BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic sectional view illustrating one example of construction of a substrate processing apparatus for use in carrying out a substrate processing method according to the present invention.
FIG. 2 is a schematic plan view of the substrate processing apparatus illustrated in FIG. 1.
FIG. 3 shows one example for carrying out the substrate processing method according to the invention, and is a chart of indicating the rotation speed of a substrate in each position of a discharge nozzle with respect to the surface of the substrate.
FIGS. 4 are views illustrating results of comparison between the state of liquid splash when making scan rinse by the substrate processing method according to the invention, and the state of liquid splash when making scan rinse by the conventional method.
FIG. 5 is a schematic sectional view illustrating another construction example of a substrate processing apparatus for use in carrying out a substrate processing method according to this invention.
FIG. 6 is a schematic sectional view illustrating a further construction example of a substrate processing apparatus for use in carrying out a substrate processing method according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Hereinafter, the best mode for carrying out the present invention is described referring to the drawings.
FIGS. 1 and 2 illustrates one example of construction of a substrate processing apparatus for use in carrying out a substrate processing method according to the invention, and in which FIG. 1 is a schematic sectional view of a substrate processing apparatus and FIG. 2 is a schematic plan view thereof.
This substrate processing apparatus makes a cleaning treatment (rinse treatment) after a substrate, on which surface a resist film having been exposed is formed, has been processed. The substrate processing apparatus is provided with a spin chuck 10 holding a substrate W in a horizontal posture, a rotary shaft 12 to which upper end portion the spin chuck 10 is fixed and which is supported in a vertical direction, and a rotation motor 14 of which rotary shaft is connected to the rotary shaft 12 and which causes the spin chuck 10 and the rotary shaft 12 to rotate about the vertical shaft. A cup 16 is disposed around the spin chuck 10 so as to surround a substrate W on the spin chuck 10. The cup 16 is supported in a reciprocally movable manner in a vertical direction, and has a drainage tube 18 connected in communication to the bottom of the cup 16. Further, although illustration thereof is omitted in FIGS. 1 and 2, there is provided a mechanism of feeding a developer onto a substrate W, for example, a developer feeding mechanism including a developer discharge nozzle in lower end of which a slit-like outlet is formed, and while a developer is being discharged from this slit-like outlet, causing this developer discharge nozzle to linearly move in the horizontal direction orthogonal to this slit-like outlet to feed the developer onto the substrate W to be evenly spread thereon; or a developer feeding mechanism including a developer discharge nozzle formed of a straight nozzle, supporting this developer discharge nozzle so as to reciprocate between the discharge position where the outlet at the leading end is located right over the center of the substrate W and the stand-by position, and discharging a developer from the leading end outlet of the developer discharge nozzle over the center of the substrate W.
Furthermore, in the side vicinity of the cup 16, there is provided a DI water discharge nozzle 20 for discharging a cleaning solution (rinse), for example, DI water from an outlet at the leading edge. The DI water discharge nozzle 20 is connected to channel to a DI water supply source through a DI water feed tube 22. A pump 24, a filter 26, and an opening/closing control valve 28 are interposed in the DI water feed tube 28. The DI water discharge nozzle 20 is held by a nozzle-holding portion 30 so as to be pivotable in the horizontal plane, and is pivoted in the horizontal plane by a pivotal driving mechanism not illustrated. In addition, the DI water discharge nozzle 20 is arranged such that while DI water is being discharged onto the surface of the substrate W from the outlet at the leading end, as indicated by the arrow a in FIG. 2, the outlet is scanned from the position opposed to the center of the substrate W to the position opposed to the circumferential edge of the substrate W, and further such that the outlet is reciprocated between the stand-by position of being spaced apart outward from the cup 16 as indicated by the two-dot-chain lines, and the position of the outlet being located right over the center of the substrate W.
Further, this substrate processing apparatus is provided with a controller 34 for controlling a driver 32 of the rotation motor 14 to adjust the number of revolutions of the rotation motor 14, being thus the rotation speed of the substrate W. With this controller 34, the number of revolutions of the rotation motor 14 is controlled so that the rotation speed of the substrate W is decreased in the process that the outlet of the DI water discharge nozzle 20 is scanned from the position opposed to the center of the substrate W to the position opposed to the circumferential edge of the substrate W. More specifically, as indicated by the solid line A, at a time point at which the outlet of the DI water discharge nozzle 20 is moved by a predetermined distance from the center of the substrate W (at a time point of reaching a radial position of 60 mm spaced apart from the center of the substrate W in the illustrated example), the substrate W is controlled so as to decrease in rotation speed of the substrate (to reduce in speed from the number of revolutions being in the range of 1800 rpm to 2100 rpm to the number of revolutions being in the range of 1000 rpm to 1200 rpm). It is preferable that the timing of switching the rotation speed of the substrate W is controlled with a microcomputer on the basis of an operating program. Alternatively, it is preferable that the position of the DI water discharge nozzle 20 is detected with an encoder, and the rotation speed of the substrate W is switched with signals detected from this encoder; that the rotation speed of the substrate W is switched at a time point when a predetermined time period has passed since the time point of scanning of the DI water discharge nozzle 20 being started; or that the rotation speed of the substrate W is switched at a time point when the number of rotations of the substrate W has reached a predetermined number of rotations. Furthermore, the number of times of the rotation speed of the substrate W being changed is not limited to once as shown in FIG. 3, but the rotation speed of the substrate W may be decreased stepwise. Alternatively, as the outlet of the DI water discharge nozzle 20 is traveled from the position opposed to the center of the substrate W to the position opposed to the circumferential edge of the substrate W, the rotation speed of the substrate W may be controlled so as to decrease by degrees, for example, decrease linearly.
