JP2009021409A - Freezing processor, freezing processing method, and substrate processing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently freeze a liquid membrane formed on a surface of a substrate to be processed while suppressing stress concentration. <P>SOLUTION: Cooling gas having temperature lower than the coagulating point of DIW forming liquid membranes 11f and 11b is supplied toward a reverse surface of the substrate W to freeze the liquid membranes 11f and 11b. Further, the cooling gas is discharged locally to a reverse-surface center part of the substrate W to make cooling capability higher for the reverse-surface center part than for reverse-surface circumferential edges of the substrate W. Consequently, liquid membrane parts out of the whole liquid membranes 11f and 11b corresponding to the substrate center part are first frozen and then the liquid membrane freezing advances toward the substrate edges. Therefore, liquid membrane parts corresponding to the edges of the substrate W are frozen lastly. Consequently, part of stress due to volume expansion is released in an outer circumferential direction at the parts frozen lastly, i.e. edges of the liquid membranes to suppress the stress concentration. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  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 present invention relates to a freezing processing apparatus that freezes a liquid film formed on a surface to be processed of various substrates (hereinafter simply referred to as “substrate”), a substrate processing apparatus including the freezing processing apparatus, and a freezing processing method.

  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. In particular, such a freezing technique is used as part of a cleaning process for a substrate. In other words, fine contaminants such as particles adhering to the substrate surface without collapsing the pattern formed on the substrate surface with the miniaturization, higher functionality, and higher accuracy of devices typified by semiconductor devices. It has become increasingly difficult to remove. Therefore, particles adhering to the substrate surface are removed using the above-described freezing technique as follows.

  First, a liquid is supplied to the substrate surface to form a liquid film on the substrate surface. Subsequently, 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, thereby removing the particles from the substrate surface together with the frozen film.

  Here, as the liquid film freezing technique for freezing the liquid film formed on the substrate surface, there are the following. For example, the apparatus described in Patent Document 1 is provided with a cooling plate for cooling the substrate below zero to form a frozen film. The cooling plate is made of a metal material such as aluminum, and is disposed at the bottom of the chamber. In addition, a plurality of protrusions are formed on the upper surface of the cooling plate, and the substrate supports the protrusions while being slightly separated from the upper surface of the cooling plate. In addition, a tube for pouring a cooling medium is embedded in a serpentine shape inside the cooling plate. For this reason, the substrate held on the cooling plate by the supply of the cooling medium is cooled to form a frozen film.

Japanese Patent No. 3343013 (FIG. 1)

  By the way, in the apparatus employing the above-described freezing method, the following problems may occur. That is, in the above apparatus, the entire lower surface of the substrate is simultaneously cooled by the cooling plate, and the freezing of the liquid film formed on the substrate is started overall and simultaneously. Then, freezing proceeds in each part of the liquid film. At this time, with the volume expansion due to freezing, a relatively large stress may be generated at the position where the freezing is finally completed. For example, when freezing progresses from the peripheral part of the liquid film and the central part is finally frozen, the final frozen part freezes while receiving stress intensively from the periphery. As a result, stress concentration occurs on the substrate at the final frozen site, which may adversely affect the patterns and circuits formed on the substrate.

  In addition, when a liquid film is formed on the surface of the substrate facing the cooling plate, that is, the lower surface of the substrate, it is necessary to provide a sufficient distance between the substrate and the cooling plate. This is because if the liquid film is frozen in a state where the substrate and the cooling plate are arranged close to each other, the substrate and the cooling plate are firmly bonded via the frozen film. Similar considerations are necessary when a liquid film is formed only on the upper surface of the substrate. This is because there is a possibility that the liquid constituting the liquid film has sneak around the lower surface of the substrate. Therefore, when the liquid film is frozen using the cooling plate, it is necessary to provide a sufficient distance to prevent the liquid freezing between the substrate and the cooling plate. As a result, the distance between the substrate and the cooling plate is widened, the cooling heat from the cooling plate hardly reaches the substrate, and it is difficult to perform an efficient freezing process.

  The present invention has been made in view of the above problems, and a freezing processing apparatus capable of efficiently freezing a liquid film formed on a processing surface of a substrate while suppressing the occurrence of stress concentration, and the freezing processing It is an object of the present invention to provide a substrate processing apparatus and a freezing method provided with the apparatus.

  A freezing processing apparatus according to the present invention is a freezing processing apparatus for freezing a liquid film formed on a surface to be processed of a substrate, and in order to achieve the above object, a substrate holding means for holding the substrate in a horizontal posture, and a liquid A lower cooling means for supplying a cooling gas having a temperature lower than the freezing point of the liquid constituting the film toward the lower surface of the substrate held by the substrate holding means to freeze the liquid film, the lower cooling means being a cooling gas The substrate is discharged locally toward the lower surface center portion of the substrate, and the entire substrate is cooled in a state where the cooling capacity for the lower surface center portion is higher than that of the lower surface peripheral edge portion of the substrate.

  A freezing method according to the present invention is a freezing method for freezing a liquid film formed on a surface to be processed of a substrate, and in order to achieve the above object, a substrate holding step for holding the substrate in a horizontal posture, And a liquid film freezing step for freezing the liquid film by supplying a cooling gas having a temperature lower than the freezing point of the liquid constituting the liquid film toward the lower surface of the substrate. By locally discharging the cooling gas toward the substrate, the cooling capacity for the lower surface central portion is made higher than the cooling capacity for the lower surface peripheral portion of the substrate, and the freezing of the liquid film proceeds from the substrate central portion toward the substrate peripheral portion. It is characterized by that.

  In the invention configured as described above (freezing apparatus and method), a cooling gas having a temperature lower than the freezing point of the liquid constituting the liquid film is supplied toward the lower surface of the substrate on which the liquid film is formed on the surface to be processed. Then, the liquid film is frozen. In other words, when only the upper surface of the substrate is the surface to be processed and a liquid film is formed on the upper surface of the substrate, the cooling heat of the cooling gas is directly applied to the lower surface of the substrate, and the lower surface of the substrate is the processed surface. In the case where a liquid film is formed on the lower surface of the substrate, cold heat from the cooling gas is applied through the liquid film. Therefore, regardless of the position of the substrate, the substrate and the liquid film are cooled by cold heat, and the liquid film is efficiently frozen.

