JP2012212758A - Substrate processing method and substrate processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate processing method and a substrate processing apparatus which can increase the rate of particle removal even if the contact angle of the front surface of a substrate is small.SOLUTION: A substrate W is held on a spin chuck 2 in a substantially horizontal position while directing the front surface Wf upward. The front surface Wf of the substrate W is then subjected to hydrophobing by supplying a hydrophobic agent thereto from a hydrophobic agent discharge nozzle 5. Subsequently, a process liquid is supplied to the front surface Wf of the substrate W from a process liquid discharge nozzle 97, and a liquid membrane of process liquid is formed. Thereafter, cooling gas is discharged to the front surface Wf of the substrate W from a cooling gas discharge nozzle 3, and the liquid membrane is frozen. Finally, a melting liquid is discharged to the front surface Wf of the substrate W from a melting liquid discharge nozzle 6, and the frozen membrane is melted and removed.

Description

  The present invention relates to a substrate processing method and a substrate processing apparatus for performing a process of freezing a liquid film formed on a surface of a substrate. Examples of substrates to be processed include semiconductor wafers, liquid crystal display substrates, plasma display substrates, FED (Field Emission Display) substrates, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, and photomasks. Substrate, solar cell substrate and the like.

  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. That is, minute contamination such as particles adhering to the surface of the substrate without collapsing the pattern formed on the surface of the substrate with the miniaturization, higher functionality, and higher accuracy of devices typified by semiconductor devices It has become increasingly difficult to remove material. Therefore, particles adhering to the surface of the substrate are removed using the above-described freezing technique as follows.

  First, a liquid is supplied to the surface of the substrate 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 surface of the substrate to which particles are attached. Finally, particles are removed together with the frozen film from the surface of the substrate by removing the frozen film from the surface of the substrate. For example, in the apparatus described in Patent Document 1, a substrate is accommodated in a processing chamber, a removal fluid such as steam or ultrapure water vapor is supplied to the surface of the substrate, and a liquid film is formed by the removal fluid on the surface of the substrate. . Subsequently, a cooling gas having a temperature below the freezing temperature of the removal fluid is injected into the processing chamber, the cooling gas is circulated in the processing chamber, the liquid film on the surface of the substrate is frozen, and the surface of the substrate is A frozen membrane is formed on the entire surface. Thereafter, the frozen film is thawed to remove particles adhering to the surface of the substrate. That is, in the apparatus described in Patent Document 1, the liquid film is generated by volume expansion when frozen, and the pressure acting on the particles reduces the adhesion between the particles and the substrate, thereby removing the particles from the surface of the substrate. Like to do.

Japanese Patent Laid-Open No. 3-145130

  By the way, when the inventor conducted various experiments, it became clear that the removal rate of particles increased as the thickness of the liquid film formed on the surface of the substrate increased. The reason why the particle removal rate increases is considered to be that as the thickness of the liquid film increases, the liquid film is generated by volume expansion when frozen, and the pressure acting on the particles also increases.

  However, when the contact angle of the surface of the substrate is small, the liquid flows down from the end surface of the substrate when the liquid film is formed on the surface of the substrate, so that the thickness of the liquid film formed on the surface of the substrate is sufficient. Can not be secured. Therefore, the particle removal rate cannot be increased.

  Accordingly, an object of the present invention is to provide a substrate processing method and a substrate processing apparatus capable of increasing the particle removal rate even when the contact angle of the surface of the substrate is small.

  The invention according to claim 1 for achieving the object includes a substrate holding step (S1) for holding the substrate substantially horizontally, and supplying a hydrophobizing agent to the substrate held in the substrate holding step. A hydrophobizing step (S2) for hydrophobizing the surface of the substrate, and a liquid for supplying a processing liquid to the surface of the substrate hydrophobized in the hydrophobizing step to form a liquid film of the processing liquid on the surface of the substrate The substrate processing method includes a film forming step (S4) and a freezing step (S5) in which the liquid film formed in the liquid film forming step is cooled and the liquid film is frozen. In addition, the alphanumeric characters in parentheses represent corresponding components in the embodiments described later. The same applies hereinafter.

  According to the present invention, the hydrophobizing agent is first supplied to the substrate held almost horizontally. Thereby, the surface of the substrate is hydrophobized. Thereafter, the treatment liquid is supplied to the surface of the hydrophobized substrate. When the surface of the substrate is hydrophobic, that is, when the contact angle of the surface of the substrate is large, the treatment liquid tends to stay on the end surface of the substrate. Therefore, the thickness of the liquid film of the processing liquid formed on the surface of the substrate increases. Therefore, since the liquid film of the treatment liquid having a sufficient thickness can be frozen in the freezing step, the particle removal rate can be increased.

