) is set to about 4 mm. Here, the upper limit of the distance L at which the rinse liquid (DIW) can be supplied to the rotation center W0 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 central portion of the surface is a hydrophobic surface. As for the upper limit value of the distance from the rotation axis J to the solvent discharge port 97a (discharge port center), as long as the substrate rotation speed is set to 1500 rpm, the rotation axis J described above is used. Is basically the same as the upper limit (20 mm) of the distance L from the rinsing liquid discharge port 96a (discharge port center).

  On the other hand, with respect to the distance from the rotation axis J to the gas discharge port 98a (discharge port center), a gap space formed between the blocking member 9 (plate member 90) positioned at the opposing position and the substrate surface Wf. As long as nitrogen gas can be supplied to SP, it is not particularly limited and is optional. However, from the viewpoint of blowing nitrogen gas onto a solvent layer made of a low surface tension solvent formed on the substrate surface Wf as described later and discharging the solvent layer from the substrate W, the gas discharge port 98a has a rotational axis J. It is preferable to provide at the top or in the vicinity thereof.

  A space portion formed between the inner wall surface of the rotation support shaft 91 and the outer wall surface of the insertion shaft 95 constitutes the outer gas supply path 99, and the lower end of the outer gas supply path 99 is an annular outer gas. The discharge port 99a is formed. That is, the blocking member 9 includes an outer gas discharge port 99a in addition to a gas discharge port 98a for discharging nitrogen gas toward the center of the substrate surface Wf, and a rinse liquid discharge port 96a, a solvent discharge port 97a, and a gas discharge port. It is provided radially outward with respect to 98a and so as to surround the rinse liquid discharge port 96a, the solvent discharge port 97a, and the gas discharge port 98a. The opening area of the outer gas discharge port 99a is much larger than the opening area of the gas discharge port 98a. Thus, since two types of gas discharge ports are provided in the blocking member 9, nitrogen gas having different flow rates and flow rates can be discharged from the 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 removing the solvent layer of the low surface tension solvent on the substrate surface Wf from the substrate surface Wf, supply nitrogen gas to the center of the surface of the substrate W at a relatively small flow rate and at a high speed. Is desired. Therefore, in the case (1), nitrogen gas is mainly discharged from the outer gas discharge port 99a, and in the case (2), nitrogen gas is mainly discharged from the gas discharge port 98a. Nitrogen gas can be supplied toward the substrate surface Wf at an appropriate flow rate and flow rate depending on the use of the gas.

  Further, the tip (lower end) of the insertion shaft 95 is not flush with the lower surface 90a of the plate-like member 90, and is retracted upward from the same plane including the lower surface 90a (FIG. 3). According to such a configuration, it is possible to diffuse the nitrogen gas before the nitrogen gas discharged from the gas discharge port 98a reaches the substrate surface Wf and reduce the flow rate of the nitrogen gas to some extent. That is, if the flow rate of nitrogen gas from the gas discharge port 98a is too high, the nitrogen gas from the outer gas discharge port 99a interferes with each other and the solvent layer of the low surface tension solvent on the substrate surface Wf is discharged from the substrate W. 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 nitrogen gas from the gas discharge port 98a is relaxed, and the solvent layer of the low surface tension solvent on the substrate surface Wf can be reliably discharged from the substrate W.

  Returning to FIG. 1, the description will be continued. An upper end portion of the rinsing liquid supply path 96 is connected to a DIW supply source constituted by a factory utility or the like via a rinsing liquid valve 83. When the rinsing liquid valve 83 is opened, the DIW is discharged from the rinsing liquid discharge port 96a. Can be discharged as a rinsing liquid.

  The upper end of the solvent supply path 97 is connected to the solvent supply unit 7. The solvent supply unit 7 includes a cabinet unit 70 for generating a low surface tension solvent, and the low surface tension solvent generated in the cabinet unit 70 can be pumped to the solvent supply path 97. 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, and various organic solvent components such as ethyl alcohol and methyl alcohol may be used. The organic solvent component is not limited to a liquid, and various alcohol vapors may be dissolved in DIW as an organic solvent component to produce a low surface tension solvent.

