JP2010027816A - Substrate processing method and substrate processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate processing method by which cleaning treatment is properly carried out to the main surface of one side of a substrate while suppressing a damage to a pattern formed on a main surface of the other side of the substrate. <P>SOLUTION: By freezing a liquid film 11f formed on a surface Wf of a substrate W, DIW within gaps of a pattern PT is solidified together with DIW deposited on the surface Wf of the substrate and is formed as a part of a frozen film 13f, so that the pattern PT is structurally reinforced by the frozen film 13f. In addition, while supplying a low temperature treatment liquid to the back surface Wb of the substrate, ultrasonic cleaning is carried out to the back surface Wb of the substrate by applying ultrasonic vibration to a liquid film 11b of the low temperature treatment liquid formed on the back surface Wb of the substrate. Thus, since the back surface Wb of the substrate is cleaned by the ultrasonic cleaning while the pattern PT is reinforced by the frozen film 13f, the back surface Wb of the substrate is properly cleaned by ultrasonic cleaning without damaging the pattern PT by the ultrasonic cleaning. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a substrate processing method and a substrate processing apparatus for cleaning the other main surface of a substrate having a pattern formed on one main surface of both main surfaces. The substrate includes a semiconductor wafer, a photomask glass substrate, a liquid crystal display glass substrate, a plasma display glass substrate, a FED (Field Emission Display) substrate, an optical disk substrate, a magnetic disk substrate, Various substrates such as magneto-optical disk substrates (hereinafter simply referred to as “substrates”) are included.

  Conventionally, a technique of freezing a liquid film by cooling the substrate with the liquid film attached to the surface of the substrate is used as one of the processes for the substrate. For example, Patent Document 1 and Patent Document 2 use such a freezing technique as one of the cleaning processes for the substrate. In this freeze cleaning process, after the liquid is supplied to the substrate surface to form a liquid film on the substrate surface, the liquid film is frozen by cooling the substrate. As a result, a frozen film is generated on the substrate surface to which the particles are attached. Finally, the frozen film is removed from the substrate surface by supplying a rinsing liquid to the frozen film or applying acoustic energy, thereby removing particles from the substrate surface together with the frozen film.

  Such a freezing technique may also be used to remove a photoresist film formed on the substrate surface. For example, in patent document 3, liquid nitrogen is dripped with respect to the photoresist film formed in the silicone wafer surface, and a photoresist film is frozen. Then, the silicone wafer having the frozen film is immersed in an ultrasonic cleaning tank storing methanol and ultrasonically cleaned.

JP 2008-71875 A (FIG. 7) US Patent Application Publication No. 2003/0015517 JP 7-66119 A (paragraph 0024)

  By the way, in Patent Document 1, for example, a frozen film is formed not only on the surface of a substrate on which a fine pattern is formed but also on the back surface of the substrate on which no pattern is formed, and freeze cleaning on the back surface of the substrate is executed. However, when such a double-sided freeze cleaning process is performed, it is difficult to increase the removal rate of particles adhering to the back surface of the substrate without collapsing the pattern on the substrate surface side. Therefore, while the substrate surface is subjected to freeze cleaning treatment (liquid film formation-freezing-removal), it may be possible to supply ultrasonic treatment liquid to the back surface of the substrate and execute ultrasonic cleaning. During removal, the pattern located on the opposite side of the ultrasonic wave application position may be damaged.

  The present invention has been made in view of the above problems, and a substrate processing method and a substrate processing capable of satisfactorily cleaning the other main surface of the substrate while suppressing damage to the pattern formed on the one main surface of the substrate. An object is to provide an apparatus.

  The present invention relates to a substrate processing method and apparatus for cleaning the other main surface of a substrate having a pattern formed on one main surface of both main surfaces, and is configured as follows to achieve the above object. ing. That is, in the substrate processing method according to the present invention, a liquid film forming step for forming a liquid film on one main surface, a freezing step for freezing the liquid film on one main surface, and a frozen film formed by the freezing step are mainly used. And an ultrasonic cleaning step of ultrasonically cleaning the other main surface in a state of existing on the surface. Further, the substrate processing apparatus according to the present invention includes a freezing means for freezing a liquid film formed on one main surface of the substrate, and the other main surface in a state where the frozen film formed by the freezing means exists on the one main surface. And ultrasonic cleaning means for ultrasonic cleaning.

  In the invention (substrate processing method and apparatus) configured as described above, a liquid film is formed on one main surface of both main surfaces of the substrate, and the liquid constituting the liquid film enters inside the gap of the pattern. The liquid film is frozen to form a frozen film on one main surface. At this time, the liquid that has entered the gap between the patterns is solidified together with the liquid adhering to the one main surface to become a part of the frozen film, and the pattern is structurally reinforced by the frozen film. That is, it can be regarded as a solid in which the substrate, the pattern, and the frozen film are integrated. Then, the other main surface is ultrasonically cleaned in a state where the frozen film is present on one main surface, that is, in a pattern reinforcement state. Therefore, it is possible to satisfactorily clean the other main surface of the substrate by ultrasonic cleaning while effectively preventing damage to the pattern by this ultrasonic cleaning.

  Here, the start timing of the ultrasonic cleaning may be performed after the frozen film is formed on the entire main surface by the freezing process. In this case, since all the patterns formed on the one main surface are reinforced by the frozen film, the entire other main surface of the substrate can be subjected to ultrasonic cleaning.

  In addition, it is relatively difficult to instantaneously form a frozen film on the entire one main surface of the substrate, and after the start of forming the frozen film, the frozen film gradually spreads over the entire main surface. Therefore, ultrasonic cleaning may be started while the frozen film is being formed. As a result, the freezing process and the ultrasonic cleaning process are performed in parallel to improve the throughput. However, if ultrasonic cleaning is performed on the area where the frozen film is not formed, the pattern may be damaged, so the other main surface is positioned on the opposite side of the frozen film formed on one main surface by the freezing process. It is necessary to start ultrasonic cleaning from the area to be used.

  Moreover, when performing ultrasonic cleaning, it is desirable to set the temperature of the processing liquid used in the ultrasonic cleaning processing to a temperature below the freezing point of the liquid constituting the liquid film. This is because when such a low-temperature treatment liquid is supplied to the other main surface of the substrate and subjected to ultrasonic cleaning, the pattern is frozen by effectively preventing the frozen film from melting during ultrasonic cleaning. This is because the reinforced state can be maintained.