  In the present invention, since the cooling gas is locally discharged toward the lower surface center portion of the substrate, the cooling capacity for the lower surface center portion is higher than the cooling capability for the lower surface peripheral portion of the substrate. For this reason, the liquid film portion corresponding to the central portion of the substrate in the entire liquid film is first frozen, and further freezing of the liquid film proceeds toward the peripheral portion of the substrate. Therefore, the liquid film portion corresponding to the peripheral portion of the substrate is finally frozen, and the occurrence of stress concentration is suppressed. In addition, since no pattern or circuit is formed on the periphery of the substrate, controlling the freezing process so that the periphery of the liquid film becomes the final freezing part also prevents stress concentration on the pattern. Effective above.

  Here, the substrate holding means is composed of a base plate provided facing the lower surface of the substrate at a position lower than the lower surface of the substrate, and a support member provided on the upper surface of the base plate and supporting the substrate, and a lower cooling means. May be constituted by a lower gas discharge portion that discharges cooling gas toward the lower surface central portion of the substrate through an opening provided in the central portion of the base plate. When such a configuration is adopted, the cooling gas locally discharged toward the central portion of the lower surface of the substrate further moves in the radial direction of the substrate through a space sandwiched between the base plate and the lower surface of the substrate. I will do it. Therefore, the cooling gas can be prevented from being separated from the substrate, and the liquid film freezing process can be executed with high cooling efficiency. Further, the cooling gas supplied as described above is guided by the substrate and the base plate and spreads radially around the center of the lower surface. For this reason, the freezing of the liquid film can surely proceed from the center of the substrate toward the periphery of the substrate. In order to spread the cooling gas in the radial direction of the substrate in this way, a guide member that guides the cooling gas discharged toward the central portion of the lower surface of the substrate to the peripheral portion of the lower surface of the substrate may be further provided.

  Further, the cooling gas may be supplied not only to the lower surface of the substrate but also to the upper surface of the substrate in a state where the cooling gas is supplied to the lower surface of the substrate. As a result, the liquid film can be frozen in a shorter time. As one of the gas supply modes, for example, while the cooling gas is locally discharged from the nozzle toward the upper surface of the substrate rotating around the rotation center, the nozzle is directed from the center of the upper surface of the substrate toward the peripheral edge of the upper surface. The cooling gas may be supplied to the entire upper surface of the substrate by relative movement. By this cooling gas supply, liquid film freezing from the central part to the peripheral part can be further ensured.

  Further, in order to achieve the above object, the substrate processing apparatus according to the present invention has a substrate holding means for holding the substrate having the liquid film formed on the surface to be processed in a horizontal posture and a freezing point of the liquid constituting the liquid film. A cooling gas having a temperature is supplied toward the lower surface of the substrate held by the substrate holding means to freeze the liquid film, and a post-treatment liquid is supplied to the liquid film after freezing to form the liquid film. A film removing means for removing from the surface to be processed of the substrate, and the lower cooling means locally discharges a cooling gas toward the lower surface central portion of the substrate so that the cooling ability for the lower surface central portion is higher than that of the lower peripheral edge portion of the substrate. It is characterized by enhancing.

  In the substrate processing apparatus configured as described above, as in the above-described invention (freezing processing apparatus and method), the freezing point of the liquid constituting the liquid film is directed toward the lower surface of the substrate on which the liquid film is formed on the surface to be processed. Since the liquid film is frozen by supplying the cooling gas having a lower temperature, the liquid film is efficiently frozen. In addition, since the cooling gas is locally discharged toward the central portion of the lower surface of the substrate, the cooling capacity for the central portion of the lower surface is higher than that for the peripheral edge of the lower surface of the substrate. Concentration is suppressed. Then, the post-processing liquid is supplied to the liquid film frozen in this manner, and the liquid film is removed from the surface to be processed of the substrate. Therefore, a desired surface treatment can be performed on the surface to be processed without damaging the surface to be processed of the substrate.

  According to the present invention, the liquid film is frozen by supplying the cooling gas having a temperature lower than the freezing point of the liquid constituting the liquid film toward the lower surface of the substrate on which the liquid film is formed on the processing surface. The membrane can be frozen efficiently. In addition, since the cooling gas is locally discharged toward the central portion of the lower surface of the substrate, the cooling capacity for the lower central portion is higher than that for the peripheral edge of the lower surface of the substrate, and the liquid film freezing is central. It progresses from the part toward the peripheral part, and the peripheral part of the liquid film becomes the final frozen part. As a result, part of the stress due to volume expansion can be released in the outer peripheral direction, and the stress applied to the substrate can be suppressed.

  FIG. 1 is a view showing an embodiment of a substrate processing apparatus according to the present invention. FIG. 2 is a block diagram showing a 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, by forming a liquid film on the substrate surface Wf and the back surface Wb, freezing the liquid film and then removing the frozen liquid film (frozen film) from the substrate surface Wf and the back surface Wb, This is an apparatus for performing a series of cleaning processes (liquid film formation + liquid film freezing + film removal) on the substrate W.

  The substrate processing apparatus includes a processing chamber 1 having a processing space for cleaning the substrate W therein, and the substrate W is placed in a substantially horizontal posture with the substrate surface Wf facing upward in the processing chamber 1. Cooling that discharges a cooling gas for freezing the liquid film toward the surface Wf of the substrate W held by the spin chuck 2 (corresponding to the “substrate holding means” of the present invention) that is held and rotated and the spin chuck 2 A gas discharge nozzle 3, a two-fluid nozzle 5 for supplying a droplet of a processing liquid to the substrate surface Wf, a chemical discharge nozzle 6 for discharging a chemical toward the surface Wf of the substrate W held by the spin chuck 2, and a spin A blocking member 9 is provided so as to face the surface Wf of the substrate W held by the chuck 2. As the treatment liquid, a chemical liquid or a rinse liquid such as pure water or DIW (deionized water) is used.

  Thus, in this embodiment, since the spin chuck 2 holds the substrate W in a horizontal posture with the substrate surface Wf on which the fine pattern is formed facing upward, the substrate surface Wf is the “upper surface of the substrate” of the present invention. The back surface Wb of the substrate corresponds to the “lower surface of the substrate” of the present invention. Of course, when the substrate back surface Wb is held upward, the back surface Wb corresponds to the “upper surface of the substrate” of the present invention, and the substrate surface Wf corresponds to the “lower surface of the substrate” of the present invention. In this embodiment, both the front surface Wf and the back surface Wb are treated surfaces, and a series of cleaning processes (liquid film formation + liquid film freezing + film removal) described below are executed.

