JP2012018962A - Method and apparatus for processing substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for processing a substrate, with which a substrate surface can be well cleaned while suppressing damages to a pattern formed on the substrate surface.SOLUTION: A liquid film of toluene is formed on a liquid film of DIW by supplying toluene as an intermediary liquid from an intermediary liquid supply mechanism 55 to a surface Wf of a substrate W which is held by a substrate holding means 11 and on which the liquid film of DIW is formed as a cleaning liquid. Then the DIW is solidified by discharging a nitrogen gas for solidification from a solidifying means 31 to the substrate surface Wf while applying ultrasonic waves to the DIW through the toluene by an ultrasonic wave application mechanism 51. With this method, a solidified body of DIW whose crystal size is small is formed. Therefore it is possible to thaw the solidified body in a short time later in a rinse process, decrease the number of DIW crystals released in a rinse liquid, and prevent damages to a pattern.

Description

  The present invention includes a semiconductor substrate, 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 relates to a substrate processing method and a substrate processing apparatus for performing a cleaning process on various substrates (hereinafter simply referred to as “substrates”).

  The manufacturing process of electronic components such as a semiconductor device and a liquid crystal display device includes a process of forming a fine pattern by repeatedly performing processes such as film formation and etching on the surface of the substrate. Here, in order to perform fine processing satisfactorily, it is necessary to keep the substrate surface clean, and a cleaning process is performed on the substrate surface as necessary. For example, in the apparatus described in Patent Document 1, a liquid such as deionized water (hereinafter referred to as “DIW”) is supplied to the substrate surface, and after freezing it, it is thawed and removed with a rinse solution. As a result, the substrate surface is cleaned.

  That is, in the apparatus described in Patent Document 1, the following steps are executed. First, a DIW liquid film is formed on the entire surface of the substrate by supplying DIW to the surface of the substrate. Subsequently, the supply of DIW is stopped, and low temperature nitrogen gas is supplied to the substrate surface to freeze the DIW. As a result, the DIW that has entered between the contaminant such as particles and the substrate surface becomes ice and expands so that the contaminant such as particles is separated from the substrate by a minute distance. As a result, the adhesion force between the substrate surface and contaminants such as particles is reduced, and furthermore, contaminants such as particles are detached from the substrate surface. Thereafter, by defrosting and removing the ice on the substrate surface with DIW as a rinse liquid, contaminants such as particles can be efficiently removed from the substrate surface.

Japanese Patent Laid-Open No. 2008-71875 (FIG. 3)

  However, in the above prior art, a phenomenon in which the pattern on the substrate surface after cleaning is damaged may be observed. FIG. 1 is a diagram showing an example of the result of measuring the damage of the pattern on the substrate surface Wf that has been cleaned by the above-described conventional technique, and shows that damage has occurred at a location indicated by a black dot 983 in the drawing. . A rectangle 981 indicates an area where damage is measured. Next, in order to compare with the example in which the influence of the flow of the rinsing liquid applied to the substrate surface and the movement of the liquid on the substrate surface by rotating the substrate is eliminated, the procedure until ice is formed on the substrate surface Wf is as described above. It was the same as that in the prior art, and then left in a room temperature atmosphere to thaw the ice on the substrate surface Wf. The measurement result of the pattern damage in this case is shown in FIG.

  When these are compared, the pattern on the substrate surface Wf is damaged by discharging and thawing the rinse liquid on the substrate surface Wf, and the pattern is thawed in a stationary state where the rinse liquid or the like does not flow on the substrate surface Wf. In some cases, it is understood that the pattern is not damaged.

  Next, FIG. 3 and FIG. 4 show a part of the process of thawing ice formed on the substrate surface Wf. FIG. 3 is an enlarged photograph at a magnification of 50 times in a state where ice is formed on the substrate surface Wf. Ice crystals (hereinafter referred to as “ice crystals”) 985 are formed on the substrate surface Wf. Recognize. FIG. 4 is an enlarged photograph at the same magnification as FIG. 3, showing a state in the middle of thawing ice. The DIW region 987 that is reduced by thawing and is defrosted into a liquid is a 987 area around the ice crystal 985. It can be seen that Further, it was observed that a part of the ice crystal 985 in the DIW region 987 moves as the DIW flows, for example, by applying an air flow or applying vibration.

  As described above, when the ice formed on the substrate surface Wf thaws, the ice crystal 985 that could not be thawed floats in the DIW region 987, and the DIW flows by some external force, so that the ice crystal 985 becomes the substrate surface. It is considered that damage is caused by moving on Wf and colliding with a pattern on the substrate surface Wf.

  In the cleaning of fine devices typified by semiconductors, it is strongly demanded that contaminants such as particles can be efficiently removed from the substrate surface, and that the pattern on the substrate surface should not be damaged during cleaning. ing.

  Therefore, in the process of freezing the water on the substrate surface to form ice and then thawing and removing with a rinsing solution to clean the substrate, ice crystals that could not be thawed floating in the rinsing solution during thawing. Must be prevented from colliding with the pattern.

  This invention is made in view of the said subject, and provides the substrate processing method and substrate processing apparatus which can wash | clean the substrate surface favorably, suppressing the damage to the pattern formed in the substrate surface. Objective.

  In order to solve the above-described problems, the present invention provides an ultrasonic application step for applying ultrasonic waves to a liquid film of a cleaning solution on a substrate, and a cleaning solution by cooling the cleaning liquid to which ultrasonic waves are applied by the ultrasonic application step. And a rinsing step of thawing and removing the coagulated body by supplying a rinsing liquid to the coagulated body generated by the coagulating step.

  The present invention also provides a substrate holding means for holding a substrate having a cleaning liquid film formed on the surface, and an ultrasonic wave applying means for applying an ultrasonic wave to the cleaning liquid film on the substrate surface held by the substrate holding means. A cooling liquid film of the cleaning liquid to which the ultrasonic wave is applied by the ultrasonic wave application means to generate a solidified body of the cleaning liquid on the substrate surface, and a rinsing liquid is supplied to the solidified body generated by the solidification means. And a rinsing liquid supply means for thawing and removing the coagulated body.

  In the invention configured as described above (substrate processing method and apparatus), the liquid film of the cleaning liquid is solidified by cooling the liquid film of the cleaning liquid formed on the substrate surface while applying ultrasonic waves. Thereby, the size of the crystal (ice crystal) of the solidified body of the cleaning liquid formed on the substrate can be reduced, and the ice crystal can be thawed earlier in the rinsing step of thawing and removing the solidified body of the cleaning liquid. It becomes possible. In addition, the size of ice crystals floating in the rinse liquid without being thawed completely can be reduced, so even if the ice crystals move on the substrate surface with the rinse liquid and collide with the pattern, the pattern will collapse. It is possible to reduce damage such as

  Further, a mediating liquid having a freezing point lower than that of the cleaning liquid, having a specific gravity smaller than that of the cleaning liquid and difficult to mix with the cleaning liquid is supplied to the surface of the substrate, and a liquid film of the mediating liquid is formed on the liquid film of the cleaning liquid. The method further includes a medium solution supplying step, and the ultrasonic wave applying step can apply ultrasonic waves to the liquid film of the medium solution and apply ultrasonic waves to the cleaning liquid via the medium solution.

  In the coagulation step, the cleaning liquid can be cooled to a temperature lower than the freezing point of the cleaning liquid and higher than the freezing point of the medium liquid.

  In the invention configured as described above, when the liquid film of the cleaning liquid formed on the substrate surface is solidified, the ultrasonic wave is applied via the medium liquid formed on the cleaning liquid. The ultrasonic wave application head does not adhere to the substrate surface because it does not touch the cleaning liquid and the medium does not coagulate even if the cleaning liquid coagulates.

  The method further includes a medium supply step for supplying a medium solution having a freezing point lower than the freezing point of the cleaning liquid to the back surface of the substrate, and the ultrasonic wave applying step applies an ultrasonic wave to the medium solution supplied to the back surface of the substrate, It is also possible to apply ultrasonic waves to the substrate via the substrate and further apply ultrasonic waves to the cleaning liquid via the substrate.

  Further, as the coagulation means, it is possible to supply the medium liquid supplied to the back surface of the substrate at a temperature lower than the solidification point of the cleaning liquid.

  In the invention configured as described above, ultrasonic waves are applied to the medium liquid discharged on the back surface of the substrate, and ultrasonic waves are applied to the cleaning liquid on the substrate surface through the substrate to form a solidified body of the cleaning liquid. The ultrasonic wave application head does not adhere to the substrate surface. Also, by supplying the media solution supplied to the back surface of the substrate at a temperature lower than the freezing point of the cleaning solution, the cleaning solution can be cooled through the substrate, and a solidified body of the cleaning solution can be formed on the substrate surface with a simple configuration. It becomes possible.

  According to the present invention, the crystal size of the solidified body of the cleaning liquid formed on the substrate surface is reduced by forming ultrasonic waves on the liquid film of the cleaning liquid formed on the substrate surface to form a solidified body of the cleaning liquid by cooling. Make it smaller. This makes it possible to thaw the coagulated body in a short time during thawing washing, and even if it remains unmelted, the crystal size of the coagulated body floating in the rinsing liquid can be reduced. Can reduce the damage.