  The cabinet unit 70 includes a storage tank 72 that stores a low surface tension solvent. One end of a DIW introduction pipe 73 for supplying DIW into the storage tank 72 is taken into the storage tank 72, and the other end is connected to a DIW supply source through an open / close valve 73a. Further, a flow meter 73b is interposed in the course of the DIW introduction pipe 73, and the flow meter 73b measures the flow rate of DIW introduced into the storage tank 72 from the DIW supply source. Based on the flow rate measured by the flow meter 73b, the control unit 4 controls the opening / closing valve 73a so that the flow rate of DIW flowing through the DIW introduction pipe 73 becomes a target flow rate (target value).

  Similarly, one end of the IPA introduction pipe 74 for supplying the IPA liquid into the storage tank 72 is taken into the storage tank 72, and the other end is connected to the IPA supply source via the opening / closing valve 74a. Yes. Further, a flow meter 74b is provided in the middle of the route of the IPA introduction pipe 74, and the flow meter 74b measures the flow rate of the IPA liquid introduced into the storage tank 72 from the IPA supply source. Then, the control unit 4 controls opening / closing of the opening / closing valve 74a based on the flow rate measured by the flow meter 74b so that the flow rate of the IPA liquid flowing through the IPA introduction pipe 74 becomes a target flow rate (target value).

  In this embodiment, the volume percentage of IPA in the low surface tension solvent (hereinafter referred to as “IPA concentration”) can be adjusted, that is, 100% IPA can be supplied as the low surface tension solvent, It is also possible to supply a mixed liquid in which DIW is mixed as a low surface tension solvent. When 100% IPA is always used as the low surface tension solvent, IPA may be directly supplied via a solvent valve 76 described below.

  The other end of the solvent supply pipe 75 whose one end is connected to the solvent supply path 97 is inserted into the storage tank 72, and the low surface tension solvent stored in the storage tank 72 is supplied to the solvent supply path via the solvent valve 76. 97 can be supplied. The solvent supply pipe 75 adjusts the temperature of the low surface tension solvent sent to the solvent supply pipe 75 by the metering pump 77 that feeds the low surface tension solvent stored in the storage tank 72 to the solvent supply pipe 75. And a filter 79 for removing foreign matter in the low surface tension solvent. Further, the solvent supply pipe 75 is provided with a concentration meter 80 for monitoring the IPA concentration.

  One end of a solvent circulation pipe 81 is branched and connected to the solvent supply pipe 75 between the solvent valve 76 and the concentration meter 80, and the other end of the solvent circulation pipe 81 is connected to the storage tank 72. A circulation valve 82 is interposed in the solvent circulation pipe 81. During the operation of the apparatus, the metering pump 77 and the temperature controller 78 are always driven, and while the low surface tension solvent is not supplied to the substrate W, the solvent valve 76 is closed and the circulation valve 82 is opened. As a result, the low surface tension solvent fed from the storage tank 72 by the metering pump 77 is returned to the storage tank 72 through the solvent circulation pipe 81. That is, while the low surface tension solvent is not supplied to the substrate W, the low surface tension solvent circulates in the circulation path including the storage tank 72, the solvent supply pipe 75, and the solvent circulation pipe 81. On the other hand, when it is time to supply the low surface tension solvent to the substrate W, the solvent valve 76 is opened and the circulation valve 82 is closed. As a result, the low surface tension solvent delivered from the storage tank 72 is supplied to the solvent supply path 97. As described above, while the low surface tension solvent is not supplied to the substrate W, the low surface tension solvent is circulated so that the DIW and IPA are stirred and the DIW and IPA are sufficiently mixed. be able to. Further, after the solvent valve 76 is opened, the low surface tension solvent that is adjusted to a predetermined temperature and from which foreign matters are removed can be quickly supplied to the solvent supply path 97.

  The upper ends of the gas supply path 98 and the outer gas supply path 99 are connected to the gas supply unit 18 (FIG. 2), respectively, and from the gas supply unit 18 to the gas supply path 98 and the outer side according to the operation command of the control unit 4. Nitrogen gas can be individually pumped to the gas supply path 99. Thus, nitrogen gas can be supplied to the gap space SP formed between the blocking member 9 (plate member 90) positioned at the opposing position and the substrate surface Wf.

