JP6117041B2 - Liquid processing method, liquid processing apparatus, and storage medium - Google Patents

Description

  The present invention relates to a liquid processing technique for drying a substrate after replacing the rinsing liquid on the substrate after the rinsing process with a drying liquid.

  In manufacturing a semiconductor device, a cleaning process using a chemical solution is performed on a substrate such as a semiconductor wafer. In the cleaning process, for example, a chemical solution processing step for supplying a chemical solution to the substrate by rotating the substrate and performing a predetermined chemical solution treatment on the substrate, DIW (pure water) is supplied to remove the chemical solution and residues remaining on the substrate. A rinsing process for performing the drying process and a drying process for drying the substrate are sequentially performed. For the purpose of preventing the occurrence of water marks, DIW used in the rinsing process and remaining on the substrate surface is replaced with a drying liquid such as IPA (isopropyl alcohol) prior to or at the beginning of the drying process. Thereafter, the substrate is dried by removing the drying liquid from the substrate surface (see, for example, Patent Document 1). When performing IPA replacement, IPA is supplied to the center of the substrate while rotating the substrate. There are cases in which the IPA supply position is maintained at the central portion and the IPA supply position is moved from the central portion toward the peripheral portion. In either case, the IPA is initially at the central portion of the substrate. To be supplied.

  When the hydrophobicity of the substrate surface is strong, if the flow rate of IPA supplied to the central portion of the substrate is small, an IPA liquid film continuous from the central portion to the peripheral portion of the substrate immediately after the supply of IPA is not formed on the substrate surface. There is a case. In this case, DIW remaining at the peripheral edge of the substrate may be agglomerated at the peripheral edge of the substrate, and this may dry to form a water mark. In order to avoid the occurrence of this event, it is necessary to supply IPA at a large flow rate, but on the other hand, reduction of the IPA usage amount is required.

JP 2010-045389 A

  The present invention ensures that all necessary regions of the substrate surface are liquid of the drying liquid after the start of the replacement of the rinse liquid with the drying liquid on the substrate and before the drying liquid is removed from the substrate. It aims at providing the technique which can reduce the total usage-amount of the liquid for drying, making it cover with a film | membrane.

  In a preferred embodiment, the present invention provides a rinsing step of supplying a rinsing liquid to the substrate while rotating the substrate, and rinsing the substrate, and the rinsing while rotating the substrate after the rinsing step. Supplying a drying liquid having a lower surface tension and higher volatility than the liquid to the substrate, and replacing the rinse liquid on the substrate with the drying liquid; and A drying step of removing the drying liquid supplied in the drying liquid supply step while rotating, and in the drying liquid supply step, the drying liquid is fed to the central portion of the substrate at a first flow rate. And supplying the drying liquid to the substrate at a second flow rate smaller than the first flow rate.

  In another preferred embodiment, the present invention includes a substrate holding mechanism that horizontally holds and rotates a substrate, a rinse liquid supply unit that supplies a rinse liquid to the substrate held by the substrate holding mechanism, and at least a first And a drying liquid supply unit that supplies a drying liquid to the substrate held by the substrate holding mechanism at a second flow rate smaller than the first flow rate and held by the substrate holding mechanism. After the rinsing liquid supply unit supplies the rinsing liquid to the rotating substrate, the drying liquid supply unit supplies the drying liquid at the first flow rate, and then the drying liquid at the second flow rate. A liquid processing apparatus for supplying a liquid is provided.

  In yet another preferred embodiment, the present invention includes a substrate holding mechanism that horizontally holds and rotates a substrate, a rinse liquid supply unit that supplies a rinse liquid to the substrate held by the substrate holding mechanism, and at least, A drying liquid supply unit that supplies a drying liquid to the substrate held by the substrate holding mechanism at a first flow rate and a second flow rate that is smaller than the first flow rate, the substrate holding mechanism, and the rinsing liquid A control unit comprising a computer for controlling the operation of the supply unit and the drying liquid supply unit, and a storage medium storing a program for controlling the operation of the substrate processing apparatus, the control comprising the computer The substrate processing apparatus supplies the rinse liquid to the substrate while rotating the substrate, thereby rinsing the substrate and performing the rinse process. After the rinsing step, while rotating the substrate, a drying liquid having a lower surface tension and higher volatility than the rinsing liquid is supplied to the substrate, and the rinsing liquid on the substrate is used for the drying. A drying liquid supply step for replacing with a liquid; and a drying step for removing the drying liquid supplied in the drying liquid supply step while rotating the substrate, wherein in the drying liquid supply step, Executing a liquid processing method of supplying the drying liquid to the substrate at a second flow rate smaller than the first flow rate after supplying the drying liquid to the central portion of the substrate at a first flow rate; Provide media.

