JP2009295910A - Substrate processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate processing method which can satisfactorily process a substrate surface while suppressing the usage of a rinsing solution. <P>SOLUTION: The rinsing solution is supplied to a substrate surface Wf at a first flow rate (2 (L/min)) to perform an initial rinsing process, and then the rinsing solution is supplied to the substrate surface Wf at a second flow rate (1.5 (L/min)) lower than the first flow rate to perform an intermediate rinsing process, so that the usage of the rinsing solution can be suppressed. Further, a liquid film of the rinsing solution is formed over the substrate surface Wf by using the rinsing solution at a high flow rate before the flow rate of the rinsing solution is reduced, so that the rinsing solution can spread over the substrate surface Wf for covering the entire substrate surface Wf even in the intermediate rinsing process in which the flow rate of the rinsing solution is reduced. Thus it is possible to prevent partial exposure of the substrate surface Wf and satisfactorily perform rinsing on the substrate surface Wf. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a substrate processing method for supplying a rinsing liquid onto a surface of a substrate to rinse the substrate surface. The substrates to be processed include semiconductor wafers, glass substrates for photomasks, glass substrates for liquid crystal displays, glass substrates for plasma displays, FED (Field Emission Display) substrates, optical disk substrates, and magnetic disks. And a magneto-optical disk substrate.

  The manufacturing process of an electronic component such as a semiconductor device or a liquid crystal display device includes a step of repeatedly forming a fine pattern by repeatedly performing processes such as film formation and etching on the surface of the substrate. Here, in order to perform fine processing well, it is necessary to keep the substrate surface clean. Therefore, a substrate cleaning process is performed as necessary (see Patent Documents 1 to 3). For example, in the inventions described in Patent Documents 1 and 2, after a substrate such as a semiconductor wafer is held substantially horizontally on a spin chuck, the spin chuck is rotated and a hydrofluoric acid solution is applied to the surface of the substrate held by the spin chuck. Etc. to remove foreign substances on the surface of the substrate. Thereafter, the supply of the treatment liquid is stopped, and the treatment liquid on the substrate surface is washed away by supplying a rinse liquid such as pure water or DIW (deionized water) to the substrate surface (rinsing step). In addition, after the rinsing step, the rotation speed of the spin chuck is reduced while the rinsing liquid is supplied. As a result, relatively large droplets are formed on the substrate surface (droplet growth step). Thereafter, the supply of the rinsing liquid is stopped, and the rotational speed of the spin chuck is accelerated, thereby removing the droplets from the substrate surface. Subsequent to the droplet removing step, the spin chuck is further accelerated in the rotational speed to execute spin drying. Further, in the invention described in Patent Document 3, a cleaning process using water is performed. During the cleaning process, rinse is supplied to an object to be cleaned such as a wafer to form a rinse water film. After completion, the rinse is sprayed onto the surface of the object to remove the particles from the surface of the object.

JP-A-11-288915 (FIGS. 1 and 2) Japanese Patent Laid-Open No. 2002-261064 (FIGS. 1 and 3) JP 2000-164551A (FIG. 1)

  In the prior art described above, no special consideration has been given to the flow rate of the rinse liquid supplied after the cleaning step. In particular, when the substrate surface becomes a hydrophobic surface by removing the foreign matter on the substrate surface by supplying the treatment liquid, the substrate is rinsed against a so-called hydrophobic substrate in which the contact angle of the substrate surface with the rinse liquid exceeds 50 °. When processing, etc., there were the following problems.

  When the substrate surface is hydrophobic, it is necessary to supply a relatively large flow of rinsing liquid to the substrate surface. For example, by supplying DIW at a flow rate of 2 (L / min) to the substrate from which the oxide film on the substrate surface has been removed with a hydrofluoric acid solution, particles are prevented from remaining on the substrate surface. Therefore, since a relatively large flow rate of rinsing liquid is disposable to clean the surface of the substrate satisfactorily, it is not preferable from the viewpoint of CoO (Cost of Ownership) and environmental load. On the other hand, if the flow rate of the rinsing liquid is simply reduced, particles remain on the substrate surface, which causes a problem that the substrate surface cannot be cleaned well.