  In the hydrophobizing step, a hydrophobizing agent having a temperature higher than normal temperature may be supplied to the surface of the substrate. (Claim 2) According to the present invention, the surface of the substrate can be efficiently hydrophobized. That is, when the temperature of the supplied hydrophobizing agent is increased, the reactivity between the surface of the substrate and the hydrophobizing agent can be increased. Therefore, the surface of the substrate can be hydrophobized in a shorter time. In addition, since the surface of the substrate can be hydrophobized in a short time, the amount of the hydrophobizing agent supplied to the surface of the substrate can be reduced.

  In the liquid film forming step, a processing liquid having a temperature lower than normal temperature may be supplied to the surface of the substrate. (Claim 3) According to the present invention, in the liquid film forming step, the temperature of the liquid film formed on the surface of the substrate can be lowered. Therefore, the liquid film can be frozen in a shorter time in the subsequent freezing step.

  According to a fourth aspect of the present invention, there is provided a substrate holding step (S11) for holding the substrate substantially horizontally and a liquid hydrophobizing agent for hydrophobizing the surface of the substrate with respect to the substrate held in the substrate holding step. A hydrophobizing agent liquid film forming step (S12) for forming a hydrophobizing agent liquid film on the surface of the substrate, and cooling the liquid film formed in the hydrophobizing agent liquid film forming step. A substrate processing method including a freezing step (S13) for freezing.

  According to the present invention, a liquid hydrophobizing agent is supplied to a substrate held substantially horizontally. Thereby, the surface of the substrate is hydrophobized. Further, a liquid film of a hydrophobizing agent is formed on the surface of the substrate. Similarly to the first aspect of the present invention, when the surface of the substrate is hydrophobic, the hydrophobizing agent supplied to the surface of the substrate tends to stay on the end surface of the substrate. Therefore, the thickness of the liquid film of the hydrophobizing agent formed on the surface of the substrate increases. Therefore, since the liquid film of the hydrophobizing agent having a sufficient thickness can be frozen in the freezing step, the particle removal rate can be increased.

  The invention according to claim 5 is a substrate holding means (2) for holding the substrate substantially horizontally, and a hydrophobic agent for supplying a hydrophobizing agent for hydrophobizing the surface of the substrate to the substrate held by the substrate holding means. Agent supplying means (5) and liquid film forming means for supplying the treatment liquid to the substrate having the hydrophobized agent supplied and having the surface hydrophobized to form a liquid film of the treatment liquid on the surface of the substrate (97) and a freezing means (3) for cooling the liquid film formed by the liquid film forming means and freezing the liquid film. According to the present invention, it is possible to achieve the same effects as those described in relation to the invention of claim 1.

  According to the sixth aspect of the present invention, a substrate holding means (2) for holding the substrate substantially horizontally and a liquid hydrophobizing agent for hydrophobizing the surface of the substrate are supplied to the substrate held by the substrate holding means. And hydrophobizing agent liquid film forming means (97) for forming a liquid film of the hydrophobizing agent on the surface of the substrate, and cooling the liquid film formed by the hydrophobizing agent liquid film forming means. And a freezing means (3) for freezing the substrate. According to the present invention, it is possible to achieve the same effect as that described in regard to the invention of claim 4.

It is a figure which shows the substrate processing apparatus concerning 1st Embodiment of 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 flowchart which shows operation | movement of the substrate processing apparatus of FIG. It is a figure which shows the substrate processing apparatus concerning 2nd Embodiment of this invention. It is a flowchart which shows operation | movement of the substrate processing apparatus of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 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 substrate processing apparatus is a single wafer type substrate processing apparatus used for a cleaning process for removing contaminants such as particles adhering to a surface Wf of a substrate W such as a semiconductor wafer. More specifically, after a liquid film is formed on the surface Wf of the substrate W on which the fine pattern is formed, the liquid film is frozen and then the frozen liquid film (frozen film) is removed from the surface Wf of the substrate W. In this way, the apparatus performs a series of cleaning processes (liquid film formation + liquid film freezing + film removal) on the substrate W.

  This substrate processing apparatus includes a spin chuck 2 (corresponding to the “substrate holding means” of the present invention) that rotates the substrate W while holding the substrate W in a substantially horizontal position with the surface Wf of the substrate W facing upward, and the spin chuck 2. A cooling gas discharge nozzle 3 (corresponding to the “freezing means” of the present invention) for discharging a cooling gas for freezing the liquid film toward the surface Wf of the substrate W held on the substrate, and a substrate held on the spin chuck 2 Hydrophobizing agent discharge nozzle 5 (corresponding to the “hydrophobizing agent supplying means” of the present invention) for supplying a hydrophobizing agent toward the surface Wf of W, and toward the surface Wf of the substrate W held by the spin chuck 2 A melt discharge nozzle 6 for discharging a melt for melting the frozen film, a blocking member 9 disposed opposite to the surface Wf of the substrate W held by the spin chuck 2, and a blocking member 9 are provided on the spin chuck. Substrate held in 2 Treatment liquid supplying process liquid toward the surface Wf of the discharge nozzle 97 (corresponding to "liquid film forming part" of the present invention) are provided.

