JP4767204B2 - Substrate processing method and substrate processing apparatus - Google Patents

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 substrate processing method and a substrate processing apparatus for performing a cleaning process on various substrates (hereinafter simply referred to as “substrates”).

  The manufacturing process of an electronic component such as a semiconductor device or a liquid crystal display device includes a step of repeatedly forming a fine pattern by repeatedly performing processes such as film formation and etching on the surface of the substrate. Here, in order to perform fine processing satisfactorily, it is necessary to keep the substrate surface clean, and a cleaning process is performed on the substrate surface as necessary. For example, in the apparatus described in Patent Document 1, cleaning liquid droplets generated by mixing a cleaning liquid and a gas are generated, and the liquid droplets are supplied to a substrate surface which is a surface to be processed to clean the substrate surface. The technique to be performed is described. That is, when droplets of cleaning liquid are supplied to the substrate surface, the droplets collide with contaminants such as particles adhering to the substrate surface, thereby utilizing the kinetic energy of the droplets to cause contaminants from the substrate surface. Is physically removed.

JP-A-8-318181 (FIG. 1)

  By the way, in recent years, with the miniaturization, higher functionality, and higher accuracy of devices typified by semiconductors, the occurrence of defects in the pattern formed on the substrate surface during the substrate cleaning process has become a problem. That is, in the apparatus described in Patent Document 1, the rate at which contaminants are removed from the substrate surface by adjusting the cleaning conditions (droplet generation conditions) so as to increase the kinetic energy of the droplets (hereinafter referred to as the droplets). Although the "removal rate" can be improved, there is a problem that the pattern is collapsed. On the other hand, if the cleaning conditions are adjusted so as to avoid the occurrence of pattern defects, there has been a situation where the contaminants cannot be removed sufficiently.

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

  The present invention is a substrate processing method for performing a cleaning process on a substrate surface on which a predetermined pattern is formed. In order to achieve the above object, a liquid is applied from the substrate on which the liquid is adhered to the substrate surface to the inside of the pattern gap. A liquid removing step for removing the liquid from the substrate surface while remaining, a solidified body forming step for solidifying the liquid remaining inside the pattern gap to form a solidified body inside the pattern gap, and a pattern inside the pattern gap. And a physical cleaning step of performing physical cleaning having a physical cleaning action on the substrate surface while maintaining a state in which a solidified body is formed.

  The present invention is also a substrate processing apparatus for performing a cleaning process on a substrate surface on which a predetermined pattern is formed. In order to achieve the above object, a liquid adhered to the substrate surface is liquid inside the pattern gap. A liquid removing means for removing the liquid adhering to the substrate surface from the substrate surface while remaining, and a solidified body forming means for coagulating the liquid left inside the pattern gap to form a solidified body inside the pattern gap; And a physical cleaning means for performing physical cleaning having a physical cleaning action on the substrate surface while maintaining a state in which a solidified body is formed in the gaps of the pattern.

  In the invention configured as described above (substrate processing method and apparatus), the liquid adhering to the substrate surface is removed from the substrate surface while the liquid remains in the gaps of the pattern formed on the substrate surface (liquid removal step). ). This exposes the contaminants that adhere to the substrate surface, leaving the liquid inside the gaps in the pattern. Thereafter, the liquid remaining in the pattern gap (hereinafter referred to as “internal residual liquid”) is solidified to form a solidified body (solid) in the pattern gap (solidified body forming step). Is structurally reinforced. That is, it can be regarded as a lump (solid material) in which the pattern and the solidified body are integrated. In addition, the physical cleaning (physical cleaning process) that has a physical cleaning action on the substrate surface is performed while the solidified body is formed (solidified state), thus preventing the pattern from being damaged. However, contaminants can be efficiently removed from the substrate surface. Therefore, it is possible to satisfactorily clean the substrate surface while suppressing damage to the pattern.

  Here, it is preferable to supply a solidified body removing liquid to the substrate surface after the physical cleaning step to remove the solidified body. Thereby, the contaminant adhering to the inside of the pattern gap can be removed from the substrate surface together with the solidified body.

  In addition, if the liquid is removed from the substrate surface while rotating the substrate in the liquid removing step, the liquid adhered to the substrate surface can be easily removed from the substrate surface while the liquid remains inside the pattern gap. It becomes possible.

  In addition, the form of physical cleaning performed on the substrate surface in a state in which a solidified body is formed inside the pattern gap is arbitrary. For example, physical cleaning may be performed on the substrate surface as follows. it can. That is, (1) physical cleaning is performed on the substrate surface by spraying the substrate surface with a cleaning solution having a freezing point lower than that of the internal residual liquid at a temperature higher than the freezing point of the cleaning liquid and lower than the freezing point of the internal residual liquid. (2) Substrate cooling having a substrate cooling surface adjusted to a temperature higher than the freezing point of the cleaning liquid and lower than the freezing point of the internal residual liquid, using a cleaning liquid having a lower freezing point than the internal residual liquid The substrate surface may be physically cleaned by supplying the cleaning liquid toward the substrate surface with the portion facing the back surface of the substrate. (3) The substrate is immersed in a treatment tank stored in a state where the cleaning liquid having a lower freezing point than the internal residual liquid is adjusted to a temperature higher than the freezing point of the cleaning liquid and lower than the freezing point of the liquid. May be subjected to physical cleaning. In any of the above (1) to (3), while preventing the cleaning liquid itself from solidifying, the cleaning liquid is in a state in which a solidified body is formed inside the pattern gap, that is, in a state where the pattern is structurally reinforced. Physical cleaning using can be performed on the substrate surface.

  In the above (1) and (2), the physical cleaning used in the present invention is, for example, supplied to the substrate surface by supplying droplets of the cleaning solution generated by mixing the cleaning solution and the gas toward the substrate surface. On the other hand, physical cleaning can be performed. In the above (3), the substrate surface can be physically cleaned by applying ultrasonic vibration to the substrate through a cleaning liquid, for example. However, the physical cleaning used in the present invention is not limited to these physical cleanings, but is optional as long as the solidified body formed in the gaps of the pattern can be cleaned under conditions that do not melt. For example, brush cleaning for cleaning the substrate by bringing a brush or the like into contact with the surface of the substrate, high-pressure jet cleaning for cleaning the substrate by spraying a cleaning liquid at a high pressure toward the surface of the substrate, or causing small ice particles to collide with the substrate surface. An ice scrubber for cleaning the substrate or aerosol cleaning for cleaning the substrate surface by spraying particles such as dry ice (CO 2), ice (H 2 O) or argon (Ar) solidified by cooling at high speed can be used. In particular, since ice scrubber and aerosol cleaning can be performed at a relatively low temperature, when the liquid is solidified by freezing, it is necessary to perform physical cleaning while maintaining a solidified state (solidified state). It is valid.

  According to the present invention, the liquid adhering to the substrate surface is removed from the substrate surface while the liquid remains inside the pattern gap, and then the internal residual liquid is solidified to form a solidified body inside the pattern gap. For this reason, the pattern is structurally reinforced by the solidified body. And since physical cleaning is performed on the substrate surface in such a state, the substrate surface can be cleaned well 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. FIG. 2 is a block diagram showing a control configuration of the substrate processing apparatus of FIG. This apparatus is a single-wafer type substrate processing apparatus used for a cleaning process for removing contaminants such as particles adhering to the surface Wf of a substrate W such as a semiconductor wafer. More specifically, a series of cleaning processes (liquid film forming process + rough drying process + solidified body forming process + physical cleaning process + rinsing process + main drying) as will be described later with respect to the substrate surface Wf on which the fine pattern is formed. It is the apparatus which performs a process.