  This invention is made in view of the said subject, and it aims at providing the substrate processing method which can process a substrate surface satisfactorily, suppressing the usage-amount of a rinse liquid.

  In order to achieve the above object, the present invention provides an initial rinsing step of supplying a rinsing liquid to the substrate surface at a first flow rate while rotating the substrate having a surface treated with the treatment liquid, and rotating the substrate after the initial rinsing step. However, an intermediate rinsing step for supplying the rinsing liquid to the substrate surface at a second flow rate lower than the first flow rate, and a rinsing liquid to the substrate surface at a third flow rate larger than the second flow rate after the intermediate rinsing step are performed on the substrate surface. And a liquid removal step of stopping the supply of the rinse liquid after the liquid filling step and rotating the substrate to remove the rinse liquid on the surface of the substrate. It is said.

  In the invention configured as described above, the rinsing process with the rinsing liquid is performed on the surface of the substrate processed with the processing liquid. The rinsing process is performed in two stages, an initial rinsing process and an intermediate rinsing process. Yes. That is, after the substrate is rotated, the rinsing liquid is supplied to the surface of the substrate at the first flow rate and the initial rinsing process is performed, and then the rinsing liquid is supplied to the substrate surface at the second flow rate lower than the first flow rate. The process is executed. As described above, in order to rinse and remove the processing liquid from the substrate surface, the processing liquid on the substrate surface is first washed away by the rinsing liquid having a large flow rate (first flow rate) and then the rinsing liquid having a low flow rate (second flow rate). Since the rinse treatment is finished, the amount of rinse solution used can be reduced. In addition, since the rinsing liquid film is formed on the substrate surface at a large flow rate before the rinsing liquid flow rate is reduced, the above-described liquid may be obtained even if the rinsing liquid flow rate supplied to the substrate surface is reduced. It spreads over the entire surface of the substrate in such a way as to be dragged by the flow of the film and covers the entire surface of the substrate. For this reason, although the flow rate is low, the entire surface of the substrate is covered with a rinsing liquid to prevent partial exposure of the surface of the substrate, so that the rinsing process can be favorably performed on the surface of the substrate.

  Further, in the present invention, after rinsing liquid is deposited on the substrate surface after the rinsing process, the substrate is rotated to remove the rinsing liquid on the substrate surface. The flow rate of the rinsing liquid in this liquid filling process is the intermediate rinsing process. The flow rate (third flow rate) is larger than the flow rate of the rinse liquid (second flow rate). As described above, the flow rate of the rinse liquid is set to a low flow rate before the liquid filling step, but in the present invention, the flow rate of the rinse liquid is increased in the liquid filling step instead of supplying the low flow rinse liquid as it is. Therefore, the time required for the liquid accumulation process can be shortened as compared with the case where the liquid accumulation process is performed with a low flow rate. Further, since the flow rate of the rinsing liquid in the liquid filling process is increased, it is possible to reliably prevent the rinsing liquid from spreading over the entire substrate surface and exposing a part of the substrate surface.

  Here, the initial rinsing step is a step of replacing the entire substrate surface with the rinsing liquid, that is, the timing of switching from the initial rinsing step to the intermediate rinsing step is, for example, the time when the entire substrate surface is replaced with the rinsing liquid. it can. Also, with respect to the rotation speed of the substrate, the rotation speed of the substrate in the intermediate rinsing process may be equal to or lower than the rotation speed of the substrate in the initial rinsing process, and mist generation can be prevented by reducing the rotation speed.

  Further, the rotation speed of the substrate in each process can be set as appropriate according to the processing content in each process, but the rotation speed of the substrate in the initial rinsing process is particularly suitable for the intermediate rinsing process, the liquid filling process, and the liquid It is preferable to set so as to be higher than the rotation speed of the substrate in the removing step. For example, even when the substrate surface becomes a hydrophobic surface due to the treatment with the treatment liquid, the substrate can be reliably spread over the entire substrate surface by increasing the rotation speed of the substrate and increasing the flow rate of the rinse liquid in the initial rinsing process. It is possible to prevent a part of the surface from being exposed. This provides excellent process performance.