  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.

  The spin chuck 2 is not limited to such a configuration, and for example, a vacuum suction type vacuum chuck may be employed. This vacuum chuck can hold the substrate W in a substantially horizontal posture by vacuum-sucking the lower surface of the substrate W. The vacuum chuck can rotate the substrate W while maintaining a substantially horizontal posture by rotating around the substantially vertical axis while holding the substrate W.

  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 surface Wf of the substrate W while moving along the movement trajectory T in FIG. Move along a trajectory T from the rotation 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 surface Wf 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 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 to face the surface Wf of the substrate W, the cooling gas is locally discharged from the cooling gas discharge nozzle 3 toward the surface Wf of the substrate W. Therefore, in a 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 locus T while rotating the substrate W, so that the cooling gas is transferred to the substrate W. Can be supplied over the entire surface Wf. As a result, when the liquid film 11f is formed on the surface Wf of the substrate W as will be described later, the entire liquid film 11f can be frozen and the frozen film 13f can be generated on the entire surface Wf of the substrate W. Yes.

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

  As the cooling gas, a gas having a temperature lower than the freezing point of the liquid constituting the liquid film 11f formed on the surface Wf of 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 surface Wf of the substrate W. Therefore, it is possible to prevent the surface Wf of the substrate W from being contaminated when the liquid film 11f is frozen. In this embodiment, the liquid film is discharged from the cooling gas discharge nozzle 3 toward the surface Wf of the substrate W in a state in which the liquid film 11f of DIW is formed on the surface Wf of the substrate W as described later. 11f is frozen. Therefore, the cooling gas used is adjusted to a temperature lower than the freezing point (freezing point) of DIW constituting the liquid film 11f.

  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 hydrophobizing agent discharge nozzle 5 is attached to the tip of the second arm 55. The hydrophobizing agent discharge 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 hydrophobizing agent discharge nozzle 5 is connected to a hydrophobizing agent supply unit 71 (FIG. 2) and a solvent supply unit 72 (FIG. 2). The hydrophobizing agent discharge nozzle 5 selectively discharges the hydrophobizing agent from the hydrophobizing agent supply unit 71 and the solvent from the solvent supply unit 72 toward the surface Wf of the substrate W.

  The hydrophobizing agent supply unit 71 is prepared with a liquid hydrophobizing agent heated to a predetermined temperature (for example, between room temperature and 70 ° C.), and the surface Wf of the substrate W is hydrophobic at a temperature higher than normal temperature. An agent is supplied.

  The hydrophobizing agent is supplied to the surface Wf of the substrate W and reacts with the surface Wf of the substrate W, thereby increasing the contact angle of the surface Wf of the substrate W and increasing the hydrophobicity of the surface Wf of the substrate W. . The hydrophobizing agent is, for example, a silane coupling agent. Examples of the silane coupling agent include HMDS (hexamethyldisilazane), TMS (tetramethylsilane), fluorinated alkylchlorosilane, alkyldisilazane, dimethylsilyldimethylamine, dimethylsilyldiethylamine, tetramethyldisilazane, and bis (dimethylamino). ) At least one of dimethylsilane, N, N-dimethylaminotrimethylsilane, N- (trimethylsilyl) dimethylamine and an organosilane compound.

  Further, the hydrophobizing agent may be supplied to the hydrophobizing agent nozzle 5 in a state diluted with a diluting solvent capable of dissolving the hydrophobizing agent, or supplied to the hydrophobizing agent nozzle 5 without being diluted. May be. In addition, as a dilution solvent, alcohol (monohydric alcohol), a polyhydric alcohol, a ketone, PGMEA, EGMEA, and a fluorine-type solvent are included, for example. The alcohol includes, for example, at least one of methyl alcohol, ethanol, propyl alcohol, and IPA. The polyhydric alcohol includes, for example, ethylene glycol. The ketone includes, for example, at least one of acetone and diethyl ketone. The fluorine-based solvent includes, for example, at least one of HFE and HFC.

  The solvent prepared in the solvent supply unit 72 includes, for example, at least one of alcohol, ketone, PGMEA (propylene glycol monomethyl ether acetate), EGMEA (ethylene glycol monomethyl ether), and a fluorine-based solvent. The alcohol includes, for example, at least one of methyl alcohol, ethanol, propyl alcohol, and IPA (isopropyl alcohol). The ketone includes, for example, at least one of acetone and diethyl ketone. The fluorine-based solvent includes, for example, at least one of HFE (hydrofluoroether) and HFC (hydrofluorocarbon).

