JP2012222306A - Substrate processing method and substrate processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate processing method and a substrate processing apparatus capable of preventing droplets from remaining at a lower end part of a substrate pulled up from a washing tank and impurities and particles, etc., from remaining on the substrate.SOLUTION: The substrate processing apparatus comprises: a washing tank in which washing liquid is stored and a substrate can be immersed in the washing liquid; a drying chamber which is disposed above the washing tank and is capable of housing the substrate; a substrate holding and carrying part capable of holding the plurality of substrates upright and going back and forth between the washing tank and the drying chamber; a first supply part which is provided in the drying chamber and supplies steam of an organic solvent into the drying chamber; and a second supply part capable of supplying a drying gas to a lower end part of the substrate held in the drying chamber by the substrate holding and carrying part.

Description

  The present invention relates to a substrate processing method and a substrate processing apparatus for cleaning and drying a substrate such as a semiconductor wafer or a glass substrate for manufacturing a flat panel display.

  For example, in a semiconductor device manufacturing process, a cleaning process is performed in which a semiconductor wafer (hereinafter referred to as a wafer) is cleaned in a cleaning tank in which a chemical solution is stored, thereby removing impurities and particles such as metal and organic substances attached to the wafer. Is called. For example, in the cleaning process, a plurality of wafers are held almost upright in a chemical solution stored in the cleaning tank, and the chemical solution is replaced with pure water by supplying pure water to the cleaning tank. And the wafer is dried using alcohol or the like (for example, Patent Document 1).

Japanese Patent Laid-Open No. 10-209109

  In the above-described cleaning process, when the wafer is lifted from the cleaning tank, pure water remains in the form of a film on the front surface (and the back surface) of the wafer and flows down the surface of the wafer due to gravity. At this time, droplets of pure water (including alcohol) that cannot fall from the lower end portion remain at the lower end portion of the wafer that is held almost upright. When the droplet is dried, impurities and particles contained in the droplet remain at the lower end of the wafer. Residual impurities and particles may be scattered on the surface of the wafer in a later process, which causes a reduction in manufacturing yield.

  The present invention has been made in consideration of the above circumstances, and a substrate processing method and a substrate capable of suppressing droplets from remaining at the lower end portion of the substrate pulled up from the cleaning tank and impurities or particles remaining on the substrate. The present invention relates to a processing apparatus.

  According to the first aspect of the present invention, from the cleaning tank in which the rinsing liquid is stored, the step of storing the substrate in the drying chamber disposed above the cleaning tank, and the drying chamber in which the substrate is stored Supplying a vapor of an organic solvent from the first supply unit, and applying a dry gas from the second supply unit to the droplets formed on the lower end of the substrate by the liquid film flowing down the surface of the substrate. And providing a substrate processing method.

  According to the second aspect of the present invention, at least a rinse liquid can be stored, a cleaning tank configured to be immersed in a plurality of substrates in the rinse liquid, and disposed above the cleaning tank, A drying chamber capable of accommodating a substrate; a substrate holding / conveying unit that holds the plurality of substrates upright; and is provided in the drying chamber so as to reciprocate between the cleaning tank and the drying chamber; A first supply unit configured to supply vapor of an organic solvent; a second supply unit configured to supply a dry gas to a lower end portion of the substrate held in the drying chamber by the substrate holding and conveying unit; The first supply unit and the second supply unit are controlled so that the supply of the dry gas from the supply unit is started after the supply of the vapor of the organic solvent from the first supply unit. A substrate processing apparatus including a control unit is provided.

  According to the embodiment of the present invention, it is possible to prevent the droplets from remaining at the lower end portion of the substrate pulled up from the cleaning tank and the impurities, particles, and the like from remaining on the substrate.

1 is a schematic view showing a substrate processing apparatus according to an embodiment of the present invention. 5 is a flowchart illustrating a substrate processing method according to an embodiment of the present invention. It is a schematic diagram for demonstrating the principal part of the substrate processing method by embodiment of this invention. It is the schematic which shows the modification of the substrate processing apparatus by embodiment of this invention.

  Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. In all the accompanying drawings, the same or corresponding members or parts are denoted by the same or corresponding reference numerals, and redundant description is omitted.