It is a figure which shows the damage of the pattern at the time of defrosting the ice on a board | substrate. It is a figure which shows the damage of the pattern at the time of naturally thawing the ice on a board | substrate. It is the microscope picture which showed the state of the ice on the board | substrate before thawing | decompression. It is the microscope picture which showed the state of the ice on the board | substrate during thawing | decompression. It is a top view which shows schematic structure of the substrate processing apparatus which concerns on this invention. It is a front view which shows schematic structure of the substrate processing apparatus which concerns on this invention. It is a figure which shows the whole structure of the processing unit concerning 1st embodiment. It is a figure which shows the structure of the board | substrate holding | maintenance means, board | substrate rotation means, and processing cup in the processing unit of FIG. It is a figure which shows the structure of the atmosphere interruption | blocking means in the processing unit of FIG. It is a figure which shows the structure of the ultrasonic provision means in the processing unit of FIG. It is a figure which shows the structure of the ultrasonic provision mechanism in the ultrasonic provision means of FIG. It is front sectional drawing which shows the structure of the ultrasonic application head in the ultrasonic application mechanism of FIG. It is a figure which shows the structure of the mediation liquid supply mechanism in the ultrasonic provision means of FIG. It is a figure which shows the structure of the washing | cleaning liquid supply means, the rinse means, and the drying gas supply means in the processing unit of FIG. It is a figure which shows the structure of the solidification means in the processing unit of FIG. It is a flowchart which shows operation | movement of the substrate processing apparatus concerning 1st embodiment. It is a flowchart which shows operation | movement of the ultrasonic provision and coagulation process of the substrate processing apparatus concerning 1st embodiment. It is a figure which shows the structure of the ultrasonic provision means in 2nd embodiment. It is front sectional drawing which shows the structure of the supersonic wave provision part used by 2nd embodiment. It is a figure which shows the structure of the solidification means in 2nd embodiment. It is a flowchart which shows the operation | movement of the ultrasonic provision and coagulation process of the substrate processing apparatus concerning 2nd embodiment. It is front sectional drawing which shows the structure of the ultrasonic provision nozzle used in the modification of 2nd embodiment.

  In the following description, a substrate means a semiconductor substrate, 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, and a magneto-optical substrate. Various substrates such as disk substrates. Further, the surface of the substrate on which various patterns such as circuit patterns are formed is referred to as a front surface, and the opposite surface is referred to as a back surface. Further, the surface of the substrate directed downward is referred to as a lower surface, and the surface of the substrate directed upward is referred to as an upper surface.

  In the following description, “ice crystal” refers to a DIW crystal formed in a solidification process of deionized water (hereinafter referred to as “DIW”), which will be described later, and “ice crystal size”. Means the dimension of the longest axis in the outer shape of the DIW crystal formed in the DIW solidification process.

  Embodiments of the present invention will be described below with reference to the drawings, taking a substrate processing apparatus used for processing a semiconductor substrate as an example. The present invention is not limited to the processing of semiconductor substrates, and can be applied to processing of various substrates such as glass substrates for liquid crystal displays. The substrate processing apparatus to which the present invention can be applied is not limited to the apparatus that performs the cleaning process and the drying process continuously in the same apparatus, but the apparatus that performs only a single process, the cleaning process, and the drying process. The present invention can also be applied to a case where a part is continuously performed in the same apparatus.

<First embodiment>
5 and 6 are diagrams showing a schematic configuration of the substrate processing apparatus 9 according to the present invention. FIG. 5 is a plan view of the substrate processing apparatus 9, and FIG. 6 is a front view of the substrate processing apparatus 9 of FIG. 5 viewed from the direction of the arrow X1. This apparatus is a cleaning process for removing contaminants such as particles (hereinafter referred to as “particles”) adhering to the surface of a substrate W such as a semiconductor substrate (hereinafter simply referred to as “substrate W”). 1 is a single-wafer type substrate processing apparatus.

  In the substrate processing apparatus 9, a transfer device 93 that carries the substrate W into and out of the processing unit 91 is disposed at one end (lower side in FIG. 5). At one end of the transfer device 93 (left side in FIG. 5), a cassette station 95 configured to be capable of mounting a cassette 96 that accommodates the substrate W is provided. The transfer device 93 includes a substrate transfer device 931 provided with a transfer arm 931 a for taking out the substrates W before the processing step one by one from the cassette 96 and storing the substrates W after the processing step one by one in the cassette 96. Is provided. The placement unit 951 of the cassette station 95 is configured to be able to place a cassette 96 containing, for example, 25 substrates W. The substrate transfer device 931 is configured to be movable in the horizontal and vertical directions and to be rotatable about a vertical axis.

  Next, the configuration of the processing unit 91 will be described with reference to FIG. FIG. 7 is a schematic diagram showing the configuration of the processing unit 91. The processing unit 91 includes a substrate holding unit 11 that holds a substrate W having a cleaning liquid film formed on the surface thereof in a substantially horizontal posture with the substrate surface facing upward, and the substrate holding unit 11 is held by the substrate holding unit 11. A substrate rotating means 12 that rotates together with the substrate W, and a processing cup 13 that accommodates the substrate holding means 11 inside thereof, receives scattered matter from the substrate holding means 11 and the substrate W, and exhausts and drains, and a substrate. And an atmosphere blocking unit 15 which is disposed to face the surface Wf of the substrate W held by the holding unit 11 and blocks the substrate surface Wf from the outside air.

  Further, the processing unit 91 further includes an ultrasonic wave applying unit 5 that applies ultrasonic waves to the liquid film of the cleaning liquid formed on the substrate surface Wf held by the substrate holding unit 11, and an ultrasonic wave applying unit 5. A solidification means 31 for cooling the liquid film of the cleaning liquid to which ultrasonic waves are applied to generate a solidified body of the cleaning liquid on the substrate surface Wf, a cleaning liquid supply means 21 for supplying DIW as the cleaning liquid onto the substrate surface Wf, and a solidification A rinsing liquid supply means 23 for supplying DIW as a rinsing liquid to the solidified body generated by the means 31 to defrost and remove the solidified body; a drying gas supply means 33 for supplying a drying gas to the substrate surface Wf; And a control unit 97 that controls the operation of each part of the substrate processing apparatus 9 based on a cleaning program to be described later.

  Next, the configuration of the substrate holding means 11, the substrate rotating means 12, and the processing cup 13 will be described with reference to FIG. FIG. 8 is a schematic diagram showing the configuration of the substrate holding means 11, the substrate rotating means 12 and the processing cup 13.

  First, the substrate holding means 11 will be described. A disc-shaped spin base 113 is fixed to the upper end portion of the central axis 111 of the substrate holding means 11 with a fastening component such as a screw. Near the periphery of the spin base 113, a plurality of chuck pins 115 for holding the periphery of the substrate W are provided upright. Three or more chuck pins 115 may be provided to securely hold the circular substrate W, and are arranged at equiangular intervals along the peripheral edge of the spin base 113. Each of the chuck pins 115 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. ing.

  Each chuck pin 115 is connected to an air cylinder in the chuck pin driving mechanism 116 through a known link mechanism, a swinging member, or the like. The chuck pin driving mechanism 116 is electrically connected to the control unit 97. In response to an operation command from the control unit 97 to the substrate holding unit 11, the air cylinder of the chuck pin driving mechanism 116 expands and contracts, so that each chuck pin 115 presses the outer peripheral end surface of the substrate W. It is configured to be switchable between a state and a released state in which the substrate holding portion is separated from the outer peripheral end surface of the substrate W. In addition to the air cylinder, a driving source such as a motor or a solenoid can be used as a driving source for the chuck pin 115.

  When the substrate W is delivered to the spin base 113, each chuck pin 115 is in a released state, and when performing a cleaning process or the like on the substrate W, each chuck pin 115 is in a pressed state. . When each chuck pin 115 is in a pressed state, each chuck pin 115 grips the peripheral edge of the substrate W, and the substrate W is held in a substantially horizontal posture at a predetermined interval from the spin base 113. As a result, the substrate W is held with the front surface Wf facing upward and the back surface Wb facing downward. In this embodiment, a fine pattern is formed on the surface Wf of the substrate W, and the surface Wf is a pattern formation surface.

  Next, the substrate rotating means 12 will be described. A rotation shaft of the substrate rotation means 12 including a motor is connected to the central shaft 111 of the substrate holding means 11. The substrate rotating means 12 is electrically connected to the control unit 97. When the substrate rotating unit 12 is driven by an operation command from the control unit 97, the spin base 113 fixed to the central axis 111 rotates around the rotation center A0.

  The processing cup 13 is for recovering the processing liquid and the like after being used for processing the substrate W. The processing cup 13 accommodates the spin base 113 and the chuck pin 115 and receives the processing liquid and the like scattered from the substrate W. It has a substantially cylindrical shape so that In addition, an opening 131 through which the substrate W passes is formed on the upper surface. The opening 131 is substantially circular with the rotation center A0 as the center. An exhaust liquid line (not shown) is connected to the bottom of the processing cup 13 to exhaust (exhaust liquid) the atmosphere around the substrate holding unit 11 together with fine particles such as processing liquid contained therein.

  Next, the configuration of the atmosphere blocking means 15 will be described with reference to FIG. FIG. 9 is a schematic diagram showing the configuration of the atmosphere blocking means 15. A blocking member 151 which is a substrate facing member of the atmosphere blocking means 15 is formed in a disk shape having an opening at the center. The lower surface of the blocking member 151 is a substrate facing surface that faces the surface Wf of the substrate W substantially in parallel, and is formed to have a size equal to or larger than the diameter of the substrate W. The blocking member 151 is attached substantially horizontally to the lower end portion of the support shaft 153 having a substantially cylindrical shape. The support shaft 153 is held by an arm 155 extending in the horizontal direction.