  The spin chuck 2 has a rotation support shaft 21 connected to a rotation shaft of a chuck rotation mechanism 22 including a motor, and can rotate around a rotation center A0 by driving the chuck rotation mechanism 22. A disc-shaped spin base 23 is integrally connected to the upper end portion of the rotation spindle 21 by a fastening component such as a screw. Therefore, the spin base 23 rotates around the rotation center A0 by driving the chuck rotation mechanism 22 in accordance with an operation command from the control unit 4 (FIG. 2) that controls the entire apparatus. Thus, in this embodiment, the chuck rotation mechanism 22 functions as the “rotation drive unit” of the present invention.

  Near the periphery of the spin base 23, a plurality of chuck pins 24 for holding the periphery of the substrate W are provided upright. 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. Yes. 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.

  When the substrate W is delivered to the spin base 23, the plurality of chuck pins 24 are released, and when the substrate W is cleaned, the plurality of chuck pins 24 are pressed. State. By setting the pressed state, the plurality of chuck pins 24 can grip the peripheral edge of the substrate W and hold the substrate W in a substantially horizontal posture at a predetermined interval from the spin base 23. As a result, the substrate W is held with the front surface (pattern forming surface) Wf facing upward and the back surface Wb facing downward. Thus, in this embodiment, the spin base 23 and the chuck pin 24 function as the “base plate” and “support member” of the present invention, respectively.

  A first rotation motor 31 is provided outside the spin chuck 2. A first rotation shaft 33 is connected to the first rotation motor 31. A first arm 35 is connected to the first rotation shaft 33 so as to extend in the horizontal direction, and a cooling gas discharge nozzle 3 is attached to the tip of the first arm 35. Then, the first rotation motor 31 is driven according to the operation command from the control unit 4, so that the first arm 35 can be swung around the first rotation shaft 33.

  FIG. 3 is a view showing the operation of the cooling gas discharge nozzle provided in the substrate processing apparatus of FIG. Here, FIG. 4A is a side view and FIG. 4B is a plan view. When the first rotation motor 31 is driven to swing the first arm 35, the cooling gas discharge nozzle 3 faces the substrate surface Wf while moving the trajectory T in FIG. It moves along a locus T from the center position Pc toward the edge position Pe of the substrate W. Here, the rotation center position Pc is located on the rotation center A0 of the substrate W while facing the substrate surface Wf. Further, the cooling gas discharge nozzle 3 is movable to a standby position Ps retracted to the side of the substrate W.

  The cooling gas discharge nozzle 3 is connected to a cooling gas supply unit 64 (FIG. 2), and supplies the cooling gas from the cooling gas supply unit 64 to the cooling gas discharge nozzle 3 in accordance with an operation command from the control unit 4. For this reason, when the cooling gas discharge nozzle 3 is disposed opposite to the substrate surface Wf, the cooling gas is locally discharged from the cooling gas discharge nozzle 3 toward the substrate surface Wf. Therefore, in the state where the cooling gas is discharged from the cooling gas discharge nozzle 3, the control unit 4 moves the cooling gas discharge nozzle 3 along the movement trajectory T while rotating the substrate W. It can be supplied over the entire surface of Wf. As a result, when the liquid films 11f and 11b are formed on the substrate W as will be described later, the entire liquid films 11f and 11b are frozen to generate a frozen film 13f on the entire surface of the substrate surface Wf and the substrate back surface Wb. It is possible to generate the frozen film 13b on the entire surface.

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

  As the cooling gas, a gas having a temperature lower than the freezing point of the liquid constituting the liquid films 11f and 11b formed on the substrate W, such as nitrogen gas, oxygen gas, and clean air, is used. According to such a cooling gas, it is easy to remove contaminants contained in the cooling gas using a filter or the like before supplying the gas to the substrate W. Therefore, it is possible to prevent the substrate W from being contaminated when the liquid films 11f and 11b are frozen. In this embodiment, as will be described later, a liquid film 11f made of DIW is formed on the substrate surface Wf and a liquid film 11b made of DIW is formed on the back surface Wb of the substrate from the cooling gas discharge nozzle 3 toward the substrate surface Wf. The liquid films 11f and 11b are frozen by discharging the cooling gas. Therefore, the cooling gas used is adjusted to a temperature lower than the freezing point (freezing point) of DIW constituting the liquid film 11f.

  Thus, in this embodiment, the “upper cooling means” of the present invention is configured by the nozzle 3 and the first rotation motor 31 that moves the nozzle 3 relative to the substrate W along the substrate surface Wf. The rotation motor 31 corresponds to the “relative movement mechanism” of the present invention. In this embodiment, in addition to the upper cooling means, a “lower cooling means” for supplying the same cooling gas as described above toward the substrate rear surface Wb to freeze the liquid films 11f and 11b is provided. The configuration and operation will be described in detail later.

  A second rotation motor 51 is provided outside the spin chuck 2. A second rotation shaft 53 is connected to the second rotation motor 51, and a second arm 55 is connected to the second rotation shaft 53. A two-fluid nozzle 5 is attached to the tip of the second arm 55. The two-fluid nozzle 5 can be swung around the second rotation shaft 53 by driving the second rotation motor 51 in accordance with an operation command from the control unit 4. The two-fluid nozzle 5 discharges droplets of the processing liquid generated by mixing the processing liquid and gas in order to clean the substrate surface Wf.

  FIG. 4 is a diagram showing the configuration of the two-fluid nozzle. This two-fluid nozzle is a so-called external mixing type two-fluid nozzle that generates DIW droplets by colliding DIW and nitrogen gas (N2) as processing liquid in the air (outside the nozzle). The two-fluid nozzle 5 is inserted with a processing liquid discharge nozzle 502 having a processing liquid discharge port 521 inside the body 501. The processing liquid discharge port 521 is disposed on the upper surface portion 512 of the umbrella portion 511 of the two-fluid nozzle 5. For this reason, when DIW is supplied to the processing liquid discharge nozzle 502, DIW is discharged toward the substrate W from the processing liquid discharge port 521.

  A gas discharge nozzle 503 is provided in the vicinity of the processing liquid discharge nozzle 502 and defines a ring-shaped gas passage surrounding the processing liquid discharge nozzle 502. The front end of the gas discharge nozzle 503 is tapered and this nozzle opening faces the surface of the substrate W. For this reason, when nitrogen gas is supplied to the gas discharge nozzle 503, the nitrogen gas is discharged toward the substrate W from the gas discharge port 531 of the gas discharge nozzle 503.