  Referring to FIG. 1, a substrate processing apparatus 1 according to an embodiment of the present invention is disposed above a liquid processing unit 2 that performs liquid processing on a wafer W, and a rinsing process in the liquid processing unit 2. A drying processing unit 3 for drying the finished wafer W, and a wafer guide 4 as a moving mechanism for moving a plurality of wafers W between the liquid processing unit 2 and the drying processing unit 3 are provided.

  The wafer guide 4 includes a holding unit 26 that holds, for example, 50 wafers W almost upright, and a support column 27 that supports the holding unit 26. The holding part 26 has four wafer support parts 26S extending in a direction perpendicular to the paper surface of FIG. The wafer support portion 26S has, for example, 50 notches (not shown) arranged along the longitudinal direction (direction perpendicular to the paper surface), and corresponds to the four wafer support portions 26S. The four cutouts provided support the edge of the wafer W. As a result, the wafer W is held substantially upright by the holding unit 26. Note that the wafer support portion 26S is disposed so as to avoid the lower end portion of the wafer W held almost upright.

  Moreover, the support | pillar part 27 has penetrated the cover 62 of the chamber 5 mentioned later airtightly. The support column 27 can be raised and lowered by a guide lifting mechanism 28, and the wafer W held by the holding unit 26 can be moved between the liquid processing unit 2 and the drying processing unit 3.

  The liquid processing unit 2 has a liquid processing tank 6 disposed in the box 13. In this embodiment, the liquid processing tank 6 stores diluted hydrofluoric acid (DHF) and deionized water (DIW), and stores a cleaning tank 30 that stores the wafer W and performs liquid processing, and an upper opening of the cleaning tank 30. The middle tank 31 formed so that it may surround, and the outer tank 32 formed so that the opening of the middle tank 31 may be enclosed.

  A processing liquid supply nozzle 35 for supplying DHF and DIW into the cleaning tank 30 is provided at the lower part in the cleaning tank 30. Connected to the processing liquid supply nozzle 35 is a processing liquid supply line 20 having a DHF supply line 51 for supplying DHF from the DHF supply source to the cleaning tank 30 and a DIW supply line 52 for supplying DIW from the DIW supply source. ing. One of DHF and DIW can be supplied by opening and closing the open / close valve 51a provided in the DHF supply line 51 and the open / close valve 52a provided in the DIW supply line 52 in a complementary manner. The DHF supply line 51 and the DIW supply line 52 are each provided with a flow rate controller (not shown), whereby the DHF and DIW are flow-controlled and supplied into the cleaning tank 30.

  A drainage pipe 36 provided with an open / close valve 37 is connected to the bottom of the cleaning tank 30. When the opening / closing valve 37 is opened, DHF and DIW in the cleaning tank 30 are discharged into the box 13 through the drain pipe 36. Further, a drainage pipe 141 provided with a valve is connected to the lower portion of the box 13. DHF and DIW discharged from the cleaning tank 30 into the box 13 can be discharged from the box 13 through the drain pipe 141. Further, the box 13 is provided with an exhaust pipe 142, and for example, steam generated from DHF discharged to the box 13 can be exhausted through the exhaust pipe 142.

  The middle tank 31 receives pure water that has overflowed from the upper surface opening of the cleaning tank 30. One end of a drainage pipe 41 for discharging pure water from the middle tank 31 is connected to the bottom of the middle tank 31. The other end of the drainage pipe 41 is inserted into the trap 42. Further, the trap 42 is provided with a drainage pipe 43 that opens to a position higher than the other end of the drainage pipe 41 inserted into the trap 42. Thereby, the pure water that has flowed into the trap 42 from the intermediate tank 31 through the drain pipe 41 is stored up to the height of the opening of the drain pipe 43, and is discharged from the opening of the drain pipe 43 when the pure water further flows. . With such a configuration, for example, the vapor or gas in the box 13 is suppressed from reaching the intermediate tank 31 through the drainage pipe 43 or the trap 42. For example, vapor generated from DHF discharged from the cleaning tank 30 into the box 13 can be prevented from being mixed into the liquid processing tank 6 through the drain pipe 41.

