JP2010050143A - Substrate processing method, and substrate processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate processing method and a substrate processing apparatus that dry a substrate surface by removing a solvent consisting principally of a fluorine-based solvent from the substrate surface, the drying performance being enhanced by preventing a drop of water from sticking on the substrate surface. <P>SOLUTION: After the substrate surface Wf covered with an IPA liquid is supplied with an HFE liquid to replace the IPA liquid with the HFE liquid so that the entire substrate surface Wf is covered with the HFE liquid, a high-temperature nitrogen gas is supplied to the substrate back surface Wb to heat the substrate W, and the HFE liquid is removed from the substrate surface Wf. The substrate is heated continuously until the HFE liquid is all removed from the substrate surface Wf through drying processing (removal processing). In the drying processing, the substrate W is thus heated while the high-temperature nitrogen gas is supplied to the substrate back surface Wb, so even if many steam components are present at a periphery of the substrate, no drop of water sticks on the substrate surface Wf and the substrate W is securely dried. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a substrate processing method and apparatus for drying a substrate whose surface is wet with a processing solution. Substrates to be dried include semiconductor wafers, photomask glass substrates, liquid crystal display glass substrates, plasma display glass substrates, FED (Field Emission Display) substrates, optical disk substrates, and magnetic substrates. A disk substrate, a magneto-optical disk substrate, and the like are included.

  In the manufacturing process of electronic components such as semiconductor devices and liquid crystal display devices, a chemical treatment with a chemical solution and a rinse treatment with a rinse solution such as pure water are performed, followed by a drying treatment to remove the rinse solution adhering to the substrate surface. Executed. For example, an apparatus described in Patent Document 1 includes a spin chuck that holds a substrate in a horizontal posture, a chuck rotation driving mechanism that rotates the spin chuck, a chemical solution and pure water toward the surface of the substrate held by the spin chuck, A first nozzle that supplies a rinsing liquid such as DIW (deionized water) and a second nozzle that supplies a solvent toward the surface of the substrate held by the spin chuck are provided. In the apparatus, the chemical solution process, the rinse process, the first replacement process, the second replacement process, and the drying process are performed as follows. That is, after a chemical solution such as hydrofluoric acid is supplied from the first nozzle to the substrate surface and the chemical solution processing is executed, DIW is supplied from the nozzle and the rinse processing is executed. Also, IPA (isopropyl alcohol), which is a water-soluble organic solvent having higher volatility than DIW, and a fluorine-based solvent having a lower surface tension than pure water and lower water solubility than IPA. A mixed solvent containing HFE (Hydrofluoroether) is supplied to replace the rinse liquid (DIW) on the substrate with the mixed solvent. Thereafter, only HFE is supplied to the surface of the substrate, and the mixed solvent on the surface of the substrate is replaced with HFE. Finally, the substrate surface is dried by drying off the HFE from the substrate surface by high-speed rotation of the substrate (drying process).

JP 2008-153452 A (FIGS. 1 and 3)

  Thus, by covering the entire substrate surface with HFE before the drying treatment, the drying performance can be significantly improved as compared with the case where the substrate wet with the rinse liquid is directly spin-dried. However, during the drying process, fine water droplets may adhere to the substrate surface as the HFE liquid film moves on the substrate surface, which may reduce the drying performance.

  The present invention has been made in view of the above problems, and in the substrate processing method and the substrate processing apparatus for removing a solvent mainly composed of a fluorinated solvent from the substrate surface and drying the substrate surface, water droplets adhere to the substrate surface. The purpose is to improve the drying performance.

  A substrate processing method according to the present invention is a substrate processing method for drying a substrate whose surface is wet with a processing solution, and in order to achieve the above object, a solvent containing a fluorine-based solvent as a main component is supplied to the substrate surface. A replacement step of replacing the treatment liquid with a solvent and a removal step of removing the solvent from the substrate surface after the replacement step, and heating the substrate at least until the solvent is completely removed from the substrate surface in the removal step. It is characterized by.

  In order to achieve the above object, the substrate processing apparatus according to the present invention is held by the substrate holding means for holding the substrate in a substantially horizontal posture with the substrate surface wet with the processing liquid facing upward, and the substrate holding means. A solvent supply means for supplying a solvent mainly composed of a fluorinated solvent toward the surface of the substrate and replacing the treatment liquid with the solvent, a removing means for removing the solvent from the substrate surface, and a substrate held by the substrate holding means And heating means for heating the substrate until at least the solvent is removed from the substrate surface by the removing means.

  In the invention configured as described above (substrate processing method and substrate processing apparatus), the substrate surface is dried by removing the solvent from the substrate surface covered with a solvent containing a fluorinated solvent as a main component. During the removal process, the substrate surface is dried and exposed at the end of the HFE liquid film due to HFE evaporation. At this time, vaporization heat is generated simultaneously with the HFE evaporation, and the ambient temperature in the exposed region is locally and rapidly decreased. This is considered to be the cause of the generation of water droplets described in the above “problem to be solved by the invention”. In other words, if a large amount of water vapor component exists around the exposed area, it will aggregate and adhere to the exposed area as water droplets due to the temperature drop.

  Therefore, in the present invention, during the removal process, the substrate is heated until at least the solvent is completely removed from the substrate surface, so even if a large amount of water vapor components exist around the substrate surface, Water droplet adhesion to the substrate surface is reliably prevented.

  Here, as the fluorinated solvent, for example, hydrofluoroether can be used. As a specific method of heating the substrate, for example, the substrate may be heated by supplying a high-temperature gas heated to room temperature or higher to the substrate. Alternatively, the substrate may be heated by supplying a high-temperature liquid heated to room temperature or higher from the opposite side of the substrate surface. In this case, the blocking member is placed close to the substrate surface so as to cover the substrate surface. It is desirable to supply hot liquid while placing. This is because a part of the high-temperature liquid supplied to the substrate may scatter to the substrate surface side, but the liquid adhesion to the substrate surface is surely prevented by the blocking member.