  The ultrasonic cleaning may be performed as follows. That is, the processing liquid is supplied to the other main surface to form a liquid film of the processing liquid, but ultrasonic cleaning can be performed by propagating ultrasonic vibration to the liquid film through the processing liquid. In addition, as described above, the ultrasonic vibration is propagated from the one main surface side to the other main surface and the liquid film of the processing liquid formed on the other main surface through the substrate from the one main surface side. Sonic cleaning may be performed. In any ultrasonic cleaning, ultrasonic vibration can be reliably applied and the other main surface can be ultrasonically cleaned satisfactorily.

  According to the present invention, the liquid film formed on one main surface of the substrate is frozen to reinforce the pattern with the frozen film, and the other main surface of the substrate is ultrasonically cleaned while maintaining the reinforced state. The other main surface of the substrate can be satisfactorily cleaned while suppressing damage to the pattern.

<First Embodiment>
FIG. 1 is a diagram showing a first embodiment of a substrate processing apparatus according to the present invention, and FIG. 2 is a block diagram showing a control configuration of the substrate processing apparatus of FIG. This substrate processing apparatus is a single-wafer type substrate processing apparatus used for a cleaning process for removing contaminants such as particles adhering to the front surface Wf and back surface Wb of a substrate W such as a semiconductor wafer. More specifically, the substrate processing apparatus performs freezing cleaning on the substrate surface Wf on which the fine pattern is formed, and ultrasonic waves on the back surface Wb on which the pattern is not formed. This is a device for cleaning. Thus, in this embodiment, the front surface Wf of the substrate W corresponds to the “one main surface” of the present invention, and the back surface Wb corresponds to the “other main surface” of the present invention.

  This substrate processing apparatus has a spin chuck 2 for rotating the substrate W in a state where the surface Wf of the substrate W is held in a substantially horizontal posture with the surface Wf facing upward. A disc-shaped spin base 23 is fixed to the upper end portion of the central shaft 21 of the spin chuck 2 by fastening parts such as screws. The central shaft 21 is connected to a rotation shaft of a chuck rotation mechanism 22 including a motor. When the chuck rotation mechanism 22 is driven according to an operation command from the control unit 4 that controls the entire apparatus, which corresponds to the “control means” of the present invention, the spin base 23 fixed to the central shaft 21 rotates. It rotates around the center A0.

  In addition, a plurality of chuck pins 24 for holding the peripheral portion of the substrate W are provided in the vicinity of the peripheral portion of the spin base 23. Three or more chuck pins 24 may be provided to securely hold the circular substrate W, and are arranged at equiangular intervals along the peripheral edge of the spin base 23. Each of the chuck pins 24 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 24 is configured to be switchable between a pressing state in which the substrate holding portion presses the outer peripheral end surface of the substrate W and a released state in which the substrate holding portion is separated from the outer peripheral end surface of the substrate W.

  Then, when the substrate W is delivered to the spin base 23, each chuck pin 24 is in a released state, and when performing a cleaning process on the substrate W, each chuck pin 24 is in a pressed state. When each chuck pin 24 is in a pressed state, each chuck pin 24 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 23. As a result, the substrate W is held with the front surface Wf facing upward and the back surface Wb facing downward.

  A blocking member 9 is arranged above the spin chuck 2 configured as described above. The blocking member 9 is formed in a disk shape having an opening at the center. Further, the lower surface of the blocking member 9 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 9 is attached substantially horizontally to the lower end portion of the support shaft 91 having a substantially cylindrical shape. The support shaft 91 is rotatably held around a vertical axis passing through the center of the substrate W by an arm 92 extending in the horizontal direction. The arm 92 is connected to a blocking member rotating mechanism 93 and a blocking member lifting mechanism 94.

  The blocking member rotating mechanism 93 rotates the support shaft 91 around the vertical axis passing through the center of the substrate W in accordance with an operation command from the control unit 4. Further, the control unit 4 controls the operation of the blocking member rotating mechanism 93 so that the blocking member 9 is moved in the same rotational direction as the substrate W and at substantially the same rotational speed in accordance with the rotation of the substrate W held by the spin chuck 2. Rotate.

  The blocking member elevating mechanism 94 moves the blocking member 9 close to the spin base 23 according to an operation command from the control unit 4 or conversely separates it. Specifically, the control unit 4 controls the operation of the blocking member elevating mechanism 94 to move the blocking member 9 away from the spin chuck 2 when the substrate W is carried in and out of the substrate processing apparatus. While the substrate W is raised (position shown in FIG. 1), when the substrate W is subjected to a predetermined process, the blocking member 9 is set to be opposed to the surface Wf of the substrate W held by the spin chuck 2. Lower to position.

  The support shaft 91 is hollow, and a gas supply pipe 95 extending through the opening of the blocking member 9 is inserted through the support shaft 91. The gas supply pipe 95 is connected to the dry gas supply unit 65. The dry gas supply unit 65 supplies nitrogen gas, and supplies nitrogen gas from the gas supply pipe 95 toward a space formed between the blocking member 9 and the surface Wf of the substrate W at an appropriate timing. . In this embodiment, nitrogen gas is supplied as the dry gas from the dry gas supply unit 65, but air, other inert gas, or the like may be supplied.

  A liquid supply pipe 96 is inserted into the gas supply pipe 95. A lower end portion of the liquid supply pipe 96 is extended to the opening of the blocking member 9, and a liquid discharge nozzle 97 is provided at the tip thereof. On the other hand, the upper end of the liquid supply pipe 96 is connected to the liquid supply unit 62. The liquid supply unit 62 supplies the liquid constituting the liquid film and the rinse liquid to the substrate surface Wf. In this embodiment, DIW (deionized water) is used as the liquid constituting the liquid film and the rinse liquid. Is used.

  The central axis 21 of the spin chuck 2 is hollow with a cylindrical cavity, and a cylindrical liquid supply pipe 25 for supplying liquid to the back surface Wb of the substrate W is provided inside the central axis 21. It is inserted. The liquid supply tube 25 extends to a position close to the back surface Wb, which is the lower surface side of the substrate W held by the spin chuck 2, and discharges liquid at the tip thereof toward the center of the lower surface of the substrate W. A nozzle 27 is provided. The liquid supply pipe 25 is connected to the liquid supply unit 62 described above, and supplies DIW as a rinsing liquid toward the back surface Wb of the substrate W.