  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. A spin chuck 2 that is held and rotated, a cooling gas discharge nozzle 3 that discharges a cooling gas for performing a freezing process (solidified body forming process) on the substrate W held on the spin chuck 2, and a substrate surface Wf There are provided a two-fluid nozzle 5 for supplying a droplet of cleaning liquid and a blocking member 7 disposed to face the surface Wf of the substrate W held by the spin chuck 2.

  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.

  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.

  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 of the substrate W is set above the substrate surface Wf and on the rotation center A0 of the substrate W. 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 the cooling gas supply unit 61 (FIG. 2). When the cooling gas is pumped from the cooling gas supply unit 61 in accordance with an operation command from the control unit 4, the cooling gas discharge nozzle 3 Cooling gas is discharged. And according to the operation command from the control unit 4, when the cooling gas discharge nozzle 3 is disposed close to and opposed to the substrate surface Wf and the cooling gas is discharged from the cooling gas discharge nozzle 3, it is directed toward the substrate surface Wf. Cooling gas is supplied locally. 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 (DIW) adheres to the substrate surface Wf, the region where the liquid is frozen (frozen region) is expanded from the central portion to the peripheral portion of the substrate surface Wf, and the entire surface of the substrate surface Wf is observed. Freezing is applied.

  The cooling gas supply unit 61 adjusts the temperature of the cooling gas, for example, by cooling it with a cooling source such as liquid nitrogen. As the cooling gas, it is possible to use a gas adjusted to a temperature lower than the freezing point of the liquid (internal residual liquid) remaining inside the pattern gap as described later, such as nitrogen gas, oxygen gas, and clean air. it can. In this embodiment, since DIW (deionized water) is used as the internal residual liquid, the temperature of the cooling gas is adjusted to a temperature lower than the freezing point (freezing point) of DIW. Further, when the cooling gas is used as described above, the following effects can be obtained. That is, when gas is used as the refrigerant, contaminants contained in the cooling gas can be easily and efficiently removed by inserting a filter or the like before supplying the gas to the substrate surface Wf. By using the cooling gas thus cleaned, it is possible to reliably prevent contaminants from adhering to the substrate surface Wf.

  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 sprays droplets of the cleaning liquid generated by mixing the cleaning liquid and the gas onto the substrate surface Wf.

  FIG. 4 is a diagram showing the configuration of the two-fluid nozzle. The two-fluid nozzle 5 is a so-called external mixing type two-fluid nozzle that generates cleaning liquid droplets by colliding the cleaning liquid and gas in the air (outside the nozzle). In the two-fluid nozzle 5, a cleaning liquid discharge nozzle 502 is inserted into the body 501, and a base end portion of the cleaning liquid discharge nozzle 502 is connected to the cleaning liquid supply unit 62 (FIG. 2). The cleaning liquid supply unit 62 cools the cleaning liquid having a lower freezing point than the internal residual liquid (DIW) to a temperature higher than the freezing point of the cleaning liquid and lower than the freezing point of the internal residual liquid in accordance with an operation command from the control unit 4 ( In a state where the temperature is adjusted, the pressure is fed to the cleaning liquid discharge nozzle 502. Hereinafter, the cleaning liquid thus cooled is referred to as a cooling cleaning liquid. A cleaning liquid discharge port 521 is formed at the front end portion of the cleaning liquid discharge nozzle 502 so as to be disposed on the upper surface portion 512 of the umbrella portion 511. For this reason, when the cooling cleaning liquid is supplied to the cleaning liquid discharge nozzle 502, the cooling cleaning liquid is discharged toward the substrate W from the cleaning liquid discharge port 521. For example, isopropyl alcohol (freezing point: −89.5 ° C.) is used as the cleaning liquid. The cleaning liquid is not limited to isopropyl alcohol (IPA), and various organic solvent components such as ethyl alcohol (freezing point: −114.5 ° C.) and methyl alcohol (freezing point: −98 ° C.) may be used. Moreover, you may make it use the liquid mixture which mixed these organic solvent components and DIW.

  A gas discharge nozzle 503 is provided in the vicinity of the cleaning liquid discharge nozzle 502, and defines a ring-shaped gas passage surrounding the cleaning liquid discharge nozzle 502. The base end portion of the gas discharge nozzle 503 is connected to a nitrogen gas supply unit 63 (FIG. 2) configured by a factory utility or the like, and nitrogen gas, which is an inert gas, is supplied in response to an operation command from the control unit 4. The gas is discharged to the gas discharge nozzle 503. The front end of the gas discharge nozzle 503 is tapered and a gas discharge port 531 is opened at the front end of the gas discharge nozzle 503 so as to face the substrate surface Wf. For this reason, when nitrogen gas is supplied to the gas discharge nozzle 503, nitrogen gas is discharged from the gas discharge port 531 toward the substrate surface Wf.

  The discharge locus of the nitrogen gas discharged in this way intersects the discharge locus of the cooling cleaning liquid from the cleaning liquid discharge port 521. That is, the liquid flow of the cooling cleaning liquid from the cleaning 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 cooling cleaning liquid is quickly formed into droplets by the nitrogen gas that collides with the cooling cleaning liquid in the immediate vicinity of the cooling liquid discharging direction from the cleaning liquid discharge port 521. In this way, cleaning droplets are generated.

  Returning to FIG. 1, the description will be continued. The rotation support shaft 21 of the spin chuck 2 is a hollow shaft. A processing liquid supply pipe 25 for supplying DIW to the back surface Wb of the substrate W is inserted into the rotary spindle 21. The processing liquid supply tube 25 extends to a position close to the lower surface (back surface Wb) of the substrate W held by the spin chuck 2, and the processing liquid that discharges DIW toward the center of the lower surface of the substrate W at the tip thereof. A nozzle 27 is provided. The processing liquid supply pipe 25 is connected to a DIW supply unit 64 (FIG. 2) configured by a factory utility or the like, and receives DIW supply from the DIW supply unit 64.

  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 nitrogen gas supply unit 63 and can supply nitrogen gas as a drying gas to a space formed between the spin base 23 and the substrate back surface Wb. In this embodiment, nitrogen gas is supplied as a drying gas from the nitrogen gas supply unit 63, but air or other inert gas may be discharged instead of the nitrogen gas.

  A disc-shaped blocking member 7 having an opening at the center is provided above the spin chuck 2. The blocking member 7 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 7 is equal to or larger than the diameter of the substrate W. The blocking member 7 is mounted substantially horizontally on the lower end portion of a support shaft 71 having a substantially cylindrical shape, and the support shaft 71 is held rotatably about a vertical axis passing through the center of the substrate W by an arm 72 extending in the horizontal direction. . The arm 72 is connected to a blocking member rotating mechanism 73 and a blocking member lifting mechanism 74.