  The arm 155 is connected to a blocking member lifting mechanism 157. Further, the blocking member lifting mechanism 157 is electrically connected to the control unit 97. When the blocking member lifting mechanism 157 is driven by an operation command from the control unit 97 to the atmosphere blocking means 15, the blocking member 151 approaches the spin base 113 and is separated away. That is, the control unit 97 controls the operation of the blocking member lifting mechanism 157 to raise the blocking member 151 to a separation position above the substrate holding means 11 when the substrate W is carried in / out of the processing unit 91. On the other hand, when the later-described DIW is supplied to the substrate W, the substrate W is dried, or the like, the blocking member 151 is opposed to the surface Wf of the substrate W held by the substrate holding means 11. Lower to position.

  Further, the blocking member 151 is connected to the blocking member rotation mechanism 159. The blocking member rotation mechanism 159 is electrically connected to the control unit 97. When the blocking member rotation mechanism 159 is driven by an operation command from the control unit 97 to the atmosphere blocking means 15, the blocking member 151 is rotated around the vertical axis passing through the center of the support shaft 153. The blocking member rotating mechanism 159 is configured to rotate the blocking member 151 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 substrate holding unit 11.

  Next, the configuration of the ultrasonic wave applying means 5 will be described with reference to FIG. FIG. 10 is a schematic diagram showing the configuration of the ultrasonic wave applying means 5. The ultrasonic wave application means 5 has an ultrasonic wave application mechanism 51 for applying ultrasonic waves to the cleaning liquid, and a freezing point lower than the freezing point of the cleaning liquid on the liquid film of the cleaning liquid formed on the substrate surface Wf. A medium solution supplying mechanism 55 for supplying a medium solution that is small and difficult to mix with the cleaning solution and forms a liquid film of the medium solution on the liquid film of the cleaning solution, and is formed on the substrate surface Wf. Of the dual liquid film of the cleaning liquid and the medium liquid, ultrasonic waves are applied to the liquid film of the medium liquid in the upper layer, and ultrasonic waves are applied to the lower layer cleaning liquid through the medium liquid.

  First, the configuration of the ultrasonic wave application mechanism 51 will be described with reference to FIG. A head drive mechanism 511 is provided outside the processing cup 13 in the circumferential direction as a drive source for moving up and down and turning an ultrasonic wave application head 531 described later. The head driving mechanism 511 has a lifting motor 513, and a ball screw 515 is connected to the rotating shaft of the lifting motor 513. The ball screw 515 is provided alongside an upright guide 517. The elevating base 519 is slidably fitted to the guide 517 and screwed to the ball screw 515. The lifting motor 513 is electrically connected to the control unit 97. When the lifting motor 513 is driven by an operation command from the control unit 97, the lifting base 519 is lifted up and down.

  A swing motor 521 is mounted on the elevating base 519, and a swing shaft 523 is connected to a rotation shaft of the swing motor 521. One end of an arm 525 is connected to the turning shaft 523, and an ultrasonic wave application head 531 described later is held at the other end of the arm 525. Further, the turning motor 521 is electrically connected to the control unit 97. Then, when the turning motor 521 is driven by an operation command from the control unit 97, the arm 525 swings around the turning shaft 523, and the ultrasonic wave applying head 531 is held on the substrate holding means 11. Between the freezing start position in the vicinity of Wf and near the center of the substrate W, the freezing end position in the vicinity of the substrate surface Wf and near the outer edge of the substrate W, and the retracted position that is a position outside the circumferential direction of the processing cup 13. Move.

  Next, the configuration of the ultrasonic wave applying head 531 will be described with reference to FIG. FIG. 12 is a cross-sectional view showing the configuration of the ultrasonic wave applying head 531. The ultrasonic wave application head 531 is attached to the tip of the arm 525, transmits ultrasonic vibration generated by a vibrator 537 described later to a medium solution on the substrate W, and applies ultrasonic waves to the cleaning liquid via the medium solution. The ultrasonic wave application head 531 has a vibration plate 535 made of, for example, quartz attached to a bottom side opening of a main body portion 533 made of a fluororesin such as, for example, polytetrafluoroethylene. The vibration plate 535 has a disk shape in plan view, and the bottom surface thereof is a vibration surface VF.

  A vibrator 537 made of, for example, a piezoelectric vibrator is attached to the upper surface of the diaphragm 535 (the surface opposite to the vibration surface VF). The vibrator 537 is electrically connected to the ultrasonic oscillator 543 through the wiring 541, and the ultrasonic oscillator 543 oscillates a pulse signal for causing the vibrator 537 to vibrate.

  The ultrasonic oscillator 543 is electrically connected to the control unit 97. Then, when a pulse signal is output from the ultrasonic oscillator 543 to the vibrator 537 via the wiring 541 in accordance with an operation command from the control unit 97, the vibrator 537 vibrates ultrasonically and vibrates the diaphragm 535. . The pipe 313 fixed on the side surface of the ultrasonic wave applying head 531 will be described later.

  When the ultrasonic wave application head 531 is positioned at the vibration application position by the head drive mechanism 511, the distance between the vibration surface VF and the substrate surface Wf is controlled with high accuracy by drive control of the elevating motor 513.

  Next, the configuration of the medium solution supply mechanism 55 will be described with reference to FIG. FIG. 13 is a schematic diagram showing the configuration of the medium liquid supply mechanism 55.

  A turning motor 553 is provided on the outer side in the circumferential direction of the processing cup 13 as a driving source for scanning the mist supply nozzle 559. A rotation shaft 555 is connected to the turning motor 553, and an arm 557 is connected to the rotation shaft 555 so as to extend in the horizontal direction. A mist supply nozzle 559 is attached to the tip of the arm 557. Further, the turning motor 553 is electrically connected to the control unit 97. Then, when the turning motor 553 is driven by an operation command from the control unit 97, the mist supply nozzle 559 is located at a position where the mist supply nozzle 559 is disengaged around the rotation axis 555 above the substrate surface Wf and outside the processing cup 13 in the circumferential direction. It swings between certain retracted positions.

  The mist supply nozzle 559 is connected via a pipe 563 to a toluene supply unit 561 having a toluene tank, a temperature adjustment unit and a pump (not shown). Note that the pump of the toluene supply unit 561 is always operating from the time when the substrate processing apparatus 9 is activated. Further, an open / close valve 565 is inserted in the pipe 563. The on-off valve 565 is always closed. The on-off valve 565 is electrically connected to the control unit 97. When the opening / closing valve 565 is opened by an operation command from the control unit 97, toluene is pumped from the toluene supply unit 561 through the pipe 563. Accordingly, mist-like toluene is discharged from the mist supply nozzle 559 toward the substrate surface Wf. The toluene supply unit 561 may be provided inside or outside the substrate processing apparatus 9.

Here, toluene is a liquid represented by the chemical formula C ₆ H ₅ CH ₃ , and water (chemical formula: H ₂ O) is difficult to mix with each other, and the freezing point is − (minus) 95 ° C. (degrees Centigrade), Below the freezing point of water (0 ° C (Celsius)). The density is 0.864 (kg / m ³ ) and the specific gravity with respect to water is smaller than “1”. Therefore, toluene as the “medium solution” in this embodiment is difficult to mix with DIW as the “cleaning solution”, has a lower freezing point than DIW, and a specific gravity smaller than DIW. In addition, toluene may be diluted.

  Next, the configuration of the cleaning liquid supply means 21, the rinse liquid supply means 23, and the drying gas supply means 33 will be described with reference to FIG. FIG. 14 is a schematic diagram showing the configuration of the cleaning liquid supply means 21, the rinse liquid supply means 23, and the drying gas supply means 33.

  The support shaft 153 of the atmosphere blocking means 15 is hollow, and the first supply pipe 203 is inserted into the support shaft 153, and the second supply pipe 205 is inserted into the first supply pipe 203. It has a structure. The lower ends of the first supply pipe 203 and the second supply pipe 205 are extended to the opening of the blocking member 151, and a discharge nozzle 201 is provided at the tip of the second supply pipe 205.

  A drying nitrogen gas supply unit 331 having a nitrogen gas tank, a pump and a flow rate adjusting valve (not shown) is connected to the first supply pipe 203 via a pipe 333. Note that the pump of the drying nitrogen gas supply unit 331 always operates from the time when the substrate processing apparatus 9 is activated.

  A main pipe 207 is connected to the second supply pipe 205, and a first DIW supply unit 211 having a DIW tank, a temperature adjustment unit, and a pump (not shown) is connected to the main pipe 207 via the pipe 213, and A second DIW supply unit 231 having a DIW tank, a temperature adjustment unit, and a pump (not shown) is connected via a pipe 233 to each other. In addition, on-off valves 215 and 235 are inserted in the pipes 213 and 233, respectively. The on-off valves 215 and 235 are always closed. The pumps of the first DIW supply unit 211 and the second DIW supply unit 231 are always operating from the time when the substrate processing apparatus 9 is activated.

  The on-off valve 215 is electrically connected to the control unit 97. Then, when the on-off valve 215 is opened by an operation command from the control unit 97, DIW as a cleaning liquid from the first DIW supply unit 211 passes from the discharge nozzle 201 to the substrate surface Wf through the pipe 213, the main pipe 207, and the second supply pipe 205. Supplied. The first DIW supply unit 211, the on-off valve 215, the pipe 213, the main pipe 207, the second supply pipe 205, and the discharge nozzle 201 constitute the cleaning liquid supply unit 21.

  The on-off valve 235 is electrically connected to the control unit 97. Then, when the on-off valve 235 is opened by an operation command from the control unit 97, DIW as the rinse liquid from the second DIW supply unit 231 passes through the pipe 233, the main pipe 207, and the second supply pipe 205 from the discharge nozzle 201 to the substrate surface Wf. To be supplied. The second DIW supply unit 231, the on-off valve 235, the pipe 233, the main pipe 207, the second supply pipe 205, and the discharge nozzle 201 constitute the rinse liquid supply unit 23.