  By supplying the drying liquid at a relatively large flow rate before the replacement of the rinsing liquid remaining on the substrate and the drying liquid proceeds to a predetermined degree, the liquid film of the drying liquid is surely provided over the entire surface of the substrate Can be covered. In addition, after the replacement has progressed to a predetermined degree, even if the supply flow rate of the drying liquid is decreased, a necessary region on the surface of the substrate can be reliably covered with the liquid film of the drying liquid. Therefore, according to the present invention, it is ensured that all necessary areas of the substrate surface are dried after the replacement of the rinse liquid with the drying liquid on the substrate is started and before the drying liquid is removed from the substrate. The total amount of the drying liquid used can be reduced while being covered with the liquid film of the liquid.

The figure which shows schematic structure of a substrate processing system. The figure which shows schematic structure of a processing unit. The figure which shows the structure of the liquid supply part which concerns on 1st Embodiment, a flow volume adjustment part, and a process liquid supply source. The figure explaining the effect | action of 1st Embodiment. The schematic plan view of the wafer for demonstrating IPA flow volume switching. The figure which shows the structure of the liquid supply part which concerns on 2nd Embodiment, a flow volume adjustment part, and a process liquid supply source. The figure explaining the effect | action of 2nd Embodiment. The figure explaining the modification of 1st Embodiment. The figure explaining the modification of 2nd Embodiment.

  FIG. 1 is a diagram showing a schematic configuration of a substrate processing system according to the present embodiment. In the following, in order to clarify the positional relationship, the X axis, the Y axis, and the Z axis that are orthogonal to each other are defined, and the positive direction of the Z axis is the vertically upward direction.

  As shown in FIG. 1, the substrate processing system 1 includes a carry-in / out station 2 and a processing station 3. The carry-in / out station 2 and the processing station 3 are provided adjacent to each other.

  The carry-in / out station 2 includes a carrier placement unit 11 and a transport unit 12. A plurality of carriers C that accommodate a plurality of wafers W in a horizontal state are placed on the carrier placement unit 11.

  The transport unit 12 is provided adjacent to the carrier placement unit 11 and includes a substrate transport device 13 and a delivery unit 14 inside. The substrate transfer device 13 includes a substrate holding mechanism that holds the wafer W. Further, the substrate transfer device 13 can move in the horizontal direction and the vertical direction and can turn around the vertical axis, and transfers the wafer W between the carrier C and the delivery unit 14 using the substrate holding mechanism. Do.

  The processing station 3 is provided adjacent to the transfer unit 12. The processing station 3 includes a transport unit 15 and a plurality of processing units 16. The plurality of processing units 16 are provided side by side on the transport unit 15.

  The transport unit 15 includes a substrate transport device 17 inside. The substrate transfer device 17 includes a substrate holding mechanism that holds the wafer W. Further, the substrate transfer device 17 can move in the horizontal direction and the vertical direction and can turn around the vertical axis, and transfers the wafer W between the delivery unit 14 and the processing unit 16 using the substrate holding mechanism. I do.

  The processing unit 16 performs predetermined substrate processing on the wafer W transferred by the substrate transfer device 17.

  Further, the substrate processing system 1 includes a control device 4. The control device 4 is a computer, for example, and includes a control unit 18 and a storage unit 19. The storage unit 19 stores a program for controlling various processes executed in the substrate processing system 1. The control unit 18 controls the operation of the substrate processing system 1 by reading and executing the program stored in the storage unit 19.

  Such a program may be recorded on a computer-readable storage medium, and may be installed in the storage unit 19 of the control device 4 from the storage medium. Examples of the computer-readable storage medium include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnetic optical disk (MO), and a memory card.

  In the substrate processing system 1 configured as described above, first, the substrate transfer device 13 of the loading / unloading station 2 takes out the wafer W from the carrier C placed on the carrier placement unit 11 and receives the taken-out wafer W. Place on the transfer section 14. The wafer W placed on the delivery unit 14 is taken out from the delivery unit 14 by the substrate transfer device 17 of the processing station 3 and carried into the processing unit 16.