  The discharge trajectory of nitrogen gas discharged in this way intersects the DIW discharge trajectory from the processing liquid discharge port 521. That is, the liquid (DIW) flow from the processing liquid discharge port 521 collides with the gas (nitrogen gas) flow at the collision site G in the mixing region. The gas flow is discharged so as to converge at the collision site G. This mixed region is a space at the lower end of the body 501. For this reason, the DIW is quickly formed into droplets by the nitrogen gas colliding with it in the immediate vicinity of the DIW discharge direction from the processing liquid discharge port 521. In this way, cleaning droplets are generated.

  FIG. 5 is a diagram schematically showing the configuration and operation of the lower cooling means. The rotation support shaft 21 of the spin chuck 2 is a hollow shaft. As shown in FIGS. 1 and 5, a processing liquid supply pipe 25 for supplying a processing liquid to the back surface Wb of the substrate W is inserted into the rotation support shaft 21. The processing liquid supply tube 25 passes through an opening 231 provided at the center of the spin base 23 and extends to a position close to the lower surface (back surface Wb) of the substrate W held by the spin chuck 2. Further, a processing liquid nozzle 27 that discharges the processing liquid toward the center of the lower surface of the substrate W is provided at the tip of the processing liquid supply pipe 25. The treatment liquid supply pipe 25 is connected to the chemical liquid supply unit 61 and the rinsing liquid supply unit 62, and chemical liquid such as SC1 solution (mixed aqueous solution of ammonia water and hydrogen peroxide solution) is supplied from the chemical liquid supply unit 61 to the rinse liquid supply. A rinse liquid such as DIW is selectively supplied from the unit 62.

  A gap between the inner wall surface of the rotation spindle 21 and the outer wall surface of the processing liquid supply pipe 25 forms a cylindrical gas supply path 29. The gas supply path 29 is connected to the cooling gas supply unit 64 and the dry gas supply unit 65, and can selectively supply the cooling gas and the dry gas toward the central portion (lower surface central portion) of the substrate back surface Wb. It has become.

  In this embodiment, when the liquid film freezing process is executed as described later, the cooling gas is discharged toward the center of the substrate back surface Wb through the gas supply path 29. Thus, the hollow rotating support shaft 21 functions as the “lower gas discharge portion” of the present invention, and discharges the cooling gas toward the center of the lower surface of the substrate W through the opening 231. Thus, the cooling gas applied to the central portion of the lower surface of the substrate W is further circulated in the radial direction of the substrate W through a space sandwiched between the substrate back surface Wb and the spin base 23. For this reason, the substrate W and the liquid films 11f and 11b are cooled by the cooling gas supply from below, and the liquid film is frozen. Moreover, focusing on its cooling capacity (that is, the ability to freeze the substrate W and the liquid films 11f and 11b), it has the following characteristics. That is, as shown in the uppermost graph of FIG. 5, the cooling capacity corresponding to the central portion of the substrate is higher than that of the peripheral portion of the substrate. In this embodiment, since the cooling gas is circulated through the gas supply path 29, it is desirable to employ a heat insulating structure for the gas supply path 29.

  On the other hand, when performing the drying process as will be described later, the nitrogen gas is discharged as a drying gas toward the center of the substrate back surface Wb through the gas supply path 29. The nitrogen (dry) gas is supplied to a space formed between the spin base 23 and the substrate back surface Wb, similarly to the cooling gas. In this embodiment, nitrogen gas is supplied as the dry gas from the dry gas supply unit 65, but air or other inert gas may be discharged.

  Returning to FIG. 1, the description will be continued. A third rotation motor 67 is provided outside the spin chuck 2. A third rotation shaft 68 is connected to the third rotation motor 67. A third arm 69 is connected to the third rotation shaft 68 so as to extend in the horizontal direction, and a chemical liquid discharge nozzle 6 is attached to the tip of the third arm 69. Then, the third rotation motor 67 is driven in accordance with an operation command from the control unit 4 so that the chemical solution discharge nozzle 6 is retracted laterally from the discharge position and the discharge position above the rotation center A0 of the substrate W. It is possible to reciprocate between the standby position. The chemical solution discharge nozzle 6 is connected to the chemical solution supply unit 61, and a chemical solution such as an SC1 solution is pumped to the chemical solution discharge nozzle 6 in accordance with an operation command from the control unit 4.

  A disc-shaped blocking member 9 having an opening at the center is provided above the spin chuck 2. The blocking member 9 has a lower surface (bottom surface) that faces the substrate surface Wf and is substantially parallel to the substrate surface Wf. The planar size of the blocking member 9 is equal to or greater than the diameter of the substrate W. The blocking member 9 is attached substantially horizontally to a lower end portion of a support shaft 91 having a substantially cylindrical shape, and 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. The blocking member rotating mechanism 93 is configured to rotate the blocking member 9 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.

  Further, the blocking member elevating mechanism 94 can cause the blocking member 9 to face the spin base 23 in the vicinity of the spin base 23 according to an operation command from the control unit 4, or to separate the blocking member 9. Specifically, the control unit 4 operates the blocking member elevating mechanism 94 so that when the substrate W is carried into and out of the substrate processing apparatus, the separation position above the spin chuck 2 (the position shown in FIG. 1). ) To raise the blocking member 9. On the other hand, when a predetermined process is performed on the substrate W, the blocking member 9 is lowered to a facing position set very close to the surface Wf of the substrate W held by the spin chuck 2.

  The support shaft 91 is finished in a hollow shape, and a gas supply path 95 communicating with the opening of the blocking member 9 is inserted into the support shaft 91. The gas supply path 95 is connected to the dry gas supply unit 65, and nitrogen gas is supplied from the dry gas supply unit 65. In this embodiment, nitrogen gas is supplied from the gas supply path 95 to the space formed between the blocking member 9 and the substrate surface Wf during the drying process after the cleaning process for the substrate W. A liquid supply pipe 96 communicating with the opening of the blocking member 9 is inserted into the gas supply path 95, and a nozzle 97 is coupled to the lower end of the liquid supply pipe 96. The liquid supply pipe 96 is connected to the rinse liquid supply unit 62, and the rinse liquid is supplied from the rinse liquid supply unit 62, so that the rinse liquid can be discharged from the nozzle 97 toward the substrate surface Wf.

  Next, the cleaning processing operation in the substrate processing apparatus configured as described above will be described with reference to FIGS. FIG. 6 is a flowchart showing the operation of the substrate processing apparatus of FIG. FIG. 7 is a schematic diagram showing the operation of the substrate processing apparatus of FIG. In this apparatus, when an unprocessed substrate W is carried into the apparatus, the control unit 4 controls each part of the apparatus to perform a series of cleaning processes on the substrate W (liquid film formation + liquid film freezing + film removal). Is executed. Here, a fine pattern may be formed on the substrate surface Wf. That is, the substrate surface Wf is a pattern formation surface. Therefore, in this embodiment, the substrate W is carried into the processing chamber 1 with the substrate surface Wf facing upward and is held by the spin chuck 2 (step S1; substrate holding step). At this time, the blocking member 9 is in a separated position to prevent interference with the substrate W.