  In addition, it is desirable to perform the initial rinse process, the intermediate rinse process, and the liquid filling process continuously, and the flow rate of the rinse liquid while the supply of the rinse liquid to the substrate surface is continued from the initial rinse process to the liquid filling process. May be changed. By doing so, the rinsing liquid supplied to the substrate surface during the period from the initial rinsing process to the liquid filling process spreads over the entire substrate surface in the form of being dragged by the flow of the liquid film already formed on the substrate surface. Cover the whole. For this reason, it is possible to satisfactorily perform the rinsing process on the substrate surface by covering the entire substrate surface with the rinse liquid to prevent partial exposure of the substrate surface.

  According to this invention, the rinsing process includes an initial rinsing step of supplying a rinsing liquid to the substrate surface at a first flow rate, and an intermediate rinsing step of supplying a rinsing liquid to the substrate surface at a second flow rate lower than the first flow rate. Since the steps are executed in stages, the substrate surface can be satisfactorily processed while suppressing the amount of the rinse liquid used. In addition, since the rinsing liquid is supplied to the substrate surface after the rinsing process at a flow rate (third flow rate) larger than the flow rate (second flow rate) of the rinsing liquid in the intermediate rinsing process, Compared to the case where the liquid is deposited at the same flow rate as in the processing, the time required for the liquid filling process can be shortened, and the rinsing liquid is spread over the entire substrate surface by increasing the flow rate of the rinsing liquid. It is possible to reliably prevent the substrate surface from being exposed.

  FIG. 1 is a diagram showing an example of a substrate processing apparatus suitable for executing the substrate processing method according to the present invention. FIG. 2 is a block diagram showing an electrical configuration of the apparatus shown in FIG. This substrate processing apparatus is a single-wafer type substrate processing apparatus used for a cleaning process for removing unnecessary substances adhering to a surface Wf of a substrate W such as a semiconductor wafer. More specifically, chemical treatment with a chemical solution such as a hydrofluoric acid solution, rinsing treatment with a rinsing liquid such as pure water or DIW, rinsing liquid accumulation processing and liquid shaking off treatment (liquid removal treatment) are performed on the substrate surface Wf. It is an apparatus that spin-drys the substrate surface Wf after applying in order.

  The substrate processing apparatus includes a spin chuck 2 that rotates while holding the substrate W in a substantially horizontal position with the substrate surface Wf facing upward, and a chemical solution (to the surface Wf of the substrate W held by the spin chuck 2). Treatment liquid) and a nozzle 4 for discharging a rinsing liquid.

  The spin chuck 2 has a rotation support shaft 6 connected to a rotation shaft of a chuck rotation mechanism 8 including a motor, and can rotate around a rotation axis J (vertical axis) by driving the chuck rotation mechanism 8. The rotating spindle 6 and the chuck rotating mechanism 8 are accommodated in a cylindrical casing 10. Further, a disc-shaped spin base 12 is integrally connected to the upper end portion of the rotation support shaft 6 by a fastening component such as a screw. Therefore, the spin base 12 rotates about the rotation axis J by driving the chuck rotation mechanism 8 in accordance with an operation command from the control unit 14 that controls the entire apparatus. The control unit 14 also controls the chuck rotation mechanism 8 to adjust the rotation speed of the spin base 12.

  Near the periphery of the spin base 12, a plurality of chuck pins 16 for holding the periphery of the substrate W are provided upright. Three or more chuck pins 16 may be provided in order to securely hold the circular substrate W, and are arranged at equiangular intervals along the peripheral edge of the spin base 12. Each of the chuck pins 16 includes a substrate support portion that supports the peripheral portion of the substrate W from below, and a substrate holding portion that holds the substrate W by pressing the outer peripheral end surface of the substrate W supported by the substrate support portion. Yes. Each chuck pin 16 is configured to be switchable between a pressing state in which the substrate holding portion presses the outer peripheral end surface of the substrate W and a released state in which the substrate holding portion is separated from the outer peripheral end surface of the substrate W.

