JP5461107B2 - Substrate processing equipment - Google Patents

Description

  The present invention relates to a substrate processing apparatus, and more particularly to a substrate processing apparatus for drying a substrate.

  A substrate processing apparatus is an apparatus that supplies a processing liquid to the surface of a substrate such as a semiconductor wafer or a glass substrate and processes the surface of the substrate in a manufacturing process of a semiconductor device or a liquid crystal display device. Examples of the substrate processing apparatus include a resist stripping apparatus that strips a resist film that is no longer needed from the substrate surface, and a cleaning apparatus that cleans the substrate surface.

  Among such substrate processing apparatuses, there is a single wafer processing apparatus that processes substrates one by one. This single-wafer type substrate processing apparatus supplies a processing liquid to the vicinity of the center of the substrate surface while rotating the substrate in a horizontal plane (see, for example, Patent Document 1). Thereby, the processing liquid spreads and flows toward the peripheral edge of the substrate by the centrifugal force generated by the rotation of the substrate, and the substrate surface is processed.

  After the processing, the substrate processing apparatus stops supplying the processing liquid while maintaining the rotation of the substrate, while increasing the number of rotations of the substrate and shaking the processing liquid adhering to the substrate by centrifugal force to dry the substrate (substrate drying) processing). Note that the substrate processing apparatus is provided with a cup that receives the processing liquid scattered from the rotating substrate.

JP 2004-55916 A

  However, in the above-described substrate processing apparatus, when the rotation speed (rotation speed) of the substrate is increased for drying the substrate, airflow separation occurs on the substrate surface. Further, as the number of rotations of the substrate increases, the airflow discharged from the substrate slides on the inner surface of the cup. Airflow separation also occurs on the inner surface of the cup.

  Since the fluid has viscosity, a boundary layer is always generated near the surface of an object such as a substrate or a cup. This boundary layer not only affects the air resistance acting on the object surface, but also greatly affects the properties and performance of the airflow, such as whether airflow separation occurs. Therefore, it is necessary to perform boundary layer control in order to improve airflow performance, that is, to suppress airflow separation.

  Here, the boundary layer will be described in detail. When the fluid flows along the surface of the object, since the actual fluid has a viscosity, the flow velocity changes as the distance from the surface of the object changes. Is equal to the speed. A thin layer that is very close to the surface of the object and whose fluid velocity is changing is the boundary layer. The separation of the boundary layer from the object surface is airflow separation (boundary layer separation).

  Usually, an airflow is generated by the rotation of the substrate, and the airflow flows toward the outer periphery of the substrate. At this time, the processing liquid supplied to the substrate is also scattered. As described above, when the air resistance increases due to the airflow separation, the flow of the airflow deteriorates. Due to the deterioration of the air flow, the efficiency of discharging the processing liquid (mist) discharged from the substrate surface to the cup is deteriorated, and the processing liquid (mist) may stay on the substrate surface. For this reason, problems such as a long substrate drying time occur.

  The present invention has been made in view of the above, and an object thereof is to provide a substrate processing apparatus capable of shortening the substrate drying time.

A first feature according to an embodiment of the present invention is that, in a substrate processing apparatus, a rotation mechanism that holds and rotates a substrate and a surface that covers the surface from a position that faces and separates from the surface of the substrate are provided. And a flat plate provided with a plurality of curved concave portions randomly or regularly on the substrate side surface.

The second feature according to the embodiment of the present invention is that, in the substrate processing apparatus, a rotation mechanism that holds and rotates the substrate and a surface that covers the surface from a position that faces and separates from the surface of the substrate are provided. And a flat plate having a plurality of depressions provided on the surface on the substrate side so as to increase in density from the rotation center of the substrate toward the outer periphery .

  According to the present invention, the substrate drying time can be shortened.

1 is a schematic diagram illustrating a schematic configuration of a substrate processing apparatus according to an embodiment of the present invention. It is sectional drawing which expands and shows a part of substrate processing apparatus shown in FIG.

  An embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, a substrate processing apparatus 1 according to an embodiment of the present invention includes a processing box 2, a cup 3 provided in the processing box 2, and a cup 3 provided in the cup 3. Holding table 4 held in a horizontal state, table rotating mechanism 5 for rotating the holding table 4 in a horizontal plane, supply nozzle 6 for supplying a processing liquid to the substrate W on the holding table 4 from above, and supply thereof A nozzle moving mechanism 7 for moving the nozzle 6 along the surface to be processed which is the surface of the substrate W, a flat plate 8 facing the substrate W on the holding table 4, and the flat plate 8 in the Z-axis direction which is the vertical direction (see FIG. 1), a liquid supply unit 10 that supplies the processing liquid to the supply nozzle 6, a gas supply unit 11 that supplies gas to the supply nozzle 6, and a control unit 12 that controls each unit. I have.