  When the unprocessed substrate W is held on the spin chuck 2, the blocking member 9 is lowered to the facing position 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. The control unit 4 drives the chuck rotation mechanism 22 to rotate the spin chuck 2 and supplies DIW to the substrate W from the nozzles 27 and 97. Centrifugal force accompanying the rotation of the substrate W acts on the DIW supplied to the substrate W, and the DIW is uniformly spread outward in the radial direction of the substrate W, and a part thereof is shaken off the substrate. As a result, as shown in FIG. 7 (a), a liquid film having a predetermined thickness on the entire substrate surface Wf and the back surface Wb while uniformly controlling the thickness of the liquid film over the entire surface of the substrate surface Wf and the back surface Wb. Water film) can be formed (step S2; liquid film forming step). In forming the liquid film, it is not an essential requirement to shake off a part of the DIW supplied to the substrate W as described above. For example, the liquid film may be formed on the substrate W without shaking the DIW from the substrate W while the substrate W is rotated at a relatively low speed. Thus, in this embodiment, the nozzles 27 and 97 function as “liquid film forming means” of the present invention.

  Thus, when the liquid film forming step is completed, the control unit 4 places the blocking member 9 in the separated position. Then, the control unit 4 stops the supply of DIW from the nozzle 27 and discharges the cooling gas to the central portion of the substrate back surface Wb through the gas supply path 29. Thereby, the cooling heat by the cooling gas is given to the central portion of the liquid film and the central portion of the substrate W, and the central portions of the liquid films 11f and 11b are cooled first, and the cooling capability corresponding to the central portion of the substrate is It is higher than the department. In this embodiment, the control unit 4 also supplies the cooling gas from above the substrate by operating the cooling gas discharge nozzle 3 as follows in a state where the cooling gas is supplied to the substrate back surface Wb. That is, the control unit 4 moves the cooling gas discharge nozzle 3 from the standby position Ps to the cooling gas supply start position, that is, the rotation center position Pc. Then, the cooling gas is discharged from the cooling gas discharge nozzle 3 toward the surface Wf of the rotating substrate W. As described above, in the present embodiment, the cooling gas from the lower side of the substrate W and the cooling gas from the upper side are supplied to the central portion of the substrate. Therefore, as shown in FIG. , 11b, the liquid film portion corresponding to the central portion of the substrate is first frozen to form frozen films 13f and 13b. Thus, the liquid film freezing process is started (step S3).

  The control unit 4 gradually moves the cooling gas discharge nozzle 3 toward the edge position Pe of the substrate W while continuing to supply the cooling gas from the gas supply path 29 to the central portion of the substrate back surface Wb. To go. As described above, in this embodiment, the cooling capacity by the cooling gas from the lower side of the substrate W has the distribution shown in FIG. 5A, and the liquid films 11f and 11b are frozen by the movement of the nozzle 3 (frozen area). ) Is spread from the center of the substrate to the peripheral portion, and a frozen film is generated on the entire surface of the substrate front surface Wf and the back surface Wb (step S3; liquid film freezing step). In addition, by rotating the substrate W while moving the cooling gas discharge nozzle 3, it is possible to generate a frozen film on the entire surface of the substrate surface Wf and the back surface Wb while suppressing the occurrence of bias in the thickness distribution of the liquid film. However, when the substrate W is rotated at a high speed, the cooling gas diffuses due to the airflow generated by the rotation of the substrate W, and the efficiency of freezing the liquid film may deteriorate. Therefore, the rotation speed of the substrate W during the liquid film freezing step can be set to 1 to 300 rpm, for example. Further, the rotational speed of the substrate W is set in consideration of the moving speed of the cooling gas discharge nozzle 3, the temperature and flow rate of the discharge gas, and the thickness of the liquid film.

  When the liquid film freezing step is executed in this way, the volume of the liquid film that has entered between the substrate W and the particles increases (when water at 0 ° C. becomes ice at 0 ° C., the volume is about 1.1 times as large. Particles are separated from the substrate W by a minute distance. As a result, the adhesion force between the substrate W and the particles is reduced, and further, the particles are detached from the substrate W. At this time, even if a fine pattern is formed on the substrate surface Wf, the pressure applied to the pattern by the volume expansion of the liquid film is equal in all directions, that is, the force applied to the pattern is canceled out. Therefore, only the particles can be selectively prioritized and removed from the substrate surface Wf without peeling or collapsing the pattern.

  When the freezing of the liquid film is completed, the control unit 4 moves the cooling gas discharge nozzle 3 to the standby position Ps and arranges the blocking member 9 at the facing position. Further, the control unit 4 stops the supply of the cooling gas from the gas supply path 29. Then, DIW is supplied from the nozzle 97 and the processing liquid nozzle 27 to the front and back surfaces Wf and Wb of the substrate W as the rinse liquid before the frozen films 13f and 13b are melted. Thereby, the frozen films 13f and 13b of the substrate W are thawed by DIW. Further, the centrifugal force due to the rotation of the substrate W acts on the frozen films 13 f and 13 b and the DIW supplied to the substrate W. As a result, the frozen films 13f and 13b containing particles are removed from the substrate W and discharged out of the substrate (step S4; film removal step). Thus, in this embodiment, the nozzle 97 and the treatment liquid nozzle 27 also function as the “film removing unit” of the present invention. In this film removal step, it is preferable to rotate the blocking member 9 together with the rotation of the substrate W. Thereby, the liquid component adhering to the blocking member 9 is shaken off, and it is possible to prevent the mist-like processing liquid from entering the space formed between the blocking member 9 and the substrate surface Wf from the periphery of the substrate. .

  In the film removal step, the upper frozen film 13f may be thawed and removed as follows. That is, after the liquid film is frozen, the control unit 4 supplies the DIW droplets to the substrate surface Wf while swinging the two-fluid nozzle 5 above the substrate W in a state where the blocking member 9 is disposed at the separated position. Thereby, the droplet collides with the particle adhering to the substrate surface Wf, and the particle is physically removed (physical cleaning) by the kinetic energy of the droplet. Therefore, it is possible to easily remove particles from the substrate surface Wf and to clean the substrate surface Wf satisfactorily. In this case, the two-fluid nozzle 5 functions as the “film removing means” of the present invention.