  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 a processing liquid 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 back surface discharges the processing liquid toward the center of the lower surface of the substrate W at the tip. A treatment liquid discharge nozzle 27 is provided. The treatment liquid supply pipe 25 is connected to the chemical liquid supply unit 61 (FIG. 2) and the rinsing liquid supply unit 62 (FIG. 2), and the SC1 solution (mixed aqueous solution of ammonia water and hydrogen peroxide water) is supplied from the chemical liquid supply unit 61. The rinse liquid such as DIW is selectively supplied from the rinse liquid supply 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 a dry gas supply unit 65 (FIG. 2), and can supply nitrogen gas as a dry gas to a space formed between the spin base 23 and the back surface Wb of the substrate W. . 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.

  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 rotating shaft 68 so as to extend in the horizontal direction, and the melt 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 melt discharge nozzle 6 is moved laterally from the discharge position and the discharge position above the rotation center A 0 of the substrate W. It can be reciprocated between the retracted standby position. The melt discharge nozzle 6 is connected to the melt supply unit 73 (FIG. 2), and a melt such as warm water or SC1 solution is pumped to the melt 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 is a substrate-facing surface that faces the surface Wf of the substrate W substantially in parallel, and has a planar size that is equal to or larger 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 surface Wf of the substrate W 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 processing liquid discharge nozzle 97 is coupled to the lower end of the liquid supply pipe 96. The liquid supply pipe 96 is connected to the processing liquid supply unit 74 (FIG. 2). When the processing liquid is supplied from the processing liquid supply unit 74, the processing liquid is supplied from the processing liquid discharge nozzle 97 to the surface Wf of the substrate W. It is possible to discharge towards. A processing liquid cooled to a predetermined temperature (for example, 0 ° C. to 2 ° C.) is prepared in the processing liquid supply unit 74, and a processing liquid having a temperature lower than normal temperature is supplied to the surface Wf of the substrate W. As the treatment liquid, chemical liquid or pure water, DIW (deionized water), carbonated water, electrolytic ion water, hydrogen water, ozone water, dilute concentration (for example, about 10 to 100 ppm) hydrochloric acid water, or the like is used.

  Next, the cleaning processing operation in the substrate processing apparatus configured as described above will be described with reference to FIG. FIG. 4 is a flowchart 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 surface Wf of the substrate W. That is, the surface Wf of the substrate W is a pattern formation surface. Therefore, in this embodiment, the substrate W is carried into the apparatus with the surface Wf of the substrate W facing upward and is held by the spin chuck 2 (step S1; corresponding to the “substrate holding process” of the present invention). . Note that the blocking member 9 is in a separated position and prevents interference with the substrate W.

  When the unprocessed substrate W is held on the spin chuck 2, the control unit 4 drives the chuck rotating mechanism 22 to rotate the spin chuck 2 and also drives the second rotation motor 51 to make the hydrophobizing agent. The discharge nozzle 5 is moved to a discharge position above the rotation center A0 of the substrate W. Then, the hydrophobizing agent heated to a temperature higher than normal temperature is supplied from the hydrophobizing agent discharge nozzle 5 to the surface Wf of the substrate W. The hydrophobizing agent supplied to the surface Wf of the substrate W is uniformly spread outward in the radial direction of the substrate W by the centrifugal force accompanying the rotation of the substrate W, and is supplied to the entire surface Wf of the substrate W. As a result, the surface Wf of the substrate W is hydrophobized (step S2; corresponding to the “hydrophobizing step” of the present invention).

  After the hydrophobizing agent is supplied to the surface Wf of the substrate W for a predetermined time, the discharge of the hydrophobizing agent from the hydrophobizing agent discharge nozzle 5 is stopped, and the solvent is supplied from the hydrophobizing agent discharge nozzle 5 to the surface Wf of the substrate W. Supplied. The solvent is also supplied to the entire surface of the substrate W by centrifugal force accompanying the rotation of the substrate W. Thereby, the hydrophobizing agent adhering to the substrate W is replaced with the solvent (step S3). Then, after the solvent is supplied to the surface Wf of the substrate W over a predetermined time, the discharge of the solvent from the hydrophobizing agent discharge nozzle 5 is stopped, and the hydrophobizing agent discharge nozzle 5 is moved to the standby position.

  Next, the control unit 4 drives the blocking plate elevating mechanism 94 so that the blocking member 9 is lowered to the facing position and is disposed close to the surface Wf of the substrate W. As a result, the surface Wf of the substrate W is covered in a state of being close to the substrate facing surface of the blocking member 9 and is blocked from the ambient atmosphere of the substrate W. Then, the control unit 4 supplies DIW, which is an example of the processing liquid, from the processing liquid discharge nozzle 97 to the surface Wf of the substrate W while being cooled to a temperature lower than normal temperature. A centrifugal force accompanying the rotation of the substrate W acts on the DIW supplied to the surface Wf of the substrate W, and the DIW is evenly spread outward in the radial direction of the substrate W, and a part thereof is shaken off the substrate. Thereby, the thickness of the liquid film is uniformly controlled over the entire surface Wf of the substrate W, and a liquid film (water film) having a predetermined thickness is formed on the entire surface Wf of the substrate W (Step S4; book) This corresponds to the “liquid film forming step” of the invention).