  In the outer tub 32, pure water is always stored. Further, the annular seal plate 46 is arranged so that the lower part thereof is immersed in pure water in the outer tub 32 and the upper end thereof is in close contact with the lower plate of the shutter box 11 disposed above the outer tub 32. It is installed. With such a configuration, the outer tub 32 has a sealing function using pure water, and the atmosphere of the cleaning tub 30 can be prevented from leaking to the outside. Note that an exhaust pipe 136 provided with an opening / closing valve 137 is connected to the shutter box 11 so that the atmosphere in the shutter box 11 can be exhausted.

  The drying processing unit 3 is provided with a chamber 5 that accommodates the wafer W. The chamber 5 includes a substantially rectangular tube-shaped main body 61 that can accommodate the wafer W held by the wafer guide 4, and a lid 62 that opens and closes the upper surface opening of the main body 61. The lower surface opening of the main body 61 can be opened and closed by a shutter 10 described later.

The lid 62 has a substantially semicircular cross-sectional shape that is convex upward. The lid 62 can be raised and lowered by a lid raising / lowering mechanism 64, and when the lid 62 is lifted from the main body 61, the wafer W is carried into and out of the main body 61. Specifically, the holding portion 26 of the wafer guide 4 is maintained above the main body portion 61, the wafer W is transferred between the holding portion 26 and an external transfer device (not shown), and the wafer guide 4 is moved up and down. As a result, the wafer W is loaded and unloaded.
When the lid 62 is placed on the main body 61, the lid 62 can airtightly close the upper surface opening of the main body 61 via the seal member 63.

  Two first gas supply nozzles 71 are provided in the chamber 5. The two first gas supply nozzles 71 extend along the longitudinal direction (perpendicular to the paper surface) of the holding unit 26, one on each side of, for example, 50 wafers W held by the holding unit 26. The first gas supply nozzle 71 is preferably longer than a holding range in which 50 wafers W are held in the holding unit 26. Further, the first gas supply nozzle 71 is provided with a plurality of gas discharge holes 71a (see FIG. 2) arranged at predetermined intervals along the longitudinal direction thereof. A processing gas supply pipe 21 is connected to the first gas supply nozzle 71. A steam generator 22 is connected to the processing gas supply pipe 21. The steam generator 22 is connected to a nitrogen gas supply source (not shown) by a gas pipe 24 provided with an opening / closing valve 83a, a flow rate controller 24a, a heater 24h, and an opening / closing valve 83b, and the opening / closing valve 82a and the flow rate controller 23a. , And a gas pipe 23 provided with an open / close valve 82b. Nitrogen gas whose flow rate is controlled by the flow rate controller 24 a is heated by the heater 24 h and supplied to the steam generator 22, and IPA whose flow rate is controlled by the flow rate controller 23 a is supplied to the steam generator 22. As a result, IPA vapor is generated in the steam generator 22, and IPA vapor is supplied to the first gas supply nozzle 71 through the processing gas supply pipe 21 using nitrogen gas as a carrier gas, and the gas discharge hole 71 a of the first gas supply nozzle 71. To the main body 61.

  In addition, the gas discharge hole 71a provided in the first gas supply nozzle 71 opens upward from the horizontal direction. Preferably, the gas discharge hole 71 a is provided so that the IPA vapor discharged from the gas discharge hole 71 a is sprayed obliquely upward without directly contacting the wafer W accommodated in the chamber 5. More preferably, in the gas discharge part 71a, the IPA vapor passes through the upper left and upper right of the wafer W, rises toward the upper part of the inner peripheral surface of the lid 62, merges and lowers at the upper center of the lid 62, and the wafer It is provided so as to flow in between the W and flow down along the surface of the wafer W.

In the chamber 5, two second gas supply nozzles 72 are provided. The second gas supply nozzle 72 is disposed below the corresponding first gas supply nozzle 71 and substantially parallel to the first gas supply nozzle 71. In the present embodiment, the second gas supply nozzle 72 has the same configuration as the first gas supply nozzle 72 except that a plurality of gas discharge holes 72a (see FIG. 2) are opened downward from the horizontal direction. Have. The second gas supply nozzle 72 is connected to a dry gas supply source by a dry gas supply pipe 25 provided with an open / close valve 86a, a flow rate controller 25a, a heater 25h, and an open / close valve 86b. Thereby, the dry gas from the dry gas supply source is supplied to the second gas supply nozzle 72 through the dry gas supply pipe 25 and supplied from the gas discharge hole 72 a of the second gas supply nozzle 72. As the dry gas, an inert gas such as nitrogen gas or a rare gas, or a purified dry gas (or dry air) can be used.
The gas discharge hole 72a of the second gas supply nozzle 72 is provided so as to open toward the lower end portion of the wafer W accommodated in the chamber 5 and discharge the dry gas toward the lower end portion. It is preferable.