  In addition, when the treatment liquid is pure water, it is desirable to start heating the substrate immediately before the replacement step, which can increase the substrate temperature in the removal step, and water vapor components present around the substrate surface are removed from the substrate. It is possible to more reliably prevent agglomeration and adhesion. On the other hand, when the processing liquid is an organic solvent, it is desirable to start heating the substrate immediately after the entire processing liquid on the substrate surface is replaced with the fluorine-based solvent. This is because the flash point of the organic solvent is considered to be relatively low, and is to reduce the risk of flashing due to substrate heating.

  According to this invention, when the solvent containing a fluorine-based solvent as a main component is removed from the substrate surface and the substrate surface is dried, the substrate is heated at least until the solvent is completely removed from the substrate surface. Therefore, it is possible to prevent the water vapor component existing around the substrate surface from aggregating and adhering to the substrate surface, thereby improving the drying performance.

  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 an electrical configuration for controlling the substrate processing apparatus of FIG. The substrate processing apparatus 1 is a single-wafer type substrate processing apparatus used for a cleaning process for removing unnecessary substances attached to the surface of a substrate W such as a semiconductor wafer. More specifically, (1) chemical treatment with a chemical solution such as hydrofluoric acid on the substrate surface, (2) rinse treatment with a rinse solution such as pure water or DIW, and (3) a rinse liquid film on the substrate surface in a paddle shape (4) a first replacement process for replacing the rinse liquid on the substrate W with the IPA liquid, (5) a second replacement process for replacing the IPA liquid on the substrate W with the HFE liquid, (6) This is an apparatus that executes a removal process of removing the HFE liquid from the substrate W and drying the substrate W.

  In the substrate processing apparatus 1, a fan filter unit (FFU) 4 is disposed on the ceiling portion of the processing chamber 2. The fan filter unit 4 has a fan 4a and a filter 4b. In the fan filter unit 4, the gas sent from the upper space of the apparatus 1 is sent toward the filter 4 b by the fan 4 a and cleaned by the filter 4 b, and then sent into the central space of the processing chamber 2.

  A spin chuck 6 is disposed in the central space. The spin chuck 6 rotates the substrate W while maintaining the substrate surface Wf facing upward, and functions as the “substrate holding means” of the present invention. Further, in the spin chuck 6, the rotation support shaft 8 is connected to the rotation shaft of the chuck rotation mechanism 10 (FIG. 2) including a motor, and the spin chuck 6 is rotated by the rotation of the chuck rotation mechanism 10 (vertical axis). It can be rotated around. The rotating spindle 8 and the chuck rotating mechanism 10 are accommodated in a cylindrical casing 14. In addition, a disc-shaped spin base 16 is integrally connected to the upper end portion of the rotation spindle 8 by a fastening component such as a screw. Therefore, the spin base 16 rotates around the rotation axis by driving the chuck rotation mechanism 10 in accordance with an operation command from the control unit 18. Further, the control unit 18 controls the chuck rotation mechanism 10 to adjust the rotation speed of the spin base 16.

  Near the peripheral edge of the spin base 16, a plurality of chuck pins 12 for holding the peripheral edge of the substrate W are provided upright. Three or more chuck pins 12 may be provided in order to securely hold the circular substrate W, and are arranged at equiangular intervals along the peripheral edge of the spin base 16. Each of the chuck pins 12 includes a substrate support portion that supports the peripheral edge 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 12 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 16, the plurality of chuck pins 12 are released, and when performing substrate processing to be described later on the substrate W, the plurality of chuck pins 12 are pressed. State. By setting the pressing state in this manner, the plurality of chuck pins 12 can hold 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 16. As a result, the substrate W is supported with its front surface facing upward and the back surface facing downward. The substrate holding mechanism is not limited to the chuck pins 12, and a vacuum chuck that sucks the back surface of the substrate and supports the substrate W may be used.

  Two types of nozzle arms 22 and 24 are provided at a position above the substrate W held by the spin chuck 6 so as to be swingable in a horizontal plane. A chemical liquid supply nozzle 26 and a rinse liquid supply nozzle 28 are attached to the tip of one nozzle arm 22. An IPA liquid supply nozzle 30 (FIG. 3) and an HFE liquid supply nozzle 32 (FIG. 3) are attached to the tip of the other nozzle arm 24.

  Of these four nozzles, the chemical supply nozzle 26 is connected to a chemical supply unit 34 (FIG. 2). The chemical solution supply unit 34 can supply a chemical solution suitable for substrate cleaning such as hydrofluoric acid or BHF (Buffered Hydrofluoric acid) to the nozzle 26 side. Then, when the chemical solution supply unit 34 pumps the chemical solution toward the chemical solution supply nozzle 26 in accordance with a command from the control unit 18, the chemical solution is discharged toward the substrate W from the nozzle 26. Similarly to the chemical liquid supply nozzle 26, the rinse liquid supply unit 36 (FIG. 2) is also connected to the rinse liquid supply nozzle 28, and the rinse liquid (DIW) is discharged toward the substrate W that has been subjected to the chemical liquid treatment. The rinse process can be executed. A nozzle arm moving mechanism 38 is connected to the nozzle arm 22 to which these nozzles 26 and 28 are attached, and the nozzle arm moving mechanism 38 is operated in accordance with an operation command from the control unit 18, whereby a substrate is obtained. The nozzles 26 and 28 are movable between a discharge area above the surface of W and a standby position retracted laterally from the discharge area. Further, also in the discharge region, the nozzle arm moving mechanism 38 allows the nozzles 26 and 28 to reciprocate between the upper center part and the upper peripheral part of the substrate surface.