  When forming the liquid film, it is not an essential requirement to shake off a part of the DIW supplied to the surface Wf of the substrate W as described above. For example, a liquid film may be formed on the surface Wf of the substrate W without shaking the DIW from the substrate W in a state where the rotation of the substrate W is stopped or in a state where the substrate W is rotated at a relatively low speed.

  Here, the hydrophobicity of the surface Wf of the substrate W is enhanced in a hydrophobizing step performed prior to the supply of DIW. Accordingly, since DIW supplied to the surface Wf of the substrate W tends to stay at the edge position of the substrate W, the thickness of the liquid film formed in the liquid film forming process is the same as the surface of the substrate that has not been subjected to the hydrophobic treatment. It is larger than the liquid film that is formed.

  Thus, when the liquid film forming step is completed, the control unit 4 places the blocking member 9 in the separated position and 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 discharge nozzle 3 is gradually moved toward the edge position Pe of the substrate W while discharging the cooling gas from the cooling gas discharge nozzle 3 toward the surface Wf of the rotating substrate W.

  As a result, as shown in FIG. 3, the region (frozen region) in which the liquid film 11 f is frozen out of the surface region of the surface Wf of the substrate W is expanded from the central portion to the peripheral portion of the surface Wf of the substrate W. A frozen film 13f is generated on the entire surface Wf (step S5; corresponding to the “freezing step” of the present invention). In addition, by rotating the substrate W while moving the cooling gas discharge nozzle 3, it is possible to generate the frozen film 13 f on the entire surface Wf of the substrate W 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 discharged from the cooling gas discharge nozzle 3 is diffused by the air flow generated by the rotation of the substrate W, and the efficiency of freezing the liquid film is deteriorated. The rotation speed of the substrate W during the process is 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 freezing process is performed in this manner, the volume of the liquid film that has entered between the surface Wf of the substrate W and the particles increases (when water at 0 ° C. becomes ice at 0 ° C., the volume is about 1.1. The particles are separated from the surface Wf of the substrate W by a minute distance. As a result, the adhesion force between the surface Wf of the substrate W and the particles is reduced, and further, the particles are detached from the surface Wf of the substrate W. At this time, even if a fine pattern is formed on the surface Wf of the substrate W, 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 surface Wf of the substrate W without peeling or collapsing the pattern.

  Further, as the thickness of the liquid film increases, the pressure that acts on the particles increases due to volume expansion when the liquid film freezes, so that the particle removal rate increases. In this embodiment, the hydrophobization step is performed prior to the liquid film formation step, whereby the thickness of the liquid film formed on the surface Wf of the substrate W in the liquid film formation step can be increased. The removal rate can be increased.

  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 drives the third rotation motor 67 to move the melt discharge nozzle 6 to the rotation center A0 of the substrate W. Is moved to the discharge position above. Then, before the frozen film 13f is melted, hot water (an example of a melt) and a rinse liquid of about 80 ° C. are supplied to the front and back surfaces Wf and Wb of the substrate W from the melt discharge nozzle 6 and the back surface treatment liquid discharge nozzle 27, respectively. . As a result, the frozen film on the surface Wf of the substrate W is thawed with hot water. Further, the centrifugal force due to the rotation of the substrate W acts on the frozen film 13f and the hot water supplied to the surface Wf of the substrate W. As a result, the frozen film 13f containing particles is removed from the surface Wf of the substrate W and discharged out of the substrate (step S7). Further, the rinsing liquid spreads over the entire back surface of the substrate W by the rotation of the substrate W, and the back surface Wb of the substrate W is rinsed. After the hot water and the rinse liquid are supplied for a predetermined time, the melt discharge nozzle 6 is moved to the standby position.

  Thus, when the film removal process is completed and the cleaning process (liquid film formation + liquid film freezing + film removal) of the substrate W is completed, the substrate W is subsequently dried. The control unit 4 drives the blocking plate elevating mechanism 94 so that the blocking member 9 is lowered to the opposing position and is disposed close to the surface Wf of the substrate W. Then, the rotational speeds of the chuck rotating mechanism 22 and the blocking member rotating mechanism 93 are increased to rotate the substrate W and the blocking member 9 at a high speed. Thereby, the drying process (spin drying) of the substrate W is executed (step S7). Furthermore, in this drying process, by supplying nitrogen gas from the gas supply paths 95 and 29, the space sandwiched between the blocking member 9 and the surface Wf of the substrate W and the back surface Wb of the spin base 23 and the substrate W are provided. The space between the two is a nitrogen gas atmosphere. Thereby, the drying of the substrate W is promoted, and the drying time can be shortened.