  A receiving member 21 is fixedly attached around the casing 2. Cylindrical partition members 23a, 23b, and 23c are erected on the receiving member 21. A space between the outer wall of the casing 2 and the inner wall of the partition member 23a forms the first drainage tank 25a, and a space between the outer wall of the partition member 23a and the inner wall of the partition member 23b serves as the second drainage tank 25b. The space between the outer wall of the partition member 23b and the inner wall of the partition member 23c forms the third drainage tank 25c.

  The bottoms of the first drain tank 25a, the second drain tank 25b, and the third drain tank 25c are formed with outlets 27a, 27b, 27c, respectively, and each outlet is connected to a different drain. ing. For example, in this embodiment, the first drainage tank 25a is a tank for collecting used chemical liquid and communicated with a recovery drain for collecting and reusing the chemical liquid. The second drainage tank 25b is a tank for draining the used rinse liquid, and communicates with a waste drain for disposal processing. Further, the third drainage tank 25c is a tank for draining the used low surface tension solvent, and communicates with a waste drain for disposal processing.

  A splash guard 6 is provided above the drainage tanks 25a to 25c. The splash guard 6 is provided so as to be movable up and down with respect to the rotation axis J of the spin chuck 1 so as to surround the periphery of the substrate W held in a horizontal posture on the spin chuck 1. The splash guard 6 has a shape that is substantially rotationally symmetric with respect to the rotation axis J, and includes three guards 61, 62, and 63 that are concentrically arranged with the spin chuck 1 from the radially inner side toward the outer side. ing. The three guards 61, 62, 63 are provided so that the height decreases in order from the outermost guard 63 toward the innermost guard 61, and the upper ends of the guards 61, 62, 63 are in the vertical direction. It arrange | positions so that it may be settled in the surface extended to.

  The splash guard 6 is connected to the guard lifting mechanism 65 and operates the lifting drive actuator (for example, an air cylinder) of the guard lifting mechanism 65 in accordance with an operation command from the control unit 4, so that the splash guard 6 is spin chucked. 1 can be moved up and down. In this embodiment, the splash guard 6 is moved up and down stepwise by driving the guard lifting mechanism 65, whereby the processing liquid scattered from the rotating substrate W is separated into the first to third drain tanks 25a to 25c and drained. It is possible to make it.

  On the upper part of the guard 61, a groove-shaped first guide portion 61a that is inwardly opened in a cross-sectional shape is formed. Then, by placing the splash guard 6 at the highest position (hereinafter referred to as “first height position”) during the chemical treatment, the chemical liquid scattered from the rotating substrate W is received by the first guide portion 61a, and the first discharge is performed. It is guided to the liquid tank 25a. Specifically, the chemical liquid splashing from the rotating substrate W is arranged by arranging the splash guard 6 so that the first guide portion 61a surrounds the periphery of the substrate W held by the spin chuck 1 as the first height position. Is guided to the first drainage tank 25 a through the guard 61.

  In addition, an inclined portion 62 a that is inclined obliquely upward from the radially outer side to the inner side is formed on the upper portion of the guard 62. Then, the rinsing liquid splashed from the rotating substrate W is received by the inclined portion 62a by positioning the splash guard 6 at a position lower than the first height position (hereinafter referred to as “second height position”) during the rinsing process. And guided to the third drainage tank 25b. Specifically, as the second height position, the splash guard 6 is arranged so that the inclined portion 62a surrounds the periphery of the substrate W held by the spin chuck 1, so that the rinsing liquid scattered from the rotating substrate W can be obtained. It passes between the upper end of the guard 61 and the upper end of the guard 62 and is guided to the second drainage tank 25b.

  Similarly, on the upper part of the guard 63, an inclined portion 63a that is inclined obliquely upward from the radially outer side to the inner side is formed. Then, by placing the splash guard 6 at a position lower than the second height position (hereinafter referred to as “third height position”) during the replacement process, the low surface tension solvent scattered from the rotating substrate W is inclined to the inclined portion 63a. And is guided to the second drainage tank 25c. Specifically, as the third height position, the splash guard 6 is disposed so that the inclined portion 63a surrounds the periphery of the substrate W held by the spin chuck 1, so that the low surface tension scattered from the rotating substrate W is obtained. The solvent passes between the upper end portion of the guard 62 and the upper end portion of the guard 63 and is guided to the third drainage tank 25c.