  Further, a gap between the inner wall surface of the central shaft 21 and the outer wall surface of the liquid supply pipe 25 is a gas supply passage 29 having a ring-shaped cross section. The gas supply path 29 is connected to the dry gas supply section 65, and nitrogen is formed in a space formed between the spin base 23 and the back surface Wb of the substrate W from the dry gas supply section 65 through the gas supply path 29. Gas is supplied.

  In the substrate processing apparatus according to the first embodiment, the cooling gas discharge nozzle 3 is provided so as to be able to discharge the liquid film freezing cooling gas toward the surface Wf of the substrate W held by the spin chuck 2. Further, a nozzle drive mechanism 31 is provided to drive the nozzle 3. In the nozzle drive mechanism 31, a rotation motor 32 is provided on the outer side in the circumferential direction of the spin chuck 2. An arm 34 is connected to the rotary shaft 33 of the rotary motor 32 so as to extend in the horizontal direction, and the cooling gas discharge nozzle 3 is attached to the tip of the arm 34. When the rotary motor 32 is driven in accordance with an operation command from the control unit 4, the arm 34 swings around the rotary shaft 33, and the nozzle 3 moves as follows.

  3A and 3B are views showing the movement of the cooling gas discharge nozzle. FIG. 3A is a side view and FIG. 3B is a plan view. When the rotary motor 32 is driven based on the operation command from the control unit 4 and the arm 34 swings, the cooling gas discharge nozzle 3 faces the surface Wf of the substrate W as shown in FIG. , It moves along the movement trajectory T. This movement trajectory T is a trajectory heading from the rotation center position Pc to the edge position Pe. Here, the rotation center position Pc is located above the substrate W and above the rotation center A0 of the substrate W, and the edge position Pe is located above the outer peripheral edge of the substrate W. That is, the rotary motor 32 moves the cooling gas discharge nozzle 3 relative to the substrate W along the surface Wf of the substrate W. Further, the cooling gas discharge nozzle 3 is movable on the extended line of the movement trajectory T to a standby position Ps that is retracted laterally from the position facing the substrate W.

  The cooling gas discharge nozzle 3 is connected to a cooling gas supply unit 64. The cooling gas supply unit 64 supplies cooling gas to the cooling gas discharge nozzle 3 in accordance with an operation command from the control unit 4. When the cooling gas discharge nozzle 3 is disposed at a position opposed to the surface Wf of the substrate W and the cooling gas is supplied from the cooling gas supply unit 64 to the cooling gas discharge nozzle 3, the cooling gas discharge nozzle 3 moves to the surface Wf of the substrate W. The cooling gas is locally discharged toward the head. Then, in response to the operation command from the control unit 4, the rotation motor 32 moves the cooling gas discharge nozzle 3 while the spin chuck 2 rotates the substrate W while the cooling gas is discharged from the cooling gas discharge nozzle 3. When moved along the movement trajectory T, the cooling gas is supplied over the entire surface Wf of the substrate W. Therefore, by supplying the cooling gas to the substrate surface Wf on which the liquid film 11f is formed by DIW from the liquid discharge nozzle 97 as described above, the entire liquid film 11f is frozen, and the surface Wf of the substrate W is A frozen film 13f is generated on the entire surface.

  The height of the cooling gas discharge nozzle 3 from the surface Wf of the substrate W varies depending on the amount of cooling gas supplied, but is set to, for example, 50 mm or less, preferably about several mm. The height of the cooling gas discharge nozzle 3 and the supply amount of the cooling gas from the surface Wf of the substrate W are as follows: (1) From the viewpoint of efficiently applying the cold heat of the cooling gas to the liquid film 11f; It is experimentally determined from the viewpoint of stably freezing the liquid film 11f so that the liquid surface of the liquid film 11f is not disturbed by the gas.

  The cooling gas has a freezing point of the liquid constituting the liquid film 11f formed on the surface Wf of the substrate W, that is, a temperature lower than 0 ° C. in this embodiment. The cooling gas is generated, for example, by flowing nitrogen gas through a pipe passing through the liquid nitrogen stored in the tank, and is cooled to, for example, −100 ° C. in this embodiment. Note that oxygen gas, clean air, or the like may be used instead of nitrogen gas. Since the cooling gas is used in this way, contaminants contained in the cooling gas can be easily removed by passing a filter or the like before supplying the gas to the surface Wf of the substrate W, and the liquid film 11f is frozen. In this case, the surface Wf of the substrate W can be prevented from being contaminated. Thus, in this embodiment, the cooling gas discharge nozzle 3 corresponds to the “cooling gas discharge means” of the present invention, and the rotary motor 32 corresponds to the “relative movement mechanism” of the present invention.

  Returning to FIG. 1, the description will be continued. In this embodiment, a receiving member 51 is fixedly attached around the spin chuck 2. In the receiving member 51, three cylindrical partition members are erected and three spaces are formed as a drainage tank. Above these drainage tanks, a splash guard 52 is provided so as to be movable up and down with respect to the rotation axis of the spin chuck 2 so as to surround the periphery of the substrate W held in a horizontal posture on the spin chuck 2. Yes. The splash guard 52 has a shape that is substantially rotationally symmetric with respect to the rotation axis, and includes three guards arranged concentrically with the spin chuck 2 from the radially inner side toward the outer side. Then, the splash guard 52 is lifted and lowered stepwise by driving a guard lifting mechanism (not shown), so that the liquid film forming DIW, the rinsing liquid and the processing liquid described below are separated from the rotating substrate W. It is possible to drain.

  A nozzle mounting member 522 is provided on the uppermost part of the outermost guard 521 among the splash guards 52 configured as described above, and the ultrasonic cleaning nozzle 7 is disposed with the discharge port 71 facing the rotation axis of the spin chuck 2. The nozzle mounting member 522 is attached. Then, when the splash guard 52 is lowered to the lowest position as shown in FIG. 1, the ultrasonic cleaning nozzle 7 is positioned at a position lower than the back surface Wb of the substrate W held by the spin chuck 2, and the ultrasonic wave The discharge port 71 of the cleaning nozzle 7 is directed from the outer peripheral side of the spin chuck 2 to the central portion of the substrate back surface Wb. When the processing liquid is pumped from the processing liquid supply unit 63 to the ultrasonic cleaning nozzle 7 in this positioning state, the processing liquid is supplied from the discharge port 71 to the substrate back surface Wb, and the liquid film of the processing liquid (see FIG. 4) on the substrate back surface Wb. 11b) is formed.