  Further, in the process of drying the surface Wf of the substrate W in the drying process, a force that attracts the patterns may be generated and the patterns may collapse. In particular, collapse tends to occur in patterns with a high aspect ratio. In this case, if the contact angle of the surface Wf of the substrate W, that is, the surface of the pattern is increased, the force for attracting the patterns decreases, and the pattern collapse can be suppressed. In the present embodiment, the surface Wf of the substrate W is hydrophobized in the hydrophobizing step. Therefore, the contact angle of the surface of the pattern formed on the surface Wf of the substrate W is increased. Therefore, in the drying process, the fine pattern formed on the surface Wf of the substrate W is prevented from being collapsed by the surface tension of the liquid adhering to the surface Wf of the substrate W. After the drying process, the rotation of the substrate W is stopped, and the processed substrate W is unloaded from the apparatus (step S8).

  As described above, according to the present embodiment, the surface Wf of the substrate W is hydrophobized by supplying the hydrophobizing agent to the surface Wf of the substrate W prior to the liquid film forming step. Accordingly, in the liquid film forming step, DIW supplied to the surface Wf of the substrate W tends to stay at the edge position of the substrate W, and the thickness of the liquid film formed on the surface Wf of the substrate W increases. Therefore, the thickness of the frozen film generated on the surface Wf of the substrate W can be further increased, and the particle removal rate can be increased.

  Further, according to the present embodiment, since the surface Wf of the substrate W is hydrophobized by the hydrophobizing agent, the fine pattern formed on the surface Wf of the substrate W can be prevented from collapsing in the drying process. .

  In addition, according to the present embodiment, since the liquid hydrophobizing agent heated to a predetermined temperature is supplied in the hydrophobizing step, the hydrophobizing treatment of the surface Wf of the substrate W can be performed efficiently. . That is, by increasing the temperature of the hydrophobizing agent, the reactivity between the surface Wf of the substrate W and the hydrophobizing agent is increased, and the surface Wf of the substrate W can be hydrophobized in a shorter time. Further, since the surface Wf of the substrate W can be hydrophobized in a short time, the amount of the hydrophobizing agent supplied to the surface Wf of the substrate W can be reduced.

  Further, according to the present embodiment, DIW cooled to a predetermined temperature is supplied to the surface Wf of the substrate W in the liquid film forming step. Therefore, the temperature of the DIW liquid film formed on the surface Wf of the substrate W can be lowered. Thereby, in the subsequent freezing process, the liquid film of DIW can be frozen in a short time.

  In this embodiment, the frozen film is removed by supplying hot water to the surface Wf of the substrate W. However, the frozen film may be removed by performing chemical cleaning on the surface Wf of the substrate W. That is, the SC1 solution (mixed aqueous solution of ammonia water and hydrogen peroxide solution) may be supplied from the melt discharge nozzle 6 to the surface Wf of the substrate W instead of warm water. Here, since the zeta potential (electrokinetic potential) of the solid surface in the SC1 solution has a relatively large value, the SC1 solution is between the surface Wf of the substrate W and the particles on the surface Wf of the substrate W. By being satisfied, a large repulsive force acts between the surface Wf of the substrate W and the particles. Therefore, the detachment of particles from the surface Wf of the substrate W can be further facilitated, and the particles can be effectively removed from the surface Wf of the substrate W.

  Further, the SC1 solution may be supplied from the back surface treatment liquid discharge nozzle 27 to the back surface Wb of the substrate W simultaneously with the supply of the SC1 solution to the front surface Wf of the substrate W. Thereby, even when the contaminant is attached to the back surface Wb of the substrate W, 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.

  FIG. 5 is a view showing a second embodiment of the substrate processing apparatus according to the present invention. The substrate processing apparatus according to the second embodiment is different from the first embodiment in that a liquid hydrophobizing agent is discharged from the processing liquid discharge nozzle 97. That is, the treatment liquid discharge nozzle 97 is connected to the hydrophobizing agent supply unit 71 (FIG. 2). A liquid hydrophobizing agent is discharged from the treatment liquid discharge nozzle 97 toward the surface Wf of the substrate W from the hydrophobizing agent supply unit 71. Furthermore, in the second embodiment, a hydrophobizing agent cooled to a predetermined temperature (for example, 0 ° C. to 2 ° C.) is prepared in the hydrophobizing agent supply unit 71, and the surface Wf of the substrate W has a normal temperature. A lower temperature hydrophobizing agent is supplied. In the second embodiment, the hydrophobizing agent discharge nozzle 5 and the configuration related thereto are omitted. Further, a solvent is discharged from the melt discharge nozzle 6 as a melt. As a kind of solvent, it is the same as that of the solvent supplied from the solvent supply part 72 in 1st Embodiment. Since other configurations and operations are basically the same as those in the first embodiment, the same reference numerals are given here and description thereof is omitted.

  Next, a cleaning process operation in the substrate processing apparatus according to the second embodiment will be described with reference to FIG. FIG. 6 is a flowchart showing the operation of the substrate processing apparatus of FIG. First, as in the first embodiment, the substrate W is loaded into the apparatus and held by the spin chuck 2 (step S11; corresponding to the “substrate holding step” of the present invention).