  The IPA liquid supply nozzle 30 is connected to the IPA liquid supply unit 40 (FIG. 2). The IPA liquid supply unit 40 can supply a 100% IPA liquid or an IPA liquid diluted with pure water to the nozzle 30 side. When the IPA liquid supply unit 40 pumps the IPA liquid toward the IPA liquid supply nozzle 30 in accordance with a command from the control unit 18, the IPA liquid is discharged toward the substrate W from the nozzle 30.

Similarly to the IPA liquid supply nozzle 30, an HFE liquid supply unit 42 (FIG. 2) is connected to the HFE liquid supply nozzle 32. The HFE liquid supply unit 42 can supply the HFE liquid as a “solvent containing a fluorinated solvent as a main component” of the present invention. This “HFE liquid” has characteristics such as lower surface tension than IPA and DIW, fast evaporation, and no flammability. As the “HFE liquid”, for example, trade name Novec manufactured by Sumitomo 3M Limited. (Registered trademark) series HFE can be used. Specifically, as HFE, for example, Novec 7100 / 7100DL (chemical formula: C ₄ F ₉ OCH ₃ ), Novec 7200 (chemical formula: C ₄ F ₉ OC ₂ H ₅ ), Novec 7300 (chemical formula: C ₆ F ₁₃ OCH ₃₎ ) Etc. can be used. Then, when the HFE liquid supply unit 42 pumps the HFE liquid toward the HFE liquid supply nozzle 32 in accordance with a command from the control unit 18, the HFE liquid is discharged from the nozzle 32 toward the substrate W. In this way, the HFE liquid supply nozzle 32 functions as the “solvent supply means” of the present invention, and the HFE liquid can be supplied to the center of the surface of the substrate W.

  A nozzle arm moving mechanism 44 is connected to the nozzle arm 24 to which the nozzles 30 and 32 are attached, and the nozzle arm moving mechanism 44 is driven in accordance with an operation command from the control unit 18, whereby the substrate W The nozzles 30 and 32 are movable between a discharge area above the surface of the nozzle and a standby position retracted laterally from the discharge area.

  A receiving member 46 is fixedly attached around the casing 14. Three cylindrical partition members are erected on the receiving member 46. Three spaces are formed as drainage tanks 48 a to 48 c by the combination of these partition members and the casing 14. A splash guard (cup) 50 is disposed above the drain tanks 48a to 48c along the rotation axis of the spin chuck 6 so as to surround the periphery of the substrate W held in the spin chuck 6 in a horizontal posture. It can be moved up and down. The splash guard 50 has a substantially rotationally symmetric shape with respect to the rotation axis, and includes two guards arranged concentrically with the spin chuck 6 from the radially inner side toward the outer side. Then, the splash guard 50 is lifted and lowered stepwise by driving the guard lifting mechanism 52, whereby the chemical liquid and the rinse liquid scattered from the rotating substrate W can be separated and discharged.

  In this embodiment, the rotation support shaft 8 has a hollow tube structure, and is formed at the upper end of a nozzle that is supplied with high-temperature nitrogen gas from the gas heating unit 54 and disposed in the internal space of the rotation support shaft 8. It is possible to discharge high-temperature nitrogen gas from the nozzle hole (not shown) toward the back surface of the substrate. The gas heating unit 54 is constituted by an apparatus described in, for example, Japanese Patent Application Laid-Open Nos. 11-281154 and 2000-74485. That is, the inlet end portion of the gas heating unit 54 is connected to a utility (utility) of a factory where the substrate processing apparatus 1 is installed, and receives supply of nitrogen gas at room temperature. In addition, inside the gas heating unit 54, the heating container is heated by flowing a high-frequency current through the coil, and the temperature of the nitrogen gas rises as nitrogen gas flows through the heating container. In this way, the high-temperature nitrogen gas heated to a temperature higher than the normal temperature is supplied from the outlet end of the gas heating unit 54 to the rotary support shaft 8. Then, the gas heating unit 54 is driven in accordance with an operation command from the control unit 18, whereby high-temperature nitrogen gas is supplied toward the back surface of the substrate W to heat the temperature of the substrate W to a temperature higher than room temperature. be able to. Thus, in the first embodiment, the gas heating unit 54 functions as the “heating means” of the present invention, and high-temperature nitrogen gas is used as the heat medium.

  Next, the operation of the substrate processing apparatus 1 configured as described above will be described in detail with reference to FIG. FIG. 3 is a diagram showing the operation of the substrate processing apparatus of FIG. In this embodiment, the control unit 18 controls each part of the apparatus according to a program stored in a memory (not shown) to perform a chemical solution process, a rinse process, a paddle formation process, a first replacement process, a second process on the substrate W. A replacement process and a drying process (removal process) are performed. Among these, in the first replacement treatment, the IPA solution is used as the “treatment solution” of the present invention.

  The control unit 18 lowers the splash guard 50 and causes the spin chuck 6 to protrude from the opening 50 a of the splash guard 50. At this time, both the nozzle arms 22 and 24 are retracted to the outside of the splash guard 50. In this state, an unprocessed substrate W is carried into the processing chamber 2 by a substrate transport robot (not shown). More specifically, the substrate W is carried into the apparatus with the substrate surface facing upward, and is held by the spin chuck 6. Following this, the splash guard 50 is raised by one step and the chemical liquid processing is performed on the substrate W (step S1).

  In the chemical processing, the nozzle arm moving mechanism 38 moves the nozzle arm 22 so that the chemical supply nozzle 26 is positioned above the center of the substrate surface, and the substrate W held on the spin chuck 6 by driving the chuck rotating mechanism 10. Is rotated at a rotation speed (for example, 800 rpm) determined within a range of 200 to 120 rpm. Further, the chemical solution supply unit 34 feeds hydrofluoric acid as a chemical solution toward the chemical solution supply nozzle 26 and supplies it from the nozzle 26 to the substrate surface. The hydrofluoric acid supplied to the central portion of the substrate surface in this way is expanded in the radial direction by centrifugal force, and etching processing (chemical solution processing) of the substrate surface with hydrofluoric acid is performed.