  The processing liquid supply unit 63 has a tank for storing, as a processing liquid, a mixed liquid in which DIW is mixed with alcohol, for example, IPA (isopropyl alcohol) and the freezing point is lowered below the freezing point of DIW. Further, in the processing liquid supply unit 63, the processing liquid sent out from the tank is adjusted to a temperature below the freezing point of DIW by a heat exchanger (not shown), and then this temperature-controlled processing liquid (hereinafter referred to as “low temperature processing liquid”). ) Is pumped into the nozzle through the inlet 72 of the ultrasonic cleaning nozzle 7.

  A vibrator 73 is disposed inside the nozzle to apply ultrasonic vibration to the low-temperature treatment liquid. More specifically, as shown in FIG. 1, the vibrator 73 is disposed on the opposite side of the discharge port 71 in the discharge direction (reference numeral 74 in the drawing) of the low-temperature treatment liquid discharged from the discharge port 71. When the pulse signal is output from the ultrasonic oscillator 75 to the vibrator 73 based on the control signal from the control unit 4, the vibrator 73 is ultrasonically vibrated. As a result, ultrasonic vibration propagates to the liquid film 11b (see FIG. 4C) of the low temperature processing liquid formed on the substrate back surface Wb via the low temperature processing liquid, and the back surface Wb is ultrasonically cleaned. Further, when the processing liquid supply unit 63 is operated while the output of the pulse signal from the ultrasonic oscillator 75 is stopped, the low temperature processing liquid can be supplied to the substrate back surface Wb without applying ultrasonic vibration. ing.

  Next, the cleaning processing operation in the substrate processing apparatus configured as described above will be described with reference to FIG. FIG. 4 is a diagram schematically showing a cleaning process for the front and back surfaces of the substrate. In FIGS. 5, 7, and 9, which will be described later, in order to clarify whether or not the ultrasonic vibration in the low-temperature processing liquid is propagated, the low-temperature processing liquid with ultrasonic propagation is particularly On the other hand, the low-temperature treatment liquid without the low-temperature treatment liquid is simply referred to as “low-temperature treatment liquid”. In this substrate processing apparatus, as shown in FIG. 1, when the substrate is carried in, the blocking member 9 is retracted to a separated position above the spin chuck 2 to prevent interference with the substrate W, and the substrate surface Wf is directed upward. The substrate W is carried into the apparatus in the state of being directed and held by the spin chuck 2. In this embodiment, the control unit 4 operates the heat exchanger to prepare the low-temperature processing liquid in the processing liquid supply unit 63 at the time of loading the substrate, that is, before forming a liquid film described below.

  When the unprocessed substrate W is held on the spin chuck 2, the control unit 4 raises the splash guard 52 and surrounds the periphery of the substrate W held on the spin chuck 2 in a horizontal posture by the splash guard 52. Further, the blocking member 9 is lowered to a facing position facing the substrate surface Wf, and is disposed close to the substrate surface Wf. As a result, the substrate surface Wf is covered in the state of being close to the substrate facing surface of the blocking member 9 and is blocked from the ambient atmosphere of the substrate W. Then, the control unit 4 drives the chuck rotating mechanism 22 to rotate the spin chuck 2. Further, DIW is supplied from the nozzle 97 to the substrate surface Wf. Here, by rotating the substrate W at a predetermined rotation speed, the DIW supplied to the substrate surface Wf is uniformly spread outward in the radial direction of the substrate W, and a part thereof is shaken out of the substrate. Thus, the thickness of the liquid film is uniformly controlled over the entire surface of the substrate surface Wf, and a liquid film (film made of DIW) 11f having a predetermined thickness is formed on the entire substrate surface Wf (FIG. 4A). ). As a result, the gap between the particles adhering to the substrate surface Wf and the substrate surface Wf is filled with DIW, and DIW also enters the gap between the patterns PT formed on the substrate surface Wf. Note that the liquid film 11f may be formed by supplying DIW while the substrate W is stationary.

  Thus, when the liquid film forming process is completed, the freezing process is performed on the substrate W having the liquid film 11f. That is, the control unit 4 disposes the blocking member 9 in the separated position, and discharges the cooling gas from the cooling gas discharge nozzle 3 while moving the cooling gas discharge nozzle 3 from the standby position Ps to the cooling gas supply start position, that is, the rotation of the substrate W. Move to center position Pc. Then, the cooling gas discharge nozzle 3 is gradually moved toward the edge position Pe of the substrate W while discharging the cooling gas toward the surface Wf of the substrate W being rotated. As a result, as shown in FIG. 3, the liquid film 11f formed on the substrate surface Wf is locally frozen to form a frozen film 13f, and the frozen film 13f is moved to the center of the substrate surface Wf as the nozzle 3 moves. It is spread from the part to the peripheral part. When the scanning of the nozzle 3 is completed, the entire liquid film 11f formed on the substrate surface Wf is frozen, and a frozen film 13f is formed on the entire surface of the substrate surface Wf.

  When the freezing process is performed in this manner, the volume of the liquid film 11f entering between the substrate surface Wf and the particles adhering to the substrate surface Wf increases, and the particles are separated from the substrate surface Wf by a minute distance. Further, as shown in FIG. 4B, DIW that has entered the gap between the patterns PT is solidified together with DIW adhering to the substrate surface Wf to become a part of the frozen film 13f, and the pattern PT is structured by the frozen film 13f. Will be reinforced. That is, the substrate W, the pattern PT, and the frozen film 13f can be regarded as an integrated solid.

  When the freezing of the liquid film 11f is completed, the control unit 4 moves the cooling gas discharge nozzle 3 to the standby position Ps. Subsequently, as shown in FIG. 1, the control unit 4 lowers the splash guard 52 to the lowest position, and then pumps the low-temperature processing liquid from the processing liquid supply unit 63 to the ultrasonic cleaning nozzle 7, thereby discharging the outlet 71. The low temperature treatment liquid is supplied to the substrate back surface Wb. As a result, a liquid film 11b of the low temperature treatment liquid is formed on the substrate back surface Wb. Further, along with the supply of the low-temperature treatment liquid, the control unit 4 operates the ultrasonic oscillator 75 to give a pulse signal to the vibrator 73, so that the vibrator 73 is ultrasonically vibrated. As a result, ultrasonic vibration propagates to the liquid film 11b through the low-temperature processing liquid, and the entire back surface Wb is ultrasonically cleaned (FIG. 4C). Since the low-temperature processing liquid supplied to the substrate W during this ultrasonic cleaning has a temperature lower than the freezing point (0 ° C.) of DIW, the frozen film 13f remains frozen and the pattern PT is reinforced. The ultrasonic cleaning process is executed in the state where it is kept. In this back surface ultrasonic cleaning process, it is desirable to reduce the rotational speed of the substrate W to a rotational speed at which the low temperature processing liquid does not scatter around the spin chuck 2.