  In addition, an exhaust port 73 is formed in the lower portion of the side wall of the main body 61 of the chamber 5, and the exhaust port 73 is connected to an exhaust device (both not shown) via a predetermined pipe. The exhaust device is activated while the IPA vapor or the dry gas is supplied into the chamber 5, whereby the IPA vapor or the dry gas is exhausted from the chamber 5. Further, when the lid 62 of the chamber 5 is open, the exhaust device is activated so that the down flow of clean gas from the fan filter unit (FFU) 12 described later is exhausted through the main body 61 of the chamber 5. good.

  A shutter 10 is provided between the liquid processing unit 2 and the drying processing unit 3. The shutter 10 is accommodated in the shutter box 11 when the wafer W is moved between the liquid processing unit 2 and the drying processing unit 3 and when liquid processing is performed in the liquid processing unit 2, and therefore, the liquid processing unit. 2 and the drying processing unit 3 communicate with each other. On the other hand, when the wafer W is accommodated in the drying processing unit 3 and the drying process is performed, the shutter 10 is in close contact with the lower end of the drying processing chamber 3 through the seal member 135, and thereby the airtightness in the drying processing chamber 3 is reduced. Kept. The upper surface of the shutter 10 is inclined from both ends toward the center, and a drainage port (not shown) is formed at the center. Further, a pump (not shown) as a suction mechanism is connected to the drain port. As a result, pure water flowing down from the wafer W pulled up from the liquid processing tank 6 into the chamber 5 is discharged from the chamber 5. An aspirator may be used as the suction mechanism instead of the pump.

  Further, the substrate processing apparatus 1 is supplied with clean gas from a fan filter unit (FFU) 12 provided above, and a downflow due to the clean gas is generated. Thereby, the liquid processing unit 2 and the drying processing unit 3 are placed in a clean atmosphere.

  Furthermore, the substrate processing apparatus 1 is provided with a control unit 99 that controls each part (components and components) of the substrate processing apparatus 1. The control unit 99 includes, for example, a computer including a central processing unit (CPU) and a memory device, and can execute a computer program that causes the substrate processing apparatus 1 to perform a substrate processing method described later. This computer program is stored in the computer-readable recording medium 99a, loaded into the memory device of the control unit 99, and executed by the control unit. The computer readable recording medium 99a may be, for example, a flexible disk, an optical disk, a semiconductor memory, or the like. Further, the computer program may be loaded into the memory device of the control unit 99 not through the computer-readable recording medium 99a but through a predetermined network.

  Next, a substrate processing method according to an embodiment of the present invention performed using the above-described substrate processing apparatus 1 will be described with reference to FIGS. 2 and 3. FIG. 3 schematically shows the wafer W and the gas supply from the gas supply nozzles 71 and 72 in the main steps of the substrate processing method, and the chamber 5 and the shutter 10 are omitted.

  First, the wafer W is loaded into the chamber 5 of the drying processing unit 3 (step S21). Specifically, the lid 62 of the chamber 5 is lifted from the main body portion 61, and 50 wafers are transferred from the transfer device outside the substrate processing apparatus 1 to the holding portion 26 of the wafer guide 4 above the main body portion 61 of the chamber 5. W is delivered. The transferred wafer W is supported almost upright by the wafer support portion 26S. Next, the wafer guide 4 is lowered, the wafer W is accommodated in the main body 61, and the lid 62 is closed.

  Next, by accommodating the shutter 10 in the shutter box 11, the chamber 50 of the drying processing unit 3 is communicated with the cleaning tank 30 of the liquid processing unit 2, and the wafer guide 4 is lowered. Thereby, the wafer W is immersed in the DHF supplied and stored in the cleaning tank 30 through the DHF supply line 51 (step S22), and the front surface (and the back surface) of the wafer W is cleaned by DHF.