  The processing box 2 is a processing chamber that accommodates the cup 3, the holding table 4, and the like. At the top of the processing box 2, a fan 2a with a filter for downflow is provided. The fan 2 a is electrically connected to the control unit 12, and its driving is controlled by the control unit 12.

  The cup 3 is formed in a cylindrical shape, and encloses the holding table 4 from the periphery and accommodates it inside. The upper part of the peripheral wall of the cup 3 is inclined toward the inner side in the radial direction, and is opened so that the substrate W on the holding table 4 is exposed. The cup 3 receives the processing liquid scattered from the rotating substrate W. A discharge pipe (not shown) for discharging the received processing liquid is provided at the bottom of the cup 3.

  As shown in FIG. 2, the cup 3 has a plurality of depressions 3a over the entire inner surface M1. This depression 3a is usually called a dimple. The recess 3a is a curved recess, and is provided randomly or regularly to generate turbulent flow. These indentations 3a make the boundary layer turbulent, and air flow separation at the inner surface M1 of the cup 3 is suppressed, and the air resistance of the inner surface M1 is reduced.

  Returning to FIG. 1, the holding table 4 is provided on the upper side of the cup 3 so as to be rotatable in a horizontal plane. The holding table 4 detachably holds a substrate W such as a wafer or a glass substrate by a clamping member 4a such as a chuck pin. Here, the upper surface (in FIG. 1) of the substrate W is the surface to be processed, and the lower surface (in FIG. 1) is the back surface.

  The table rotating mechanism 5 includes a rotating shaft 5a connected to the holding table 4 and a motor 5b serving as a drive source for rotating the rotating shaft 5a. The motor 5 b is provided outside the processing box 2 and is electrically connected to the control unit 12, and its driving is controlled by the control unit 12. The table rotating mechanism 5 rotates the rotating shaft 5a in the R direction (in FIG. 1) by the motor 5b. The table rotating mechanism 5 and the holding table 4 described above constitute a rotating mechanism that holds and rotates the substrate W.

  The supply nozzle 6 is movably disposed above the holding table 4 and supplies the processing liquid to the surface to be processed of the substrate W on the holding table 4. For example, the supply nozzle 6 is a two-fluid nozzle that uses two fluids. The supply nozzle 6 includes an inner cylinder serving as a central flow path to which a processing liquid is supplied as a first fluid, an outer cylinder serving as a ring-shaped flow path that accommodates the inner cylinder and is supplied with gas as a second fluid, and the like. The treatment liquid is formed into droplets (atomized) from the nozzle holes of the inner cylinder and ejected by the gas discharged from the nozzle holes of the outer cylinder. The supply nozzle 6 is a two-fluid nozzle that uses two fluids, but is not limited to this. For example, a one-fluid nozzle that supplies only liquid may be used.

  The nozzle moving mechanism 7 includes an arm 7a that supports the supply nozzle 6, a rotating shaft 7b that is connected to the arm 7a, and a motor 7c that is a driving source for rotating the rotating shaft 7b. The motor 7 c is provided outside the processing box 2 and is electrically connected to the control unit 12, and its driving is controlled by the control unit 12. The nozzle moving mechanism 7 rotates the rotating shaft 7b by the motor 7c, and causes the supply nozzle 6 to move along the surface to be processed of the substrate W in the X-axis direction (in FIG. 1) that is the radial direction of the substrate W via the arm 7a. Move. The nozzle moving mechanism 7 also has a mechanism for moving the supply nozzle 6 in the Z-axis direction (in FIG. 1) which is the vertical direction.

  The flat plate 8 is provided so as to be substantially parallel to the surface to be processed of the substrate W on the holding table 4, and is formed to be movable in the Z-axis direction (in FIG. 1). The flat plate 8 prevents the processing liquid from scattering from the rotating substrate W when the substrate W is dried. The gap (separation distance) between the flat plate 8 and the surface to be processed of the substrate W on the holding table 4 is set to, for example, about several tens mm to 1 cm in consideration of drying of the substrate W and prevention of scattering of the processing liquid. ing.

  As shown in FIG. 2, the flat plate 8 has a plurality of depressions 8a over the entire inner surface M2, which is the surface on the holding table 4 side. This depression 8a is usually called a dimple. The recess 8a is a curved recess, and is provided randomly or regularly to generate turbulent flow. A turbulent flow is generated by these depressions 8a, and the air resistance between the substrate W on the holding table and the flat plate 8 which is separated from and faces the substrate W is reduced.