With the use of a substrate processing apparatus illustrated in FIGS. 1 and 2, a developer is fed onto a resist film having been exposed and formed on the surface of a substrate W, to make processing of the resist film; thereafter DI water is fed onto the substrate W while the substrate W being rotated at a comparatively low speed to make the cleaning treatment; the developer is washed out to be removed from the resist film on the surface of the substrate W; and subsequently the substrate W is brought in rotation at a comparatively high speed to make the spin drying (scan rinse). In making the scan rinse, the substrate W is rotated at a comparatively high speed, for example, at a rotation speed within the range of 1800 rpm to 2100 rpm, as well as the DI water discharge nozzle 20 is scanned while DI water is being discharged onto the substrate W from the outlet of the DI water discharge nozzle 20. On that occasion, in the process that the outlet of the DI water discharge nozzle 20 is traveled from the position opposed to the center of the substrate W to the position opposed to the circumferential edge of the substrate W, at a time point when the outlet of the DI water discharge nozzle 20 has reached a predetermined position, for example, the radial position of 60 mm spaced apart from the center of the substrate W, the rotation speed of the substrate W is switched to reduce to the rotation speed in the range of, for example, 1000 rpm to 1200 rpm. When the outlet of the DI water discharge nozzle 20 has reached the position opposed to the circumferential edge of the substrate W, feeding of DI water onto the substrate W from the DI water discharge nozzle 20 is stopped, and the DI water discharge nozzle 20 is made to move to the stand-by position. Then, when the drying of the substrate W has completed, the rotation of the substrate W is stopped.
Illustrated in FIG. 4 are results of comparison between the state of liquid splash when making scan rinse in the above-mentioned method (indicated by the solid line in FIG. 3), and the state of liquid splash when making scan rinse without change in the rotation speed of the substrate W as in the conventional method. The surface state of the substrate W when making scan rinse with the substrate W kept in rotation speed of 2500 rpm as indicated by the broken line B in FIG. 3 is illustrated in FIG. 4(b), and the surface state of the substrate W when making scan rinse with the substrate W kept in rotation speed of 1800 rpm to 2100 rpm as indicated by the broken line C in FIG. 3 is illustrated in FIG. 4(c). As illustrated, the state of liquid splash is improved by decreasing the rotation speed of the substrate. When making scan rinse in the method according to this invention, as illustrated in FIG. 4(a), as compared with the case of making scan rinse with the substrate kept in rotation speed of 1800 rpm to 2100 rpm, the liquid splash of DI water at the circumferential edge portion of the substrate W is suppressed further, and thus liquid droplets due to liquid splash are found to be prevented from being splashed to the surface on the center side from the substrate W to adhere.
Now, FIG. 5 is a schematic sectional view illustrating another construction example of a substrate processing apparatus for use in carrying out the substrate processing method according to the invention.
This substrate processing apparatus is provided with a bypass tube 36 branched off on the way from the DI water feed tube 22. This bypass tube 36 is constructed in channel so as to meet the DI water feed tube 22 again. There is provided an electromagnetic three-way valve 38 at the branch position between the DI water feed tube 22 and the bypass tube 36. There is interposed in the bypass tube 36 a flow regulating valve 40 for decreasing the flow of DI water to be fed to the DI water discharge nozzle 20. Furthermore, this substrate processing apparatus is provided with a controller 42 acting to control switching operation of the electromagnetic three-way valve 38.