  The wafer W carried into the processing unit 16 is processed by the processing unit 16, then unloaded from the processing unit 16 by the substrate transfer device 17, and placed on the delivery unit 14. Then, the processed wafer W placed on the delivery unit 14 is returned to the carrier C of the carrier placement unit 11 by the substrate transfer device 13.

  Next, a schematic configuration of the processing unit 16 will be described with reference to FIG. FIG. 2 is a diagram showing a schematic configuration of the processing unit 16.

  As shown in FIG. 2, the processing unit 16 includes a chamber 20, a substrate holding mechanism 30, a processing fluid supply unit 40, and a recovery cup 50.

  The chamber 20 accommodates the substrate holding mechanism 30, the processing fluid supply unit 40, and the recovery cup 50. An FFU (Fan Filter Unit) 21 is provided on the ceiling of the chamber 20. The FFU 21 forms a down flow in the chamber 20.

  The substrate holding mechanism 30 includes a holding unit 31, a support unit 32, and a driving unit 33. The holding unit 31 holds the wafer W horizontally. The support | pillar part 32 is a member extended in a perpendicular direction, a base end part is rotatably supported by the drive part 33, and supports the holding | maintenance part 31 horizontally in a front-end | tip part. The drive unit 33 rotates the column unit 32 around the vertical axis. The substrate holding mechanism 30 rotates the support unit 31 by rotating the support unit 32 using the drive unit 33, thereby rotating the wafer W held by the support unit 31. .

  The processing fluid supply unit 40 supplies a processing fluid to the wafer W. The processing fluid supply unit 40 is connected to a processing fluid supply source 70.

  The collection cup 50 is disposed so as to surround the holding unit 31, and collects the processing liquid scattered from the wafer W by the rotation of the holding unit 31. A drain port 51 is formed at the bottom of the recovery cup 50, and the processing liquid collected by the recovery cup 50 is discharged from the drain port 51 to the outside of the processing unit 16. Further, an exhaust port 52 for discharging the gas supplied from the FFU 21 to the outside of the processing unit 16 is formed at the bottom of the recovery cup 50.

  Next, details of the processing fluid supply unit 40 and the processing fluid supply source 70 according to the first embodiment will be described with reference to FIG.

  The processing fluid supply unit 40 includes a chemical nozzle 401, a rinse nozzle 402, a first drying liquid nozzle 403, a second drying liquid nozzle 404, and a drying gas nozzle 405.

  These nozzles 401 to 405 can be moved by a nozzle moving mechanism. In the present embodiment, the nozzle moving mechanism is configured by a nozzle arm 40a, a guide rail 40b, and a drive unit (not shown). The nozzles 401 to 405 are attached to the nozzle holding portion at the tip of the nozzle arm 40a. The nozzle arm 40 a can translate along the guide rail 40 b, thereby positioning each nozzle (401 to 405) directly above the center of the wafer W held by the substrate holding mechanism 30. In addition, each nozzle (401 to 405) can be moved in the radial direction of the wafer W toward the peripheral edge of the wafer W. The nozzles 401 to 405 are arranged in this order along the radial direction of the wafer W. All the nozzles 401 to 405 need not be held by one nozzle arm 40a, and may be held by a plurality of nozzle arms. Further, the nozzle arm 40a is not limited to one that translates, and any nozzle arm (401 to 405) may be used as long as it can move the nozzles (401 to 405) above the central portion and the peripheral portion of the wafer W.

The first drying liquid nozzle 403 is a large-diameter nozzle suitable for discharging the drying liquid at a relatively large flow rate, and the second drying liquid nozzle 404 is discharged from the first drying liquid nozzle 403. This is a small-diameter nozzle suitable for discharging the drying liquid at a relatively small flow rate smaller than the flow rate of the drying liquid.

  The chemical nozzle 401 is connected to a chemical supply source 701 via a pipe line 410 provided with an on-off valve 411 and a flow rate adjustment valve 412. In this example, DHF (dilute hydrofluoric acid) is used as the chemical solution. The chemical solution supply unit is configured by the chemical solution nozzle 401, the pipe line 410 provided with the valves 411 and 412, and the like.

  The rinse nozzle 402 is connected to a rinse liquid supply source 702 via a pipe line 420 provided with an on-off valve 421 and a flow rate adjustment valve 422. In this example, DIW (pure water) is used as the rinse liquid. The rinse liquid supply unit is configured by the rinse nozzle 402, the pipe line 420 provided with the valves 421 and 422, and the like.