  Further, the substrate transfer means (not shown) is not moved by causing the spin chuck 1 to protrude from the upper end of the splash guard 6 at a position lower than the third height position (hereinafter referred to as “retraction position”). It is possible to place the processed substrate W on the spin chuck 1 and receive the processed substrate W from the spin chuck 1.

  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 timing chart showing the operation of the substrate processing apparatus of FIG. 6 and 7 are schematic views showing the operation of the substrate processing apparatus of FIG. In this apparatus, the control unit 4 controls each part of the apparatus according to a program stored in a memory (not shown) and performs a series of processes on the substrate W. That is, the control unit 4 positions the splash guard 6 at the retracted position and causes the spin chuck 1 to protrude from the upper end portion of the splash guard 6. In this state, when an unprocessed substrate W is carried into the apparatus by the substrate transport means (not shown), the substrate W is subjected to a cleaning process (chemical solution process + rinsing process + paddle forming process + replacement region forming process). + Replacement process + Dry process). 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 9 is located at a position above the spin chuck 1 and prevents interference with the substrate W.

  Subsequently, the control unit 4 arranges the splash guard 6 at the first height position (position shown in FIG. 1), and performs the chemical treatment 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 rotation speed (for example, 800 rpm) determined within a range of 200 to 1200 rpm by driving the chuck rotation mechanism 13. Then, the chemical solution valve 31 is opened to supply hydrofluoric acid as a chemical solution from the chemical solution discharge nozzle 3 to the substrate surface Wf (HF supply). The hydrofluoric acid supplied to the substrate surface Wf is spread by centrifugal force, and the entire substrate surface Wf is treated with a chemical solution using hydrofluoric acid. The hydrofluoric acid shaken off from the substrate W is guided to the first drainage tank 25a and reused as appropriate.

  When the chemical processing is completed, the chemical discharge nozzle 3 is moved to the standby position. And the splash guard 6 is arrange | positioned in a 2nd height position, and the rinse process is performed with respect to the board | substrate W as "wet process" of this invention. That is, the rinsing liquid valve 83 is opened, and the rinsing liquid is discharged from the rinsing liquid discharge port 96a of the blocking member 9 located at the separated position (DIW supply). Simultaneously with the discharge of the rinsing liquid, the blocking member 9 is lowered toward the facing position and positioned at the facing 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 hydrofluoric acid is shaken off from the substrate W after the chemical treatment, the substrate surface Wf begins 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 98a and the outer gas discharge port 99a of the blocking member 9. Here, nitrogen gas is mainly discharged from the outer gas discharge port 99a. That is, the flow rate balance of the nitrogen gas discharged from both discharge ports is such that a relatively large flow rate of nitrogen gas is discharged from the outer gas discharge port 99a while the flow rate of the nitrogen gas discharged from the gas discharge port 98a is very small. Adjust.

In the nitrogen gas flow rate shown in FIG. 5, the broken line represents the gas flow rate discharged from the outer gas discharge port 99a, and the solid line represents the total gas flow rate discharged from the gas discharge port 98a and the outer gas discharge port 99a. As shown in FIG. 5, the flow rate of nitrogen gas discharged when supplying DIW as a rinsing liquid to the substrate surface Wf is, for example, 100 SLM (standard
Of these, 95 SLM is supplied from the outer gas discharge port 99a, while the remaining 5 SLM is supplied from the gas discharge port 98a.

  The gas flow rate is not limited to the above, but the gas flow rate from the gas discharge port 98a is preferably 5 SLM to 40 SLM, and the gas flow rate from the outer gas discharge port 99a is preferably about 95 SLM to 100 SLM.

  The rinse liquid supplied from the rinse liquid discharge port 96a 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 (wet processing step). That is, the hydrofluoric acid remaining on the substrate surface Wf is washed away by the rinse liquid corresponding to the treatment liquid of the present invention and removed from the substrate surface Wf. The used rinsing liquid shaken off from the substrate W is guided to the second drainage tank 25b and discarded. Further, the nitrogen gas is supplied to the gap space SP, so that the 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 (first speed) of the substrate W during the rinsing process is set to, for example, 600 rpm (FIG. 6A).