  Here, the first DIW supply unit 211 supplies DIW whose temperature is adjusted to, for example, 1 ° C. (Celsius) in a cleaning liquid supply process described later. In addition, the second DIW supply unit 231 supplies DIW whose temperature is adjusted to, for example, 40 ° C. (degrees Celsius) in order to defrost and remove the DIW solidified body remaining on the substrate surface Wf in a rinsing process described later. The first DIW supply unit 211 and the second DIW supply unit 231 may be provided inside the substrate processing apparatus 9 or may be provided outside.

  The drying nitrogen gas supply unit 331 is connected to the first supply pipe 203 via a pipe 333. The drying nitrogen gas supply unit 331 is electrically connected to the control unit 97. The drying nitrogen gas supply unit 331 opens an internal flow rate adjustment valve in accordance with an operation command from the control unit 97 and supplies room temperature nitrogen gas to the substrate surface Wf via the pipe 333 and the first supply pipe 203. . The drying nitrogen gas supply unit 331, the pipe 333, and the first supply pipe 203 constitute the drying gas supply means 33. Note that the drying nitrogen gas supply unit 331 may be provided inside or outside the substrate processing apparatus 9.

  Next, the configuration of the coagulation means 31 will be described with reference to FIG. FIG. 15 is a schematic diagram showing the configuration of the coagulation means 31. The freezing nitrogen gas supply unit 311 of the coagulation means 31 includes a nitrogen gas tank that stores gaseous nitrogen gas (not shown), a pump that pumps nitrogen gas, a flow rate adjustment valve that adjusts the flow rate of nitrogen gas, and liquid nitrogen that stores liquid nitrogen A heat exchanger immersed in liquid nitrogen in the tank and liquid nitrogen tank is provided.

  The nitrogen gas tank is connected to the inlet of the heat exchanger via a pump and a flow rate adjustment valve, and the outlet of the heat exchanger is connected to one end of the pipe 313. The other end of the pipe 313 extends to the ultrasonic wave application head 531. Note that the pump of the freezing nitrogen gas supply unit 311 always operates from the time when the substrate processing apparatus 9 is activated.

  The freezing gas supply unit 311 is electrically connected to the control unit 97. This freezing gas supply unit 313 opens the flow rate adjustment valve so as to reach a predetermined flow rate according to an operation command from the control unit 97, and, for example, nitrogen gas at −20 degrees Celsius (degrees Celsius) is supplied via the pipe 313. To the substrate surface Wf. The freezing nitrogen gas supply unit 311 may be provided inside or outside the substrate processing apparatus 9.

  The refrigerant supplied from the freezing gas supply unit 311 is not limited to nitrogen gas, and other gases such as dry air, oxygen gas, and argon gas may be used. The means for cooling the refrigerant is not limited to liquid nitrogen, and a low-temperature liquid such as liquid helium can be used, and it is also possible to electrically cool using a Peltier element.

  Returning to FIG. The pipe 313 extending to the ultrasonic wave application head 531 is fixed to the outer surface of the main body 533 of the ultrasonic wave application head 531 using a bracket. The opening 315 at the tip of the pipe 313 is fixed so that the vibration surface VF of the ultrasonic wave application head 531 is positioned above the liquid surface of the liquid film in a state where the vibration surface VF is in contact with the liquid film on the substrate surface Wf. The freezing nitrogen gas from the nitrogen gas supply unit 311 is discharged onto the surface of the liquid film.

  Note that the pipe 313 is attached to the side opposite to the moving direction of the ultrasonic wave applying head 531 (upstream side of the moving direction of the ultrasonic wave applying head 531) represented by an arrow X2 in FIG. Is preferred. That is, in this embodiment, the ultrasonic wave application head 531 moves from the vicinity of the center of the substrate W to the vicinity of the outer edge in the coagulation process described later, and therefore the pipe 313 is attached to the center side of the substrate W with respect to the ultrasonic wave application head 531. Is preferred. This is because the ultrasonic wave is reflected at the interface between the liquid and the solid, so that if the ultrasonic wave is attached to the moving direction side of the ultrasonic wave applying head 531 (downstream side of the moving direction of the ultrasonic wave applying head 531), the liquid is directly below the vibration surface VF. This is because an interface between the DIW and the solid DIW may be generated, and in this case, the ultrasonic waves are reflected at these interfaces, and it is difficult to apply the ultrasonic waves to the DIW as the cleaning liquid with a stable strength.

  The control unit 97 is a CPU that performs various arithmetic processes, a ROM that is a read-only memory that stores basic programs, a RAM that is a readable and writable memory that stores various information, and a magnet that stores control software and data. Have a disc. In the magnetic disk, the cleaning conditions corresponding to the substrate W are stored in advance as a cleaning program (also called a recipe). The CPU reads the contents into the RAM, and the CPU executes the substrate according to the contents of the cleaning program read into the RAM. Each part of the processing device 9 is controlled. The control unit 97 is connected to an operation unit (not shown) used for creating / changing a cleaning program and selecting a desired one from a plurality of cleaning programs.

  Next, the cleaning processing operation in the substrate processing apparatus 9 configured as described above will be described with reference to FIGS. FIG. 16 is a flowchart showing the operation of the substrate processing apparatus 9 of FIGS. 5 and 6, and FIG. 17 is a flowchart showing details of step S03 of FIG.

  Unless otherwise specified in the following description, when the blocking member 151 is in the opposing position, the atmosphere blocking unit 15 causes the blocking member 151 to rotate at approximately the same number of rotations in the direction in which the substrate rotating unit 12 rotates the substrate holding unit 11. It shall rotate.

  This will be described with reference to FIG. First, a cleaning program corresponding to a predetermined substrate W is selected and executed by an operation unit (not shown). Thereafter, in preparation for carrying the substrate W into the processing unit 91, the following operation is performed according to an operation command from the control unit 97.

  That is, the atmosphere blocking unit 15 stops the rotation of the blocking member 151, and the substrate rotating unit 12 stops the rotation of the substrate holding unit 11. The atmosphere blocking unit 15 moves the blocking member 151 to the separated position, and the substrate rotating unit 12 positions the substrate holding unit 11 at a position suitable for delivery of the substrate W. After the substrate holding means 11 is positioned at a position suitable for delivery of the substrate W, the substrate holding means 11 brings the chuck pins 115 into a released state.

  Further, the ultrasonic wave application means 5 moves the ultrasonic wave application head 531 and the mist supply nozzle 559 to the retracted positions (positions where the ultrasonic wave application head 531 and the mist supply nozzle 559 are out of the processing cup 13 in the circumferential direction). To do. Furthermore, the on-off valves 215, 235, and 533c are closed, and the freezing nitrogen gas supply unit 311 and the drying nitrogen gas supply unit 331 stop supplying the freezing nitrogen gas and the drying nitrogen gas, respectively. Further, the ultrasonic oscillator 543 stops the ultrasonic oscillation.

  First, a substrate carry-in process for carrying an unprocessed substrate W into the processing unit 91 is performed. When preparation for loading the substrate W into the processing unit 91 is completed, the substrate transport device 931 takes out the substrate W from a predetermined position of the cassette 96 placed on the placement unit 951 in accordance with an operation command from the control unit 97, and performs processing. It carries in to the unit 91 (step S01).

  When the unprocessed substrate W is loaded into the processing unit 91 and placed on the substrate support portion of the chuck pin 115, the chuck pin driving mechanism 116 is operated by the operation command from the control unit 97 to the substrate holding means 11. The chuck pin 115 is pressed.

  When the unprocessed substrate W is held by the substrate holding unit 11, the blocking member lifting mechanism 157 lowers the blocking member 151 to the proximity position by the operation command from the control unit 97 to the atmosphere blocking unit 15, and the substrate surface Wf. Place close together. Then, according to the operation command of the control unit 97, the substrate rotating unit 12 starts rotating the substrate holding unit 11 at, for example, 100 rpm, and the rotation at the rotation number is continued. Further, the on-off valve 215 is opened by an operation command from the control unit 97 to the cleaning liquid supply means 21. Accordingly, DIW as a cleaning liquid is supplied from the discharge nozzle 201 to the substrate surface Wf through the pipe 233, the main pipe 207, and the second supply pipe 205 from the first DIW supply unit 211.

  The DIW as the cleaning liquid supplied to the substrate surface Wf spreads uniformly over the entire surface of the substrate surface Wf due to the centrifugal force accompanying the rotation of the substrate W, and forms a DIW liquid film (water film) on the substrate surface Wf. At this time, DIW enters the pattern gap due to the flow of DIW (step S02). The rotation speed of the substrate W is set so that the DIW on the substrate surface Wf flows and the DIW enters into the gaps of the pattern. This process of supplying DIW as the cleaning liquid to the substrate surface Wf corresponds to the “cleaning liquid supply process” in the present invention. When the cleaning liquid supply process is completed, the on-off valve 215 is closed by an operation instruction from the control unit 97 to the cleaning liquid supply means 21.

  In this embodiment, it is preferable to use DIW whose temperature is adjusted to about 0 to 2 ° C. (degrees Celsius) as the cleaning liquid. Because the temperature of the DIW liquid film is relatively high, toluene is supplied onto the DIW liquid film as described later, and the DIW liquid film is formed before the toluene liquid film is formed on the DIW liquid film. The film evaporates. This is to prevent the pattern from collapsing, and to shorten the time required for solidifying the DIW, which will be described later.