  The first drying liquid nozzle 403 is connected to a drying liquid supply source 703 via a pipe line 430 provided with an on-off valve 431 and a flow rate adjustment valve 432. As the drying liquid, any organic solvent that is miscible (compatible) with the rinsing liquid (pure water), has a lower surface tension than the rinsing liquid, and has higher volatility than the rinsing liquid can be used. . In this embodiment, IPA (isopropyl alcohol) is used as the drying liquid.

  The second drying liquid nozzle 404 is connected to a drying liquid supply source 703 via a conduit 440 provided with an on-off valve 441 and a flow rate adjustment valve 442. The pipe line 440 branches from the pipe line 430. The first and second drying liquid nozzles 403 and 404, the pipe line 430 provided with valves 431 and 432, the pipe line 440 provided with valves 441 and 442, and the like constitute a drying liquid supply unit. .

The drying gas nozzle 405 is connected to a drying gas supply source 705 via a pipe line 450 in which an on-off valve 451 and a flow rate adjustment valve 452 are interposed. In this example, nitrogen (N ₂ ) gas, which is a clean gas with low humidity and low oxygen concentration, is used as the drying gas. As the drying gas, low-humidity clean air called clean dry air can be used instead of nitrogen gas. A drying gas supply unit is configured by the drying gas nozzle 405, the pipe line 450 provided with the valves 451 and 452, and the like.

  With the above configuration, each of the nozzles 401 to 405 can supply (discharge) the processing fluid toward the wafer W at a controlled flow rate. The chemical liquid supply source 701, the rinse liquid supply source 702, the drying liquid supply source 703, and the drying gas supply source 705 correspond to the processing fluid supply source 70 shown in FIG.

  Next, the operation of the liquid processing apparatus will be described with reference to FIG. First, the wafer W is loaded into the processing unit 16 by the substrate transfer device 17 and held by the substrate holding mechanism 30. Next, the wafer W starts to rotate by operating the driving unit 33. The wafer W continues to rotate until the drying process described later is completed.

[Chemical solution processing]
First, the chemical nozzle 401 is positioned directly above the center of the wafer W, and DHF is supplied from the chemical nozzle 401 to the center of the surface of the wafer W over a predetermined time (see FIG. 4A). The supplied DHF spreads by centrifugal force and flows toward the outside of the wafer W. At this time, the entire surface of the wafer W is covered with a DHF liquid film. Unnecessary natural oxide film or silicon oxide film present on the surface of the wafer W is removed by DHF.

[Rinse processing]
Next, the supply of DHF is stopped, and the rinse nozzle 402 is positioned immediately above the center of the wafer W, and DIW is supplied from the rinse nozzle 402 to the center of the surface of the wafer W over a predetermined time (FIG. 4). (See (b)). The supplied DIW spreads by the centrifugal force and flows toward the outside of the wafer W. At this time, the entire surface of the wafer W is covered with a liquid film of DIW. As a result, the chemical solution (DHF) remaining on the surface of the wafer W and the reaction product during the chemical treatment are washed away by the DIW and removed from the surface of the wafer W. The surface of the wafer W is hydrophobic at the end of the rinsing process at the latest.

[Drying process]
When the rinsing process is completed, the drying process is executed. In this drying process, IPA as a drying liquid is supplied to the wafer W and DIW remaining on the surface of the wafer W is replaced with IPA (drying liquid supply process), and the IPA is shaken off or evaporated to give the wafer. It is roughly divided into two stages: a stage (drying process) of drying the wafer W by removing IPA from the top of W.

<Drying liquid supply process>
The explanation will continue from the end of the rinsing process. After supplying DIW from the rinse nozzle 402 to the wafer W for a predetermined time, the supply of DIW is stopped. The first drying liquid nozzle 403 is positioned directly above the center of the wafer W, and the IPA from the first drying liquid nozzle 403 to the center of the surface of the wafer W, and the IPA liquid to the entire surface of the wafer W. A large flow rate (first flow rate) sufficient to form a film is supplied over a first predetermined time (see FIG. 4C). The supplied IPA spreads by centrifugal force and flows toward the outside of the wafer W. At this time, the entire surface of the wafer W is covered with the IPA liquid film. As a result, DIW remaining on the surface of the wafer W is replaced with IPA.