  When the ultrasonic cleaning of the back surface Wb is completed, the output of the pulse signal to the vibrator 73 is stopped, and the pumping of the low-temperature processing liquid from the processing liquid supply unit 63 to the ultrasonic cleaning nozzle 7 is stopped. Thereafter, the splash guard 52 is raised to the original position to surround the periphery of the substrate W held by the spin chuck 2. Further, the blocking member 9 is disposed at the opposing position, and the blocking member 9 is rotated together with the spin chuck 2. Further, before the frozen film 13f is melted, DIW is supplied from the nozzle 97 and the nozzle 27 to the front and back surfaces Wf and Wb of the substrate W that is rotationally driven, respectively. As a result, the supply of DIW to the front and back surfaces Wf and Wb of the substrate W being rotated is started, and the thawing process of the frozen film 13f by DIW and the rinsing process of the front surface Wf and the back surface Wb are executed. As a result, the frozen film 13f containing particles is melted and rinsed and removed from the substrate surface Wf, and the treatment liquid adhering to the back surface Wb is rinsed and removed (FIG. 4D). In this embodiment, during the rinsing process, the control unit 4 supplies nitrogen gas to the space between the substrate W and the spin base 23 and between the substrate W and the blocking member 9 so as to change the ambient atmosphere around the substrate W. Inert gas atmosphere.

  After the rinsing process, the control unit 4 increases the rotation speeds of the motors of the chuck rotating mechanism 22 and the blocking member rotating mechanism 53 to rotate the substrate W and the blocking member 9 at high speed. Thereby, the drying process (spin drying) of the substrate W is executed. After the drying process of the substrate W, the rotation of the substrate W and the blocking member 9 is stopped and the supply of nitrogen gas to the substrate W is stopped. Thereafter, the processed substrate W is unloaded.

  As described above, according to the first embodiment, by freezing the liquid film 11f formed on the surface Wf of the substrate W, the DIW that has entered the gap between the patterns PT is combined with the DIW that adheres to the substrate surface Wf. To become a part of the frozen film 13f. Therefore, the pattern PT is structurally reinforced by the frozen film 13f. Then, while supplying the low-temperature processing liquid to the substrate back surface Wb, ultrasonic vibration is applied to the liquid film 11b of the low-temperature processing liquid formed on the substrate back surface Wb to ultrasonically clean the substrate back surface Wb. As described above, since the substrate back surface Wb is ultrasonically cleaned while the pattern PT is reinforced by the frozen film 13f, the pattern PT is not damaged by the ultrasonic cleaning, and the substrate back surface Wb is satisfactorily cleaned by ultrasonic cleaning. It can be washed.

  In addition, since the temperature of the processing liquid used for ultrasonic cleaning is set to a temperature below the freezing point of the liquid (DIW in this embodiment) constituting the liquid film 11f on the substrate surface side, the frozen film 13f is used during ultrasonic cleaning. Can be effectively prevented from melting. That is, by using the low temperature treatment liquid, the pattern PT can be reliably reinforced by the frozen film 13f from the start to the end of the ultrasonic cleaning process, and the ultrasonic cleaning process of the substrate back surface Wb can be performed satisfactorily. it can.

<Second Embodiment>
In the first embodiment, the low-temperature treatment liquid is supplied to the substrate back surface Wb after the formation of the frozen film 13f. However, when the liquid film is formed or the liquid film is frozen while the addition of ultrasonic vibration is prohibited. The processing liquid may be supplied to the substrate back surface Wb, which contributes to an improvement in throughput. This embodiment will be described with reference to FIG.

  FIG. 5 is a schematic view showing a second embodiment of the substrate processing apparatus according to the present invention. The second embodiment has the same configuration as that of the substrate processing apparatus of FIG. 1, and is different only in the supply mode of the low temperature processing liquid. Hereinafter, the second embodiment will be described focusing on the differences.

  In the second embodiment, when the unprocessed substrate W is held on the spin chuck 2, the control unit 4 lowers the splash guard 52 to the lowest position as shown in FIG. Further, the blocking member 9 is lowered to a facing position facing the substrate surface Wf, and is disposed close to the substrate surface Wf. The control unit 4 drives the chuck rotating mechanism 22 to rotate the spin chuck 2 and supplies DIW from the nozzle 97 to the substrate surface Wf to form a DIW liquid film 11f on the substrate surface Wf. In parallel with this, the control unit 4 does not output a pulse signal to the vibrator 73, that is, in a state in which generation of ultrasonic vibration is prohibited, the processing liquid supply unit 63 supplies the ultrasonic cleaning nozzle 7. On the other hand, the low temperature processing liquid is pumped, and the low temperature processing liquid is supplied from the discharge port 71 to the substrate back surface Wb (FIG. 5A). That is, a low-temperature treatment liquid is supplied from the nozzle 7 to the substrate back surface Wb to form a liquid film 11b of the low-temperature treatment liquid to lower the temperature of the substrate W and the liquid film 11f, while the ultrasonic vibration to the liquid film 11b is reduced. No grant has been made.

  Also, as shown in FIG. 5B, the supply of the low temperature processing liquid to the substrate back surface Wb is continued after the liquid film forming process, and the substrate W and the liquid film 11f are kept cooled as in the first embodiment. Similarly, the freezing process is executed. Then, when the frozen film 13f is formed on the entire surface of the substrate surface Wf and the reinforcement of the pattern PT is completed, the output of the pulse signal to the vibrator 73 is started, and the liquid film 11b on the substrate back surface Wb is applied via the low temperature processing liquid. Ultrasonic vibration is applied to start ultrasonic cleaning of the back surface Wb of the substrate ((c) in the figure).

  After the start of the ultrasonic cleaning process, as in the first embodiment, the output of the pulse signal to the vibrator 73 is stopped after completion of the ultrasonic cleaning of the back surface Wb, and from the processing liquid supply unit 63. The pumping of the low temperature treatment liquid to the ultrasonic cleaning nozzle 7 is stopped. Further, after the splash guard 52 is raised to the original position to surround the periphery of the substrate W held on the spin chuck 2, the blocking member 9 is disposed at the opposing position, and the blocking member 9 is rotated together with the spin chuck 2. However, the thawing process of the frozen film 13f by DIW and the rinsing process of the front surface Wf and the back surface Wb are executed. Furthermore, after the drying process (spin drying) of the substrate W is performed, the processed substrate W is carried out.