To carry out scan rinse with the use of the substrate processing apparatus illustrated in FIG. 5, a substrate W is rotated at a constant speed of comparatively high speed, for example, at a rotation speed of 1800 rpm to 2100 rpm; DI water is fed to the DI water discharge nozzle 20 through the DI water feed tube 22; and the DI water discharge nozzle 20 is scanned while DI water is being discharged onto the substrate W from the outlet of the DI water discharge nozzle 20. On that occasion, in the process that the outlet of the DI water discharge nozzle 20 is traveled from the position opposed to the center of the substrate W to the position opposed to the circumferential edge of the substrate W, at a time point when the outlet of the DI water discharge nozzle 20 has reached a predetermined position, for example, the radial position of 60 mm spaced apart from the center of the substrate W, the electromagnetic three-way valve 38 is switched in response to a control signal from the controller 42, and thus the DI water is arranged to feed the DI water discharge nozzle 20 through the bypass tube 36 via the flow regulating valve 40. Accordingly, in the vicinity of the circumferential edge of the substrate W, the discharge flow of DI water to be discharged onto the surface of the substrate W from the outlet of the discharge nozzle 20 is decreased as compared with that in the vicinity of the center of the substrate W. As a result, the liquid splash of DI water at the circumferential edge portion of the substrate W is suppressed, and thus liquid droplets due to liquid splash will be prevented from being splashed to the surface on the center side from the substrate W to adhere.
Furthermore, in the apparatus construction illustrated in FIG. 5, the discharge flow of DI water from the discharge nozzle 20 is decreased only once. However, it is preferable to be in such an apparatus construction that the discharge flow of DI water from the discharge nozzle 20 can be decreased stepwise in the process of the outlet of the DI water discharge nozzle 20 traveling from the position opposed to the center of the substrate W to the position opposed to the circumferential edge of the substrate W; or it is preferable to be in such an apparatus construction that the discharge flow of DI water from the discharge nozzle 20 is decreased by degrees as the outlet of the DI water discharge nozzle 20 is traveled from the position opposed to the center of the substrate W to the position opposed to the circumferential edge of the substrate W.
In addition, FIG. 6 is a schematic sectional view illustrating a further construction example of the substrate processing apparatus for use in carrying out the substrate processing method according to this invention.
This substrate processing apparatus, as is the apparatus illustrated in FIG. 5, is provided with a bypass tube 44 branched off on the way from the DI water feed tube 22 to meet the DI water feed tube 22 again. There is provided an electromagnetic three-way valve 46 at the branch position between the DI water feed tube 22 and the bypass tube 44. Further, there is interposed in the bypass tube 44 a pressure-reducing valve 48 for reducing the feed pressure of DI water to the DI water discharge nozzle 20. Furthermore, this apparatus is provided with a controller 50 acting to control switching operation of the electromagnetic three-way valve 46.
To carry out scan rinse with the use of the substrate processing apparatus illustrated in FIG. 6, a substrate W is rotated at a constant speed of comparatively high speed, for example, at a rotation speed of 1800 rpm to 2100 rpm; DI water is fed to the DI water discharge nozzle 20 through the DI water feed tube 22; and the DI water discharge nozzle 20 is scanned while the DI water is being discharged onto the substrate W from the outlet of the DI water discharge nozzle 20. On that occasion, in the process that the outlet of the DI water discharge nozzle 20 is traveled from the position opposed to the center of the substrate W to the position opposed to the circumferential edge of the substrate W, at a time point when the outlet of the DI water discharge nozzle 20 has reached a predetermined position, for example, the radial position of 60 mm spaced apart from the center of the substrate W, the electromagnetic three-way valve 46 is switched in response to a control signal from the controller 50, and thus the DI water is arranged to feed the DI water discharge nozzle 20 through the bypass tube 44 via the pressure-reducing valve 40. Accordingly, in the vicinity of the circumferential edge of the substrate W, the discharge pressure of DI water to be discharged onto the surface of the substrate W from the outlet of the discharge nozzle 20 is decreased as compared with that in the vicinity of the center of the substrate W. As a result, as is the apparatus illustrated in FIG. 5, the liquid splash of DI water at the circumferential edge portion of the substrate W is suppressed, and thus liquid droplets due to liquid splash will be prevented from being splashed to the surface on the center side from the substrate W to adhere.
Furthermore, in the apparatus construction illustrated in FIG. 6, the discharge pressure of DI water from the discharge nozzle 20 is decreased only once. However, it is preferable to be in such an apparatus construction that the discharge pressure of DI water from the discharge nozzle 20 can be decreased stepwise in the process of the outlet of the DI water discharge nozzle 20 traveling from the position opposed to the center of the substrate W to the position opposed to the circumferential edge of the substrate W; or it is preferable to be in such an apparatus construction that the discharge pressure of DI water from the discharge nozzle 20 is decreased by degrees as the outlet of the DI water discharge nozzle 20 is traveled from the position opposed to the center of the substrate W to the position opposed to the circumferential edge of the substrate W.
While the presently preferred embodiments of the present invention have been shown and described, it is to be understood that these disclosures are for the purpose of illustration and that various changes and modifications may be made without departing from the scope of the invention as set forth in the appended claims.
Patent Application
20070267047