  When shifting from the state in which the rinse nozzle 402 supplies DIW to the state in which the first drying liquid nozzle 403 supplies IPA, the end of the period in which the rinse nozzle 402 supplies DIW, and the first The beginning of the period during which the drying liquid nozzle 403 supplies the IPA may overlap in time. Specifically, for example, when the rinse nozzle 402 is positioned immediately above the central portion of the wafer W and supplies DIW to the central portion of the wafer W, the second nozzle positioned slightly outside the central portion of the wafer W is used. The discharge of IPA is started from the first drying liquid nozzle 403, and then the nozzle arm 40a is moved so that the DIW from the rinse nozzle 402 is positioned when the first drying liquid nozzle 403 is positioned directly above the center of the wafer W. May be stopped.

  After the elapse of the first predetermined time, the supply of IPA from the first drying liquid nozzle 403 is stopped, and the second drying liquid nozzle 404 is positioned immediately above the center of the wafer W, and the second drying liquid nozzle 404 is located. IPA is supplied from the liquid nozzle 404 to the center of the surface of the wafer W at a small flow rate (second flow rate smaller than the first flow rate) for a second predetermined time (see FIG. 4D). Also at this time, the entire surface of the wafer W is covered with the IPA liquid film. As a result, the DIW remaining on the surface of the wafer W is further replaced with IPA (when the IPA replacement is not completed at the end of the first predetermined time). The timing of switching from the first drying liquid nozzle 403 to the second drying liquid nozzle 404 will be described later.

  When shifting from the state in which the first drying liquid nozzle 403 supplies IPA to the state in which the second drying liquid nozzle 404 supplies IPA, the first drying liquid nozzle 403 supplies IPA. The end of the period during which the second drying liquid nozzle 404 supplies the IPA may overlap in time. Specifically, for example, when the first drying liquid nozzle 403 is located immediately above the center portion of the wafer W and supplies IPA to the center portion of the wafer W, it is slightly outside the center portion of the wafer W. When the discharge of IPA is started from the second drying liquid nozzle 404 positioned at the first position, the nozzle arm 40a is moved, and then the first drying liquid nozzle 404 is positioned immediately above the center of the wafer W. The supply of IPA from the drying liquid nozzle 403 may be stopped.

  The nozzle arm 40a is moved while continuing to discharge IPA at a small flow rate from the second drying liquid nozzle 404 from the middle of the second predetermined time described above, and the second drying liquid nozzle 404 is moved to the wafer. Move toward the peripheral edge of W. Nitrogen gas is discharged from the drying gas nozzle 405 toward the surface of the wafer W when the drying gas nozzle 405 is located immediately above the central portion of the wafer W, or slightly before or after that point (FIG. 4). (See (e)). While maintaining this state, the nozzle arm 40a is moved until the drying gas nozzle 405 reaches a position almost directly above the periphery of the wafer W (see FIGS. 4F and 4G). The discharge of IPA from the second drying liquid nozzle 404 ends when the second drying liquid nozzle 404 reaches a position almost directly above the periphery of the wafer W (end of the second predetermined time).

  As described above, in the process of moving the supply position of the IPA from the central portion to the peripheral portion of the wafer W, the entire area of the surface of the wafer W outside the radial position where the IPA is supplied, that is, the ring-shaped The area is covered with an IPA liquid film, and the inner diameter of the ring-shaped area gradually increases as the IPA supply position moves. In the region not covered with the IPA liquid film on the inner side of the ring, the IPA moves outward and the IPA evaporates due to the centrifugal force, so the region is dried. That is, in the present embodiment, when viewed as the whole wafer W, the drying liquid supply process and the drying process are performed simultaneously. However, if it sees for every area | region of the wafer W surface, the drying process will be performed after the liquid supply process for drying.

  In the present embodiment, the nitrogen gas supply position is moved from the center of the wafer W to the peripheral edge while maintaining the supply position of the nitrogen gas inward of the IPA supply position. Becomes an atmosphere of low humidity and low oxygen concentration, and water marks are hardly generated.

  After the state shown in FIG. 4G, the drying process may be continued by stopping the discharge of the nitrogen gas from the drying gas nozzle 405 and continuously rotating the wafer W (preferably at a higher speed). Good.

  When the drying process including the drying liquid supply process and the drying process is completed as described above, the rotation of the wafer W is stopped. As a result, a series of processing on the wafer W is completed. Thereafter, the wafer W is unloaded from the processing unit 16 by the substrate transfer device 17.