  Thus, when the film removal process is completed and the cleaning process of the substrate W (liquid film formation + liquid film freezing + film removal) is completed (YES in step S5), the drying process of the substrate W is subsequently executed. On the other hand, depending on the surface state of the substrate front surface Wf and the back surface Wb that are the surfaces to be processed, or the particle size and type of the particles to be removed, the particles may not be sufficiently removed from the substrate W by a single cleaning process. is there. In this case (NO in step S5), the liquid film freezing process and the film removing process are repeatedly executed after the film removing process is completed. That is, the rinse liquid (DIW) remains on the substrate W after the film removal process. For this reason, even if a liquid film is not newly formed on the substrate W, the substrate W is covered with the liquid film of the rinse liquid. Therefore, when the liquid film freezing step is executed after the membrane removing step, a frozen membrane composed of the rinse liquid is generated. Then, by removing the frozen film in the film removing step, particles adhering to the substrate surface Wf are removed from the substrate surface Wf together with the frozen film. In this way, the film removal process and the liquid film freezing process are repeatedly performed a predetermined number of times, whereby particles are removed from the substrate surface Wf. It should be noted that the number of repeated executions may be defined in advance as a process recipe, and the film removal process and the liquid film freezing process may be repeated for the number of executions defined by an appropriately selected process recipe.

  When the cleaning of the substrate W is completed, the control unit 4 increases the rotational speeds of the motors of the chuck rotating mechanism 22 and the blocking member rotating mechanism 93 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 (step S6). Further, in this drying process, by supplying nitrogen gas from the gas supply paths 95 and 29, a space sandwiched between the blocking member 9 and the substrate surface Wf and between the spin base 23 and the substrate back surface Wb are provided. The sandwiched space is a nitrogen gas atmosphere. Thereby, the drying of the substrate W is promoted, and the drying time can be shortened. After the drying process, the rotation of the substrate W is stopped, and the processed substrate W is unloaded from the processing chamber 1 (step S7).

  As described above, according to this embodiment, the lower cooling means is provided to freeze the liquid films 11f and 11b formed on the substrate W. That is, by supplying a cooling gas having a temperature lower than the freezing point of the liquid (DIW) constituting the liquid films 11f and 11b toward the lower surface of the substrate W (substrate back surface Wb in this embodiment), the liquid films 11f and 11b. Is freezing. Therefore, not only when the substrate W is positioned close to the spin base 23, but also when the substrate W is positioned relatively far away, the substrate W and the liquid films 11 f and 11 b are surely secured by the cooling heat from the cooling gas. The liquid films 11f and 11b can be efficiently frozen.

  In this embodiment, since the cooling gas is locally discharged toward the center of the lower surface of the substrate W, as shown in the graph of FIG. It is higher than the cooling capacity with respect to the peripheral edge of the lower surface. For this reason, the liquid film portion corresponding to the central part of the substrate (the portion corresponding to the frozen films 13f and 13b in FIG. 7B) of the entire liquid films 11f and 11b is first frozen, and subsequently, the liquid film is frozen. Progress toward the peripheral edge of the substrate. Accordingly, the liquid film portion corresponding to the peripheral portion of the substrate W is finally frozen. As a result, a part of the stress due to volume expansion is released in the outer peripheral direction at the part that is finally frozen, that is, the peripheral part of the liquid film, and the stress concentration is suppressed. Further, since no pattern or circuit is formed on the periphery of the substrate W, controlling the periphery of the liquid films 11f and 11b to the final frozen portion also causes stress concentration at the position where the pattern is formed. Can be effectively prevented.

  In addition, a spin base 23 is provided facing the lower surface of the substrate at a position lower than the lower surface of the substrate W (substrate back surface Wb in this embodiment), and the substrate W is held in a state of being spaced upward from the spin base 23. Has been. Then, since the cooling gas is supplied to the lower surface of the substrate through the opening 231 of the spin base 23, the cooling gas cools the central portion of the lower surface of the substrate W and is then sandwiched between the spin base 23 and the lower surface of the substrate. The substrate W moves in the radial direction through the space. Therefore, the cooling gas can be prevented from being separated from the substrate W, and the freezing process can be executed with high cooling efficiency. In addition, since the cooling gas that moves in the space spreads radially around the central portion of the lower surface, the freezing of the liquid films 11f and 11b can be reliably advanced from the central portion of the substrate toward the peripheral portion of the substrate.

  In this embodiment, not only the lower cooling means but also the upper cooling means for supplying the cooling gas toward the upper surface of the substrate is provided, and the liquid film freezing process is performed by both. The time required for processing can be shortened. In addition, in this embodiment, the cooling gas is locally discharged from the nozzle 3 toward the upper surface of the substrate W (the substrate surface Wf in this embodiment liquid), and the central portion of the upper surface of the substrate W rotating the nozzle 3. Since the cooling gas is supplied to the entire upper surface of the substrate W by being relatively moved from the upper surface to the peripheral portion of the upper surface, the liquid film freezing from the central portion of the substrate to the peripheral portion can be further ensured.

  Further, in this embodiment, DIW is supplied as a post-treatment liquid to the liquid film frozen as described above, that is, the frozen films 13f and 13b, and the frozen films 13f and 13b are removed from the substrate W. Therefore, the substrate W can be cleaned without damaging the substrate W. In this embodiment, DIW is used as the post-treatment liquid, but the frozen film may be removed by performing chemical cleaning on the substrate W as shown in FIG. That is, after freezing the liquid films 11f and 11b, the control unit 4 arranges the chemical solution discharge nozzle 6 at the discharge position and pumps the SC1 solution to the chemical solution discharge nozzle 6. Accordingly, the SC1 solution is supplied from the chemical solution discharge nozzle 6 to the substrate surface Wf. Here, since the zeta potential (electrokinetic potential) of the solid surface in the SC1 solution has a relatively large value, the space between the substrate surface Wf and the particles on the substrate surface Wf is filled with the SC1 solution. A large repulsive force acts between the substrate surface Wf and the particles. Therefore, the detachment of particles from the substrate surface Wf can be further facilitated, and the particles can be effectively removed from the substrate surface Wf. Further, simultaneously with the supply of the SC1 solution to the substrate surface Wf, the SC1 solution is also supplied from the treatment liquid nozzle 27 to the substrate back surface Wb. Thereby, the contaminant can be effectively removed from the substrate W by the chemical cleaning action of the SC1 solution. After cleaning with the SC1 solution, DIW is supplied to the front and back surfaces Wf and Wb of the substrate W, and a rinsing process using DIW is performed.