  After the wafer W is cleaned by DHF for a predetermined period, DIW is supplied from the processing liquid supply nozzle 35 into the cleaning tank 30 while the wafer W is placed in the cleaning tank 30, and the DHF in the cleaning tank 30 is changed. The wafer W is rinsed by replacing with DIW (step S23). At this time, DHF or DIW overflowed from the cleaning tank 30 is received by the intermediate tank 31 and discharged through the drain pipe 41 and the trap 42.

  After monitoring the DHF concentration in the cleaning tank 30 by the concentration sensor 53 and confirming that the DHF concentration has dropped below a predetermined concentration, the wafer guide 4 picks up the wafer W from the cleaning tank 30. This completes the rinsing.

When the wafer W is picked up from the cleaning tank 30 and accommodated in the chamber 5 of the drying processing unit 3 (step S24), the shutter 10 is closed and the chamber 5 is sealed. In addition, an aspirator (not shown) is activated, and pure water deposited on the shutter 10 from the wafer W is discharged from an exhaust port (not shown) provided in the center of the shutter 10. At this time, as shown in FIG. 3A, pure water remains as a liquid film on almost the entire front surface (and back surface) of the wafer W.
Next, the exhaust device (not shown) is activated to exhaust the interior of the chamber 5 through the exhaust pipe 73, and as shown in FIG. 3 (b), the IPA vapor enters the chamber 5 from the first gas supply nozzle 71. Is supplied (step S25). In the present embodiment, as described above, the IPA vapor supplied from the first gas supply nozzles 71 located on both sides of the wafer W is supplied toward the inner surface of the lid 62, hits the inner surface, joins, and then joins the wafer W. It flows toward. Thus, when the liquid film of pure water remaining on the surface of the wafer W is exposed to IPA vapor (or IPA gas), the IPA vapor dissolves in the liquid film of pure water, and the surface of the wafer W is a liquid film of an IPA aqueous solution. It will be covered with. However, since the surface tension of the IPA aqueous solution is smaller than the surface tension of pure water and cannot remain on the surface of the wafer W, it flows down the surface of the wafer W as shown in FIG. . As a result, the surface of the wafer W is not wetted with the IPA aqueous solution from above.

  As an example of the conditions in this step (S25), the flow rate of nitrogen gas supplied to the steam generator 22 (FIG. 1) is, for example, from 20 liters / minute (l / min) to 300 l / min, preferably From 70 l / min to 150 min. Further, the temperature of the nitrogen gas heated by the heater 24h may be set to a temperature sufficient to evaporate (vaporize) IPA, for example, a temperature in the range from 140 ° C to 230 ° C. Furthermore, the flow rate of IPA supplied to the steam generator 22 may be, for example, from 0.1 cc / min to 6.0 cc / min. The supply time of the IPA vapor from the first gas supply nozzle 71 may be about 60 seconds, for example.

Next, as shown in FIG. 3C, only nitrogen gas is supplied from the first gas supply nozzle 71 (step S26). This is performed by closing the open / close valves 82a and 82b of the gas pipe 23 shown in FIG. Moisture and IPA remaining on the surface of the wafer W are evaporated by this nitrogen gas, and the surface of the wafer W is dried. In this embodiment, the flow rate controller 24a and the heater 24h (FIG. 1) at this time are set to be the same as when supplying IPA vapor. Further, the supply time of nitrogen gas may be 80 seconds.
After the supply of nitrogen gas from the first gas supply nozzle 71 is stopped, nitrogen gas is supplied from the second gas supply nozzle 72 toward the lower end portion of the wafer W in step S27. At this time, at the lower end of the wafer W, as shown in FIG. 3C, there are droplets in which the IPA aqueous solution that has flowed down the surface of the wafer W remains without being dropped. However, as shown in FIG. 3 (d), it is blown off by the nitrogen gas from the second gas supply nozzle 72. In this way, as shown in FIG. 3E, the cleaned surface (including the lower end portion) of the wafer W is dried.

  Next, the supply of nitrogen gas and the exhaust of the chamber 5 are stopped (step S28), and the lid 52 of the chamber 5 is lifted from the main body 61. Then, the wafer W is unloaded from the chamber 5 in accordance with a procedure reverse to the procedure for loading the wafer W into the chamber 5 (step S29), and the processing for the wafer W is completed.