  Next, the timing of switching from the first drying liquid nozzle 403 to the second drying liquid nozzle 404 will be described. From the time when DIW supply is completed and the discharge of IPA to the center of the wafer W is started until the replacement from DIW to IPA is completed, the wafer W is used in the rinsing process on the wafer W. There is a mixed liquid of the remaining DIW and the newly supplied IPA (hereinafter referred to as “DIW / IPA mixed liquid”). If the supply flow rate of IPA is small immediately after the DIW supply is finished and the discharge of the IPA to the center of the wafer W is started, the DIW / IPA mixed solution spreads toward the periphery of the wafer W due to centrifugal force. The state of the film cannot be maintained over the entire region, and a phenomenon of branching in a streak shape occurs as shown in FIG. When such a phenomenon occurs, a DIW lump or a low IPA concentration DIW / IPA mixed liquid lump is formed in the peripheral area of the wafer W as schematically shown in FIG. Then, drying unevenness may occur and a water mark may occur.

  In order not to cause such a phenomenon, the supply flow rate of IPA must be increased. By doing so, the total amount of the DIW / IPA mixed solution is increased, and a liquid film of the DIW / IPA mixed solution is formed continuously (without interruption) over the entire surface of the wafer W.

  However, when the supply flow rate of IPA is increased, naturally, a large amount of IPA is required to process one wafer W. In order to solve this problem, in the present embodiment, at the initial stage of the drying liquid supply step, IPA is supplied at a flow rate at which the liquid film of the DIW / IPA mixed solution is formed without interruption throughout the entire surface of the wafer W. Thereafter, the supply flow rate of IPA was reduced during the drying liquid supply process. As the IPA supply time elapses, the IPA concentration in the DIW / IPA mixture increases and the surface tension of the DIW / IPA mixture decreases. It has been found that if the surface tension is lowered, the liquid film of the DIW / IPA mixed solution having the lowered surface tension is formed on the entire surface of the wafer W even when the supply flow rate of the IPA is reduced.

  Appropriate switching timing from the large flow rate IPA supply to the small flow rate IPA supply can be obtained by experiments. Factors to be considered include the state of the wafer surface (degree of hydrophobicity, surface irregularities), the number of wafer rotations, the IPA supply flow rate at a small flow rate, and the like.

  According to the above embodiment, it is possible to reduce the amount of IPA used while ensuring that the entire necessary area of the surface of the wafer W is covered with the liquid film of IPA.

  Further, according to the above-described embodiment, the IPA supply flow rate is reduced in the middle, so that the IPA mist which is scattered from the wafer W to the outside and collides with the recovery cup 50 and is floated around the wafer W. The amount of can be reduced. For this reason, it is possible to prevent or suppress such mist from reattaching to the already dried portion of the surface of the wafer W. Further, when discharging the IPA while the nozzle (second drying liquid nozzle 404) moves outward in the radial direction of the wafer W, if the discharge flow rate of the IPA is small, the discharged IPA rebounds on the surface of the wafer W. It is possible to prevent or suppress the droplets from adhering again to the already dried portion of the surface of the wafer W. Note that if IPA reattaches to the already dried portion of the surface of the wafer W, it may cause generation of particles.

  In the first embodiment, the large-diameter first drying liquid nozzle 403 and the small-diameter second drying liquid nozzle 404 are used. However, the present invention is not limited to this. That is, as the second embodiment, as shown in FIG. 6, the second drying liquid nozzle 404 having a small diameter can be eliminated. In this case, the flow rate of the IPA discharged from the first drying liquid nozzle 403 can be changed by adjusting the opening degree of the flow control valve 432 corresponding to the large-diameter first drying liquid nozzle 403. It is apparent from FIG. 6 that the second embodiment is the same as the first embodiment except that the second drying liquid nozzle 404 and the corresponding components 440, 441, and 442 are eliminated. In the second embodiment, redundant description of the same components as those in the first embodiment is omitted.

  In the second embodiment, IPA is supplied to the central portion of the surface of the wafer W from a state where the IPA is supplied to the central portion of the surface of the wafer W at a large flow rate (see FIG. 7C). When switching to the current state (see FIG. 7D), it is not necessary to move the first and second drying liquid nozzles 403 and 404 as in the first embodiment, so that the switching can be performed smoothly. There is an advantage that you can. On the other hand, in the first embodiment described above, there is an advantage that IPA can be discharged under optimum conditions because the nozzles having the discharge port diameter suitable for the discharge flow rate are selectively used. Since the large-diameter first drying liquid nozzle 403 tends to cause dripping when the liquid is not discharged compared to the small-diameter second drying liquid nozzle 404, the second drying liquid nozzle 403 When the liquid nozzle 404 for scanning performs scan ejection (see FIGS. 4E, 4F, etc.), the first drying liquid nozzle 403 is radially outward of the wafer W from the second drying liquid nozzle 404. It is desirable to be located at.