  More specifically, the surface to be processed (surface) of the substrate W on the holding table 4 is wet with the processing liquid. Therefore, in order to efficiently discharge the cleaning liquid on the surface to be processed of the substrate W, it is effective to increase the airflow velocity above the substrate W. First, by disposing the flat plate 8 so as to face the substrate W at a narrow interval, the space volume between them becomes small, so that the flow velocity of the discharged gas can be increased. Furthermore, air resistance can be reduced by devising the surface shape of the flat plate 8. That is, by providing each recess 8a over the entire inner surface M2 of the flat plate 8, turbulence is generated on the inner surface M2 side of the flat plate 8, and the air resistance passing through the surface of the flat plate 8 can be reduced. As a result, airflow separation does not occur, and the airflow flowing between the substrate W and the flat plate 8 can be accelerated. As a result, the mist-like processing liquid is quickly discharged from between the substrate W and the flat plate 8. The drying time can be shortened.

  Returning to FIG. 1, the flat plate moving mechanism 9 includes an arm 9a that supports the flat plate 8, a support 9b that supports the arm 9a so as to be movable in the Z-axis direction (in FIG. 1), and an arm 9a along the support 9b. And a motor 9c serving as a drive source for moving the motor. The motor 9 c is provided outside the processing box 2 and is electrically connected to the control unit 12, and its driving is controlled by the control unit 12. The flat plate moving mechanism 9 moves the arm 9a in the Z-axis direction (in FIG. 1) by the motor 9c, and moves the flat plate 8 in the Z-axis direction via the arm 9a.

  The liquid supply unit 10 is connected to the supply nozzle 6 via a pipe 10 a serving as a liquid supply flow path and a valve 10 b provided in the middle of the flow path of the pipe 10 a, and supplies liquid to the supply nozzle 6. . The valve 10 b is electrically connected to the control unit 12, and its driving is controlled by the control unit 12. Here, when the process for the substrate W is a resist stripping process for removing the resist film, a resist stripping solution such as sulfuric acid is supplied to the supply nozzle 6 as a liquid, and the process is a cleaning process for removing particles. In this case, a cleaning liquid such as pure water is supplied to the supply nozzle 6 as a liquid.

  The gas supply unit 11 is connected to the supply nozzle 6 via a pipe 11 a serving as a gas supply flow path and a valve 11 b provided in the flow path of the pipe 11 a, and supplies gas to the supply nozzle 6. . The valve 11 b is electrically connected to the control unit 12, and its driving is controlled by the control unit 12. Here, when the process for the substrate W is a resist stripping process for removing the resist film, a gas such as ozone gas, nitrogen gas, air, or the like is supplied as a gas to the supply nozzle 6, and the process removes particles. In the case of processing, an inert gas such as nitrogen gas is supplied to the supply nozzle 6 as a gas.

  The control unit 12 includes a microcomputer that centrally controls each unit and a storage unit that stores substrate processing information and various programs related to substrate processing. Based on the substrate processing information and various programs, the control unit 12 moves the supply nozzle 6 in the X-axis direction by the nozzle moving mechanism 7 to be positioned near the center of the substrate W, and in that state, the holding table is moved by the table rotating mechanism 5. The substrate processing for supplying the processing liquid onto the processing surface of the rotating substrate W is performed by the supply nozzle 6 while rotating 4.

  Thereafter, the control unit 12 stops the supply of the processing liquid while maintaining the rotation of the substrate W, and moves the supply nozzle 6 in the X-axis direction by the nozzle moving mechanism 7 so as to retract from the substrate W. On the other hand, the control unit 12 moves the flat plate 8 from the uppermost standby position to the dry position (position in FIG. 1) of the predetermined gap by the flat plate moving mechanism 9, and further increases the rotation speed of the substrate W. The processing liquid adhering to W is spun off by centrifugal force to perform the spin dry process (substrate drying process) for drying the substrate W. The standby position is a position that does not prevent the supply nozzle 6 from supplying the processing liquid to the processing surface of the substrate W on the holding table 4, and the drying position is a processing surface and a flat plate of the substrate W on the holding table 4. 8 is a position at which the gap with 8 becomes a predetermined value of, for example, several tens of mm to 1 cm.

  During the spin dry process described above, the boundary layer becomes a turbulent flow due to the respective depressions 8a on the inner surface M2 of the flat plate 8, so that air flow separation on the inner surface M2 of the flat plate 8 is suppressed. As a result, the air resistance between the substrate W on the holding table 4 and the flat plate 8 that is spaced apart and opposed to the substrate W is reduced, so that airflow separation on the surface of the substrate W is also suppressed. That is, in the space between the substrate W on the holding table 4 and the flat plate 8 that is separated and opposed to the substrate W, a turbulent flow is actively generated on the flat plate 8 side by each recess 8a, and the air resistance of the space Since the airflow does not occur and the airflow flowing between the substrate W and the flat plate 8 can be accelerated, the mist-like processing liquid is quickly discharged from between the substrate W and the flat plate 8. The drying time of the substrate W can be shortened. Therefore, as compared with the case where the air flow separation phenomenon occurs, it is possible to realize a high-speed drying and low damage treatment, and it is possible to suppress the air flow separation phenomenon with a simple structure.