  The blocking member rotating mechanism 73 rotates the support shaft 71 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 blocking member rotating mechanism 73 is configured to rotate the blocking member 7 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 74 can cause the blocking member 7 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 7. Specifically, the control unit 4 operates the blocking member raising / lowering mechanism 74 so that when the substrate W is carried into and out of the apparatus, the control unit 4 is moved to a separation position (position shown in FIG. 1) above the spin chuck 2. The blocking member 7 is raised. On the other hand, when a predetermined process is performed on the substrate W, the blocking member 7 is lowered to a proximity position set very close to the surface Wf of the substrate W held by the spin chuck 2.

  The support shaft 71 is finished to be hollow, and a gas supply path 75 communicating with the opening of the blocking member 7 is inserted into the support shaft 71. The gas supply path 75 is connected to the nitrogen gas supply unit 63, and nitrogen gas is supplied from the nitrogen gas supply unit 63. In this embodiment, nitrogen gas is supplied from the gas supply path 75 to the space formed between the blocking member 7 and the substrate surface Wf when drying the substrate W. A liquid supply pipe 76 communicating with the opening of the blocking member 7 is inserted into the gas supply path 75, and a nozzle 77 is coupled to the lower end of the liquid supply pipe 76. The liquid supply pipe 76 is connected to the DIW supply unit 64, and DIW can be discharged from the nozzle 77 toward the substrate surface Wf by supplying DIW from the DIW supply unit 64.

  Next, the cleaning processing operation in the substrate processing apparatus configured as described above will be described with reference to FIGS. FIG. 5 is a flowchart showing the operation of the substrate processing apparatus of FIG. FIG. 6 is a schematic diagram for explaining the operation of the substrate processing apparatus of FIG. In this apparatus, when an unprocessed substrate W is carried into the processing chamber 1, the control unit 4 controls each part of the apparatus to perform a series of cleaning processes (liquid film forming process + rough drying) on the surface Wf of the substrate W. Step + solidified body forming step + physical washing step + rinsing step + main drying step). Here, a fine pattern FP is 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. Note that the blocking member 7 is located at 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 7 is lowered to the close 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 7 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 and supplies DIW from the nozzle 77 to the substrate surface Wf. As a result, as shown in FIG. 6A, centrifugal force is applied to DIW supplied to the substrate surface Wf to uniformly spread DIW and form a liquid film (water film) 11 on the entire surface of the substrate surface Wf (see FIG. 6A). Step S1). At this time, DIW enters the gap of the pattern FP due to the flow of DIW. That is, the rotation speed of the substrate W is set so that the DIW on the substrate surface Wf flows and the DIW enters the gaps of the pattern FP.

  Subsequently, the supply of DIW is stopped, and the substrate W held on the spin chuck 2 is rotated at a relatively low speed, and the substrate W is roughly dried. That is, the DIW is removed from the substrate surface Wf while the DIW that has entered the gaps in the pattern FP remains (step S2: liquid removal step). In this rough drying process, the substrate W is dried until the DIW above the pattern FP is removed, that is, the upper surface of the pattern FP is exposed (FIG. 6B). Such drying conditions (rotation speed, drying time, etc. of the substrate W) are set by experimentally obtaining in advance using the same type of substrate W as the substrate W to be cleaned. Therefore, if the drying conditions set in this way are defined in a processing recipe in which the details of the cleaning process are described in advance, the above-described dry state can be obtained without actually confirming the dry state of the substrate W. Substrate drying can be performed. That is, by drying the substrate based on the specified drying conditions, only DIW (internal residual liquid) that remains in the gaps of the pattern FP remains among the DIW that adheres to the substrate surface Wf, while other DIWs remain. Can be substantially removed from the substrate surface Wf. Thus, in this embodiment, the spin chuck 2 functions as the “liquid removing means” of the present invention.

  Further, the rough drying process of the substrate W is executed as described above for the following reason. That is, after the rough drying process, the freezing process (coagulated body forming process) and the physical cleaning process are performed as described later. However, if the freezing process and the physical cleaning process are performed without performing the rough drying process, The freezing process is performed while the particles P adhering to the substrate surface Wf are covered with the liquid film 11, and the particles P are buried in the frozen film. As a result, when physical cleaning is performed with the frozen film solidified (freezing state) after the freezing process, it is difficult to remove the particles P in the frozen film from the substrate surface Wf. Thus, in this embodiment, the substrate W is roughly dried to expose relatively large particles P on the substrate surface Wf.

  Next, a freezing process (solidified body forming process) is performed on the substrate W in which DIW remains in the gaps of the pattern FP. That is, the control unit 4 disposes the blocking member 7 at the separation position, and discharges the cooling gas from the cooling gas discharge nozzle 3 while the cooling gas discharge nozzle 3 is supplied from the standby position Ps, that is, the rotation center position of the substrate W. Move to 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. Thereby, as shown in FIG.3 (b), the area | region (frozen area | region) in which DIW was frozen is extended from the center part of the substrate surface Wf to a peripheral part. As a result, as shown in FIG. 6C, the solidified body 13 is formed inside the gap of the pattern FP over the entire surface of the substrate surface Wf (step S3: solidified body forming step). For this reason, the pattern FP is structurally reinforced by the solidified body 13. That is, the pattern FP and the solidified body 13 can be regarded as a lump (solid matter) in which the pattern FP and the solidified body 13 are integrated. Thus, in this embodiment, the cooling gas discharge nozzle 3 functions as the “solidified body forming means” of the present invention.

  Then, a physical cleaning process is performed on the substrate surface Wf while the solidified body 13 is formed (frozen state) (step S4: physical cleaning process). That is, as shown in FIG. 6D, the control unit 4 sprays a droplet of the cooling cleaning liquid onto the substrate surface Wf while swinging the two-fluid nozzle 5 above the rotating substrate W. Thereby, the droplets of the cooling cleaning liquid collide with the particles P adhering to the substrate surface Wf, and the particles P are physically removed (physical cleaning) by the kinetic energy of the droplets (FIG. 6E). Here, since the cooling cleaning liquid is cooled (temperature controlled) to a temperature lower than the freezing point of the internal residual liquid, the solidified body 13 formed inside the gap of the pattern FP is cleaned in a solidified state (frozen state). It can be performed. Moreover, since the particles P are exposed to the substrate surface Wf by the rough drying process, they are efficiently removed from the substrate surface Wf by collision with the droplets. For this reason, the particles P are removed from the substrate surface region excluding the inside of the gap of the pattern FP while the pattern FP is structurally reinforced by the solidified body 13. Thus, in this embodiment, the two-fluid nozzle 5 functions as the “physical cleaning means” of the present invention.

  Here, in the physical cleaning using the two-fluid nozzle, the particles are removed from the substrate surface Wf by using the kinetic energy of the droplets to collide with the particles adhering to the substrate surface Wf. In such physical cleaning, it is possible to improve the particle removal rate from the substrate surface Wf by increasing the kinetic energy of the droplets by changing the cleaning conditions such as increasing the gas flow rate. On the other hand, if the kinetic energy of the droplets is increased without taking any measures on the substrate to be processed, the pattern FP is damaged. Therefore, in this embodiment, the solidified body 13 is formed inside the gap of the pattern FP, and physical cleaning is performed in a state where the pattern FP is structurally reinforced. Thereby, even if the cleaning condition is changed so as to increase the kinetic energy of the droplet, the pattern FP can be prevented from being damaged. Therefore, the particle removal rate can be improved while suppressing damage to the pattern FP.