  It is clear from FIG. 7 that the operation of the second embodiment is the same as that of the first embodiment except for the points described above. In the second embodiment, redundant description of the same operation as that of the first embodiment is omitted.

  In the first and second embodiments, after the IPA is supplied to the center of the wafer W at a small flow rate for a predetermined time, the movement of the IPA supply position outward in the radial direction (nozzle scanning operation) is started. However, the present invention is not limited to this. Immediately after the IPA supply flow rate is switched from a large flow rate to a small flow rate, the movement of the IPA supply position to the outside in the radial direction may be started. The IPA supply flow rate may be switched from a large flow rate to a small flow rate immediately after the movement of the IPA supply position radially outward is started.

  In the first and second embodiments, the IPA supply position is moved radially outward (nozzle scanning operation), but this operation can be omitted. That is, as shown in FIGS. 8D and 9D, the IPA supply position may always be fixed at the center of the wafer surface, and after the IPA supply is stopped, the IPA may be shaken off and removed. Furthermore, when supplying nitrogen gas as shown in FIGS. 8E and 9E, the nitrogen gas supply position may be fixed to the center of the wafer surface, or supply of nitrogen gas may be performed. It may be performed while moving the position radially outward (nozzle scanning operation). Except for the above points, the actions shown in FIGS. 8 and 9 are the same as the actions shown in FIGS.

  In all the embodiments described above, the nitrogen gas is supplied to the wafer W from the nozzle 405 attached to the nozzle arm 40a. However, the present invention is not limited to this, and other means, for example, provided above the wafer W. If an atmosphere suitable for drying (low humidity atmosphere or low humidity low oxygen concentration atmosphere) is established around the wafer W by the atmosphere adjusting means, the nozzle 405 may not be provided.

  Moreover, in all the embodiments described above, the supply flow rate of IPA has two stages of the first flow rate and the second flow rate, but is not limited to this, and the flow rate is changed to three or more steps. Also good. Further, the first flow rate (large flow rate) and the second flow rate (small flow rate) do not have to be constant fixed flow rates, and may be flow rates that change within a predetermined range.

  Although the above embodiment is particularly effective for drying the wafer W whose surface is hydrophobic after the rinsing process, the surface of the wafer W to be processed may not be hydrophobic. Note that “the surface becomes hydrophobic after the rinsing process” means that when the surface of the wafer W is changed to hydrophobicity by the chemical treatment, the hydrophilic layer covering the surface of the wafer W is removed by the chemical treatment and the hydrophobicity is removed. When the surface is exposed, there are various cases such as (but not limited to) the case where the surface is hydrophobic before the chemical treatment but is still hydrophobic after the chemical treatment.

  Further, the substrate to be processed is not limited to a semiconductor wafer, and may be a substrate made of another material such as a ceramic substrate or a glass substrate.

W substrate 30 substrate holding mechanism
40a arm (nozzle arm)
402, 420, 421, 422 Rinse liquid supply unit 403, 430, 431, 432, 404, 440, 441, 442 Drying liquid supply unit
403 1st nozzle (first drying liquid nozzle)
404 second nozzle (second liquid nozzle for drying)

Claims (9)