  Further, when performing the above-described rinsing process and the processes described later (paddle formation process, replacement region formation process, replacement process, and drying process), the plate-like member 90 of the blocking member 9 is rotated in the same rotational direction as the substrate W and Rotate at approximately the same rotational speed. Thereby, it is possible to prevent a relative rotational speed difference from being generated between the lower surface 90a of the plate-like member 90 and the substrate surface Wf, and to suppress the occurrence of an entrained air current in the gap space SP. For this reason, it is possible to prevent the mist-like rinse liquid and the low surface tension solvent from entering the gap space SP and adhering to the substrate surface Wf. Further, by rotating the plate member 90, it is possible to shake off the rinsing liquid and the low surface tension solvent adhering to the lower surface 90a and prevent the rinsing liquid and the low surface tension solvent from staying on the lower surface 90a.

  When the rinsing process for a predetermined time is completed, a paddle forming process is executed next. That is, the control unit 4 decelerates the rotation speed of the substrate W to a second speed slower than the first speed after the rinsing process is completed. As a result, the rinsing liquid discharged from the rinsing liquid discharge port 96a is accumulated on the substrate surface Wf, and a DIW liquid film is formed in a paddle shape (paddle forming process). In this embodiment, the control unit 4 sets the second speed to 10 rpm, continues supplying the rinse liquid for 9 seconds, then closes the rinse liquid valve 83 and discharges the rinse liquid from the rinse liquid discharge port 96a. Stop. As a result, a DIW liquid film is formed as shown in FIG. Although the second speed is not limited to 10 rpm, the second speed is within a range that satisfies the condition that the centrifugal force acting on the rinsing liquid is smaller than the surface tension acting between the rinsing liquid and the substrate surface Wf. Two speeds need to be set. This is because the above conditions must be satisfied in order to form a rinse liquid film in a paddle shape.

  Then, after the DIW supply is stopped, the control unit waits until a predetermined time (in this embodiment, 0.5 second) elapses and the film thickness t1 of the paddle-like DIW liquid film becomes substantially uniform over the entire surface of the substrate W. 4 arranges the splash guard 6 in the third height position. Subsequently, the solvent valve 76 is opened to discharge the low surface tension solvent from the solvent discharge port 97a. Here, 100% IPA is prepared in advance in the cabinet unit 70, and the IPA is discharged from the solvent discharge port 97a toward the center of the surface of the substrate surface Wf at a low flow rate, for example, 100 (mL / min). Is done. By this IPA supply, as shown in FIG. 6C, the central portion of the DIW liquid film is replaced with IPA at the central portion of the surface of the substrate W, and the replacement region SR is formed in the liquid film (replacement region forming process). .

  When 3 seconds elapse from the IPA supply, the control unit 4 accelerates the rotation speed of the substrate W from 10 rpm to 300 rpm while continuing the IPA supply. As a result, the replacement region SR expands in the radial direction of the substrate W, and the entire surface of the substrate surface Wf is replaced with the low surface tension solvent (replacement process). In this embodiment, as will be described below, the rotational speed of the substrate W is accelerated in two stages.

  The control unit 4 accelerates the rotation speed of the substrate W from 10 rpm to 100 rpm over 0.5 seconds (first replacement process). Thus, the acceleration of the rotation speed increases the centrifugal force acting on the liquid film (DIW region + IPA region (replacement region SR)) on the substrate surface Wf, and the DIW is shaken off and the replacement region SR expands in the radial direction. (FIG. 6 (d)). At this time, the thickness of the liquid film on the substrate surface Wf is reduced to a thickness t2 corresponding to the rotational speed, and when a predetermined time (1 second in this embodiment) has elapsed, all the DIW existing on the outer peripheral portion of the surface of the substrate W is all. While being shaken off from the substrate W, the replacement region SR is uniformly spread over the entire surface of the substrate surface Wf, and the substrate surface Wf is entirely covered with the IPA liquid film.

  In the next second replacement process, the control unit 4 accelerates the rotation speed of the substrate W from 100 rpm to 300 rpm over 0.5 seconds. This is performed in order to replace the rinse liquid remaining in the gaps of the fine pattern FP formed on the substrate surface Wf (“residual DIW” in FIG. 7A) with IPA. In other words, the IPA largely flows on the substrate surface Wf due to the acceleration of the rotation speed, whereby the residual DIW is replaced with IPA in the gaps of the fine pattern FP (FIG. 7B). This ensures that the DIW adhering to the substrate surface Wf is replaced with IPA. Thus, the residual DIW is increased by increasing the acceleration (= (300-100) /0.5) in the second replacement process to be higher than the acceleration (= (100-10) /0.5) in the first replacement process. The replacement efficiency of can be increased. The used IPA shaken off from the substrate W is guided to the third drain tank 25c and discarded.