  Thus, when the physical cleaning process for a predetermined time is completed, the control unit 4 places the blocking member 7 in the proximity position and rotates the blocking member 7 together with the spin chuck 2. Further, nitrogen gas is supplied to the space between the substrate W and the spin base 23 and between the substrate W and the blocking member 7 so that the ambient atmosphere of the substrate W is an inert gas atmosphere and is solidified from the nozzle 77 and the processing liquid nozzle 27. DIW is supplied to the front and back surfaces Wf and Wb of the substrate W that is rotationally driven, respectively, as the body removing liquid. Thereby, the solidified body 13 is melted and removed from the substrate surface Wf (step S5: solidified body removing step). Further, contaminants adhering to the inside of the gaps of the pattern FP are removed from the substrate surface Wf together with the solidified body 13. Here, since the contaminants adhering to the inside of the gaps of the pattern FP are in a state where the adhesion to the pattern surface is reduced or detached from the pattern surface, by removing the solidified body 13 from the substrate surface Wf, the substrate surface Wf is removed. Contaminants are easily removed from That is, the internal residual liquid (DIW) freezes (solidifies) and expands in volume due to the execution of the freezing process, so that the adhesion between the pattern surface and the contaminant is weakened or the contaminant is detached from the pattern. For this reason, in the solidified body removing process, by removing the solidified body 13, the contaminant inside the gap of the pattern FP can be efficiently removed together with the solidified body 13 from the substrate surface Wf.

  When the solidified body removing process is completed, a main drying process (finish drying) of the substrate W is executed (step S6). That is, the supply of DIW is stopped, and the substrate W is dried by rotating the substrate W and the blocking member 7. Here, it is preferable to perform spin drying of the substrate W after replacing DIW adhering to the inside of the gap of the pattern FP with a low surface tension liquid such as IPA whose surface tension is lower than that of DIW. This can effectively prevent the pattern FP from collapsing when the substrate is dried. After the drying process of the substrate W, the rotation of the substrate W and the blocking member 7 is stopped and the supply of nitrogen gas to the substrate W is stopped. Thereafter, the processed substrate W is unloaded from the processing chamber 1.

  As described above, according to this embodiment, after the DIW liquid film 11 is formed on the substrate surface Wf and DIW is introduced into the gap of the pattern FP, the DIW remains while remaining in the gap of the pattern FP. DIW is removed from the surface Wf. This exposes the particles P adhering to the substrate surface Wf leaving DIW inside the gaps of the pattern FP. Thereafter, the DIW (internal residual liquid) remaining inside the gaps of the pattern FP is frozen to form the solidified body 13, so that the pattern FP is structurally reinforced by the solidified body 13. Since physical cleaning is performed using the two-fluid nozzle 5 while maintaining such a state, it is possible to efficiently remove the particles P from the substrate surface Wf while preventing the pattern FP from being damaged. it can. Therefore, the substrate surface Wf can be cleaned well while suppressing damage to the pattern FP. Moreover, according to this embodiment, a series of cleaning processes (liquid film forming process + rough drying process + coagulated body forming process + physical cleaning process + rinsing process + main drying process) are performed in a single processing chamber. Therefore, it is not necessary to transfer the substrate W between the cleaning processes. For this reason, the throughput of the apparatus can be improved.

  Further, according to this embodiment, a cleaning liquid having a freezing point lower than that of the internal residual liquid (DIW) is mixed with nitrogen gas while being cooled to a temperature higher than the freezing point of the cleaning liquid and lower than the freezing point of the internal residual liquid. A droplet of the cleaning liquid (cooling cleaning liquid) is generated. Since the cooling cleaning liquid droplets are supplied to the substrate surface Wf for physical cleaning, the solidified body 13 is formed in the gaps of the pattern FP while preventing the cooling cleaning liquid itself from freezing. That is, physical cleaning can be performed on the substrate surface Wf with the pattern FP structurally reinforced.

Second Embodiment
FIG. 7 is a plan layout view showing a second embodiment of the substrate processing apparatus of the present invention. In this substrate processing apparatus, the spin processing unit 10 and the freeze cleaning unit 20 are disposed separately from each other by a fixed distance, and the substrate transport mechanism 30 is disposed between them. Among these apparatuses, the spin processing unit 10 is a unit that executes a liquid film forming process, a rough drying process (liquid removing process), and a coagulated body removing process. Specifically, the spin processing unit 10 forms the liquid film 11 on the substrate surface Wf to allow DIW to enter the gap of the pattern FP, and then leave the DIW that has entered the gap of the pattern FP to remain. DIW is removed from the substrate surface Wf. Then, the substrate W is transported to the freeze cleaning unit 20 by the substrate transport mechanism 30 with the internal residual liquid (DIW) adhered inside the gap of the pattern FP. In the freeze cleaning unit 20, after the internal residual liquid (DIW) is frozen to form the solidified body 13, the substrate surface Wf is subjected to physical cleaning while maintaining the frozen state. The substrate W that has undergone physical cleaning is transported to the spin processing unit 10 by the substrate transport mechanism 30, and the solidified body removing process is performed on the substrate W by the spin processing unit 10, and then dried (finish drying). . Since the substrate transport mechanism 30 uses a mechanism that has been frequently used, description of the configuration and operation is omitted here.

  FIG. 8 is a diagram showing a configuration of a spin processing unit provided in the substrate processing apparatus of FIG. The configuration of the spin processing unit 10 is the same as the configuration of the substrate processing apparatus shown in FIG. 1 except that the cooling gas discharge nozzle 3 and the two-fluid nozzle 5 are not provided. Therefore, other substrate processes other than the freezing process (solidified body forming process) using the cooling gas discharge nozzle 3 and the physical cleaning process using the two-fluid nozzle 5, that is, the liquid film forming process, the rough drying process (liquid removing process). The solidified body removing process and the main drying process can be executed in the spin processing unit 10 in the same manner as in the first embodiment.

  FIG. 9 is a diagram showing a configuration of a freeze cleaning unit provided in the substrate processing apparatus of FIG. The freeze cleaning unit 20 includes a cooling plate 42 (corresponding to the “substrate cooling unit” of the present invention) that is disposed to face and oppose the substrate W. The cooling plate 42 has a substrate cooling surface 42a that is substantially horizontal and larger than the plane size of the substrate W, and a plurality of spherical proximity balls 43 (supporting means) project from the substrate cooling surface 42a. . Inside the cooling plate 42, a refrigerant path 44 is formed substantially parallel along the substrate cooling surface 42 a, and both ends of the refrigerant path 44 are connected to the refrigerant supply unit 45. The refrigerant supply unit 45 includes a cooling mechanism that cools the refrigerant, and a pumping mechanism such as a pump that pumps the refrigerant to the refrigerant path 44 and circulates the refrigerant path 44. Therefore, the refrigerant is supplied from the refrigerant supply unit 45, and the refrigerant that has exited the refrigerant path 44 is returned to the refrigerant supply unit 45 again. Note that any coolant may be used as long as the substrate cooling surface 42a is cooled (temperature controlled) to a temperature higher than the freezing point of the cleaning liquid supplied from the two-fluid nozzle 5 and lower than the freezing point of the internal residual liquid (DIW). . The cooling plate 42 is formed of a metal such as aluminum in consideration of cold heat conductivity or quartz in consideration of cleanliness.