  As described above, according to the second embodiment, since the ultrasonic cleaning process is performed on the back surface Wb of the substrate in a state where the pattern PT is structurally reinforced by the frozen film 13f, the same effects as the first embodiment are obtained. Is obtained. Further, in the second embodiment, unlike the first embodiment, as shown in FIGS. 5A and 5B, a low-temperature processing liquid is supplied to the substrate back surface Wb before and during the liquid film freezing process, Since W and the liquid film 11f are cooled, the time required for the liquid film 11f to freeze is shortened compared to the first embodiment. Therefore, according to the second embodiment, the throughput can be improved compared to the first embodiment.

<Third Embodiment>
FIG. 6 is a view showing a third embodiment of the substrate processing apparatus according to the present invention, and FIG. 7 is a schematic view showing the operation of the substrate processing apparatus of FIG. The third embodiment is greatly different from the first embodiment in the supply mode and supply timing of the low-temperature treatment liquid. That is, in the third embodiment, the liquid supply pipe 25 is connected to the discharge port 71 of the ultrasonic cleaning nozzle 7. The inlet 72 of the ultrasonic cleaning nozzle 7 is connected to the liquid supply unit 62 and the processing liquid supply unit 63, and DIW is supplied from the liquid supply unit 62 and low-temperature processing liquid is supplied from the processing liquid supply unit 63. Supply is performed selectively. Therefore, when DIW is pumped into the nozzle through the introduction port 72, DIW is supplied as a rinse liquid to the central portion of the substrate back surface Wb through the discharge port 71, the liquid supply pipe 25, and the nozzle 27 of the nozzle 7. . On the other hand, when the low temperature processing liquid is pumped into the nozzle through the introduction port 72, the low temperature processing liquid is supplied to the central portion of the substrate back surface Wb through the discharge port 71, the liquid supply pipe 25, and the nozzle 27 of the nozzle 7. The When a pulse signal is given to the vibrator 73 in parallel with the supply of the low temperature processing liquid, ultrasonic vibration is given to the liquid film 11b of the low temperature processing liquid formed on the substrate back surface Wb via the low temperature processing liquid. Ultrasonic cleaning of the substrate back surface Wb is executed. Since the other basic configuration is the same as that of the first embodiment, the same reference numeral is assigned to the same configuration, and the description of the configuration is omitted.

  Next, the cleaning operation in the third embodiment will be described with reference to FIG. In the third embodiment, the substrate is loaded, the liquid film is formed, and the liquid film is frozen as in the first embodiment (FIG. 7A), but ultrasonic cleaning is started during the liquid film freezing process. Is done. That is, at the initial stage of liquid film freezing, the frozen film 13f is formed at the center of the substrate surface Wf as shown in FIG. As the nozzle 3 moves, the frozen film 13f is spread from the central portion of the substrate surface Wf to the peripheral portion, and in the later stage of the liquid film freezing, the liquid film 11f formed on the substrate surface Wf is formed by the completion of the scanning of the nozzle 3. The whole is frozen, and a frozen film 13f is formed on the entire surface of the substrate surface Wf. Thus, the range in which the frozen film 13f is formed changes with time. Therefore, in the third embodiment, the control unit 4 selectively pumps the low temperature processing liquid to the nozzle 7 during the liquid film freezing process and supplies the low temperature processing liquid to the central portion of the substrate back surface Wb. By controlling the flow rate of the liquid, the rotation speed of the substrate W, and the like, the supply region of the low-temperature treatment liquid on the substrate back surface Wb is controlled to be within the region located on the opposite side of the frozen film 13f formed on the substrate surface Wf. ing. Accordingly, as shown in FIG. 5B, since the frozen film 13f is formed only in the vicinity of the center portion of the substrate surface Wf at the initial stage of the liquid film freezing, the liquid film 11b of the low temperature processing solution is also near the center portion of the substrate back surface Wb. Only formed. In addition, a pulse signal is given from the ultrasonic oscillator 75 to the vibrator 73 in accordance with an operation command from the control unit 4, and ultrasonic vibration is given to the liquid film 11b through the low-temperature treatment liquid, and the central portion of the substrate back surface Wb is applied. On the other hand, ultrasonic cleaning is performed.

  Further, as the liquid film freezing process proceeds, the control unit 4 causes the flow rate of the low temperature processing liquid, the rotation speed of the substrate W, etc. as the formation range of the frozen film 13f widens as shown in FIG. To increase the area of the liquid film 11b of the low-temperature treatment liquid (however, the range of the liquid film 11b is limited to the area located on the opposite side of the frozen film 13f as described above). As a result, the range of the back surface of the substrate to be ultrasonically cleaned spreads from the central portion to the peripheral portion, and the entire back surface of the substrate Wb is ultrasonically cleaned as the frozen film 13f is formed on the entire surface of the substrate Wf. In the third embodiment, the periphery of the substrate W held by the spin chuck 2 is splashed in order to supply the ultrasonic low-temperature treatment liquid from the nozzle 27 disposed below the center of the back surface to the center of the substrate back surface Wb. The ultrasonic cleaning of the substrate back surface Wb can be performed while being surrounded by the guard 52.

  When the ultrasonic cleaning of the back surface Wb is completed in this way, the output of the pulse signal to the vibrator 73 is stopped and the pumping of the low-temperature processing liquid from the processing liquid supply unit 63 to the ultrasonic cleaning nozzle 7 is stopped. Thereafter, the splash guard 52 is raised to the original position to surround the periphery of the substrate W held by the spin chuck 2. Further, the blocking member 9 is disposed at the opposing position, and the blocking member 9 is rotated together with the spin chuck 2. Furthermore, the nozzle 7 is switched so that DIW is supplied, and the DIW is supplied from the nozzle 97 and the nozzle 27 to the front and back surfaces Wf and Wb of the substrate W that is rotationally driven before the frozen film 13f is melted. As a result, the supply of DIW to the front and back surfaces Wf and Wb of the substrate W being rotated is started, and the thawing process of the frozen film 13f by DIW and the rinsing process of the front surface Wf and the back surface Wb are executed. As a result, the frozen film 13f containing particles is melted and rinsed and removed from the substrate surface Wf, and the treatment liquid adhering to the back surface Wb is rinsed and removed ((d) in the figure).