  As shown in FIG. 5, the nitrogen gas flow rates from the gas discharge port 98a and the outer gas discharge port 99a are maintained at the same flow rate as in the rinsing process until the replacement process is completed. As described above, by performing the rinsing process and the replacement process while continuously supplying a relatively large flow rate and a low-speed nitrogen gas to the substrate surface Wf in a state where the blocking member 9 is disposed close to the substrate surface Wf, the ambient atmosphere is obtained. It is possible to suppress the components of the chemical solution and the rinse solution contained in the mist from entering the gap space SP. In particular, it is possible to effectively suppress the generation of a watermark due to the mist of the rinsing liquid being mixed into the IPA covering the substrate surface Wf in the replacement process.

  Thus, when the replacement 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, 1000 rpm). Thereby, the IPA adhering to the substrate surface Wf is shaken off, and the drying process (spin drying) of the substrate W is executed (drying process). At this time, since the low surface tension solvent has entered the gaps between the patterns, it is possible to prevent pattern collapse and the occurrence of watermarks. Further, since the gap space SP is filled with nitrogen gas supplied from the gas discharge port 98a and the outer gas discharge port 99a, the drying time is shortened and the liquid component (low surface tension solvent) adhering to the substrate W is reduced. The generation of watermarks can be more effectively suppressed by reducing the elution of the oxidizable substances.

  Further, in the drying process, by increasing the flow rate of nitrogen gas from 100 SLM to 140 SLM (FIG. 5), wraparound of mist and the like is more reliably prevented. At this time, the discharge amount from the outer gas discharge port 99a is not changed much (from 95 SLM to 100 SLM), while the discharge amount from the gas discharge port 98a is greatly increased (from 5 SLM to 40 SLM), thereby the center of the substrate surface Wf. A nitrogen gas flow having a high flow rate can be supplied to the section. By doing so, IPA can be efficiently discharged from the central portion of the substrate toward the peripheral portion.

  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. The supply of nitrogen gas is preferably continued at least until the substrate stops rotating. Then, the splash guard 6 is positioned at the retracted position, and the spin chuck 1 is protruded from above the splash guard 6. 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.

  As described above, according to this embodiment, the replacement region SR is formed and enlarged while supplying IPA having a low flow rate of 100 (mL / min) to the central portion of the substrate surface Wf. Accordingly, the amount of IPA used for replacing the entire surface of the substrate with IPA is greatly reduced as compared with the conventional technique (a large amount of IPA is supplied to the substrate surface to replace the entire surface of the substrate with IPA at once). be able to.

  In this embodiment, the rotational speed of the substrate W is reduced to the second speed, the DIW liquid film is increased to the thickness t1, and the IPA is supplied to the center of the surface of the substrate W while maintaining this state. An IPA replacement region SR is formed at the center of the surface Wf. At this time, IPA may be mixed into the DIW region located around the replacement region SR in the liquid film on the substrate surface Wf, but the liquid film on the substrate surface Wf becomes relatively thick (thickness t1). Therefore, the generation of Marangoni convection at the mixing position can be suppressed. As a result, the problem that the substrate surface Wf is partially dried can be effectively prevented.

  Here, the replacement process may be performed by continuing the IPA supply while maintaining the rotation speed of the substrate W at the second speed, but the rotation speed of the substrate W is higher than the second speed as in the present embodiment. (100 rpm) may be accelerated. This is because after the replacement region SR is formed, the distance from the IPA supply position (the center of the surface of the substrate W) to the DIW region on the substrate W increases, so that IPA is mixed around the replacement region SR. This is because the possibility of doing so is low. Therefore, in this embodiment, by accelerating the rotation speed of the substrate W, the centrifugal force acting on the liquid film (DIW region + replacement region SR) on the substrate surface Wf increases, and the time required for replacement with IPA is increased. Shortened. Further, as the rotational speed increases, the liquid film becomes thinner, and the amount of IPA used to cover the entire substrate surface can be reduced.