  As described above, in the substrate processing method according to the embodiment of the present invention, even if a droplet remains at the lower end portion of the wafer W when the wafer W held upright is picked up from the cleaning tank 30, the second It can be blown off by nitrogen gas from the gas supply nozzle 72. Since there is a possibility that impurities and particles remain in the droplets remaining at the lower end, the droplets may be dried and impurities, particles, and the like may remain on the wafer W. However, according to the substrate processing method according to the embodiment of the present invention, it is possible to blow off the liquid droplets, and thus it is possible to suppress impurities and particles from remaining on the wafer W.

  In addition, according to the substrate processing method using the substrate processing apparatus 1 according to the embodiment of the present invention, since the IPA vapor does not directly hit the liquid film of pure water on the wafer W, it is uniform with the IPA aqueous solution. A liquid film is formed and can flow uniformly from the upper surface of the wafer W. If the IPA vapor directly hits the liquid film, the IPA concentration in that part increases, and the liquid film in that part flows down quickly. As a result, the liquid film is divided, and there is a possibility that the liquid film above the portion becomes droplets and remains on the surface of the wafer W. However, according to the substrate processing method, since the liquid film can flow down uniformly, it is possible to suppress the droplets from remaining on the surface of the wafer W. Therefore, the surface of the cleaned wafer W can be dried without producing a watermark.

  The present invention has been described above with reference to some embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made in light of the appended claims. .

  For example, the supply of nitrogen gas from the second gas supply nozzle 72 (step S27) may be started before the supply of nitrogen gas from the first gas supply nozzle 71 (step S26) is completed. It may be performed simultaneously with the supply of nitrogen gas from the supply nozzle 71 (step S26). In this way, it is possible to blow off the droplets remaining on the lower end portion of the wafer W while drying the surface of the wafer W (excluding the lower end portion), so that the processing time can be shortened.

  Further, the supply of nitrogen gas from the second gas supply nozzle 72 (step S27) may be performed so as to overlap in time with the supply of IPA vapor from the first gas supply nozzle 71 (step S25). In particular, it is preferable to supply nitrogen gas from the second gas supply nozzle 72 toward the lower end almost simultaneously with the liquid film of the IPA aqueous solution flowing down the surface of the wafer W and the droplets remaining on the lower end of the wafer W. . After that, it is preferable to switch the gas supplied from the first gas supply nozzle 71 from IPA vapor to nitrogen gas and dry the entire surface of the wafer W.

  Further, IPA vapor as a dry gas may be supplied from the second gas supply nozzle 72. In this case, before supplying the nitrogen gas from the first gas supply nozzle 71 and drying the surface of the wafer W with the nitrogen gas (before step S26), the second gas supply nozzle 72 is applied to the lower end of the wafer W. It is preferable to supply the IPA vapor (step S27). Further, before the supply of the IPA vapor from the first gas supply nozzle 71 (step S25) is stopped, the IPA vapor is supplied from the second gas supply nozzle 72 toward the lower end portion of the wafer W (step S27). More preferred. Furthermore, when the IPA vapor supply from the first gas supply nozzle 71 (step S25) causes the liquid film of the IPA aqueous solution to flow down the surface of the wafer W and the droplets remain at the lower end of the wafer W, the second gas supply is performed. More preferably, the IPA vapor is supplied from the nozzle 72 toward the lower end. Then, after the supply of IPA vapor from the first gas supply nozzles 71 and 72 is stopped, the surface of the wafer W is further dried by supplying nitrogen gas from the first gas supply nozzle 71.

  In the above-described embodiment, the dry gas is supplied from the second gas supply nozzle 2 toward the lower end portion of the wafer W, and the liquid droplets remaining on the lower end portion of the wafer W are blown off. As long as the droplet can be dropped from the lower end, the drying gas supply method is not limited. For example, as shown in FIG. 4A, the second gas supply nozzle 72 is arranged at substantially the same height as the lower end portion of the wafer W accommodated in the chamber 5, and the horizontal direction extends from the second gas supply nozzle 72. Dry gas may be supplied. In this way, the droplet remaining on the lower end of the wafer W can be swung by the dry gas and fall from the lower end.