A rinsing step of supplying a rinsing liquid to the substrate while rotating the substrate, and rinsing the substrate;
After the rinsing step, while rotating the substrate, a drying liquid having a lower surface tension and higher volatility than the rinsing liquid is supplied to the substrate, and the rinsing liquid on the substrate is dried. A drying liquid supply process for substituting with a liquid for use;
A drying step of removing the drying liquid supplied in the drying liquid supply step while rotating the substrate,
In the drying liquid supply step, after the drying liquid is supplied to the central portion of the substrate at a first flow rate, the drying liquid is supplied to the substrate at a second flow rate smaller than the first flow rate. And
The supply of the drying liquid at the first flow rate is performed by a first nozzle, and the supply of the drying liquid at the second flow rate is performed with a discharge port having a smaller discharge port diameter than the first nozzle. The liquid processing method characterized by performing by 2 nozzles .   The liquid processing method according to claim 1, wherein when the drying liquid is supplied at the second flow rate, the supply position of the drying liquid is moved from the central portion of the substrate toward the peripheral portion.   The liquid processing method according to claim 2, wherein the drying liquid is supplied to the central portion of the substrate at the second flow rate before the drying liquid supply position is moved toward the peripheral edge of the substrate.   When the supply position of the drying liquid is moved toward the peripheral edge of the substrate, the drying gas is supplied to the substrate while moving the supply position toward the peripheral edge of the substrate. The liquid processing method according to claim 2, wherein a drying gas supply position is maintained radially inward of the drying liquid supply position. A rinsing step of supplying a rinsing liquid to the substrate while rotating the substrate, and rinsing the substrate;
After the rinsing step, while rotating the substrate, a drying liquid having a lower surface tension and higher volatility than the rinsing liquid is supplied to the substrate, and the rinsing liquid on the substrate is dried. A drying liquid supply process for substituting with a liquid for use;
A drying step of removing the drying liquid supplied in the drying liquid supply step while rotating the substrate,
In the drying liquid supply step, after the drying liquid is supplied to the central portion of the substrate at a first flow rate, the drying liquid is supplied to the substrate at a second flow rate smaller than the first flow rate. And
When supplying the drying liquid at the second flow rate, the supply position of the drying liquid is moved from the center of the substrate toward the peripheral edge, and at this time, the supply position of the drying liquid is more than the supply position of the drying liquid. A liquid processing method, characterized in that the drying liquid is supplied so that the entire area of the substrate surface radially outside is covered with the liquid film of the drying liquid. A substrate holding mechanism for horizontally holding and rotating the substrate;
A rinsing liquid supply unit for supplying a rinsing liquid to the substrate held by the substrate holding mechanism;
A drying liquid supply unit configured to supply a drying liquid to the substrate held by the substrate holding mechanism at least at a first flow rate and a second flow rate smaller than the first flow rate;
With
The drying liquid supply unit has a first nozzle and a second nozzle that discharge the drying liquid, and a discharge port diameter of the first nozzle is larger than a discharge port diameter of the second nozzle,
After supplying the rinse liquid from the rinse liquid supply unit to the substrate held and rotated by the substrate holding mechanism, the drying liquid is supplied at the first flow rate by the first nozzle of the drying liquid supply unit. Thereafter, the liquid processing apparatus supplies the drying liquid at the second flow rate by the second nozzle . The drying liquid supply unit includes an arm for moving the second nozzle, and the drying liquid supply unit is configured to supply the first flow rate from the first nozzle to the central portion of the substrate. After supplying the drying liquid, the second nozzle is moved by the arm, thereby moving the supply position of the drying liquid from the central portion to the peripheral portion of the substrate while moving the second nozzle from the second nozzle . The liquid processing apparatus according to claim 6 , wherein the drying liquid is supplied at a flow rate of 10 μm. A substrate holding mechanism for horizontally holding and rotating the substrate;
A rinsing liquid supply unit for supplying a rinsing liquid to the substrate held by the substrate holding mechanism;
A drying liquid supply unit configured to supply a drying liquid to the substrate held by the substrate holding mechanism at least at a first flow rate and a second flow rate smaller than the first flow rate;
With
After supplying the rinse liquid by the rinse liquid supply unit to the substrate held and rotated by the substrate holding mechanism, the drying liquid is supplied at the first flow rate by the first nozzle of the drying liquid supply unit . Thereafter , when the drying liquid is supplied by the second nozzle at the second flow rate and the drying liquid is supplied at the second flow rate, the supply position of the drying liquid is set at the center of the substrate. The drying liquid is supplied so that the entire area of the substrate surface that is radially outward from the supply position of the drying liquid is covered with the liquid film of the drying liquid. A liquid processing apparatus. A substrate holding mechanism for rotating the substrate is horizontally held, the rinsing liquid supply section for supplying a rinsing liquid to the substrate held by the substrate holding mechanism, the drying liquid to the substrate held by the previous SL substrate holding mechanism Controlling the operation of a substrate processing apparatus comprising: a drying liquid supply unit to be supplied; and a control unit comprising a computer for controlling operations of the substrate holding mechanism, the rinse liquid supply unit, and the drying liquid supply unit The substrate processing apparatus performs the liquid processing method according to any one of claims 1 to 5 by being executed by a control unit including the computer. A storage medium to be executed.

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