  A plurality of lift pins 46 are disposed in the cooling plate 42 so as to penetrate in the vertical direction, and the substrate W is moved by the lift pins 46 and a pin lifting mechanism 47 including an air cylinder for lifting and lowering the lift pins 46. A proximity / separation mechanism is configured to approach / separate the substrate cooling surface 42a. The lift pin 46 can support the substrate W at the upper end thereof, and the substrate transfer height for transferring the substrate W between the substrate transfer mechanism 30 and the substrate W by the lift of the pin lift mechanism 47 (indicated by a two-dot chain line). The upper end of the cooling plate 42 is buried below the substrate cooling surface 42a of the cooling plate 42 (precisely below the proximity ball 43), so that the substrate W is placed on the substrate cooling surface 42a (accurately). Can be placed on the proximity ball 43 (solid line position).

  A two-fluid nozzle 5 is disposed above the cooling plate 42. Although it is the same as that of the first embodiment in that the cleaning fluid having a freezing point lower than that of the internal residual liquid (DIW) is discharged from the two-fluid nozzle 5, in this embodiment, the cleaning liquid is set to a temperature lower than the freezing point of the internal residual liquid. It is not necessary to cool (temperature control). That is, during the execution of the physical cleaning process, it is possible to maintain the state (the frozen state) in which the solidified body 13 is formed by the cooling heat from the cooling plate 42 as described later, and it is not necessary to use a cooled cleaning liquid.

  Next, the operation of the substrate processing apparatus configured as described above will be described with reference to FIGS. When the unprocessed substrate W is carried into the spin processing unit 10, the substrate W is held by the spin chuck 2 with the surface Wf on which the pattern FP is formed facing upward. Thereafter, similar to the first embodiment, the liquid film forming process (step S1) and the rough drying process (step S2) are performed on the substrate surface Wf. Thus, DIW is removed from the substrate surface Wf while leaving DIW (internal residual liquid) inside the gaps of the pattern FP (liquid removal step).

  Subsequently, the substrate W is transported from the spin processing unit 10 to the freeze cleaning unit 20 by the substrate transport mechanism 30. Specifically, the substrate W having DIW remaining in the gaps of the pattern FP is unloaded from the spin processing unit 10 by the substrate transport mechanism 30, and then loaded into the freeze cleaning unit 20 and placed on the lift pins 46. . Prior to loading the substrate W into the freeze cleaning unit 20, the lift pins 46 are raised to the substrate delivery height.

  When the substrate W is placed on the lift pins 46, the control unit 4 controls the pin lifting mechanism 47 to lower the lift pins 46. Then, the substrate W is brought close to the substrate cooling surface 42 a of the cooling plate 42 and placed on the proximity ball 43. As a result, the substrate back surface Wb is in contact with and supported by the proximity ball 43, and the substrate back surface Wb is opposed to the substrate cooling surface 42a with a small gap between the substrate cooling surface 42a and the cooling plate. 42. Therefore, in a state where the substrate W is supported by the proximity balls 43 and is close to the substrate cooling surface 42a, the substrate W is cooled from the back side by conduction of cold heat from the substrate cooling surface 42a. As a result, the internal residual liquid is frozen and the solidified body 13 is formed inside the gap of the pattern FP (step S3; solidified body forming step). Thereby, the pattern FP is structurally reinforced by the solidified body 13. Thus, in this embodiment, the cooling plate 42 functions as the “solidified body forming means” of the present invention.

  Then, in a state where the substrate W is cooled by the cold heat from the substrate cooling surface 42a, droplets of the cleaning liquid are sprayed on the substrate surface Wf while the two-fluid nozzle 5 is swung over the substrate W. Here, the freezing point of the cleaning liquid is lower than the freezing point of the internal residual liquid (DIW), and the substrate cooling surface 42a is cooled to a temperature higher than the freezing point of the cleaning liquid and lower than the freezing point of the internal residual liquid. While preventing freezing, physical cleaning with droplets of the cleaning liquid is executed in a state where the solidified body 13 is formed inside the gap of the pattern FP (freezing state) (step S4; physical cleaning step). Thereby, the particles P are removed from the substrate surface area excluding the inside of the gap of the pattern FP while preventing the pattern FP from being damaged.

  When the physical cleaning process for a predetermined time is thus completed, the control unit 4 controls the pin lifting mechanism 47 to raise the lift pin 46 and guide it to the substrate transfer height. When the lift pins 46 are guided to the substrate delivery height, the substrate W is delivered to the substrate transport mechanism 30. Thereafter, the substrate transport mechanism 30 unloads the substrate W from the freeze cleaning unit 20 and transports it to the spin processing unit 10.

  When the substrate W is loaded into the spin processing unit 10, it is held by the spin chuck 2. Then, a solidified body removing process is performed on the substrate W held on the spin chuck 2 (step S5). Thereby, the solidified body 13 is melted and removed from the substrate surface Wf, and contaminants adhering to the inside of the gap of the pattern FP are removed from the substrate surface Wf (solidified body removing step). Thereafter, a main drying process (finish drying) of the substrate W is executed (step S6).

  As described above, according to this embodiment, DIW (internal residual liquid) remaining in the gaps of the pattern FP is frozen to form the solidified body 13 in the same manner as in the first embodiment, and the pattern FP is structured. Is reinforced. Then, physical cleaning is performed using the two-fluid nozzle 5 in a state where the pattern FP is reinforced in this way. Therefore, the substrate surface Wf can be cleaned well while suppressing damage to the pattern FP.

  Further, according to this embodiment, the droplets of the cleaning liquid having a lower freezing point than the internal residual liquid are supplied to the substrate surface Wf and cooled to a temperature higher than the freezing point of the cleaning liquid and lower than the freezing point of the internal residual liquid. Physical cleaning is performed while the cooling plate 42 having the substrate cooling surface 42a is opposed to the substrate back surface Wb. Therefore, physical cleaning is performed on the substrate surface Wf in a state where the solidified body 13 is formed inside the gap of the pattern FP, that is, in a state where the pattern FP is structurally reinforced, while preventing the cleaning liquid itself from freezing. be able to. In addition, in the first embodiment, the solidified body forming process is executed using the cooling gas discharge nozzle 3, while the frozen state of the solidified body 13 during physical cleaning is discharged from the two-fluid nozzle 5 while the cleaning liquid is cooled. In contrast to this, in this embodiment, the solidified body 13 can be maintained in a frozen state during execution of the solidified body forming process and physical cleaning only by arranging the cooling plate 42 close to the substrate W. it can.

<Third Embodiment>
FIG. 10 is a plan layout view showing a third embodiment of the substrate processing apparatus of the present invention. In this substrate processing apparatus, a plurality of substrates W can be subjected to a cleaning process (liquid film forming process + rough drying process + solidified body forming process + physical cleaning process + rinsing process + main drying process). It has become. In this substrate processing apparatus, a processing unit in which substrate transport mechanisms 600 are arranged separately from each other, that is, a spin processing unit 100 (corresponding to “liquid removing means” of the present invention), a freezing processing unit 200 (“solidified body of the present invention”). Forming means), physical cleaning processing unit 300 (corresponding to “physical cleaning means” of the present invention), rinsing processing unit 400 and drying processing unit 500 to be sequentially transferred to perform a series of cleaning processes.