  When the substrate W is delivered to the spin base 12, the plurality of chuck pins 16 are released, and when the substrate processing described later is performed on the substrate W, the plurality of chuck pins 16 are pressed. State. By setting the pressing state in this way, the plurality of chuck pins 16 can grip the peripheral edge of the substrate W and hold the substrate W in a substantially horizontal posture at a predetermined interval from the spin base 12. As a result, the substrate W is supported with its front surface Wf facing upward and the back surface Wb facing downward. The substrate holding means is not limited to the chuck pins 16, and a vacuum chuck that sucks the substrate back surface Wb and supports the substrate W may be used.

  The nozzle 4 is connected to the liquid supply unit 20 via the valve 18. The liquid supply unit 20 selectively supplies the chemical liquid and the rinse liquid to the nozzle 4 and can adjust the flow rate and concentration of each liquid. That is, the liquid supply unit 20 has a mixing valve 22, and a hydrofluoric acid supply system and a DIW supply system are connected to the mixing valve 22.

  Among these supply systems, the hydrofluoric acid supply system includes a hydrofluoric acid supply source 24, a pipe 26 connecting the hydrofluoric acid supply source 24 and the mixing valve 22, and a hydrofluoric acid supplied to the mixing valve 22 through the pipe 26. And a flow rate controller 28 for controlling the flow rate of the acid. The flow rate controller 28 includes a flow rate adjustment valve (electrically operated valve) 30, a flow meter 32, and a flow rate control unit (not shown). The flow rate control unit detects and calculates a flow rate signal measured by the flow meter 32. Then, the flow rate adjusting valve 30 is controlled so that the flow rate of hydrofluoric acid fed to the mixing valve 22 becomes the set flow rate given from the control unit 14.

  The DIW supply system is configured in the same manner as the hydrofluoric acid supply system. That is, the DIW supply system includes a pipe 36 that connects the DIW supply source 34 and the mixing valve 22, and a flow rate controller 38 that is inserted into the pipe 36 and controls the flow rate of DIW supplied to the mixing valve 22. The flow rate controller 38 includes a flow rate adjustment valve (electric valve) 40, a flow meter 42, and a flow rate control unit (not shown). The flow rate control unit detects and calculates a flow rate signal measured by the flow meter 42. The flow rate adjustment valve 40 is controlled so that the DIW flow rate fed to the mixing valve 22 becomes the set flow rate given from the control unit 14. Note that the DIW supply source 34 is not an indispensable component of the above apparatus, and DIW supplied from a DIW supply apparatus that is one of the utilities of the factory where the apparatus is installed may be used.

  As described above, in the present embodiment, the liquid supply unit 20 configured as described above controls the hydrofluoric acid flow rate and DIW flow rate fed to the mixing valve 22, thereby hydrofluoric acid in the hydrofluoric acid solution prepared by the mixing valve 22. The hydrofluoric acid solution can be supplied to the nozzle 4 while directly and dynamically adjusting the concentration and the flow rate of the hydrofluoric acid solution. Further, the liquid supply unit 20 controls the DIW flow rate by the flow rate controller 38 in a state in which the supply of hydrofluoric acid to the mixing valve 22 is stopped, thereby adjusting the DIW flow rate directly and dynamically, and using the DIW as a rinse liquid. It is possible to supply to.

  A receiving member 44 is fixedly attached around the casing 10. Three cylindrical partition members are erected on the receiving member 44. And three spaces are formed as a drainage tank by the combination of these partition members and the casing 10. Above these drainage tanks, a splash guard 46 is provided so as to be movable up and down with respect to the rotation axis J of the spin chuck 2 so as to surround the periphery of the substrate W held in a horizontal posture on the spin chuck 2. ing. The splash guard 46 has a shape that is substantially rotationally symmetric with respect to the rotation axis J, and includes three guards arranged concentrically with the spin chuck 2 from the radially inner side toward the outer side. Then, the splash guard 46 is lifted and lowered stepwise by driving a guard lifting mechanism (not shown), so that the hydrofluoric acid solution and the rinsing liquid scattered from the rotating substrate W can be separated and discharged. Yes.