  Next, a toluene liquid film is formed on the DIW liquid film formed on the substrate surface Wf, and cooling is performed while applying ultrasonic waves to the DIW liquid film through the toluene liquid film. The ultrasonic wave application / coagulation treatment (step S03) for forming a DIW coagulation body on the substrate surface Wf will be described with reference to FIG.

  First, the medium solution supplying step will be described. In response to an operation command from the control unit 97, the substrate rotating means 12 decelerates the rotation speed of the substrate holding means 11 to 10 rpm, for example, and the rotation at the rotation speed is continued. Further, in response to an operation command from the control unit 97 to the atmosphere blocking means 15, the blocking member elevating mechanism 157 moves the blocking member 151 to the separated position. Thereafter, the turning motor 553 of the medium liquid supply mechanism 55 moves the mist supply nozzle 559 to the discharge position in accordance with an operation command from the control unit 97 to the ultrasonic wave application unit 5.

  After the mist supply nozzle 559 is positioned at the discharge position, the open / close valve 565 of the medium liquid supply mechanism 55 is opened by an operation command from the control unit 97 to the ultrasonic wave applying unit 5. As a result, toluene as a medium liquid is sent from the toluene supply unit 561 to the mist supply nozzle 559 via the pipe 563, and mist-like toluene is discharged from the mist supply nozzle 559 toward the substrate surface Wf (step S101). ).

  As a result, a double liquid film structure is formed in which a liquid film of toluene as a medium is present on a liquid film of DIW as a cleaning liquid formed on the substrate surface Wf. Toluene as a mediator solution having a freezing point lower than that of DIW as a cleaning liquid, a specific gravity smaller than DIW, and difficult to mix with DIW is supplied to the substrate surface Wf. The step of forming a liquid film corresponds to the “medium liquid supply step” in the present invention. When the medium liquid supply step is completed, the opening / closing valve 565 of the medium liquid supply mechanism 55 is closed by the operation command from the control unit 97 to the ultrasonic wave applying means 5, and the turning motor 553 moves the mist supply nozzle 559 to the retracted position. Moving.

  Here, the mediating liquid in the first embodiment is preferably a liquid that is difficult to mix with the cleaning liquid and has a specific gravity smaller than that of the cleaning liquid. This is because when the medium liquid is difficult to mix with the cleaning liquid and the specific gravity is small, the above-mentioned double liquid film structure is stable, and the dual liquid film is also used when coagulating the cleaning liquid DIW while applying the ultrasonic wave described later. This is because the structure is stably maintained. Furthermore, since toluene as a medium is difficult to mix with DIW, mixing with DIW as a cleaning liquid does not cause a change in freezing point or a change in ice crystal size. Toluene as a mediator in the first embodiment is less likely to mix with DIW as a cleaning fluid, has a low freezing point, and toluene has a lower specific gravity than DIW and is therefore preferred as a mediator.

  Further, in order to form a double liquid film structure, toluene is supplied in a mist form to the substrate surface Wf on which the DIW liquid film is formed, thereby forming a liquid film of toluene. The structure can be formed stably. Further, since the substrate W is rotated simultaneously with the supply of the mist-like toluene, the toluene liquid film can be formed flat and uniformly on the entire upper surface of the DIW liquid film. As a result, the thickness of the DIW liquid film can be made uniform, and the ultrasonic energy is uniformly applied to the DIW liquid film in the solidification process described later, so that the solidification of DIW having the same ice crystal size can be achieved. A body can be formed.

  Next, an ultrasonic application process and a coagulation process will be described. In response to an operation command from the control unit 97, the substrate rotating means 12 accelerates the rotation speed of the substrate holding means 11 to, for example, 50 rpm, and the rotation at the rotation speed is continued. Further, the head drive mechanism 511 moves the ultrasonic wave application head 531 to the freezing start position according to an operation command from the control unit 97 to the ultrasonic wave application unit 5.

  In a state where the ultrasonic wave application head 531 is positioned at the freezing start position and the vibration surface VF is in contact with the liquid film of toluene, the ultrasonic oscillator 543 outputs a pulse signal in response to an operation instruction from the control unit 97 to the ultrasonic wave application unit 5. Start oscillation. As a result, the vibrator 537 vibrates ultrasonically, vibrates the diaphragm 535, and ultrasonic vibration is applied from the vibrating surface VF to the toluene liquid film. At the same time, in accordance with an operation instruction from the control unit 97 to the coagulation means 31, the freezing nitrogen gas supply unit 311 starts supplying the freezing nitrogen gas.

The ultrasonic wave applied to the toluene liquid film from the ultrasonic wave applying head 531 has a frequency and energy that do not cause cavitation in the DIW liquid film, for example, a frequency of 3 MHz and 0.6 W / cm ² . Granted with energy.

  The freezing nitrogen gas supplied from the opening 315 to the substrate surface Wf via the piping 313 from the freezing nitrogen gas supply unit 311 is discharged onto the surface of the toluene liquid film, thereby cooling the toluene liquid film. Thus, the DIW liquid film in contact with the toluene liquid film is indirectly cooled. As a result, a DIW solidified body is formed on the substrate surface Wf. Since this freezing nitrogen gas is adjusted to a temperature lower than the freezing point of DIW and higher than the freezing point of toluene, for example, a temperature of Celsius- (minus) 20 ° C. (degrees Celsius), only DIW is obtained without solidifying toluene. Can be solidified.

  While the ultrasonic wave is being applied from the ultrasonic wave applying unit 5 to the toluene liquid film, the head drive mechanism 511 causes the ultrasonic wave applying head 531 to move to the center of the substrate W in response to an operation instruction from the control unit 97 to the ultrasonic wave applying unit 5. Swing from near freezing start position to freezing end position near outer edge. Thus, by rotating the ultrasonic wave application head 531 from the vicinity of the center of the substrate W to the vicinity of the outer edge while rotating the substrate W, a solidified body of DIW can be formed over the entire surface of the substrate surface Wf. Step S102).

  The process of applying ultrasonic waves to the liquid film of toluene as a medium and applying ultrasonic waves to DIW as a cleaning liquid through toluene corresponds to the “ultrasonic application process” in the present invention. Moreover, the nitrogen gas for freezing adjusted to the temperature lower than the freezing point of DIW and higher than the freezing point of toluene is discharged to the dual liquid film of DIW and toluene to which ultrasonic waves are applied by the ultrasonic wave applying step. Thus, the process of cooling the lower DIW through the upper toluene and producing a solidified body of DIW corresponds to the “solidification process” in the present invention.

  Due to the solidification process, the volume of DIW entering between the particles and the substrate surface Wf increases (when water at 0 ° C (degrees Celsius) becomes ice at 0 ° C (degrees Celsius), the volume increases to about 1.1 times. Particles) and the like are separated from the substrate surface Wf by a minute distance. As a result, the adhesion force between the substrate surface Wf and the particles or the like is reduced, and further particles and the like are detached from the substrate surface Wf, and the solidified body of DIW is removed by a rinsing process described later, Particles and the like are also removed. Further, by solidifying DIW while applying ultrasonic waves from the ultrasonic wave applying head 531, the particles are solidified while giving vibration energy to the particles and the like, and the effect of detaching the particles and the like from the substrate surface Wf is promoted.

Here, the water molecule (chemical formula: H ₂ O), which is the main component of DIW, is formed by covalently bonding oxygen (atomic symbol: O) and hydrogen (atomic symbol: H). Oxygen has a high electronegativity, and a hydrogen atom covalently bonded to such an atom is a non-covalent bond with a lone pair of other nearby atoms (in the case of water, oxygen atoms of other water molecules). It is also bonded by hydrogen bonds, which are sex attractive interactions.

  In addition, when the liquid water is cooled and solidified, ice crystals are generated. Crystallization in which crystals are formed consists of two stages: nucleation and crystal growth. “Nucleation” is a stage in which molecules dispersed in a liquid gather to form a cluster (group) with a size of several nanometers, and the resulting cluster becomes a nucleus that is a seed for subsequent crystal growth. “Crystal growth” refers to the growth of completed nuclei.

  The molecular network of hydrogen, which is liquid water, is formed randomly, and there are few parts where molecules are gathered so that they can be the core of ice crystals. When the water in such a state is cooled, a small group of molecules becomes nuclei, and crystals grow from the nuclei to become ice crystals. In this case, since the distance between adjacent nuclei is large, the crystal growth range is large, and finally a large ice crystal is generated.

  Since pure water is slightly ionized without any external action, hydroxide ions (OH-) and hydrogen ions (H +) exist in the water. The ionized hydroxide ions and hydrogen ions become the original water molecules even after recombination, and the balance between ionization and recombination is maintained as a whole.

  When energy such as ultrasonic waves is applied to liquid water from the outside, recombination of hydroxide ions (OH−) and hydrogen ions (H +) is prevented, and the ionized state of water molecules can be maintained for a long time. . When ionized hydroxide ions and hydrogen ions are present in a network of water molecules formed randomly by hydrogen bonding, water molecules gather around it and a cluster that can be the nucleus of the crystal is generated. The The number of clusters due to this phenomenon is larger in unit volume than when no energy is applied from the outside. As a result, the range of crystal growth becomes smaller, and the ice crystals finally formed become smaller.

  In the first embodiment, the ultrasonic wave is applied from the ultrasonic wave application means 5 to the toluene liquid film, and at the same time, the freezing nitrogen gas is discharged from the coagulation means 31 to the DIW liquid film via the toluene liquid film. By applying ultrasonic waves to stably generate a cluster of water molecules and cooling it together, a DIW solidified body having fine crystals can be generated.