  Further, the replacement process may be completed when the entire surface Wf of the substrate is covered with IPA, but in this embodiment, the rotational speed of the substrate W is further increased to 300 rpm from this state. Since the replacement process is performed, the residual DIW of the fine pattern FP can be reliably replaced with IPA. Therefore, the collapse of the pattern can be further effectively suppressed.

  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, the rotation speed of the substrate W is accelerated in two stages in the replacement process, but may be accelerated in three stages or more. Further, the rotation speed of the substrate W may be continuously accelerated in the replacement process.

  In the above embodiment, the replacement region forming process is performed while rotating the substrate W at the same rotational speed as the paddle forming process, that is, the second speed. Alternatively, the replacement region forming process may be executed while rotating at a low speed. In short, while maintaining the rotation speed of the substrate at the second speed or less, the low surface tension solvent is supplied to the center of the surface of the substrate to form the replacement region with the low surface tension solvent, thereby providing the same effect as the above embodiment. Is obtained.

  Moreover, in the said embodiment, although IPA is used as a low surface tension solvent, the liquid mixture of IPA and DIW may be created in the cabinet part 70, and this may be used as a low surface tension solvent. Moreover, the production | generation method of a liquid mixture is not limited to this. For example, an organic solvent component such as IPA may be mixed in-line on a liquid supply path for supplying DIW toward the liquid supply path (or nozzle) of the blocking member to generate a mixed liquid. Further, the liquid mixture generating means such as the cabinet section is not limited to being provided in the substrate processing apparatus, and the liquid mixture generated in another apparatus provided separately from the substrate processing apparatus is provided in the substrate processing apparatus. It may be supplied to the substrate surface Wf via a blocking member. Further, a solvent essentially containing a surfactant may be used instead of the solvent containing an organic solvent component such as IPA.

  In the above embodiment, DIW is used as the rinse liquid. However, a liquid containing a component that does not have a chemical cleaning action on the substrate surface Wf such as carbonated water (DIW + CO2) may be used as the rinse liquid. Good. In this case, a mixture of a liquid (carbonated water) having the same composition as the rinse liquid adhering to the substrate surface Wf and an organic solvent component may be used as the mixed liquid. Further, while carbonated water is used as the rinse liquid, the mixed liquid may be a mixture of DIW, which is the main component of carbonated water, and an organic solvent component. Further, while DIW is used as the rinsing liquid, the mixed liquid may be a mixture of carbonated water and an organic solvent component. In short, a mixture of a liquid adhering to the substrate surface Wf, a liquid having the same main component, and an organic solvent component may be used as the mixed liquid. In addition to DIW and carbonated water, hydrogen water, dilute concentration (for example, about 1 ppm) ammonia water, dilute hydrochloric acid, and the like can be used as the rinse liquid.

  Next, examples of the present invention will be shown. However, the present invention is not limited by the following examples as a matter of course, and it is needless to say that the present invention can be implemented with appropriate modifications within a range that can meet the gist of the preceding and following descriptions. These are all included in the technical scope of the present invention.

  FIG. 8 is a timing chart showing a substrate processing method according to a comparative example. The point that this comparative example is greatly different from the embodiment of the present invention (FIG. 5) is the content of processing performed between the rinsing process and the drying process. That is, in the embodiment of the present invention, as described above, the replacement region forming process and the replacement process are performed after the rinsing process. On the other hand, in the comparative example, although the rotation speed of the substrate W is reduced to 300 rpm after the rinsing process, the liquid film is in a non-paddle state and the film thickness is thin. Then, the IPA supply is continued for 16 seconds at a low flow rate (100 mL / min) while maintaining the rotation speed, and the DIW liquid film on the substrate surface Wf is replaced with the IPA liquid film. Thereafter, the rotation speed of the substrate W is accelerated to 1000 rpm, and the drying process is executed.

  Thus, when the number of particles (particle size: 0.06 μm or more) adhering to the substrate surface Wf processed by the comparative example was evaluated using a particle evaluation apparatus SP1-TBI manufactured by KLA-Tencor, the number of particles Increased by 432. Further, when the substrate surface Wf was monitored, the particle distribution shown in FIG. 9A was observed. In the figure, white circle lines indicate peripheral edges of the substrate W, and white dots indicate particles adhering to the substrate surface Wf.