  Further, as shown in FIG. 4B, the dry gas may be supplied from the second gas supply nozzle 72 upward in the horizontal direction. In this case, the dry gas collides near the lower end of the wafer W, and turbulence is generated. As a result, the droplet remaining on the lower end of the wafer W can be swung and fall. Further, as shown in FIG. 4C, the dry gas may be supplied from the second gas supply nozzle 72 downward from the horizontal direction. In this case, since the dry gas hits the upper surface of the shutter 10 and flows upward, the droplet at the lower end of the wafer W can be swung from below. Thereby, a droplet can fall.

  Further, the first gas supply nozzle 71 may be configured to be rotatable about the central axis so that IPA vapor or nitrogen gas can be supplied upward (diagonally upward) and downward (diagonally downward). . According to this, the first gas supply nozzle 71 can supply the IPA vapor, the nitrogen gas for drying the surface of the wafer W, and the dry gas toward the lower end of the wafer W.

  Furthermore, in the above-described embodiment, the IPA vapor and the nitrogen gas for drying the surface of the wafer W are switched and supplied from the first gas supply nozzle 71, but the nitrogen gas for drying the surface of the wafer W is supplied. May be provided separately from the first gas supply nozzle 71.

  In the above-described embodiment, when the first gas supply nozzle 71 switches from IPA vapor to nitrogen gas for drying the surface of the wafer W, the set temperatures of the flow controller 24a and the heater 24 (FIG. 1) are set. Although it is the same, the temperature of the nitrogen gas when supplying the nitrogen gas may be changed. For example, the flow rate of nitrogen gas for drying the surface of the wafer W may be set to 350 ml / min, and the temperature may be set to 200 ° C.

  Further, the supply of nitrogen gas from the first gas supply nozzle 71 (step S26) may not be performed depending on circumstances. For example, if the surface of the wafer W can be dried as a result of increasing the temperature in the chamber 5 by supplying IPA vapor from the first gas supply nozzle 71, step S26 may be omitted.

  Further, although the four wafer support portions 26S are provided in the holding portion 26 of the wafer guide 4, at least two wafer support portions 26S may be provided. Also in this case, the two wafer support portions 26S are arranged avoiding the lower end portion of the wafer W.

  Further, it is optically detected that droplets are formed at the lower end portion of the wafer W, and based on the detection, a dry gas is supplied from the second gas supply nozzle 72 toward the lower end portion of the wafer W. May be. Such detection includes a laser light source that emits laser light toward the lower end of the wafer W held by the holding unit 26 in the chamber 5 and a light reception that receives the laser light reflected by the lower end of the wafer W. This is possible by providing the container in the main body 61 of the chamber 5. That is, since the laser light is scattered by the droplets formed on the lower end portion of the wafer W, the formation of droplets on the lower end portion of the wafer W can be detected when the amount of light received by the light receiver is reduced. Further, the reflected light may be received by irradiating the laser beam to the position above the lower end of the wafer W, that is, the position above the portion covered with the droplet. In this way, when a droplet is formed at the lower end of the wafer W, the liquid film disappears at the position above it, so that scattering by the liquid film is reduced. Therefore, it is possible to detect the formation of droplets at the lower end of the wafer W as the amount of light received by the light receiver increases. Further, a laser beam is emitted from a laser beam source so that the optical path of the laser beam is in contact with the lower end surface of the wafer W, and the laser beam is received by a light receiver. Also good. Further, instead of the laser light source, for example, a predetermined light source such as a light emitting diode or a lamp, and a predetermined optical system for converting light emitted from the light source into substantially parallel light may be used.

Further, in the above-described embodiment, the case where the wafer W is cleaned by DHF is exemplified, but only DIW can be used as the cleaning liquid. In this case, the open / close valve 51a of the DHF supply line 51 shown in FIG. 1 may be kept closed. Further, instead of the DHF supply source, another chemical supply source may be connected to the cleaning tank 30. As another chemical solution, for example, alcohol (for example, isopropyl alcohol (IPA)), SC1 (NH ₄ OH + H ₂ O ₂ + H ₂ O), SC2 (HCl + H ₂ O ₂ + H ₂ O), or the like can be used. Further, as the chemical, buffered hydrofluoric acid (BHF), or the like may be used HNO _3.