  Further, the ultrasonic wave application head is in contact with only the liquid film of toluene. Therefore, even if the underlying DIW liquid film is solidified to be changed into a DIW solidified body, the upper toluene liquid film remains in a liquid state, and the ultrasonic wave application head 531 has a two-dimensional surface on the substrate surface Wf. It is possible to form a DIW solidified body smoothly without sticking to the heavy liquid film.

  When the ultrasonic wave application head 531 turns to the freezing end position and a DIW coagulation body is formed on the entire surface of the substrate surface Wf, the ultrasonic wave application process and the coagulation process are completed. After the ultrasonic application step and the coagulation step are completed, the ultrasonic oscillator 543 stops the oscillation of the pulse signal and the head drive mechanism 511 receives the ultrasonic application head 531 according to an operation instruction from the control unit 97 to the ultrasonic application unit 5. Is moved to the retracted position. Further, the discharge of the freezing nitrogen gas from the freezing nitrogen gas supply unit 311 is stopped by the operation instruction from the control unit 97 to the solidifying means 31.

  Next, the rinsing process will be described with reference to FIG. In response to an operation instruction from the control unit 97 to the atmosphere blocking means 15, the blocking member lifting mechanism 157 moves the blocking member 151 to the opposite position. After the blocking member 151 is positioned at the facing position, the opening / closing valve 235 is opened by an operation instruction from the control unit 97 to the rinsing liquid supply means 23.

  Accordingly, DIW as a rinse liquid whose temperature is adjusted to, for example, 40 ° C. (degrees Celsius) from the second DIW supply unit 231 is discharged from the discharge nozzle 201 via the pipe 233, the main pipe 207, and the second supply pipe 205. Wf is supplied. As a result, the toluene liquid film on the substrate surface Wf is removed, and a rinsing process is performed to melt and remove the DIW solidified body (step S04). This process of supplying a rinse liquid to the coagulated body produced by the coagulation process and thawing and removing the coagulated body corresponds to the “rinsing process” in the present invention.

  When the temperature of the DIW solidified body rises, melting proceeds from the periphery of the crystal, that is, from the boundary portion with the adjacent crystal. Thereby, before the melting of the crystal is completed, the adhesion with the adjacent crystal is lost, and the DIW crystal floats in the DIW which is the rinse liquid.

  At this time, if the ice crystal size is large, it takes time to melt all, so if some external force (in the first embodiment, the flow of DIW as the rinsing liquid or the centrifugal force due to the rotation of the substrate W) is applied, it melts. The remaining ice crystal moves and collides with the pattern formed on the substrate surface Wf to cause damage such as collapse of the pattern.

  On the other hand, when the ice crystal size is small, the time required for melting is short, so that the ice crystal melts before colliding with the pattern. Further, even if the melt remains and collides with the pattern, since the ice crystal size itself is small, damage to the pattern is reduced.

  After the rinsing step, the on-off valve 235 is closed by an operation command from the control unit 97 to the rinsing liquid supply means 23.

  Next, a drying process for drying the substrate W is performed. In response to an operation command from the control unit 97 to the drying gas supply means 33, the drying nitrogen gas supply unit 331 starts supplying the drying nitrogen gas.

  Accordingly, the drying nitrogen gas from the drying nitrogen gas supply unit 331 is supplied to the substrate surface Wf via the pipe 333 and the first supply pipe 203. The nitrogen gas for drying fills the space between the blocking member 151 positioned at the opposing position and the substrate surface Wf, thereby preventing the substrate surface Wf from coming into contact with the outside air.

  After the substrate surface Wf is blocked from the outside air, the substrate holding means 11 and the blocking member 151 are rotated at, for example, 1500 rpm by the operation command from the control unit 97 to the substrate rotating means 12 and the atmosphere blocking means 15, and the rotation is performed at the rotation speed. Will continue. Thereby, the centrifugal force is applied to the DIW that is the rinse liquid remaining on the substrate surface Wf to remove it, and the substrate surface Wf is dried (step S05).

  After the drying of the substrate W is completed, the drying nitrogen gas supply unit 331 stops the supply of the drying nitrogen gas according to an operation command from the control unit 97 to the drying gas supply means 33. Further, the substrate rotating unit 12 stops the rotation of the substrate holding unit 11 in accordance with an operation command from the control unit 97. Further, the blocking member rotating mechanism 159 stops the rotation of the blocking member 151 by an operation command from the control unit 97 to the atmosphere blocking means 15. After the rotation of the substrate holding means 11 is stopped, the substrate rotating means 12 positions the substrate holding means 11 at a position suitable for delivery of the substrate W according to an operation command from the control unit 97. Further, the blocking member lifting mechanism 157 moves the blocking member 151 to the retracted position by an operation command from the control unit 97 to the atmosphere blocking means 15.

  Finally, a substrate unloading process for unloading the substrate W from the processing unit 91 is performed. After the substrate holding unit 11 is positioned at a position suitable for delivery of the substrate W, the chuck pin driving mechanism 116 opens the chuck pin 115 according to an operation command from the control unit 97 to the substrate holding unit 11.

  Thereafter, in response to an operation command from the control unit 97, the substrate transport device 931 takes out the processed substrate W in the processing unit 91 and carries it into a predetermined position of the cassette 96 placed on the placement unit 951 (step S06). ), A series of processing ends.

  As described above, in the first embodiment, the ultrasonic wave is applied from the ultrasonic wave applying unit 5 to the toluene liquid film, and the freezing nitrogen gas is discharged from the coagulating unit 31 to pass through the toluene liquid film. Ultrasonic waves are applied to the liquid film of DIW, and water molecules are stably generated, and then cooled, thereby generating fine crystal ice.

  This makes it possible to thaw ice crystals quickly in the rinsing process for thawing and removing the DIW solidified material on the substrate surface Wf, and also to reduce the size of ice crystals remaining in the rinsing liquid. It becomes. Therefore, it is possible to effectively prevent damage to the pattern formed on the substrate surface Wf.

In the first embodiment, toluene is used as a mediator. However, if the liquid has a lower freezing point than DIW, which is a cleaning liquid, is difficult to mix with DIW, and has a low density, use another liquid. Is also possible. For example, hexane (chemical formula: C ₆ H _14, density: 0.658 (kg / m ³ ), freezing point: − (minus) 100 ° C. (degrees Celsius)), heptane (chemical formula: C ₇ H _16, density: 0.681) (Kg / m ³ ) Freezing point: − (minus) 91 ° C. (Celsius)), Octane (chemical formula: C ₈ H ₁₈ ) Density: 0.701 (kg / m ³ ) Freezing point: − (minus) 8 degrees C. (Celsius)). These liquids may be diluted.

  In the first embodiment, the start of ultrasonic application in the ultrasonic application process and the start of discharge of freezing nitrogen gas in the coagulation process are performed at the same time, but these timings may not be simultaneous. . That is, the freezing nitrogen gas may be discharged to the DIW to which the ultrasonic wave is applied by the ultrasonic wave applying means 5, and the ultrasonic wave applying process is started first, and then the head driving mechanism 511 applies the ultrasonic wave. The head 531 may start turning, and the solidification process may be started when the opening 315 at the tip of the pipe 313 comes directly above the center of the substrate W, and the freezing nitrogen gas may be discharged onto the substrate surface Wf. In addition, after starting the ultrasonic wave application process, the ultrasonic wave is spread over the entire DIW on the substrate surface Wf by maintaining the state as it is for a predetermined time, and then the rotation of the ultrasonic wave application head 531 is started. May be started.

  In the first embodiment, the pipe 313 from the freezing nitrogen gas supply unit 311 is fixed to the ultrasonic wave application head 531 to form the DIW solidified body. However, the DIW solidified body is formed. Is not limited to this. For example, a nozzle for discharging freezing nitrogen gas and a driving mechanism for driving the nozzle are provided separately from the head driving mechanism 511, and in the solidification process, following the rear of the moving direction of the ultrasonic wave applying head 531 for freezing. It is also possible to discharge nitrogen gas. Further, instead of discharging the freezing nitrogen gas to the substrate surface Wf, it is also possible to discharge the DIW solidified body from the back surface side of the substrate W to the substrate back surface Wb.

  Further, the mediating liquid supply mechanism 13 in the first embodiment is eliminated and the mediating liquid supply process is not performed, and the ultrasonic wave application head 531 of the ultrasonic wave application unit 5 is brought into contact with the liquid film of DIW as the cleaning liquid on the substrate surface Wf. It is also possible to form a DIW coagulation by discharging the nitrogen gas for freezing into the DIW liquid film while applying ultrasonic waves directly to the DIW liquid film.

  As shown in FIG. 12, the pipe 313 connected to the freezing nitrogen gas supply unit 311 is fixed on the side opposite to the moving direction of the ultrasonic wave application head 531 during the coagulation process, so The region where DIW is solidified by the freezing nitrogen gas discharged from the opening 315 is behind the moving direction of the ultrasonic wave application head 531 in the solidification process (upstream side of the moving direction of the ultrasonic wave application head 531).

  Accordingly, by moving the ultrasonic wave application head 531 at a speed faster than the speed at which the freezing of DIW on the substrate surface Wf proceeds by the freezing nitrogen gas discharged from the opening 315, the solidified body of DIW is converted into the ultrasonic wave application head. No contact with the vibration surface VF of 531 occurs. Accordingly, the ultrasonic wave application head 531 does not adhere to the liquid film on the substrate surface Wf, and a DIW solidified body can be formed smoothly.