  On the other hand, for the eight substrates W, the number of particles (particle size: 0.06 μm or more) adhering to the substrate surface Wf processed by the embodiment of the present invention is measured using the particle evaluation apparatus SP1-TBI. When evaluated, changes in the number of particles were (+9), (+53), (-125), (-173), (-132), (-107), and (+26), respectively. It can be seen that the adhesion of particles is significantly more stable than in the comparative example. Further, when the substrate surfaces Wf of six of these eight substrates W were monitored, the particle distributions shown in FIGS. 9B to 9G were observed.

  As is clear from these results, according to the present invention, even when the flow rate of the low surface tension solvent is reduced in order to reduce the amount of the low surface tension solvent used, the replacement region is formed as in the present invention. By performing the treatment and the replacement treatment, the substrate surface Wf can be satisfactorily dried.

  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 for performing a drying process on the entire surface of a substrate including the substrate.

DESCRIPTION OF SYMBOLS 1 ... Spin chuck 4 ... Control unit (control means)
7. Solvent supply unit (supply means)
13 ... Chuck rotating mechanism (substrate rotating means)
17 ... chuck pin (substrate holding means)
J: Rotating shaft SR ... Replacement area Wf ... Substrate surface W ... Substrate

Claims (8)

A wet processing step of performing wet processing on the substrate surface using a processing liquid while rotating the substrate in a substantially horizontal state at a first speed;
A paddle forming step of reducing the rotational speed of the substrate to a second speed and forming a liquid film of the processing liquid on the substrate in a paddle shape;
While maintaining the rotation speed of the substrate below the second speed, a low surface tension solvent having a surface tension lower than that of the processing liquid is supplied to the center of the surface of the substrate to form a replacement region by the low surface tension solvent. A replacement region forming step,
A replacement step of supplying the low surface tension solvent to the center of the surface to expand the replacement region in the radial direction of the substrate and replacing the entire surface of the substrate with the low surface tension solvent;
A drying step of removing the low surface tension solvent from the substrate surface after the substitution step and drying the substrate surface;
A substrate processing method, wherein the processing liquid is supplied to the substrate surface in the paddle forming step.   The substrate processing method according to claim 1, wherein the rotation speed of the substrate is reduced from the first speed to the second speed while supplying the processing liquid to the substrate surface.   3. The substrate processing method according to claim 1, wherein in the replacing step, the substrate is rotated at a rotational speed higher than the second speed.   The substrate processing method according to claim 3, wherein in the replacing step, the rotation speed of the substrate is accelerated as time passes.   5. The substrate processing method according to claim 4, wherein in the replacing step, the rotation speed of the substrate is accelerated in multiple stages, and the acceleration when the rotation speed is accelerated is increased as the rotation speed increases. After the wet treatment of the substrate surface using the treatment liquid, the treatment liquid on the substrate surface is replaced with a low surface tension solvent having a lower surface tension than the treatment liquid, and then the low surface tension solvent is removed from the substrate surface. In the substrate processing apparatus for drying the substrate surface,
Substrate holding means for holding the substrate in a substantially horizontal posture;
Substrate rotating means for rotating the substrate held by the substrate holding means around a predetermined rotation axis;
Supply means for supplying the low surface tension solvent to the center of the surface of the substrate held by the substrate holding means;
Control means for adjusting the rotation speed of the substrate by controlling the substrate rotation means,
The control means sets the rotational speed in the wet processing to the first speed, and reduces the rotational speed to the second speed before supplying the low surface tension solvent to the liquid film of the processing liquid on the substrate. In a paddle shape
The supply means supplies the low surface tension solvent in a state where the rotation speed of the substrate is maintained at the second speed or less to form a replacement region by the low surface tension solvent at the center of the surface of the substrate. Subsequently, the low surface tension solvent is supplied to the replacement region to expand the replacement region in the radial direction of the substrate, and the entire surface of the substrate is replaced with the low surface tension solvent.
The substrate processing is characterized in that the processing liquid is supplied to the substrate surface while the control means rotates the substrate at the second speed to form the liquid film of the processing liquid in a paddle shape. apparatus.   The substrate processing apparatus according to claim 6, wherein the control unit reduces the rotation speed of the substrate from the first speed to the second speed while the processing liquid is supplied to the substrate surface. The substrate processing apparatus according to claim 6, wherein the control unit accelerates the rotation speed of the substrate to a rotation speed higher than the second speed after the replacement region is formed.

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