  Subsequently, the control unit 4 increases the rotation speed of the motors of the chuck rotating mechanism 22 and the blocking member rotating mechanism 53 to rotate the substrate W and the blocking member 9 at high speed, and executes the drying process (spin drying) of the substrate W. The processed substrate W is unloaded.

  As described above, according to the third embodiment, since the ultrasonic cleaning process is performed during the freezing of the liquid film, the throughput can be improved as compared with the first embodiment. Further, by controlling the flow rate of the low-temperature treatment liquid, the rotation speed of the substrate W, and the like, the region where the supply region of the low-temperature treatment liquid on the substrate back surface Wb is located on the opposite side of the frozen film 13f formed on the substrate surface Wf. Therefore, the frozen film 13f always exists on the opposite side of the ultrasonic cleaning region (formation range of the liquid film 11b), and the pattern PT is structurally reinforced. Therefore, it is possible to reliably prevent the pattern PT from being damaged by the ultrasonic cleaning.

  In the third embodiment, unlike the first and second embodiments, the periphery of the substrate W held by the spin chuck 2 is always surrounded by the splash guard 52 during the cleaning process. It is possible to reliably prevent the low temperature processing liquid from being scattered around the apparatus.

<Fourth embodiment>
FIG. 8 is a view showing a fourth embodiment of the substrate processing apparatus according to the present invention, and FIG. 9 is a schematic view showing the operation of the substrate processing apparatus of FIG. The fourth embodiment differs greatly from the first embodiment in that ultrasonic vibration is applied from the substrate surface side. That is, in the fourth embodiment, the liquid supply pipe 25 is connected not only to the liquid supply unit 62 but also to the processing liquid supply unit 63, so that DIW is supplied from the liquid supply unit 62 and low temperature from the processing liquid supply unit 63. The supply of the processing liquid is selectively executed. Further, the ultrasonic cleaning nozzle 7 is provided so as to be able to discharge the ultrasonic low-temperature treatment liquid toward the surface Wf of the substrate W held by the spin chuck 2. In addition, a nozzle drive mechanism 81 is provided to drive the nozzle 7. In this nozzle drive mechanism 81, the rotation motor 82 is provided on the outer side in the circumferential direction of the spin chuck 2. An arm 84 is connected to the rotary shaft 83 of the rotary motor 82 so as to extend in the horizontal direction, and the ultrasonic cleaning nozzle 7 is attached to the tip of the arm 84. When the rotary motor 82 is driven in accordance with an operation command from the control unit 4, the arm 84 swings around the rotary shaft 83 and moves in the same manner as the cooling gas discharge nozzle 3. Since the other basic configuration is the same as that of the first embodiment, the same reference numeral is assigned to the same configuration, and the description of the configuration is omitted.

  Next, the cleaning operation in the fourth embodiment will be described with reference to FIG. In the fourth embodiment, substrate loading, liquid film formation, and liquid film freezing are executed in the same manner as in the first embodiment (FIGS. 7A and 7B). Then, as shown in FIG. 5C, when the liquid film freezing process is completed, the control unit 4 selectively pumps the low-temperature processing liquid to the liquid supply pipe 25 to send the low-temperature processing liquid from the nozzle 27 to the back surface of the substrate. The liquid film 11b of the low-temperature processing liquid is formed by supplying the central portion of Wb and spreading it over the entire back surface of the substrate. On the other hand, on the substrate surface Wf side, a low-temperature treatment liquid is supplied from the nozzle 7 to the substrate surface Wf, and a pulse signal is given from the ultrasonic oscillator 75 to the vibrator 73 in response to an operation command from the control unit 4. Ultrasonic vibration is applied to the liquid film 11b through the liquid, the frozen film 13f, and the substrate W, and ultrasonic cleaning is performed on the substrate back surface Wb. In the fourth embodiment, since the ultrasonic low-temperature treatment liquid is supplied from the substrate surface Wf side, the substrate W held by the spin chuck 2 is surrounded by the splash guard 52 as in the third embodiment. The ultrasonic cleaning of the substrate back surface Wb can be performed as it is. Thus, in the fourth embodiment, the nozzle 27 corresponds to the “first nozzle” of the present invention, and the low-temperature processing liquid supplied from the nozzle 27 corresponds to the “first processing liquid” of the present invention. The nozzle 7 corresponds to the “second nozzle” of the present invention, and the ultrasonic low-temperature processing liquid supplied from the nozzle 7 corresponds to the “second processing liquid” of the present invention.

  When the ultrasonic cleaning of the back surface Wb is completed in this way, the output of the pulse signal to the vibrator 73 is stopped and the pumping of the low-temperature processing liquid from the processing liquid supply unit 63 to the ultrasonic cleaning nozzle 7 is stopped. Thereafter, the blocking member 9 is disposed at the opposing position, and the blocking member 9 is rotated together with the spin chuck 2. Furthermore, the nozzle 7 is switched so that DIW is supplied, and the DIW is supplied from the nozzle 97 and the nozzle 27 to the front and back surfaces Wf and Wb of the substrate W that is rotationally driven before the frozen film 13f is melted. As a result, the supply of DIW to the front and back surfaces Wf and Wb of the substrate W being rotated is started, and the thawing process of the frozen film 13f by DIW and the rinsing process of the front surface Wf and the back surface Wb are executed. As a result, the frozen film 13f containing particles is melted and rinsed and removed from the substrate surface Wf, and the treatment liquid adhering to the back surface Wb is rinsed and removed ((d) in the figure).

  Subsequently, the control unit 4 increases the rotation speed of the motors of the chuck rotating mechanism 22 and the blocking member rotating mechanism 53 to rotate the substrate W and the blocking member 9 at high speed, and executes the drying process (spin drying) of the substrate W. The processed substrate W is unloaded.

  As described above, according to the fourth embodiment, since the pattern PT is structurally reinforced by the frozen film 13f as in the first embodiment, the ultrasonic cleaning process is performed on the substrate back surface Wb. The same effects as those of the first embodiment can be obtained. In the fourth embodiment, unlike the first embodiment, the periphery of the substrate W held by the spin chuck 2 is always surrounded by the splash guard 52 during the cleaning process. Can be reliably prevented from scattering around the apparatus.