<Second embodiment>
Next, a second embodiment of the substrate processing apparatus according to the present invention will be described with reference to FIG. 18, FIG. 19, FIG. FIGS. 18 and 20 are schematic views showing a configuration of the processing unit 911 according to the second embodiment that is different from the processing unit 91 according to the first embodiment. FIG. 19 is a front sectional view of an ultrasonic wave application unit used in the processing unit 911 in the second embodiment, and FIG. 20 is a flowchart showing details of the ultrasonic wave application / coagulation process in the second embodiment.

  First, the second embodiment is greatly different from the first embodiment in that the liquid film of the medium liquid is not formed on the liquid film of the cleaning liquid on the substrate surface Wf as in the first embodiment. This is a point in which a medium liquid imparted with ultrasonic waves is discharged from the back surface side of the substrate to the substrate back surface Wb and solidifies while applying ultrasonic waves to the liquid film of the cleaning liquid on the substrate surface Wf via the substrate W. Accordingly, the second embodiment does not include the ultrasonic wave application unit 5 in the first embodiment, and the medium liquid is configured to be discharged onto the substrate back surface Wb, and includes the ultrasonic wave application unit 621 in the piping path through which the medium liquid passes. .

  In the first embodiment, the pipe 313 of the coagulation unit 31 is fixed to the ultrasonic wave application head 531 of the ultrasonic wave application unit 5 and moves along with the movement of the ultrasonic wave application head 531. In 2 embodiment, it is comprised as the solidification means which has an independent drive mechanism.

  The other configurations are basically the same as those of the substrate processing apparatus 9 and the processing unit 91 shown in FIGS. 5 to 16, and therefore, in the following description, the different points are described, and the same reference numerals are given to the different points. Therefore, description of the configuration is omitted.

  First, the ultrasonic wave provision means 61 in 2nd embodiment is demonstrated using FIG. FIG. 18 is a schematic diagram showing the configuration of the ultrasonic wave applying means 61 in the second embodiment.

  The central axis 111 of the substrate holding means 11 is hollow, and a supply pipe 208 is inserted through the inside. The supply pipe 208 is connected via a pipe 633 to a toluene supply section 631 having a toluene tank, a temperature adjustment unit, and a pump (not shown). Note that the pump of the toluene supply unit 631 is always operating from the time when the substrate processing apparatus 92 is activated. In addition, an opening / closing valve 635 is inserted in the pipe 633. The on-off valve 635 is always closed. The on-off valve 635 is electrically connected to the control unit 971. The toluene supply unit 631 may be provided inside or outside the substrate processing apparatus.

  An opening is provided at the center of the spin base 113, an upper end portion of the supply pipe 208 extends to the opening of the spin base 113, and a discharge nozzle 209 is provided at the tip of the supply pipe 208. When the on-off valve 635 of the medium solution supply unit 613 is opened in response to an operation command from the control unit 971 to the ultrasonic wave application unit 61, for example, 1 ° C. (Celsius) toluene is supplied from the toluene supply unit 631 to the pipe 633 and the supply pipe. Through 208, the ink is supplied from the discharge nozzle 209 to the back surface Wb of the substrate.

  An ultrasonic wave application unit 621 is inserted in the supply pipe 208. FIG. 19 is a front sectional view showing the structure of the ultrasonic wave applying unit 621. The ultrasonic wave imparting unit 621 has openings in the upper and lower sides and a part of the side surface thereof. For example, a body portion 641 made of a fluororesin such as polytetrafluoroethylene, and a side surface of the body portion 641. A diaphragm 643 made of, for example, quartz fixed to the opening 647 and a vibrator 645 made of, for example, a piezoelectric vibrator fixed to the outside of the body 641 of the diaphragm 643.

  The opening 651 provided on the lower side of the trunk portion 641 in FIG. 19 is provided on the supply pipe 208 connected to the toluene supply portion 631 via the pipe 633 and on the upper side of the trunk portion 641 in FIG. The opening 649 is connected to the supply pipe 208 connected to the discharge nozzle 209 and the pipe, respectively. Accordingly, toluene supplied from the toluene supply unit 631 to the supply pipe 208 via the pipe 633 flows from the opening 651 to the inside of the trunk portion 641 and flows from the opening 649 to the discharge nozzle 209.

  The vibrator 645 is electrically connected to the ultrasonic oscillator 625 through a wiring 623. The ultrasonic oscillator 625 is electrically connected to the control unit 971. When a pulse signal is output from the ultrasonic oscillator 625 to the vibrator 645 via the wiring 623 in accordance with an operation command from the control unit 971 to the ultrasonic wave applying unit 61, the vibrator 645 is ultrasonically vibrated, and the vibration plate 643 is ultrasonically vibrated, and ultrasonic vibration is imparted to toluene filled in the body 641.

  Next, the solidification means 35 in 2nd embodiment is demonstrated using FIG. FIG. 20 is a schematic diagram showing the configuration of the solidifying means 35.

  The nozzle drive mechanism 351 has the same mechanism as the nozzle drive mechanism 531 in the first embodiment. In other words, the turning motor 353 is provided on the outer side in the circumferential direction of the processing cup 13 as a driving source for scanning the discharge nozzle 359. A turning shaft 355 is connected to the turning motor 353, and an arm 357 is connected to the turning shaft 355 so as to extend in the horizontal direction. A discharge nozzle 359 is attached to the tip of the arm 357. Further, the turning motor 353 is electrically connected to the control unit 971. Then, when the turning motor 353 is driven in accordance with the operation command from the control unit 971, the discharge nozzle 359 starts the freezing start position in the vicinity of the center of the substrate W around the turning shaft 355 and the freezing end in the vicinity of the outer edge of the substrate W. It swings between a position and a retracted position that is a position outside the circumferential direction of the processing cup 13.

  The discharge nozzle 359 of the nozzle drive mechanism 351 stores, via a pipe 365, a nitrogen gas tank that stores gaseous nitrogen gas (not shown), a pump that pumps nitrogen gas, a flow rate adjustment valve that adjusts the flow rate of nitrogen gas, and liquid nitrogen. A liquid nitrogen tank and a freezing nitrogen gas supply unit 363 having a heat exchanger immersed in liquid nitrogen in the liquid nitrogen tank are connected to a pipe line. The nitrogen gas tank is connected to the inlet of the heat exchanger via a pump and a flow control valve, and the outlet of the heat exchanger is connected to one end of the pipe 365. Note that the pump of the freezing nitrogen gas supply unit 363 always operates from the time when the substrate processing apparatus 92 is activated.

  The freezing nitrogen gas supply unit 363 is electrically connected to the control unit 971. Then, according to an operation command from the control unit 971 to the refrigerant supply unit 361, the flow rate adjustment valve is opened to a predetermined flow rate, and a temperature lower than the freezing point (0 ° C. (Celsius)) of DIW as a cleaning liquid, For example, nitrogen gas at Celsius− (minus) 20 ° C. (Celsius) is supplied from the discharge nozzle 359 to the substrate surface Wf via the pipe 365.

  The refrigerant supplied from the freezing nitrogen gas supply unit 363 is not limited to nitrogen gas, and other gases such as dry air, oxygen gas, and argon gas may be used. The means for cooling the refrigerant is not limited to liquid nitrogen, and a low-temperature liquid such as liquid helium can be used, and it is also possible to electrically cool using a Peltier element.

  Next, the cleaning processing operation in the substrate processing apparatus 92 configured as described above will be described. In the second embodiment, similarly to the first embodiment, a substrate carry-in process for carrying the substrate W into the processing unit 911 and a cleaning liquid supply process for supplying DIW as a cleaning liquid onto the substrate surface Wf are performed. After the DIW liquid film as the cleaning liquid is formed on the entire substrate surface Wf by the cleaning liquid supply process, the on-off valve 215 is closed by an operation instruction from the control unit 971 to the cleaning liquid supply means 21.

  Next, ultrasonic application / coagulation treatment will be described with reference to FIG. In response to an operation command from the control unit 971, the substrate rotating unit 12 accelerates the rotation of the substrate holding unit 11 to, for example, 100 rpm, and the rotation at the rotation number is continued. Further, in response to an operation command from the control unit 971 to the atmosphere blocking unit 15, the blocking member lifting mechanism 157 moves the blocking member 151 to the retracted position. After the blocking member 151 moves to the retracted position, the discharge nozzle 359 moves to the freezing start position in accordance with an operation instruction from the control unit 971 to the coagulation means 35.

  Thereafter, according to an operation instruction from the control unit 971 to the ultrasonic wave application unit 61, the on-off valve 635 of the medium solution supply unit 553 is opened, and toluene as a medium solution from the toluene supply unit 631 passes through the pipe 633 and the supply pipe 208. Then, it is supplied from the discharge nozzle 209 to the back surface Wb of the substrate. Here, the temperature of toluene is adjusted to, for example, 1 ° C. (Celsius) so as not to increase the temperature of the liquid film of DIW as a cleaning liquid formed on the substrate surface Wf through the substrate.

  Further, in response to an operation instruction from the control unit 971 to the ultrasonic wave applying unit 611, the ultrasonic oscillator 625 starts oscillation of a pulse signal. As a result, the vibrator 645 vibrates ultrasonically, vibrates the diaphragm 643, and ultrasonic vibration is applied to toluene flowing in the body 641 of the ultrasonic wave applying unit 621. Thereby, toluene to which ultrasonic vibration is applied is supplied to the substrate back surface Wb, and ultrasonic vibration is applied to the liquid film of DIW formed on the substrate surface Wf via the substrate W (S201).