  Next, an embodiment of the substrate processing method according to the present invention will be described in detail with reference to FIGS. FIG. 3 is a graph showing an embodiment of the substrate processing method according to the present invention. FIG. 4 is a schematic view showing an embodiment of the substrate processing method according to the present invention. 3 is a graph showing the rotation speed of the substrate W held on the spin chuck 2, and the lower row shows the flow rate of the rinsing liquid discharged from the nozzle 4 toward the substrate surface Wf in the rinsing process and the liquid filling process. It is a graph to show. In this embodiment, the control unit 14 controls each part of the apparatus according to a program stored in a memory (not shown) to perform a chemical liquid process, a rinse process, a liquid build-up process, a liquid swing-off process (liquid removal process) on the substrate W. ) And drying treatment. Of these, the hydrofluoric acid solution used in the chemical treatment corresponds to the “treatment liquid” of the present invention, and the substrate that has undergone the chemical treatment corresponds to the “substrate having a surface treated with the treatment liquid” of the present invention. ing.

  The control unit 14 lowers the splash guard 46 so that the spin chuck 2 protrudes from the upper end portion of the splash guard 46. In this state, an unprocessed substrate W is carried into the apparatus by a substrate transport means (not shown). More specifically, the substrate W is carried into the apparatus with the substrate surface Wf facing upward and is held by the spin chuck 2. Following this, the splash guard 46 is raised and chemical processing is started on the substrate W.

  In the step of executing the chemical treatment (chemical step), the nozzle 4 is moved above the center of the substrate surface Wf, and the substrate W held by the spin chuck 2 by driving the chuck rotating mechanism 8 is within the range of 200 to 1200 rpm. Rotate at a rotation speed determined by (for example, 800 rpm). On the other hand, in the liquid supply unit 20, a hydrofluoric acid solution is prepared as a chemical solution. That is, a set flow rate for hydrofluoric acid is supplied from the control unit 14 to the hydrofluoric acid flow controller 28, and hydrofluoric acid is sent to the mixing valve 22 at the set flow rate. Further, a set flow rate for DIW is supplied from the control unit 14 to the DIW flow rate controller 38, and DIW is sent to the mixing valve 22 at the set flow rate. Thus, hydrofluoric acid and DIW are mixed in the mixing valve 22 to prepare a hydrofluoric acid solution having a desired concentration and a desired flow rate. Then, by opening the valve 18, a hydrofluoric acid solution having a desired concentration is supplied from the nozzle 4 to the substrate surface Wf at a predetermined flow rate, for example, 2 (L / min). In this chemical process, since the substrate W is rotating at a relatively high rotational speed as described above, the hydrofluoric acid supplied to the central portion of the substrate surface Wf is instantly spread by centrifugal force, and the substrate surface caused by hydrofluoric acid. The etching process (chemical solution process) of Wf is performed as a whole and almost simultaneously, and a uniform etching process is started.

  When the above-described chemical solution process is continued for a predetermined time and a desired etching process is completed, the set flow rate for hydrofluoric acid is set to zero and the supply of hydrofluoric acid to the mixing valve 22 is stopped. Then, in a state where the splash guard 46 is disposed at the height position for the rinsing process, the two-stage rinsing process is executed as follows. First, in the initial rinsing step, the flow rate controller 38 supplies DIW to the mixing valve 22 while adjusting the DIW flow rate to a relatively high flow rate, for example, 2 (L / min) in response to a command from the control unit 14. As a result, 2 (L / min) DIW is pumped from the liquid supply unit 20 toward the nozzle 4 as a rinse liquid. The rinsing liquid thus supplied to the central portion of the substrate surface Wf receives centrifugal force and pushes out the hydrofluoric acid solution on the substrate surface Wf from the substrate surface Wf as shown in FIG. In addition, in the present embodiment, a relatively large flow rate of the rinsing liquid is supplied to the substrate surface Wf, so that the rinsing liquid is entirely hydrophobic even though the substrate surface Wf is hydrophobic due to the chemical treatment. The substrate surface Wf can be covered with the rinsing liquid. In this embodiment, the valve 18 is maintained in an open state at the time of switching from the chemical processing to the rinsing processing and from the rinsing processing to the liquid filling processing described later. Although it is configured to discharge, the discharge mode of the rinse liquid may be changed and set by opening and closing the nozzle 4 as necessary.