  First, the spin processing unit 100 will be described. FIG. 11 is a diagram showing a configuration of a spin processing unit provided in the substrate processing apparatus of FIG. The spin processing unit 100 includes a processing chamber 101, and within the processing chamber 101, a liquid film forming process and a rough drying process can be performed on a plurality of substrates W at once. A plurality of substrates W are held in the processing chamber 101 by the substrate holder 110 while being separated from each other and stacked on each other. The substrate holding unit 110 extends in the vertical direction to hold each of the plurality of substrates W in a substantially horizontal posture, for example, three substrate holding columns 111 and the top and bottom of the three substrate holding columns 111. And a ring-shaped support plate 112 for connecting and fixing the ends. The support plate 112 is supported by the rotation support shaft 102 so as to be rotatable about the vertical axis. The rotation support shaft 102 is connected to the rotation shaft of the spin motor 103, and the substrate W held by the substrate holder 110 is rotated about the vertical axis by driving the spin motor 103.

  A DIW supply nozzle 104 is provided corresponding to each of the plurality of substrates W held by the substrate holding unit 110. Each DIW supply nozzle 104 is connected to a side surface of a supply pipe 105 extending in the stacking direction of the substrates W, and DIW supplied from a DIW supply unit (not shown) is passed through the supply pipe 105 to the DIW supply nozzle 104. And discharged from the DIW supply nozzle 104 toward the front surface Wf of the corresponding substrate W. Further, a drain port 106 is provided at the bottom of the processing chamber 101, and the liquid component discharged from the substrate W can be drained out of the system from the drain port 106.

  Next, the freezing processing unit 200 will be described. FIG. 12 is a diagram showing a configuration of a freezing processing unit provided in the substrate processing apparatus of FIG. The freezing processing unit 200 includes a processing tank 201 in which a processing space SP that can accommodate a plurality of substrates W is formed. In the freezing unit 200, a lifter 202 is provided so as to be movable up and down between an internal position of the processing tank 201 (position shown in FIG. 12) and an upper position of the processing tank 201, and is lifted and lowered by a lifter driving mechanism 202a. Is done. Accordingly, the plurality of substrates W can be arranged at the upper position of the processing bath 201 and the position accommodated in the processing space SP while the plurality of substrates W are held by the substrate holding guide 203 included in the lifter 202.

  An inner wall surface 211 of the processing tank 201 serves as a cooling surface for cooling the processing space SP, and a refrigerant path 204 is formed along the inner wall surface 211 so as to surround the processing space SP. Both ends of the refrigerant path 204 are connected to the refrigerant supply unit 205. The refrigerant supply unit 205 includes a cooling mechanism that cools the refrigerant, and a pumping mechanism such as a pump that pumps the refrigerant to the refrigerant path 204 and circulates the refrigerant path 204. Therefore, the refrigerant is supplied from the refrigerant supply unit 205, and the refrigerant that has exited the refrigerant path 204 is returned to the refrigerant supply unit 205 again. Any refrigerant that cools the temperature of the processing space SP to a temperature lower than the freezing point of the internal residual liquid (DIW) via the inner wall surface 211 may be used.

  The upper part of the processing tank 201 is a substrate carry-in / out entrance, and can be opened and closed by driving a shutter 206 by a shutter drive mechanism 207. In a state where the upper part of the processing tank 201 is opened, a plurality of substrates W are carried in and out by the lifter driving mechanism 202a from the opened part, while the processing space SP inside the processing tank 201 is closed while the upper part of the processing tank 201 is closed. Can be a sealed space. Further, the outer wall of the processing tank 201 and the shutter 206 are covered with a heat insulating material 208 in order to increase the cooling efficiency of the processing space SP in a sealed state.

  Next, the physical cleaning processing unit 300 will be described. FIG. 13 is a diagram showing a configuration of a physical cleaning unit provided in the substrate processing apparatus of FIG. The physical cleaning processing unit 300 performs physical cleaning on the plurality of substrates W by applying ultrasonic vibration to the plurality of substrates W via the cleaning liquid. The physical cleaning processing unit 300 includes a processing tank 301 that stores a cleaning liquid, and a lifter 302 that houses a plurality of substrates W in an upright posture is disposed inside the processing tank 301. The lifter 302 can be raised and lowered between an internal position of the processing tank 301 (position shown in FIG. 13) and an upper position of the processing tank 301, and is lifted and lowered by a lifter driving mechanism 302a. The lifter 302 includes three substrate holding guides 303 for holding a plurality of substrates W.

  In the vicinity of the inner bottom portion of the processing tank 301, two tubular cleaning liquid supply nozzles 304 are respectively arranged in a substantially horizontal direction. A plurality of discharge holes 305 for discharging the cleaning liquid are formed in these cleaning liquid supply nozzles 304, respectively. The cleaning liquid supply nozzles 304 communicate with the cleaning liquid supply unit 307 via the cleaning liquid supply pipe 306. When the cleaning liquid is pumped from the cleaning liquid supply unit 307, the cleaning liquid is supplied from the cleaning liquid supply nozzles 304 to the processing tank 301. Is done. The cleaning liquid discharged from each cleaning liquid supply nozzle 304 overflows from the opening at the top of the tank while the cleaning liquid ejected from the left and right sides forms an upward flow at the center of the tank. A contaminant that diffuses into the cleaning liquid by the overflowed cleaning liquid is received in the overflow tank 309 together with the cleaning liquid, and is discharged outside the tank.

  The cleaning liquid supply unit 307 cools (temperature-controls) the cleaning liquid having a lower freezing point than the internal residual liquid (DIW) to a temperature higher than the freezing point of the cleaning liquid and lower than the freezing point of the internal residual liquid. To pump. Thereby, the inside of the processing tank 301 is filled with the cooled cleaning liquid (cooled cleaning liquid). Instead of supplying the cooling cleaning liquid from the cleaning liquid supply unit 307, the cleaning liquid supplied from the cleaning liquid supply unit 307 to the treatment tank 301 is cooled to a temperature higher than the freezing point of the cleaning liquid and lower than the freezing point of the internal residual liquid. You may comprise.

  Further, an outer tank 311 is disposed so as to surround a part of the bottom portion and the peripheral side portion of the processing tank 301. A propagation liquid for propagating ultrasonic vibrations is stored in the outer tank 311. An ultrasonic transducer 312 is installed below the outer tank 311. The ultrasonic vibrator 312 is driven by a high frequency transmitter (not shown), and the ultrasonic vibration generated by the ultrasonic vibrator 312 is processed from the propagation liquid stored in the outer tank 311 and the bottom wall surface of the processing tank 301. It is transmitted to the cleaning liquid in the tank 301. Thereby, ultrasonic vibration is applied to the substrate W immersed in the cleaning liquid via the cleaning liquid.

  Next, the operation of the substrate processing apparatus configured as described above will be described with reference to FIGS. When the unprocessed substrate W is carried into the spin processing unit 100, it is held by the substrate holding unit 110. Then, when DIW is supplied from the DIW supply nozzle 104 to each surface Wf of the plurality of substrates W while rotating the substrate W by driving the spin motor 103, a liquid film is formed on the surface Wf of each substrate W (step). S1). At this time, DIW enters the pattern gap due to the flow of DIW. After that, the substrate W is roughly dried by stopping the supply of DIW while continuing the rotation of the substrate W. Thus, DIW is removed from the substrate surface Wf while leaving DIW (internal residual liquid) in the gaps of the pattern (step S2; liquid removal step).