<Others>
The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in the above embodiment, DIW is used as the liquid for forming the liquid film of the present invention. However, the present invention is not limited to this. For example, pure water, carbonated water, hydrogen water, degassed water, dissolved oxygen, dissolved nitrogen and the like are dissolved. You may use the chemical | medical solution etc., such as the pure water which adjusted the gaseous component, and SC1 solution (mixed aqueous solution of ammonia water and hydrogen peroxide water).

  In the above embodiment, a solute that does not form a solid solution with the liquid (DIW in the embodiment) is dissolved in the liquid that constitutes the liquid film (IPA in the embodiment) to lower the freezing point than the liquid. The liquid component to be used is arbitrary and may be any liquid component having a temperature equal to or lower than the freezing point of the liquid. For example, chemical liquid such as SC1, pure water, carbonated water, hydrogen water, degassed water, dissolved oxygen, dissolved nitrogen, etc. Pure water with a dissolved gas component adjusted can be used. In addition, phenomena other than the above-described freezing point depression may be used. For example, the same supercooled liquid as the liquid (DIW in the embodiment) constituting the liquid film 11f may be used as the processing liquid.

  The present invention relates to a semiconductor wafer, a glass substrate for photomask, a glass substrate for liquid crystal display, a glass substrate for plasma display, a substrate for FED (Field Emission Display), an optical disk substrate, a magnetic disk substrate, a magneto-optical disk substrate, etc. The substrate can be applied to a substrate processing apparatus and a substrate processing method for ultrasonically cleaning the other main surface without damaging a pattern formed on the one main surface.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows 1st Embodiment of the substrate processing apparatus concerning this invention. It is a block diagram which shows the control structure of the substrate processing apparatus of FIG. It is a figure which shows a motion of a cooling gas discharge nozzle. It is a figure which shows typically the washing process with respect to the surface of a board | substrate, and a back surface. It is a schematic diagram which shows 2nd Embodiment of the substrate processing apparatus concerning this invention. It is a figure which shows 3rd Embodiment of the substrate processing apparatus concerning this invention. It is a schematic diagram which shows operation | movement of the substrate processing apparatus of FIG. It is a figure which shows 4th Embodiment of the substrate processing apparatus concerning this invention. It is a schematic diagram which shows operation | movement of the substrate processing apparatus of FIG.

Explanation of symbols

3. Cooling gas discharge nozzle (cooling gas discharge means)
7 ... Ultrasonic cleaning nozzles 11b, 11f ... Liquid film 13f ... Frozen film 22 ... Chuck rotation mechanism 27 ... Nozzle 31 ... Rotation motor (relative movement mechanism)
73 ... Vibrator W ... Substrate Wf ... Substrate surface (one main surface)
Wb: Substrate back surface (the other main surface)

Claims (11)

In the substrate processing method for cleaning the other main surface of the substrate, in which a pattern is formed on one main surface of both main surfaces,
A liquid film forming step of forming a liquid film on the one main surface;
A freezing step of freezing the liquid film on the one main surface;
A substrate processing method comprising: an ultrasonic cleaning step of ultrasonically cleaning the other main surface in a state where the frozen film formed by the freezing step is present on the one main surface.   The substrate processing method according to claim 1, wherein the ultrasonic cleaning step is executed after a frozen film is formed on the entire surface of the one main surface by the freezing step.   The ultrasonic cleaning step is started during the execution of the freezing step, and the ultrasonic cleaning is started from a region of the other main surface located on the opposite side of the frozen film formed on the one main surface by the freezing step. The substrate processing method according to claim 1, which is a process.   The ultrasonic cleaning step is a step of supplying a treatment liquid having a temperature equal to or lower than a freezing point of the liquid constituting the liquid film to the other main surface to perform ultrasonic cleaning. The substrate processing method as described.   5. The substrate processing according to claim 4, wherein the ultrasonic cleaning step is a step of ultrasonic cleaning by propagating ultrasonic vibration to a liquid film of the processing liquid formed on the other main surface through the processing liquid. Method.   In the ultrasonic cleaning step, ultrasonic cleaning is performed by propagating ultrasonic vibrations from the one main surface side to the liquid film of the processing liquid formed on the other main surface and the other main surface through the substrate. The substrate processing method according to claim 4, which is a process. In the substrate processing apparatus for cleaning the other main surface of the substrate, in which a pattern is formed on one of the main surfaces,
Freezing means for freezing a liquid film formed on one main surface of the substrate;
A substrate processing apparatus comprising: an ultrasonic cleaning unit that ultrasonically cleans the other main surface in a state where the frozen film formed by the freezing unit exists on the one main surface. The ultrasonic cleaning means includes
A nozzle for supplying a treatment liquid having a temperature below the freezing point of the liquid constituting the liquid film to the other main surface;
Ultrasonic vibration is propagated to the liquid film of the processing liquid formed on the other main surface by applying ultrasonic vibration to the processing liquid discharged from the nozzle toward the other main surface. The substrate processing apparatus according to claim 7, further comprising a vibrator for sonic cleaning. A control means for controlling a range of a liquid film formed on the other main surface by the processing liquid supplied from the nozzle;
The ultrasonic cleaning means starts supplying the processing liquid from the nozzle during freezing of the liquid film by the freezing means,
The substrate processing apparatus according to claim 8, wherein the control unit controls a liquid film range of the processing liquid on the other main surface within a range of a frozen film formed on the one main surface by the freezing unit. The ultrasonic cleaning means includes
A first nozzle for supplying a first treatment liquid having a temperature below the freezing point of the liquid constituting the liquid film to the other main surface;
A second nozzle for supplying a second treatment liquid having a temperature below the freezing point of the liquid constituting the liquid film to the one main surface;
A liquid film of the first processing liquid formed on the other main surface through the substrate by applying ultrasonic vibration to the second processing liquid discharged from the second nozzle toward the one main surface. The substrate processing apparatus according to claim 7, further comprising: a vibrator that performs ultrasonic cleaning by propagating ultrasonic vibration to the substrate. The freezing means includes
A cooling gas discharge section that locally discharges a cooling gas having a temperature lower than the freezing point of the liquid constituting the liquid film formed on the one main surface toward the one main surface;
A relative movement mechanism for moving the cooling gas discharge section relative to the substrate along the one main surface;
11. The liquid film formed on the one main surface is frozen by moving the cooling gas discharge portion relative to the substrate by the relative movement mechanism while discharging the cooling gas from the cooling gas discharge portion. The substrate processing apparatus as described in any one of these.

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