  By the way, in the said embodiment, since process liquids, such as a rinse liquid, are discharged from the process liquid nozzle 27 with respect to the substrate lower surface, a process liquid may fall to the gas supply path 29. FIG. Then, the dropped processing liquid may be frozen and block the gas supply path 29. Therefore, for example, as shown in FIG. 9A, a flange portion 271 having an outer diameter equal to or larger than that of the gas supply path 29 may be attached to the tip portion of the nozzle 27. Accordingly, the flange portion 271 covers the gas supply path 29 from above, and the processing liquid can be prevented from entering the gas supply path 29. Further, instead of the flange portion 271, an umbrella portion 272 may be provided as shown in FIG. That is, the umbrella portion 272 extends in an umbrella shape obliquely downward from the tip of the nozzle 27 and covers the gas supply path 29 from above. Thereby, the same effect as the flange part 271 is obtained. Note that, when either the flange portion 271 or the umbrella portion 272 is adopted, the outer peripheral ends of the flange portion 271 and the umbrella portion 272 are separated from the rotation support shaft 21 and the spin base 23 and are supplied from the gas supply path 29. The gas flowing around from the lower surface side such as the flange portion 271 is supplied to the lower surface central portion of the substrate W.

  In addition, in order to efficiently cool the entire substrate W with the cooling gas supplied through the gas supply path 29, not only the central portion of the lower surface is intensively cooled with the cooling gas but also the cooling gas is supplied to the substrate W. It is necessary to feed evenly to the outer peripheral edge. Therefore, for example, as shown in FIG. 10, four guide members 273 are attached to the tip of the nozzle 27 at 90 ° intervals, and the cooling gas discharged to the center of the lower surface of the substrate W is transferred to the lower peripheral edge of the substrate W. You may comprise so that it may guide. By providing the guide member 273 in this way, the cooling gas spreads uniformly over the entire circumference of the outer peripheral edge of the substrate W. As a result, the entire substrate W can be efficiently and uniformly cooled, and uniform frozen films 13f and 13b can be formed. In this embodiment, four guide members 273 are attached to the tip of the nozzle 27 in a propeller shape, but the number of guide members 273 and the arrangement relationship thereof are arbitrary.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in the above embodiment, the upper cooling means is provided in addition to the lower cooling means. However, the configuration of the upper cooling means is not limited to the above embodiment, and the upper cooling means is formed on the upper surface of the substrate W held by the spin chuck 2. What supplies a cooling gas toward can be used.

  In the above embodiment, the liquid films 11f and 11b formed on the substrate W are frozen by combining the lower cooling means and the upper cooling means. However, the liquid film freezing process is executed using only the lower cooling means. You may do it. Also in this case, the above-described effects can be obtained. However, when a liquid film is formed on the upper and lower surfaces or when it is desired to shorten the time required for freezing, it is desirable to combine the upper cooling means with the lower cooling means.

  Moreover, in the said embodiment, although a series of washing | cleaning processes are performed with respect to the upper surface and lower surface of the board | substrate W, the application range of this invention is not limited to this, Cleaning process (only one surface ( The present invention can also be applied to an apparatus that performs (liquid film formation + liquid film freezing + membrane removal).

  In the above-described embodiment, liquid (DIW) is supplied to the processing surface of the substrate W in the processing chamber 1 to form a liquid film on the processing surface of the substrate W. The substrate W on which the liquid film is formed may be carried into the processing chamber 1.

  In the above embodiment, the liquid film is formed on the substrate W by DIW. However, the liquid film may be formed by another rinse liquid. For example, the liquid film may be formed using carbonated water, hydrogen water, dilute ammonia water (for example, about 1 ppm), dilute hydrochloric acid, or the like. Furthermore, a liquid film may be formed using a chemical solution in addition to the rinse solution. For example, when the liquid film freezing step and the film removing step using the chemical solution are repeatedly performed, the liquid film composed of the chemical solution remaining on the substrate W in the film removing step is frozen in the liquid film freezing step. .

  Further, in the above-described embodiment, the transition to the film removal process is immediately performed after the completion of the freezing of the liquid film. However, the tact time may be adjusted by shifting the transition timing to the film removal process to the rear side. In this case, the substrate W stands by inside the apparatus while the frozen film is formed, but the frozen film functions as a protective film. As a result, it is possible to reliably prevent the surface to be processed of the substrate W from being contaminated.

  In the above embodiment, cleaning with the SC1 solution (SC1 cleaning) is performed as the chemical cleaning mainly having a chemical cleaning action on the substrate surface Wf, but as the chemical cleaning performed in the present invention, It is not limited to SC1 cleaning. For example, wet cleaning using chemical solutions such as an alkaline solution other than the SC1 solution, an acidic solution, an organic solvent, a surfactant, or the like as a treatment liquid, or a combination of them as an appropriate treatment liquid can be used.

  In the above embodiment, cleaning with droplets (droplet cleaning) using a two-fluid nozzle is performed as physical cleaning mainly having a physical cleaning action on the substrate surface Wf. The physical cleaning performed is not limited to droplet cleaning. For example, scrub cleaning for cleaning the substrate W by bringing a brush, sponge, or the like into contact with the substrate surface Wf as physical cleaning, particles adhering to the substrate surface Wf are vibrated and detached by ultrasonic vibration, or processing liquid Examples thereof include cavitation generated inside and ultrasonic cleaning for cleaning the substrate W by causing bubbles to act on the substrate surface Wf. Furthermore, the frozen liquid film may be removed from the substrate surface Wf by performing cleaning that combines physical cleaning and chemical cleaning as necessary on the substrate surface Wf.

  In the above embodiment, when performing physical cleaning by discharging liquid droplets from a two-fluid nozzle, droplet cleaning is performed using a so-called external mixing type two-fluid nozzle. The droplet cleaning may be performed using a so-called internal mixing type two-fluid nozzle. That is, the processing liquid and the gas may be mixed inside the two-fluid nozzle to generate cleaning droplets and discharged from the nozzle discharge port toward the substrate W.

  In the above embodiment, when a freezing apparatus that freezes the liquid film formed on the surface to be processed of the substrate is applied to the substrate processing apparatus to remove contaminants such as particles adhering to the surface to be processed of the substrate W. However, the application of the present invention is not limited to this. For example, a liquid film (frozen film) frozen using the freezing apparatus and method according to the present invention may be used as a protective film for protecting the substrate surface. That is, by forming a liquid film on the surface to be processed of the substrate W and freezing the liquid film, the frozen film acts as a protective film for the surface to be processed of the substrate W, so that the surface to be processed of the substrate W is removed from the ambient atmosphere. Can protect against contamination. Accordingly, the substrate W can be stored or kept on standby while preventing the surface to be processed of the substrate W from being contaminated by using the frozen film as a protective film.