  When the chemical liquid processing is completed, the nozzle arm moving mechanism 38 moves the nozzle arm 22 so that the rinsing liquid supply nozzle 28 is replaced with the chemical liquid supply nozzle 26 and positioned above the center of the substrate surface. Then, the rinse liquid (DIW) is discharged from the rinse liquid supply nozzle 28. The rinsing liquid discharged onto the substrate surface in this way spreads on the surface of the substrate W due to the centrifugal force of the rotation of the substrate W, and a rinsing process using the rinsing liquid is performed. When the rinsing process is completed, a paddle forming process is executed next (step S2). That is, after the rinsing process is completed, the control unit 18 reduces the rotational speed of the substrate W to a rotational speed (5 rpm in this embodiment) slower than the rotational speed during the rinsing process. As a result, the rinse liquid discharged from the rinse liquid supply nozzle 28 is stored on the substrate surface Wf, and a rinse liquid film is formed in a paddle shape. The rotational speed during the paddle formation process is not limited to 5 rpm, but the condition that the centrifugal force acting on the rinse liquid is smaller than the surface tension acting between the rinse liquid and the substrate surface is satisfied. It is necessary to set the rotation speed within the range. This is because the above conditions must be satisfied in order to form a rinse liquid film in a paddle shape.

  When the paddle formation is completed in this way, the control unit 18 controls the nozzle arm moving mechanism 38 to move the nozzle arm 22 away from the substrate W and retract both nozzles 26 and 28 to the outside of the splash guard 50. Then, the first replacement process is started (step S3). That is, the control unit 18 controls the nozzle arm moving mechanism 44 to position the IPA liquid supply nozzle 30 above the center portion of the substrate surface Wf. Then, the IPA liquid is pumped from the IPA liquid supply unit 40, and the IPA liquid is supplied from the IPA liquid supply nozzle 30 toward the center of the surface of the substrate W. In this embodiment, the rotation speed of the substrate W is changed as the first replacement process proceeds. That is, in the first half of the IPA liquid supply, the central portion of the rinse liquid film is replaced with the IPA liquid at the center of the surface of the substrate W, and a replacement region is formed in the liquid film. The rotation speed at this time is set to the same level as the paddle formation process (in this embodiment, 10 rpm). When a predetermined time elapses after the IPA liquid supply, the rotation speed of the substrate W is accelerated from 10 rpm to 100 rpm while the IPA liquid supply is continued. Thus, the acceleration of the rotation speed increases the centrifugal force acting on the liquid film (rinsing liquid region + IPA liquid region (replacement region)) on the substrate surface, so that the rinse liquid is shaken off and the replacement region expands in the radial direction. . When a predetermined time has elapsed, the rinsing liquid present on the outer peripheral portion of the surface of the substrate W is shaken off from the substrate W, and the replacement region is spread uniformly over the entire surface of the substrate, so that the substrate surface is entirely covered with an IPA liquid film. Covered. Further, the control unit 18 accelerates the rotation speed of the substrate W from 100 rpm to 300 rpm. This is performed in order to replace the rinsing liquid remaining in the gap of the fine pattern (not shown) formed on the substrate surface Wf with the IPA liquid. That is, the IPA liquid largely flows on the substrate surface Wf due to the acceleration of the rotation speed, and thereby the residual rinse liquid is replaced with the IPA liquid in the gaps of the fine pattern. Thereby, the rinse liquid adhering to the substrate surface Wf is surely replaced with the IPA liquid.

  Subsequent to the first replacement process, the second replacement process is started (step S4). That is, the control unit 18 controls the nozzle arm moving mechanism 44 to position the HFE liquid supply nozzle 32 above the central portion of the substrate surface Wf. Then, the HFE liquid is pumped from the HFE liquid supply unit 42, and the HFE liquid is supplied from the HFE liquid supply nozzle 32 toward the center of the surface of the substrate W. In this embodiment, the rotational speed of the substrate W is also changed in the second replacement process as the process proceeds. That is, in the first half of the HFE liquid supply, the central portion of the IPA liquid film is replaced with the HFE liquid at the center of the surface of the substrate W, and the replacement region R is formed in the liquid film. The rotation speed at this time is set to the same level as the paddle formation process (in this embodiment, 10 rpm). Further, when a predetermined time has elapsed from the supply of the HFE liquid, the rotation speed of the substrate W is accelerated from 10 rpm to 100 rpm while the HFE liquid supply is continued. Thus, the acceleration of the rotational speed increases the centrifugal force acting on the liquid film (IPA liquid region + HFE liquid region (replacement region R)) on the substrate surface, and the IPA liquid is shaken off and the replacement region R expands in the radial direction. To go. When a predetermined time elapses, the IPA liquid existing on the outer peripheral portion of the surface of the substrate W is shaken off from the substrate W, and the replacement region R spreads uniformly on the entire surface of the substrate surface Wf. Covered entirely with film.

  In this embodiment, in order to detect that the IPA liquid on the substrate surface Wf is entirely replaced with the HFE liquid as described above, an internal timer (not shown) of the control unit 18 is started simultaneously with the start of the replacement process with the HFE liquid. ) Is started (step S5). In this embodiment, the time T0 required from the start of the supply of the HFE liquid until the entire substrate surface Wf is replaced with the HFE liquid is obtained in advance and stored in the memory. Then, the control unit 18 determines that the second replacement process using the HFE liquid is completed when the elapsed time T has reached the time T0 (step S6). The time T0 differs greatly depending on the processing conditions such as the size and rotation speed of the substrate W, the physical properties of the HFE liquid, and the discharge flow rate of the HFE liquid. Therefore, the time T0 corresponding to the processing conditions is obtained in advance by experiments or computer simulations. It is desirable to keep it. For example, by using an imaging device such as a CCD (Charge Coupled Device) camera, the boundary between the IPA liquid region and the replacement region R (symbol B in FIG. 3) moves to the periphery of the substrate over time, and The time T0 can be determined experimentally. The boundary B can be observed in this way because the contact angle of the HFE liquid is smaller than the contact angle of the IPA liquid. Further, related data in which the processing conditions are associated with the time T0 is stored in a memory, for example, in a recipe format, and the control unit 18 reads the time T0 corresponding to the processing conditions input by the operator or the like from the memory, and the time T0. May be set.