  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 surface Wf of the substrate W. As a result, the surface Wf of the substrate W is covered in a state of being close to the substrate facing surface of the blocking member 9 and is blocked from the ambient atmosphere of the substrate W. Then, the control unit 4 drives the chuck rotating mechanism 22 to rotate the spin chuck 2 and supplies the liquid hydrophobizing agent cooled to a predetermined temperature from the processing liquid discharge nozzle 97 to the surface Wf of the substrate W. . Centrifugal force accompanying the rotation of the substrate W acts on the hydrophobizing agent supplied to the surface Wf of the substrate W, and is spread evenly outward in the radial direction of the substrate W. Thereby, the hydrophobizing agent is supplied over the entire surface Wf of the substrate W.

  By supplying the hydrophobizing agent over a predetermined time, the surface Wf of the substrate W is hydrophobized. Thereafter, the thickness of the liquid film is uniformly controlled by setting the state in which the rotation of the substrate W is stopped or the state in which the substrate W is rotated at a relatively low speed, so that the entire surface Wf of the substrate W has a predetermined thickness. Is formed (step S12; corresponding to the “hydrophobizing agent liquid film forming step” of the present invention).

  Thus, in the second embodiment, the processing liquid discharge nozzle 97 functions as the “hydrophobizing agent liquid film forming unit” of the present invention. In the second embodiment, as in the first embodiment, the hydrophobicity of the surface Wf of the substrate W is increased by supplying the hydrophobizing agent to the surface Wf of the substrate W. Accordingly, since the hydrophobizing agent supplied to the surface Wf of the substrate W tends to stay at the edge position of the substrate W, the thickness of the hydrophobizing agent liquid film formed in the hydrophobizing agent liquid film forming step can be increased. it can.

  Thus, when the hydrophobizing agent liquid film forming step is completed, the control unit 4 places the blocking member 9 in the separated position and 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. Move. Then, the cooling gas discharge nozzle 3 is gradually moved toward the edge position Pe of the substrate W while discharging the cooling gas from the cooling gas discharge nozzle 3 toward the surface Wf of the rotating substrate W. As a result, as shown in FIG. 3, the region (frozen region) in which the liquid film 11 f is frozen out of the surface region of the surface Wf of the substrate W is expanded from the central portion to the peripheral portion of the surface Wf of the substrate W. A frozen film 13f is generated on the entire surface Wf (step S13; corresponding to the “freezing step” of the present invention). 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 freezing of the liquid film is completed, the control unit 4 moves the cooling gas discharge nozzle 3 to the standby position Ps and drives the third rotation motor 67 to move the melt discharge nozzle 6 to the rotation center A0 of the substrate W. Move to the upper discharge position. Then, before the frozen film 13f is melted, a solvent as a melt is supplied from the melt discharge nozzle 6 to the surface Wf of the substrate W. Thereby, the frozen film on the surface Wf of the substrate W is thawed by the solvent. Further, a centrifugal force due to the rotation of the substrate W acts on the frozen film 13 f and the solvent supplied to the surface Wf of the substrate W. As a result, the frozen film 13f containing particles is removed from the surface Wf of the substrate W and discharged out of the substrate (step S14). After the solvent is supplied for a predetermined time, the melt discharge nozzle 6 is moved to the standby position.

  Thus, when the film removal process is completed and the cleaning process (liquid film formation + liquid film freezing + film removal) of the substrate W is completed, the substrate W is subsequently dried. The control unit 4 drives the blocking plate elevating mechanism 94 so that the blocking member 9 is lowered to the opposing position and is disposed close to the surface Wf of the substrate W. Then, the rotational speeds of the chuck rotating mechanism 22 and the blocking member rotating mechanism 93 are increased to rotate the substrate W and the blocking member 9 at a high speed. Thereby, the drying process (spin drying) of the substrate W is executed (step S15). Furthermore, in this drying process, by supplying nitrogen gas from the gas supply paths 95 and 29, the space sandwiched between the blocking member 9 and the surface Wf of the substrate W and the back surface Wb of the spin base 23 and the substrate W are provided. The space between the two is a nitrogen gas atmosphere. Thereby, the drying of the substrate W is promoted, and the drying time can be shortened. Also in the second embodiment, since the surface Wf of the substrate W is hydrophobized in the hydrophobizing agent liquid film forming step, the fine pattern formed on the surface Wf of the substrate W may collapse in the drying process. Is prevented. After the drying process, the rotation of the substrate W is stopped, and the processed substrate W is unloaded from the apparatus (step S16).

  As described above, according to the second embodiment, by supplying the liquid hydrophobizing agent to the surface Wf of the substrate W, the liquid film of the hydrophobizing agent is formed while the surface Wf of the substrate W is hydrophobized. Is done. Thereby, the thickness of the liquid film of the hydrophobizing agent can be increased, and the particle removal rate can be increased.