  The present invention relates to a semiconductor wafer, a glass substrate for photomask, a glass substrate for liquid crystal display, a glass substrate for plasma display, a substrate for FED (Field Emission Display), a substrate for optical disk, a substrate for magnetic disk, a substrate for magneto-optical disk, etc. The present invention can be applied to a freezing processing apparatus, a freezing processing method, and a substrate processing apparatus equipped with the freezing processing apparatus for freezing a liquid film formed on the surface to be processed of the entire substrate including the substrate.

It is a figure showing one embodiment of a substrate processing device 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 operation | movement of the cooling gas discharge nozzle with which the substrate processing apparatus of FIG. 1 was equipped. It is a figure which shows the structure of a two-fluid nozzle. It is a figure which shows typically the structure and operation | movement of the downward cooling means with which the substrate processing apparatus of FIG. 1 was equipped. It is a flowchart which shows the cleaning process of the substrate processing apparatus of FIG. It is a schematic diagram which shows operation | movement of the cleaning process of the substrate processing apparatus of FIG. It is a schematic diagram which shows the operation | movement of the film | membrane removal process of the substrate processing apparatus of FIG. It is a figure which shows other embodiment of the substrate processing apparatus concerning this invention. It is a figure which shows another embodiment of the substrate processing apparatus concerning this invention.

Explanation of symbols

2 ... Spin chuck (substrate holding means)
3 ... Cooling gas discharge nozzle (upward cooling means)
5 ... Two-fluid nozzle (membrane removal means)
11b, 11f ... Liquid film 13b, 13f ... Frozen film 21 ... Rotating spindle (lower gas discharge part)
22 ... Chuck rotation mechanism (rotation drive means)
23 ... Spin base (base plate)
24 ... Chuck pin (support member)
27, 97 ... Nozzle (liquid film forming means, film removing means)
29 ... Gas supply path 31 ... Rotating motor (upper cooling means, relative movement mechanism)
231 ... Opening (of spin base) 273 ... Guide member Wf ... Substrate surface Wb ... Substrate back surface W ... Substrate

Claims (11)

In the freezing apparatus that freezes the liquid film formed on the surface to be processed of the substrate,
A substrate holding means for holding the substrate in a horizontal position;
Cooling gas having a temperature lower than the freezing point of the liquid constituting the liquid film is supplied to the lower surface of the substrate held by the substrate holding means, and includes a lower cooling means for freezing the liquid film,
The lower cooling means locally discharges the cooling gas toward the lower surface center portion of the substrate to cool the entire substrate in a state where the cooling capacity for the lower surface center portion is higher than that of the lower surface peripheral portion of the substrate. The freezing processing apparatus characterized by the above-mentioned. The substrate holding means has a base plate provided facing the lower surface of the substrate at a position lower than the lower surface of the substrate, and a support member provided on the upper surface of the base plate and supporting the substrate,
2. The freezing according to claim 1, wherein the lower cooling means includes a lower gas discharge portion that discharges the cooling gas toward a lower surface central portion of the substrate through an opening provided in a central portion of the base plate. Processing equipment.   The freezing processing apparatus according to claim 2, further comprising a guide member that guides the cooling gas discharged toward the central portion of the lower surface of the substrate to a peripheral portion of the lower surface of the substrate.   The freezing apparatus according to any one of claims 1 to 3, further comprising an upper cooling means for supplying the cooling gas toward the upper surface of the substrate held by the substrate holding means to freeze the liquid film. . A rotation driving means for rotating the substrate held by the substrate holding means around a rotation center extending in a vertical direction;
The upper cooling means locally discharges the cooling gas toward the upper surface of the substrate held by the substrate holding means, and moves the nozzle relative to the substrate along the upper surface of the substrate. A relative movement mechanism,
5. The relative movement mechanism relatively moves the nozzle from the center of the upper surface of the substrate toward the periphery of the upper surface in a state where the cooling gas is supplied to the lower surface of the substrate by the lower cooling means. Freezing processing equipment. A freezing method for freezing a liquid film formed on a surface to be processed of a substrate,
A substrate holding step for holding the substrate in a horizontal position;
A liquid film freezing step of freezing the liquid film by supplying a cooling gas having a temperature lower than the freezing point of the liquid constituting the liquid film toward the lower surface of the substrate;
In the liquid film freezing step, the cooling gas is locally discharged toward the central portion of the lower surface of the substrate, so that the cooling capability for the central portion of the lower surface is made higher than the cooling capability for the peripheral portion of the lower surface of the substrate. A freezing method characterized in that freezing of a film proceeds from the center of the substrate toward the peripheral edge of the substrate.   The freezing treatment method according to claim 6, wherein in the liquid film freezing step, the liquid film is frozen by supplying the cooling gas to the upper surface of the substrate while the cooling gas is supplied to the lower surface of the substrate.   In the liquid film freezing step, a nozzle that locally discharges the cooling gas toward the upper surface of the substrate while rotating the substrate held by the substrate holding means around a rotation center extending in a vertical direction is provided on the substrate. The freezing method according to claim 7, wherein the cooling gas is supplied to the entire upper surface of the substrate by being relatively moved from a central portion of the upper surface toward a peripheral portion of the upper surface. Substrate holding means for holding the substrate on which the liquid film is formed on the processing surface in a horizontal posture;
A lower cooling means for supplying a cooling gas having a temperature lower than the freezing point of the liquid constituting the liquid film toward the lower surface of the substrate held by the substrate holding means to freeze the liquid film;
A film removing means for supplying a post-treatment liquid to the liquid film after freezing and removing the liquid film from the treated surface of the substrate;
The substrate processing apparatus, wherein the lower cooling means locally discharges the cooling gas toward the lower surface central portion of the substrate to enhance the cooling capacity for the lower surface central portion than the lower surface peripheral portion of the substrate.   The substrate processing apparatus according to claim 9, further comprising an upper cooling unit that supplies the cooling gas toward an upper surface of the substrate held by the substrate holding unit to freeze the liquid film.   The substrate processing apparatus according to claim 9, further comprising a liquid film forming unit configured to supply the liquid to the substrate held by the substrate holding unit to form a liquid film.

Images