  Subsequently, the substrate W is transported from the spin processing unit 100 to the freezing processing unit 200 by the substrate transport mechanism 600. In the freezing processing unit 200, the lifter 202 waiting at the upper position of the processing bath 201 receives the substrate W from the substrate transport mechanism 600. Then, the lifter 202 is lowered by the operation of the lifter driving mechanism 22 a to place the substrate W at a position accommodated in the processing space SP in the processing tank 201. At this time, the shutter 206 is opened and the upper portion of the processing tank 201 is opened.

  When the substrate W is accommodated in the processing bath 201, the shutter 206 is closed. Here, since the temperature of the processing space SP in the processing tank 201 is cooled to a temperature lower than the freezing point of the internal residual liquid (DIW), the internal residual liquid freezes in each substrate W and the pattern is changed. A solidified body is formed inside the gap (step S3; solidified body forming step). Thereby, the pattern is structurally reinforced by the solidified body. When the solidified body forming process is completed, the shutter 206 is opened, the lifter 202 is raised to a position above the processing tank 201, and the substrate W is transferred to the substrate transport mechanism 600. The shutter 206 is closed until the next substrate W is transported from the spin processing unit 100.

  Subsequently, the substrate transport mechanism 600 transports the substrate W from the freezing processing unit 200 to the physical cleaning processing unit 300. In the physical cleaning processing unit 300, the lifter 302 that has been waiting in the upper position of the processing tank 301 receives the substrate W from the substrate transport mechanism 600, and lowers the lifter 302 by the operation of the lifter driving mechanism 302a. As a result, the plurality of substrates W are collectively immersed in the cooling cleaning liquid stored in the processing tank 301, and ultrasonic vibration is applied to each of the plurality of substrates W through the cooling cleaning liquid (step S4; physical cleaning). Process). Thereby, particles adhering to the substrate W are detached from the substrate W in response to the impact of ultrasonic vibration from the ultrasonic transducer 312. Since a cleaning liquid flow (upward flow) is formed in the processing tank 301 toward the upper side of the processing tank 301, the particles detached from the substrate W are discharged out of the tank together with the cleaning liquid overflowing from the processing tank 31. . In addition, since the cooling cleaning liquid is cooled (temperature-controlled) to a temperature lower than the freezing point of the internal residual liquid, the solidified body formed inside the pattern gap can be physically cleaned while being frozen. Moreover, since the particles are exposed to the substrate surface Wf by the rough drying process, they are efficiently removed from the substrate surface Wf by ultrasonic vibration.

  Here, in physical cleaning using ultrasonic waves (ultrasonic cleaning), particles adhering to the substrate W are vibrated and desorbed by ultrasonic vibration, or cavitation and bubbles generated in the cleaning liquid are allowed to act on the substrate W. Thus, particles are removed from the substrate W. In such physical cleaning, the particle removal rate from the substrate surface Wf is improved by increasing the vibration energy (ultrasonic vibration energy) reaching the substrate W by changing the cleaning conditions such as increasing the oscillation output of the ultrasonic vibrator. It is possible. On the other hand, if ultrasonic vibration energy is increased without taking any measures on the substrate side to be processed, the pattern is damaged. Therefore, in this embodiment, a solidified body is formed inside the pattern gap, and the physical cleaning is performed in a state where the pattern is structurally reinforced. Thereby, even if the cleaning conditions are changed so as to increase the ultrasonic vibration energy, the pattern can be prevented from being damaged. Therefore, the particle removal rate can be improved while suppressing damage to the pattern.

  Thus, when the physical cleaning process for a predetermined time is completed, the lifter 302 is raised and the substrate W is delivered to the substrate transport mechanism 600 at a position above the processing tank 301. Then, the substrate transport mechanism 600 transports the substrate W to the rinse processing unit 400. The rinsing unit 400 includes a rinsing tank (not shown) that stores DIW as a rinsing liquid. The substrate W is immersed in the rinsing liquid in the rinsing tank, so that the solidified body is melted and removed from the substrate surface Wf. At the same time, contaminants adhering to the inside of the pattern gap are removed from the substrate surface Wf (step S5; solidified body removing step). Thereafter, the substrate W is transported from the rinse processing unit 400 to the drying processing unit 500, and the main drying processing (finish drying) of the substrate W is performed in the drying processing unit 500 (step S6). The drying unit 500 may be a unit that dries the substrate W by heating and / or reducing the pressure in the drying chamber 41, or may be a unit that performs vapor drying.

  As described above, according to this embodiment, DIW (internal residual liquid) remaining inside the pattern gap is frozen to form a solidified body, and the pattern is structurally reinforced. Then, ultrasonic cleaning is executed in such a state that the pattern is reinforced. Therefore, the substrate W can be cleaned well while suppressing damage to the pattern.

  Further, according to this embodiment, the cleaning liquid having a freezing point lower than that of the internal residual liquid (DIW) is stored in the processing tank 301 in a state of being cooled to a temperature higher than the freezing point of the cleaning liquid and lower than the freezing point of the internal residual liquid. At the same time, physical cleaning is performed by applying ultrasonic vibration to each substrate W through the cleaning liquid while immersing the plurality of substrates W in the cleaning liquid. Therefore, physical cleaning can be performed collectively on each substrate surface Wf of the plurality of substrates W in a state in which a solidified body is formed inside the pattern gap, that is, in a state where the pattern is structurally reinforced.

<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-described embodiment, DIW is used as the liquid that remains in the gaps of the pattern, that is, the internal residual liquid. However, the present invention is not limited to this. For example, a liquid having a higher freezing point than DIW may be used as the internal residual liquid. For example, when tertiary butyl alcohol (freezing point: 25.4 ° C.) is used as the internal residual liquid, the cleaning process is performed as follows. Here, a description will be given with reference to FIGS. 5 and 6.

  First, a liquid film 11 made of third butyl alcohol is formed on the substrate surface Wf in a state where the third butyl alcohol is melted (temperature controlled to a temperature higher than the freezing point of the third butyl alcohol). Get inside. Thereafter, the third butyl alcohol is removed from the substrate surface Wf while leaving the third butyl alcohol inside the gap of the pattern FP (liquid removing step). Subsequently, the temperature is returned to room temperature (a temperature lower than the freezing point of the third butyl alcohol) to solidify the third butyl alcohol to form a solidified body 13 inside the gap of the pattern FP (solidified body forming step). Thereby, the pattern FP is structurally reinforced by the solidified body 13. Then, a physical cleaning process is performed on the substrate surface Wf using DIW as a cleaning liquid while maintaining such a state (physical cleaning process). Here, the cleaning liquid (DIW) can be used at room temperature without adjusting the temperature. Further, it is not necessary to adjust the temperature of the substrate W. Therefore, physical cleaning can be performed in a state where the solidified body 13 is formed without newly providing temperature control means for the cleaning liquid and the substrate W. Then, after removing the solidified body 13 from the substrate surface Wf using a hot water adjusted to a temperature higher than the freezing point of tertiary butyl alcohol as a solidified body removing liquid (solidified body removing step), the substrate W is dried.