  Moreover, although the case where IPA was used as an organic solvent was demonstrated, you may use organic solvents other than IPA, for example, methanol, ethanol, etc. Since methanol is highly miscible with water and can be replaced with water, the drying performance can be further improved.

  Furthermore, the substrate is not limited to a semiconductor wafer, and may be a glass substrate for liquid crystal display, a printed wiring board, a ceramic substrate, or the like.

  DESCRIPTION OF SYMBOLS 1 ... Substrate processing apparatus, 2 ... Liquid processing part, 3 ... Drying processing part, 4 ... Wafer guide, 5 ... Chamber, 6 ... Liquid processing tank, 10 ... Shutter , 11 ... Shutter box, 13 ... Box, 20 ... Process liquid supply line, 21 ... Process gas supply pipe, 22 ... Steam generator, 23 ... Gas pipe, 24 ... Gas pipe, 26... Holding part, 26S... Wafer support part, 27 .. support part, 30 .. cleaning tank, 31. Treatment liquid supply nozzle, 36 ... Drain pipe, 51 ... DHF supply line, 52 ... DIW supply line, 61 ... Main body, 62 ... Lid, 71 ... First gas Supply nozzle, 71a ... gas discharge hole, 72 ... second gas supply nozzle, 99 ... control unit, W ... wafer.

Claims (14)

Storing the substrate in a drying chamber disposed above the cleaning tank from the cleaning tank in which the rinsing liquid is stored;
Supplying an organic solvent vapor from a first supply unit to the drying chamber in which the substrate is accommodated;
Supplying a dry gas from a second supply unit to a droplet formed on a lower end portion of the substrate as a liquid film flows down the surface of the substrate.   The substrate processing method according to claim 1, further comprising supplying an inert gas to the drying chamber.   3. The substrate processing method according to claim 1, wherein the step of supplying the inert gas is performed between a step of pouring a liquid film on a surface of the substrate and a step of supplying the dry gas.   The substrate processing method according to claim 1, wherein the dry gas is supplied downward from a horizontal direction.   5. The substrate processing method according to claim 1, wherein, in the storing step, the substrate is supported at a position avoiding a lower end portion by at least two support portions. Flushing off the liquid film on the surface of the substrate comprises evacuating the vapor of the organic solvent;
Supplying the dry gas comprises exhausting the dry gas;
The substrate processing method as described in any one of Claim 1 to 5. A cleaning tank capable of storing at least a rinsing liquid and configured to immerse a plurality of substrates in the rinsing liquid;
A drying chamber disposed above the cleaning tank and capable of accommodating the plurality of substrates;
A substrate holding and conveying unit that holds the plurality of substrates upright and is provided so as to be able to reciprocate between the cleaning tank and the drying chamber;
A first supply unit that is provided in the drying chamber and supplies vapor of the organic solvent into the drying chamber;
A second supply unit capable of supplying a dry gas to the lower end of the substrate held in the drying chamber by the substrate holding and conveying unit;
The first supply unit and the second supply so that the supply of the dry gas from the second supply unit is started after the supply of the vapor of the organic solvent from the first supply unit. A substrate processing apparatus comprising: a control unit that controls the unit.   The substrate processing apparatus according to claim 7, wherein the first supply unit can supply an inert gas by switching to the vapor of the organic solvent.   The substrate processing apparatus according to claim 7, wherein the second supply unit supplies the dry gas downward from a horizontal direction.   10. The substrate holding / conveying unit includes at least two supporting units that hold the end portions of the substrate, and the at least two supporting units are disposed so as to avoid a lower end portion of the substrate. The substrate processing apparatus according to one item.   11. The apparatus according to claim 7, further comprising an exhaust unit capable of exhausting the vapor of the organic solvent supplied from the first supply unit and the dry gas supplied from the second supply unit. 2. The substrate processing apparatus according to 1. A light source unit that emits light in a direction toward the lower end of the substrate;
A light receiving unit that receives the light from the light source unit, and
The substrate processing apparatus according to claim 7, wherein a droplet formed on a lower end portion of the substrate is detected based on an amount of received light received by the light receiving unit.   The program which makes the substrate processing apparatus as described in any one of Claims 7-12 implement the substrate processing method as described in any one of Claims 1-6.   A computer-readable storage medium storing the program according to claim 13.

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