  If “YES” is determined in step S6, that is, if the IPA liquid is replaced with the HFE liquid over the entire substrate surface Wf, the control unit 18 drives the gas heating unit 54 to increase the temperature toward the back surface Wb of the substrate W. Nitrogen gas is supplied to start substrate heating (step S7). As a result, the temperature of the substrate W rises. At the same time or slightly after the start of substrate heating, the HFE liquid supply unit 42 stops supplying the HFE liquid and ends the second replacement process in response to a command from the control unit 18 and the nozzle arm moving mechanism 44 The nozzle arm 24 is moved away from the substrate W to retract both nozzles 30 and 32 to the outside of the splash guard 50 (step S8).

  Subsequently, the substrate W is rotated at a high speed of 300 to 2500 rpm (800 rpm in this embodiment) while the high-temperature nitrogen gas is continuously supplied to the substrate back surface Wb, and the HFE liquid on the substrate surface Wf is removed to remove the substrate W. The drying process is executed (step S9). Here, since a highly volatile HFE liquid is used, in this drying process (removal process), as shown in FIG. 4, the HFE liquid film moves with the centrifugal force of substrate rotation and HFE evaporation. Further, although the substrate surface Wf is dried and exposed at the end of the HFE liquid film due to HFE evaporation, the heat of vaporization is generated simultaneously with the HFE evaporation, and the ambient temperature in the exposed region is locally and rapidly decreased (see FIG. (A)). At this time, if a large amount of water vapor component is present around the exposed area, it may aggregate in the exposed area and adhere as water droplets due to the temperature drop (FIGS. (B) and (c)). Since such a phenomenon occurs sequentially as the HFE liquid film is dried and moved, a belt-like drying defect occurs. However, in this embodiment, since the drying process is performed while the substrate W is heated at least until the HFE liquid is completely removed from the substrate surface Wf, water vapor components present around the substrate surface are aggregated. Adhesion to the substrate surface can be prevented.

  When the drying process of the substrate W is completed, the control unit 18 controls the chuck rotating mechanism 10 to stop the rotation of the substrate W. Further, the control unit 18 gives a stop command to the gas heating unit 54 to stop the supply of the high-temperature nitrogen gas and stop the substrate heating (step S10). Further, the splash guard 50 is lowered, and the spin chuck 6 is protruded from above the splash guard 50. Thereafter, the substrate transfer robot carries the processed substrate W out of the substrate processing apparatus 1, and a series of substrate processing for one substrate W is completed. Then, the same processing as described above is performed for the next substrate W. In this embodiment, the drying process is continued while heating the substrate for a while after all the HFE liquid is removed from the substrate surface Wf. However, the substrate heating is performed at the same time as the entire HFE liquid is removed. You may stop only. Further, the substrate heating and the drying process may be ended at the same time when the HFE liquid is completely removed from the substrate surface Wf.

  As described above, according to the first embodiment, during the drying process (removal process), the substrate W is supplied with the high-temperature nitrogen gas to the substrate back surface Wb until at least all of the HFE liquid is removed from the substrate surface Wf. Therefore, even if a large amount of water vapor components exist around the substrate Wf, water droplets do not adhere to the substrate surface Wf, and the substrate W can be reliably dried.

  Further, in the above embodiment, since the substrate heating is started after the entire surface of the IPA liquid on the substrate surface Wf is replaced with the HFE liquid, the following effects are also obtained. That is, the flash point of the IPA liquid is relatively low (about 11 ° C.), and heating the substrate in a state where the IPA liquid is present on the substrate surface Wf involves a safety risk. Therefore, in this embodiment, since the substrate is heated after reliably detecting that the IPA liquid has been removed from the substrate surface Wf, the substrate can be satisfactorily dried while avoiding safety risks. it can.

  In the first embodiment, the supply of high-temperature nitrogen gas is stopped except when the gas heating unit 54 is driven to heat the substrate, but except when the substrate is heated via the gas heating unit 54. Alternatively, normal temperature nitrogen gas may be supplied to the substrate, and when the substrate is heated, the temperature of the nitrogen gas may be increased and supplied to the substrate.

  FIG. 5 is a diagram showing a second embodiment of the substrate processing apparatus according to the present invention. The second embodiment is greatly different from the first embodiment in the supply mode of high-temperature nitrogen gas from the gas heating unit 54. That is, as shown in the figure, in the second embodiment, an opening / closing valve 56 is inserted in a pipe communicating the internal space of the gas heating unit 54 and the rotation support shaft 8, and the opening / closing valve 56 and the gas heating unit 54 are connected to each other. The piping branches between them and extends to a heat exhaust section (not shown). In addition, an on-off valve 58 is inserted in this branch pipe. And according to the instruction | command from the control part 18, the on-off valves 56 and 58 are controlled to open and close, and the supply destination of the high temperature nitrogen gas supplied from the gas heating unit 54 is switched.

  In the second embodiment, the gas heating unit 54 is always operating, and the control unit 18 opens the on-off valve 56 and closes the on-off valve 58 and closes the gas heating unit 54 at the timing of starting substrate heating (step S7). The high-temperature nitrogen gas heated in step 1 is supplied to the substrate back surface Wb through the opening / closing valve 56 and the internal space of the rotary spindle 8 to perform substrate heating (FIG. 5A). On the other hand, at the timing of stopping the substrate heating (step S10), the control unit 18 closes the on-off valve 56, while opening the on-off valve 58 and exhausting hot nitrogen gas heated by the gas heating unit 54 through the on-off valve 58. The air is exhausted to the part (FIG. 5B). When the substrate is not heated (substrate is not heated), the on-off valves 56 and 58 are in a “closed state” and an “open state”, respectively, and the high-temperature nitrogen gas discharged from the gas heating unit 54 is hot exhausted. It is exhausted to the part.