  Further, according to the second embodiment, the hydrophobizing agent cooled to a predetermined temperature is supplied to the surface Wf of the substrate W in the hydrophobizing agent liquid film forming step. Therefore, the temperature of the liquid film of the hydrophobizing agent formed on the surface Wf of the substrate W can be lowered. Thereby, in the subsequent freezing step, the liquid film of the hydrophobizing agent can be frozen in a shorter time.

  Furthermore, according to the second embodiment, unlike the first embodiment, it is not necessary to perform a solvent replacement process for replacing the hydrophobizing agent adhering to the surface Wf of the substrate W with a solvent after the hydrophobizing step. .

  Although the first and second embodiments of the present invention have been described above, the present invention can also be implemented in other forms. In the second embodiment described above, a solvent is used as a melting solution for removing the frozen membrane. However, depending on the type of the hydrophobizing agent, warm water, an SC1 solution, or the like may be used as the melting solution. That is, when a chemical reaction occurs between the hydrophobizing agent and water, a solvent is preferably used as the melt. However, when the hydrophobizing agent and water do not react or hardly react, hot water or SC1 solution is used as the melt. Etc. may be used.

  In the first embodiment described above, after the hydrophobizing step, the hydrophobizing agent adhering to the substrate W is replaced with a solvent, and then DIW is supplied to the substrate W to perform the liquid film forming step. However, the solvent replacement process is not necessarily performed. As described above, in the case of a hydrophobizing agent that causes a chemical reaction with water, it is preferable to perform a solvent replacement treatment. However, in the case of a hydrophobizing agent that does not react or hardly reacts with water, the solvent replacement treatment is omitted. May be.

  In the first embodiment described above, the liquid hydrophobizing agent is supplied from the hydrophobizing agent discharge nozzle 5 to the surface Wf of the substrate W, but a gas hydrophobizing agent may be supplied. That is, a gas hydrophobizing agent may be used in the hydrophobizing step. In the case of using a gas hydrophobizing agent, the amount of the hydrophobizing agent used can be reduced compared to the case of using a liquid hydrophobizing agent.

  Further, in the first and second embodiments described above, the processing liquid discharge nozzle 97 is provided on the blocking member 9, but may not be provided on the blocking member 9.

  In addition, various design changes can be made within the scope of the matters described in the claims.

2 Spin Chuck 3 Cooling Gas Discharge Nozzle 4 Control Unit 5 Hydrophobizing Agent Discharge Nozzle 6 Melting Liquid Discharge Nozzle 9 Blocking Member 22 Chuck Rotating Mechanism 27 Back Surface Treatment Liquid Discharge Nozzle 97 Treatment Liquid Discharge Nozzle W Substrate Wf Surface Wb Back Surface

Claims (6)

A substrate holding step for holding the substrate substantially horizontally;
Supplying a hydrophobizing agent to the substrate held in the substrate holding step to hydrophobize the surface of the substrate; and
A liquid film forming step of supplying a treatment liquid to the surface of the substrate hydrophobized in the hydrophobic step, and forming a liquid film of the treatment liquid on the surface of the substrate;
And a freezing step of cooling the liquid film formed in the liquid film forming step and freezing the liquid film.   The substrate processing method according to claim 1, wherein in the hydrophobizing step, a hydrophobizing agent having a temperature higher than room temperature is supplied to the surface of the substrate.   The substrate processing method according to claim 1, wherein in the liquid film forming step, a processing liquid having a temperature lower than normal temperature is supplied to the surface of the substrate. A substrate holding step for holding the substrate substantially horizontally;
Hydrophobizing agent liquid film forming step of supplying a liquid hydrophobizing agent that hydrophobizes the surface of the substrate to the substrate held in the substrate holding step, and forming a hydrophobizing agent liquid film on the surface of the substrate When,
And a freezing step of cooling the liquid film formed in the hydrophobizing agent liquid film forming step and freezing the liquid film. Substrate holding means for holding the substrate substantially horizontally;
A hydrophobizing agent supplying means for supplying a hydrophobizing agent for hydrophobizing the surface of the substrate to the substrate held by the substrate holding means;
A liquid film forming means for supplying a treatment liquid to the substrate having the hydrophobizing agent supplied thereto and having a hydrophobic surface, and forming a liquid film of the treatment liquid on the surface of the substrate;
A substrate processing apparatus comprising: a freezing unit that cools the liquid film formed by the liquid film forming unit and freezes the liquid film. Substrate holding means for holding the substrate substantially horizontally;
Hydrophobizing agent liquid film forming means for supplying a liquid hydrophobizing agent for hydrophobizing the surface of the substrate to the substrate held by the substrate holding means, and forming a hydrophobizing agent liquid film on the surface of the substrate When,
A substrate processing apparatus comprising: a freezing unit that cools the liquid film formed by the hydrophobizing agent liquid film forming unit and freezes the liquid film.

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