  Further, a mixed liquid in which tertiary butyl alcohol and DIW are mixed may be used as the internal residual liquid. Thus, by mixing DIW with tertiary butyl alcohol, the freezing point of the mixed solution can be lowered below the freezing point of tertiary butyl alcohol. As a result, by changing the mixing ratio of tertiary butyl alcohol and DIW, for example, the mixture can be adjusted to coagulate (or melt the coagulated solid obtained by coagulating the mixture) at around 20 ° C. Can be improved.

  In the above embodiment, the liquid is removed from the substrate surface Wf while leaving the liquid inside the gap of the pattern FP while rotating the substrate W in the liquid removing step. It is not limited. For example, while the gas is blown onto the substrate surface Wf from an air knife (corresponding to the “liquid removing means” of the present invention), the liquid adhering to the substrate surface Wf is moved while moving the air knife relative to the substrate surface Wf in a predetermined movement direction. You may make it cut and remove. Even in this case, it is preferable to dry the substrate W to such an extent that the upper surface of the pattern FP is exposed while leaving the liquid inside the gap of the pattern FP by adjusting the flow rate of the gas ejected from the air knife.

  In the first and second embodiments described above, droplet cleaning is performed using a so-called external mixing type two-fluid nozzle that generates cleaning liquid droplets by mixing the cleaning liquid and gas outside the nozzle (in the air). However, the present invention is not limited to this, and droplet cleaning is performed using a so-called internal mixing type two-fluid nozzle that mixes cleaning liquid and gas inside the nozzle to generate droplets of the cleaning liquid. Also good.

  In the first and second embodiments, physical cleaning is performed on the substrate surface Wf by supplying droplets of the cleaning liquid from the two-fluid nozzle toward the substrate surface Wf in the physical cleaning step. The physical cleaning used in the invention is not limited to these physical cleanings, but is optional as long as the solidified body 13 formed in the gaps of the pattern FP can be cleaned under the condition that it does not melt. For example, brush cleaning for cleaning the substrate W by bringing a brush or the like into contact with the substrate surface Wf, high-pressure jet cleaning for cleaning the substrate W by spraying a cleaning liquid at a high pressure toward the substrate surface Wf, and fine ice particles on the substrate An ice scrubber for cleaning the substrate W by colliding with the surface Wf, or an aerosol cleaning for cleaning the substrate surface Wf by spraying particles such as dry ice (CO2), ice (H2O) or argon (Ar) solidified by cooling at high speed. Alternatively, ultrasonic cleaning using an ultrasonic nozzle can be used. In particular, since ice scrubber and aerosol cleaning can be performed at a relatively low temperature, when the internal residual liquid is solidified by freezing, physical cleaning is performed while keeping the solidified body 13 formed (solidified state). It is effective to do.

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

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 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 flowchart which shows operation | movement of the substrate processing apparatus of FIG. It is a schematic diagram for demonstrating operation | movement of the substrate processing apparatus of FIG. It is a plane layout figure which shows 2nd Embodiment of the substrate processing apparatus of this invention. It is a figure which shows the structure of the spin processing unit with which the substrate processing apparatus of FIG. 7 was equipped. It is a figure which shows the structure of the freezing washing | cleaning unit with which the substrate processing apparatus of FIG. 7 was equipped. It is a plane layout figure which shows 3rd Embodiment of the substrate processing apparatus of this invention. It is a figure which shows the structure of the spin processing unit with which the substrate processing apparatus of FIG. 10 is equipped. It is a figure which shows the structure of the freezing process unit with which the substrate processing apparatus of FIG. 10 was equipped. It is a figure which shows the structure of the physical cleaning process unit with which the substrate processing apparatus of FIG. 10 was equipped.

Explanation of symbols

2 ... Spin chuck (liquid removing means)
3 ... Cooling gas discharge nozzle (solidified body forming means)
5 ... Two-fluid nozzle (physical cleaning means)
13 ... Solidified body 42 ... Cooling plate (substrate cooling part, solidified body forming means)
42a ... substrate cooling surface 100 ... spin processing unit (liquid removing means)
200 ... Freezing unit (solidified body forming means)
300 ... Physical cleaning processing unit (physical cleaning means)
FP ... Pattern W ... Substrate Wb ... Substrate back surface Wf ... Substrate surface

Claims (9)

In a substrate processing method for performing a cleaning process on a substrate surface on which a predetermined pattern is formed,
A liquid removing step of removing the liquid from the substrate surface while leaving the liquid inside the gap of the pattern from the substrate having the liquid adhered to the substrate surface;
A solidified body forming step of solidifying the liquid remaining in the gap of the pattern to form a solidified body in the gap of the pattern;
A substrate processing method comprising: a physical cleaning step of performing physical cleaning having a physical cleaning action on the surface of the substrate while maintaining the state where the solidified body is formed inside the gap of the pattern.   The substrate processing method according to claim 1, further comprising a solidified body removing step of supplying a solidified body removing liquid to the substrate surface after the physical cleaning step to remove the solidified body.   The substrate processing method according to claim 1, wherein in the liquid removing step, the liquid is removed from the substrate surface while rotating the substrate.   In the physical cleaning step, a cleaning liquid having a freezing point lower than that of the liquid remaining in the gaps of the pattern is sprayed onto the substrate surface in a state adjusted to a temperature higher than the freezing point of the cleaning liquid and lower than the freezing point of the liquid. 4. The substrate processing method according to claim 1, wherein the physical cleaning is performed on the substrate surface. The substrate processing method according to claim 1, wherein the physical cleaning step is performed using a cleaning liquid having a freezing point lower than that of the liquid.
In the physical cleaning step, a substrate cooling section having a substrate cooling surface adjusted to a temperature higher than the freezing point of the cleaning liquid and lower than the freezing point of the liquid remaining in the gap of the pattern is opposed to the back surface of the substrate. A substrate processing method of supplying the cleaning liquid to the substrate surface while performing the physical cleaning on the substrate surface.   In the physical cleaning step, a cleaning liquid having a freezing point lower than that of the liquid left inside the gaps of the pattern is stored in a processing tank stored in a state adjusted to a temperature higher than the freezing point of the cleaning liquid and lower than the freezing point of the liquid. The substrate processing method according to claim 1, wherein the physical cleaning is performed on the substrate surface while the substrate is immersed.   6. The substrate processing method according to claim 4 or 5, wherein droplets of the cleaning liquid generated by mixing the cleaning liquid and gas are supplied toward the substrate surface to perform the physical cleaning on the substrate surface.   The substrate processing method according to claim 6, wherein the physical cleaning is performed on the surface of the substrate by applying ultrasonic vibration to the substrate through the cleaning liquid. In a substrate processing apparatus that performs a cleaning process on a substrate surface on which a predetermined pattern is formed,
A liquid removing means for removing the liquid adhered to the substrate surface from the substrate surface while leaving the liquid inside the gap of the pattern;
Solidified body forming means for solidifying the liquid remaining in the gap of the pattern to form a solidified body in the gap of the pattern;
A substrate processing apparatus comprising: physical cleaning means for performing physical cleaning having a physical cleaning action on the surface of the substrate while maintaining the state in which the solidified body is formed inside the gap of the pattern.

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