  As described above, according to the second embodiment, the gas heating unit 54 is always operated, and the supply destination of the high-temperature nitrogen gas is switched by the opening / closing control of the opening / closing valves 56, 58. can get. Since the gas heating unit 54 heats the heating container with the induced current and heats the nitrogen gas flowing through the heating container 54, the temperature of the nitrogen gas can be increased in a relatively short time. However, it is difficult to obtain high-temperature nitrogen gas immediately after the gas heating unit 54 is activated, and a certain amount of time is required to raise the temperature of the nitrogen gas supplied to the substrate back surface Wb to a desired temperature. Become. On the other hand, in the second embodiment, the gas heating unit 54 is always driven, and the on-off valves 56 and 58 are controlled to be opened and closed at a timing when the supply of the high-temperature nitrogen gas to the substrate back surface Wb is required. The substrate can be heated by supplying a gas to the substrate back surface Wb. Therefore, the substrate W can be efficiently heated in a short time and water droplet adhesion can be reliably prevented, and the tact time can be shortened.

  In the first and second embodiments, high-temperature nitrogen gas is used to heat the substrate W. However, a high-temperature gas obtained by heating another gas (for example, air) is supplied to the substrate back surface Wb. Then, the substrate may be heated. Further, the substrate may be heated by supplying a high temperature gas such as a high temperature nitrogen gas from the substrate surface Wf side.

  FIG. 6 is a diagram showing a third embodiment of the substrate processing apparatus according to the present invention. The third embodiment is greatly different from the first and second embodiments in the manner of heating the substrate. That is, in the first and second embodiments, the substrate W is heated using high-temperature nitrogen gas, whereas in the third embodiment, the spin base 16 is provided with a heating member 60 such as a heater. The heating member 60 heats the substrate W at the above timing. That is, in step S <b> 7, current is supplied from the control unit 18 to the heating member 60 and substrate heating by the heating member 60 is started. On the other hand, the substrate heating by the heating member 60 is stopped by stopping the current supply from the control unit 18 in step S10. Other configurations and operations are the same as those in the first embodiment and the second embodiment.

  FIG. 7 is a view showing a fourth embodiment of the substrate processing apparatus according to the present invention. FIG. 8 is a view showing the operation of the substrate processing apparatus of FIG. The fourth embodiment differs greatly from the first embodiment in that (1) it is possible to dispose the blocking member close to the substrate surface so as to cover the substrate surface, (2 ) The supply mode of the rinsing liquid (DIW), the IPA liquid and the HFE liquid, and (3) the liquid heating unit 62 is used as means for heating the substrate W, and other configurations are basically the first embodiment. Is the same. Therefore, in the following description, differences will be mainly described, and the same components will be denoted by the same or corresponding reference numerals, and description thereof will be omitted.

  In the substrate processing apparatus 1, the nozzle arm 22 and the blocking member 64 are provided above the substrate W held by the spin chuck 6. In the fourth embodiment, only the chemical solution supply nozzle 26 is attached to the tip of the nozzle arm 22, and the chemical solution can be supplied to the substrate surface Wf in the same manner as in the first embodiment.

  The blocking member 64 includes a donut-like plate-like member 66 having an opening at the center, a hollow support 68 that is hollowed inside and supports the plate-like member 66, a hollow portion of the rotary support 68, and And an insertion shaft (not shown) inserted through the opening of the plate-like member 66. The plate member 66 is disposed so as to face the surface Wf of the substrate W held by the spin chuck 6. The plate-like member 66 has a lower surface (bottom surface) 66a that is a substrate-facing surface that faces the substrate surface Wf substantially in parallel, and has a planar size that is equal to or larger than the diameter of the substrate W. The plate-like member 66 is mounted substantially horizontally on the lower end portion of the rotation support shaft 68 having a substantially cylindrical shape, and the rotation support shaft 68 is held rotatably around a rotation axis passing through the center of the substrate W by an arm 70 extending in the horizontal direction. Has been. A bearing (not shown) is interposed between the outer peripheral surface of the insertion shaft and the inner peripheral surface of the rotation support shaft 68. The arm 70 is connected to a blocking member rotating mechanism 72 and a blocking member lifting mechanism 74.

  The blocking member rotation mechanism 72 rotates the rotation support shaft 68 around the rotation axis in accordance with an operation command from the control unit 18. Due to the rotation of the rotation support shaft 68, the plate member 66 rotates together with the rotation support shaft 68. The blocking member rotating mechanism 72 is configured to rotate the plate-like member 66 (lower surface 66a) 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 6. Yes.

  Further, the blocking member lifting mechanism 74 can make the blocking member 64 close to and face the spin base 16 in accordance with an operation command from the control unit 18, or can be separated from the spin base 16. Specifically, the control unit 18 operates the blocking member lifting / lowering mechanism 74 so that when the substrate W is carried into and out of the substrate processing apparatus 1, the blocking member 64 is placed at a separation position above the spin chuck 6. Raise. On the other hand, when a predetermined process is performed on the substrate W, the blocking member 64 is moved to a predetermined facing position (see FIG. 8) set very close to the surface Wf of the substrate W held by the spin chuck 6. Is lowered. In this embodiment, after the rinsing process is started, the blocking member 64 is lowered from the separated position to the facing position, and is continuously positioned until the drying process is completed.