  The process of supplying toluene as a mediating liquid having a freezing point lower than the freezing point of DIW as a cleaning liquid to the substrate back surface Wb corresponds to the “medium liquid supplying process” in the present invention. In addition, ultrasonic waves are applied to toluene as a medium liquid supplied to the substrate back surface Wb in the medium liquid supply process, ultrasonic waves are applied to the substrate W via toluene, and further DIW as a cleaning liquid is supplied via the substrate W. The step of applying ultrasonic waves corresponds to the “ultrasonic application step” in the present invention.

  Thereafter, in accordance with an instruction from the control unit 971 to the coagulation means 35, the freezing nitrogen gas supply unit 363 starts discharging the freezing nitrogen gas, and the nozzle driving mechanism 351 completes freezing of the discharge nozzle 359 from the freezing start position. Turn to position. As a result, the nitrogen gas for freezing is supplied from the vicinity of the center of the substrate W toward the periphery of the DIW liquid film to which ultrasonic waves are applied from the back surface Wb of the substrate, and the DIW liquid film is phased into the DIW solidified body. Transition (step S202). The DIW is cooled on the DIW liquid film formed on the substrate surface Wf by discharging a freezing nitrogen gas adjusted to a temperature lower than the freezing point of the cleaning liquid and higher than the freezing point of the medium liquid. The process of forming a DIW solidified body on the entire substrate surface Wf corresponds to the “solidifying process” in the present invention.

  It is desirable that the intermediate liquid supplied to the substrate back surface Wb has a freezing point lower than the freezing point of DIW which is a cleaning liquid formed on the substrate surface Wf. This is because if a media solution having a higher freezing point than the cleaning solution is used, the media solution supplied to the back surface also solidifies when DIW on the substrate surface is solidified, and the ultrasonic wave is reflected at the gas-liquid interface of the media solution. This is because the ultrasonic wave cannot be uniformly applied to the liquid film of the cleaning liquid. Another reason is that the coagulation of the medium liquid stays in the space between the substrate back surface Wb and the top surface of the spin base 113 and clogs the discharge nozzle 209. Toluene as a medium in the second embodiment is preferable as a medium because it has a lower freezing point than DIW as a cleaning liquid.

  When the turning of the discharge nozzle 359 to the freezing end position is completed and the DIW solidified body is formed on the entire surface Wf of the substrate, the solidification process is completed. After completion of the coagulation process, in accordance with an instruction from the control unit 971 to the coagulation means 35, the freezing nitrogen gas supply unit 363 stops discharging the freezing nitrogen gas, and the nozzle driving mechanism 351a moves the discharge nozzle 359 to the retracted position. To do.

  Thereafter, in response to an instruction from the control unit 971 to the atmosphere blocking means 15, the blocking member lifting mechanism 157 moves the blocking member 151 to the opposite position, and DIW solidified body on the substrate surface Wf is removed by DIW as in the first embodiment. A rinsing process for thawing and removing, a drying process for drying the substrate surface by high-speed spin, and a substrate unloading process for unloading the processed substrate W are performed, and a series of processes is completed.

  In the second embodiment, although the freezing nitrogen gas having a temperature lower than the freezing point of DIW is supplied to the substrate surface Wf as the solidification step, toluene as a medium solution to be supplied to the substrate back surface Wb is also used. It is also possible to supply at a temperature lower than the freezing point of DIW. In this case, since cooling is performed from both the front and back of the substrate W, the time required for freezing the DIW is shortened. Further, by supplying toluene as a medium for supplying the substrate back surface Wf at a temperature lower than the freezing point of DIW without supplying the freezing nitrogen gas to the substrate surface Wf, the toluene is used as a medium for applying ultrasonic vibration. It is also possible to combine both the above function and the function as a refrigerant for solidifying DIW. Thereby, the member which the solidification means 35 requires can be omitted, and it can contribute to cost reduction.

<Modification>
Next, a modified example of the second embodiment will be described. In this modified example, unlike the second embodiment, the medium liquid to which ultrasonic waves are applied is not discharged from the discharge nozzle 209 at the center of the spin base 113, and an ultrasonic wave application nozzle is provided on the outer side in the circumferential direction of the substrate W. The medium liquid to which ultrasonic waves are applied is discharged from the outer circumferential direction toward the substrate back surface Wb.

  FIG. 21 is a front sectional view of the ultrasonic wave application nozzle 661. The ultrasonic wave imparting nozzle 661 is formed on the right side wall of the body 663 and the body 663 having a cylindrical shape on the right half and a conical shape on the left half and a circular discharge port 665 on the left end surface. The vibration plate 669 is fixed to the position of the through-hole 667 and the ultrasonic vibrator 671 is fixed to the outside of the body 663 of the vibration plate 669. Further, a through hole 673 formed in the lower side wall surface of the body portion 663 is connected to a toluene supply portion 631 via a pipe 633. The body portion 663 is formed of a material having chemical resistance such as a fluororesin.

  The ultrasonic vibrator 671 is electrically connected to the ultrasonic oscillator 625 via the cable 623, and when a pulse signal is output from the ultrasonic oscillator 625 to the ultrasonic vibrator 671, the ultrasonic vibrator 671 is supersonic. Ultrasonic vibration is applied to toluene that vibrates with sound and fills the inside of the body portion 663 via the vibration plate 669. The toluene to which this ultrasonic wave has been applied is discharged toward the back surface Wb of the substrate W from an ultrasonic wave application nozzle 661 installed on the outer side in the circumferential direction of the substrate W, and the DIW liquid on the substrate surface Wf is passed through the substrate W. It is possible to apply ultrasonic waves to the film.

In the second embodiment and the modified example of the second embodiment, toluene is used as a medium, but other liquids can be used as long as they have a freezing point lower than that of DIW as a cleaning liquid. For example, hexane (chemical formula: C ₆ H _14. Freezing point: − (minus) 100 ° C. (Celsius)), heptane (chemical formula: C ₇ H _16. Freezing point: − (minus) 91 ° C. (Celsius)), octane (chemical formula) : C ₈ H _18, Freezing point: − (minus) 56.8 ° C. (Celsius)), liquid mainly composed of hydrofluoroether (chemical formula: C ₄ F ₉ OCH ₃ , chemical formula: C ₄ F ₉ OC ₂ H ₅ , chemical formula: C ₆ F ₁₃ OCH ₃ , chemical formula: C ₃ HF ₆ —CH (CH ₃ ) O—C ₃ HF ₆ , chemical formula: C ₂ HF ₄ OCH _3, etc. Freezing point— (minus) 38 ° C. ( Celsius) or less). These liquids may be diluted.

<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 each of the above embodiments, DIW is supplied as the cleaning liquid to the substrate surface Wf, but the cleaning liquid is not limited to DIW, and pure water, ultrapure water, hydrogen water, carbonated water, etc. Even a liquid such as SC1 can be used.

DESCRIPTION OF SYMBOLS 5 Ultrasonic provision means 9 Substrate processing apparatus 11 Substrate holding means 12 Substrate rotation means 13 Processing cup 15 Atmosphere blocking means 21 Cleaning liquid supply means 23 Rinse means 51 Ultrasonic application mechanism 53 Mediated liquid supply mechanism 91 Processing unit 97 Control unit

Claims (7)

An ultrasonic wave application step for applying ultrasonic waves to the liquid film of the cleaning liquid on the substrate;
A coagulation step of generating a coagulation body of the cleaning liquid by cooling the cleaning liquid to which ultrasonic waves are applied by the ultrasonic application step;
A rinsing step of supplying a rinsing liquid to the coagulated body produced by the coagulation step and thawing and removing the coagulated body;
A substrate processing method comprising: The substrate processing method according to claim 1,
A medium having a freezing point lower than the freezing point of the cleaning liquid, having a specific gravity smaller than that of the cleaning liquid and being difficult to mix with the cleaning liquid, is supplied to the surface of the substrate; A media solution supplying step of forming a film;
The ultrasonic wave applying step is a substrate processing method in which an ultrasonic wave is applied to the liquid film of the medium solution, and an ultrasonic wave is applied to the cleaning liquid through the medium solution. The substrate processing method according to claim 1,
A medium supply step of supplying a medium having a freezing point lower than the freezing point of the cleaning liquid on the back surface of the substrate;
The ultrasonic wave application step applies ultrasonic waves to the medium liquid supplied to the back surface of the substrate, applies ultrasonic waves to the substrate via the medium liquid, and further applies ultrasonic waves to the cleaning liquid via the substrate. The substrate processing method which provides. The substrate processing method according to any one of claims 2 and 3,
The solidification step is a substrate processing method in which the cleaning liquid is cooled to a temperature lower than the freezing point of the cleaning liquid and higher than the freezing point of the medium liquid. The substrate processing method according to claim 3,
The solidification step is a substrate processing method in which the medium liquid supplied to the back surface of the substrate is supplied at a temperature lower than the freezing point of the cleaning liquid and higher than the freezing point of the medium liquid. A substrate processing method according to any one of claims 1 to 5,
A substrate processing method further comprising a cleaning liquid supply step of supplying the cleaning liquid to the substrate surface. Substrate holding means for holding a substrate having a cleaning liquid film formed on the surface;
Ultrasonic application means for applying ultrasonic waves to the liquid film of the cleaning liquid on the substrate surface held by the substrate holding means;
Coagulation means for generating a coagulation body of the cleaning liquid on the substrate surface by cooling the liquid film of the cleaning liquid to which ultrasonic waves are applied by the ultrasonic wave application means;
A rinsing liquid supply means for supplying a rinsing liquid to the solidified body produced by the coagulation means and thawing and removing the solidified body;
A substrate processing apparatus comprising:

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