  Further, the airflow (exhaust airflow) discharged from the substrate W along with the high-speed rotation of the substrate W slides on the inner surface M1 of the cup 3. At this time, since the boundary layer becomes a turbulent flow by the respective recesses 3a of the inner surface M1 of the cup 3, airflow separation on the inner surface M1 of the cup 3 is suppressed, and the air resistance of the inner surface M1 of the cup 3 is reduced. That is, by generating a turbulent flow positively by each recess 3a, it is possible to suppress air flow separation on the inner surface M1 of the cup 3, and the air resistance of the inner surface M1 of the cup 3 can be reduced. Accordingly, since the exhaust airflow efficiently flows and the discharge efficiency is improved, the drying time of the substrate W can be shortened, and further, mist scattering above the cup 3 can be prevented. As a result, it is possible to increase the number of rotations of the substrate W to realize further speeding up of drying, and in addition, it is possible to suppress the phenomenon of airflow separation with a simple structure.

  When such a depression 3a does not exist, the airflow near the upper portion of the inner surface M1 of the cup 3 has an extremely low flow velocity, which causes airflow separation. Further, if the air resistance of the inner surface M <b> 1 of the cup 3 is large, the discharge efficiency is lowered, and ascending airflow is generated as mist on the upper portion of the cup 3. When this adheres again to the substrate W, recontamination of the substrate occurs. This recontamination is also prevented by providing the recess 3a on the inner surface M1 of the cup 3.

  As described above, according to the embodiment of the present invention, by providing the plurality of recesses 8a on the inner surface M2 of the flat plate 8, the boundary layer is positively turbulent by the recesses 8a and Since the air resistance between the substrate W and the flat plate 8 that is spaced apart and opposed to the substrate W is reduced, airflow separation does not occur, and the airflow flowing between the substrate W and the flat plate 8 can be accelerated. As a result, since the mist-like processing liquid is quickly discharged from between the substrate W and the flat plate 8, the drying time of the substrate W can be shortened. In addition, the drying time of the substrate W can be shortened with a simple structure.

  In addition, by providing a plurality of indentations 3a on the inner surface M1 of the cup 3, the boundary layer is positively turbulent by the indentations 3a, and air flow separation on the inner surface M1 of the cup 3 is suppressed to prevent the inner surface M1 of the cup 3. Since the mist-like processing liquid is quickly discharged and the discharge efficiency is improved, the drying time of the substrate W can be shortened. Furthermore, the generation of ascending air current can be suppressed and re-contamination of the substrate W can be prevented. In addition, the drying time of the substrate W can be shortened with a simple structure.

  Here, since the circumferential velocity increases from the center of the flat plate 8 toward the outer periphery, the flow velocity of the airflow also increases, so that the density of each recess 8a increases from the center of the inner surface M2 of the flat plate 8 toward the outer periphery. It may be provided. In this case, since each recess 8a is provided according to the flow velocity of the airflow, airflow separation on the inner surface M2 of the flat plate 8, and consequently, airflow separation on the surface of the substrate W can be reliably suppressed, and as a result, The drying time of the substrate W can be reliably shortened.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, some components may be deleted from all the components shown in the above-described embodiment. Furthermore, you may combine the component covering different embodiment suitably. Moreover, in the above-mentioned embodiment, although various numerical values are mentioned, those numerical values are illustrations and are not limited.

DESCRIPTION OF SYMBOLS 1 Substrate processing apparatus 3 Cup 3a Depression 4 Holding table 5 Table rotation mechanism 8 Flat plate 8a Depression M1 Inner surface (surface)
M2 inner surface (surface)
W substrate

Claims (3)

A rotation mechanism for holding and rotating the substrate;
A flat plate provided so as to cover the surface from a position facing and spaced from the surface of the substrate, and a plurality of curved concave portions are provided randomly or regularly on the surface of the substrate;
A substrate processing apparatus comprising: A rotation mechanism for holding and rotating the substrate;
The substrate is provided so as to cover the surface from a position facing and spaced from the surface of the substrate.
A flat plate having a plurality of depressions provided on the surface on the side so that the density increases from the rotation center of the substrate toward the outer periphery ;
A substrate processing apparatus comprising: The substrate processing apparatus according to claim 1, further comprising a cup that is provided so as to surround the substrate from the periphery and has a plurality of depressions on a surface on the substrate side.

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