  In the blocking member 64, the rotation support shaft 68 and the insertion shaft are uniformly spaced from each other over the entire circumference, and a gas supply path is formed. When nitrogen gas is pumped to the upper end side (the upper side in FIG. 7) of the gas supply path, the nitrogen gas is discharged toward the spin chuck 6 from the lower end side opening of the gas supply path via the gas supply path. The

  On the other hand, three fluid supply paths are formed on the insertion shaft so as to extend in the vertical axis direction. That is, a rinse liquid supply path serving as a rinse liquid (DIW) path, an IPA liquid supply path serving as an IPA liquid path, and an HFE liquid supply path serving as an HFE liquid path are formed on the insertion shaft. These fluid supply paths are each formed by inserting a tube made of PFA (perfluoroalkyl vinyl ether copolymer) in the axial direction into an insertion shaft made of PTFE (polytetrafluoroethylene). The lower surfaces of the rinse liquid supply path, the IPA liquid supply path, and the HFE liquid supply path become the rinse liquid discharge port, the IPA liquid discharge port, and the HFE liquid discharge port, respectively, and the surface Wf of the substrate W held on the spin chuck 6. Is facing.

  In the present embodiment, as described above, the liquid heating unit 62 is provided as a means for heating the substrate W. The liquid heating unit 62 is connected to a utility (utility) of a factory where the substrate processing apparatus 1 is installed to receive supply of DIW at room temperature, and can supply DIW to the rotating spindle 8 by heating DIW. Yes. Then, when the liquid heating unit 62 is driven in accordance with an operation command from the control unit 18, the high temperature DIW is supplied toward the back surface of the substrate W to heat the temperature of the substrate W to a temperature higher than the normal temperature. it can. Thus, in the fourth embodiment, the liquid heating unit 62 functions as the “heating means” of the present invention, and the high-temperature DIW is used as the heat medium. Of course, the gas heating unit 54 may be used as the “heating means” as in the first embodiment.

  Next, the operation of the substrate processing apparatus 1 configured as described above will be described in detail with reference to FIG. Also in the fourth embodiment, similarly to the first embodiment, the control unit 18 controls each part of the apparatus according to the program stored in the memory to perform the chemical processing, the rinsing processing, the paddle formation processing on the substrate W, A first replacement process, a second replacement process, and a drying process (removal process) are performed.

  Similarly to the first embodiment, when an unprocessed substrate W is carried into the processing chamber 2 by a substrate transport robot (not shown), a chemical solution process is performed on the substrate W (step S1). When the chemical processing is completed, the control unit 18 controls the nozzle arm moving mechanism 38 to move the nozzle arm 22 away from the substrate W and retract the nozzle 26 to the outside of the splash guard 50. Subsequently, the control unit 18 controls the blocking member raising / lowering mechanism 74 so that the blocking member 64 faces the spin base 16 in proximity. As a result, the lower surface 66a of the plate-like member 66 is positioned substantially parallel to and in close proximity to the surface Wf of the substrate W that has been subjected to the chemical treatment, thereby covering the substrate surface Wf.

  In this state, a series of processes from the rinse process (step S2) to the drying process (step S10) are executed. In other words, the rinse liquid is pumped from the rinse liquid supply unit 36 to the rinse liquid supply path of the blocking member 64, and the rinse liquid is discharged from the rinse liquid discharge port provided in the plate-like member 66. When the rinsing process is completed, the control unit 18 reduces the rotational speed of the substrate W to a rotational speed (5 rpm in this embodiment) slower than the rotational speed during the rinsing process. As a result, the rinse liquid discharged from the rinse liquid discharge port is accumulated on the substrate surface Wf, and a rinse liquid film is formed in a paddle shape. When the paddle formation is completed, the rinsing liquid discharge is stopped and the IPA liquid is pumped from the IPA liquid supply unit 40 to the IPA liquid supply path of the blocking member 64 and the IPA liquid discharge port provided in the plate member 66 is supplied with the IPA. The liquid is discharged and the first replacement process is executed (step S3). Further, after the first replacement process, the discharge of the IPA liquid is stopped, and the HFE liquid is pumped from the HFE liquid supply unit 42 to the HFE liquid supply path of the blocking member 64 to be discharged from the HFE liquid discharge port provided in the plate member 66. HFE liquid discharge is started (step S4).

  In the fourth embodiment, as in the first embodiment, the control unit 18 simultaneously with the start of the replacement process using the HFE solution in order to detect that the entire IPA solution on the substrate surface Wf is replaced with the HFE solution. Measurement of elapsed time T by an internal timer (not shown) is started (step S5). Then, when the elapsed time T reaches the time T0, it is determined that the second replacement process using the HFE liquid is completed (step S6), and the control unit 18 drives the liquid heating unit 62 to the back surface Wb of the substrate W. Then, high-temperature DIW is supplied to start substrate heating (step S7). As a result, the temperature of the substrate W rises. In addition, the HFE liquid supply unit 42 stops the supply of the HFE liquid and ends the second replacement process in response to a command from the control unit 18 at the same time or slightly after the start of the substrate heating (step S8).

  Subsequently, while the high temperature DIW is continuously supplied to the substrate back surface Wb, the substrate W is rotated at a high speed of 300 to 2500 rpm (800 rpm in this embodiment), and the HFE liquid on the substrate surface Wf is removed to remove the substrate W. A drying process is executed (step S9). When the drying process of the substrate W is completed, the control unit 18 controls the chuck rotating mechanism 10 to stop the rotation of the substrate W, and gives a stop command to the liquid heating unit 62 to stop the supply of the high temperature DIW. Substrate heating is stopped (step S10). Then, the splash guard 50 is lowered to cause the spin chuck 6 to protrude from above the splash guard 50. Thereafter, the substrate transfer robot carries the processed substrate W out of the substrate processing apparatus 1, and a series of substrate processing for one substrate W is completed. Then, the same processing as described above is performed for the next substrate W.

  As described above, according to the fourth embodiment, during the drying process (removal process), the substrate W is supplied by supplying the high-temperature DIW to the substrate back surface Wb until at least the HFE liquid is completely removed from the substrate surface Wf. Since the substrate is heated, even if a large amount of water vapor components exist around the substrate Wf, water droplets do not adhere to the substrate surface Wf, and the substrate W can be reliably dried.

  Further, when the substrate W is heated using the high temperature DIW as described above, a part of the high temperature DIW may be scattered to the substrate surface Wf side while the high temperature DIW is supplied. However, since the high temperature DIW is supplied in a state where the substrate surface Wf is covered by the blocking member 64, it is possible to reliably prevent the scattered droplets from adhering to the substrate surface Wf.

  Further, in the fourth embodiment, the substrate heating is performed using the high temperature DIW, but the substrate heating may be performed by supplying a high temperature liquid obtained by heating another liquid to the substrate back surface Wb.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in the above embodiment, the above-mentioned Novec 7100 / 7100DL or the like is used as the “solvent containing a fluorine-based solvent as a main component” of the present invention. You may use the mixed solvent mixed. As such a mixed solvent, for example, HFE71IPA (hydrofluoroether azeotrope-like mixture) of the trade name Novec (registered trademark) series manufactured by Sumitomo 3M Limited may be used. When used as a “solvent containing a fluorinated solvent as a main component”, the first substitution process can be omitted, and the substrate processing can be simplified, the tact time can be shortened, and the cost can be reduced. The reason will be described.

  In the first to fourth embodiments, Novec 7100 / 7100DL or the like is used as the “solvent containing a fluorinated solvent as a main component” of the present invention, but these are insoluble in DIW. Therefore, it is necessary to execute the second replacement process using the HFE liquid after the first replacement process using the IPA liquid is performed. On the other hand, since Novec HFE71IPA is soluble in DIW, Novec HFE71IPA can be supplied to the substrate W on which the rinse liquid film is formed to replace the rinse liquid film with Novec HFE71IPA. For this reason, the first replacement process becomes unnecessary.

  Further, since the first replacement process is not required and the processing liquid on the substrate surface Wf is DIW immediately before the second replacement process, the substrate heating may be performed immediately before the second replacement process. For example, the substrate heating may be started during the paddle forming process. In this case, the substrate temperature in the drying process (removal process) is increased, and the water vapor component existing around the substrate surface Wf is aggregated and adhered to the substrate W. Furthermore, it can prevent reliably.

  In the above embodiment, the present invention is applied to an apparatus and a method for performing a chemical treatment, a rinsing process, a paddle process, a (first replacement process), a second replacement process, and a drying process on a substrate W such as a semiconductor wafer. However, the type and processing content of the substrate W are not limited to this, and a substrate processing method and a substrate processing apparatus for removing a solvent mainly composed of a fluorinated solvent from the substrate surface and drying the substrate surface. The present invention can be applied to.

  The present invention provides a surface of a substrate including 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, an optical disk substrate, a magnetic disk substrate, a magneto-optical disk substrate, etc. It can be applied to a substrate processing method and apparatus for drying.

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 an electrical configuration for controlling the substrate processing apparatus of FIG. 1. It is a figure which shows operation | movement of the substrate processing apparatus of FIG. It is a figure which shows typically the generation | occurrence | production mechanism of the dry defect resulting from evaporation of HFE liquid. It is a figure which shows 2nd Embodiment of the substrate processing apparatus concerning this invention. It is a figure which shows 3rd Embodiment of the substrate processing apparatus concerning this invention. It is a figure which shows 4th Embodiment of the substrate processing apparatus concerning this invention. It is a figure which shows operation | movement of the substrate processing apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Substrate processing apparatus 6 ... Spin chuck 32 ... HFE liquid supply nozzle (solvent supply means)
42 ... HFE liquid supply unit (solvent supply means)
54 ... Gas heating unit (heating means)
60 ... Heating member (heating means)
62 ... Liquid heating unit (heating means)
64 ... Shut-off member W ... Substrate Wb ... Substrate back surface Wf ... Substrate surface

Claims (9)

A substrate processing method for drying a substrate whose surface is wet with a processing solution,
A substitution step of replacing the treatment liquid with the solvent by supplying a solvent mainly containing a fluorine-based solvent to the substrate surface;
A removal step of removing the solvent from the substrate surface after the substitution step,
In the removing step, the substrate is heated until at least the solvent is removed from the surface of the substrate.   The substrate processing method according to claim 1, wherein the fluorinated solvent is hydrofluoroether.   The substrate processing method according to claim 1, wherein in the removing step, the substrate is heated by supplying a high temperature gas heated to a room temperature or higher to the substrate.   3. The substrate processing method according to claim 1, wherein in the removing step, the substrate is heated by supplying a high-temperature liquid heated to room temperature or higher from the opposite side of the substrate surface to the substrate.   5. The substrate processing method according to claim 4, wherein in the removing step, the high-temperature liquid is supplied while disposing a blocking member in proximity to the substrate surface so as to cover the substrate surface.   The substrate processing method according to claim 1, wherein when the processing liquid is pure water, heating of the substrate is started immediately before the replacement step.   The substrate according to any one of claims 1 to 5, wherein when the processing liquid is an organic solvent, heating of the substrate is started immediately after the entire processing liquid on the substrate surface is replaced with the solvent. Processing method. A substrate holding means for holding the substrate in a substantially horizontal posture with the substrate surface wet with the processing liquid facing upward;
Solvent supply means for supplying a solvent mainly composed of a fluorinated solvent toward the surface of the substrate held by the substrate holding means and replacing the treatment liquid with the solvent;
Removing means for removing the solvent from the substrate surface;
Heating means for heating the substrate held by the substrate holding means,
The substrate processing apparatus, wherein the heating unit heats the substrate at least until the solvent is removed from the substrate surface by the removing unit.   The substrate processing apparatus according to claim 8, wherein the fluorinated solvent is hydrofluoroether.

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