  In the initial rinsing process of this embodiment, the control unit 14 controls the chuck rotating mechanism 8 to rotate the substrate W at a rotation speed higher than the rotation speed of the substrate W at the time of chemical processing, for example, 1200 rpm. For this reason, it is possible to more reliably cover the hydrophobic substrate surface Wf with the rinse liquid due to the synergistic effect with the supply of the large flow rinse liquid to the substrate surface Wf as described above.

  This initial rinsing step is a step of replacing the entire substrate surface Wf with the rinsing liquid. For example, the initial rinsing step can be completed when the entire substrate surface Wf is covered with the liquid film of the rinsing liquid. Then, following this initial rinsing step, an intermediate rinsing step is performed.

  In this intermediate rinsing step, the control unit 14 reduces the DIW flow rate while the supply of hydrofluoric acid to the mixing valve 22 is stopped. In this embodiment, the flow rate controller 38 adjusts the DIW flow rate from 2 (L / min) to 1.5 (L / min) in response to a command from the control unit 14. As a result, 1.5 (L / min) DIW is pumped from the liquid supply unit 20 toward the nozzle 4 as a rinse liquid. Thus, the rinsing liquid supplied to the substrate surface Wf at a low flow rate spreads over the entire substrate surface Wf in such a manner as to be dragged by the flow of the liquid film formed on the substrate surface Wf in the initial rinsing process (see FIG. 4 (b)). For this reason, although the flow rate is low, the entire substrate surface Wf is covered with the rinsing liquid to prevent partial exposure of the substrate surface Wf, so that the rinsing process for the substrate surface Wf is performed well.

  When the rinsing process is completed, as shown in FIG. 4C, the control unit 14 controls the chuck rotation mechanism 8 to decelerate the rotation speed of the substrate W to less than 50 rpm (in this embodiment, 10 rpm) to reduce the substrate surface Wf. A rinse liquid is formed on the top. The thickness of the liquid can be adjusted by controlling the rotation speed of the substrate W, and is preferably adjusted according to the state of the substrate surface Wf. Note that the rotation speed of the substrate W is not limited to the above numerical value, and is set to an arbitrary rotation speed at which the rinse liquid can be puddle-filled, or the rotation speed of the substrate W is zero. The substrate W may be stationary.

  In this embodiment, the flow rate of the rinse liquid is adjusted in the liquid filling process. That is, the flow rate controller 38 supplies DIW to the mixing valve 22 while adjusting the DIW flow rate to a flow rate larger than the flow rate during the intermediate rinsing process, for example, 2 (L / min) in response to a command from the control unit 14. As a result, the liquid filling process proceeds while a relatively large flow of rinsing liquid is supplied from the nozzle 4. Since the flow rate of the rinsing liquid in the liquid filling process is increased in this way, the time required for the liquid filling process is shortened compared to the case where the liquid filling process is performed with the flow rate during the intermediate rinsing process, that is, with a low flow rate. . Further, since the flow rate of the rinsing liquid in the liquid filling process is increased, it is possible to reliably prevent the rinsing liquid from spreading uniformly over the entire substrate surface Wf and exposing part of the substrate surface Wf during the liquid filling process. .

  When the liquid filling process is completed in this way, the control unit 14 closes the valve 18 to stop the discharge of the rinsing liquid from the nozzle 4, and at the same time or subsequently, the nozzle 4 is moved away from the upper space of the substrate W (illustrated). Move to (omitted). Further, the control unit 14 controls the chuck rotating mechanism 8 to increase the rotation speed of the substrate W, and as shown in FIG. 4D, the rinsing liquid is shaken off on the substrate surface Wf by a centrifugal force (liquid removing step). Subsequently, the control unit 14 controls the chuck rotation mechanism 8 to further increase the rotation speed of the substrate W and perform spin drying.

  Finally, when the drying process of the substrate W is completed, the control unit 14 controls the chuck rotating mechanism 8 to stop the rotation of the substrate W. Then, the splash guard 46 is lowered to cause the spin chuck 2 to protrude from above the splash guard 46. Thereafter, the substrate transfer means carries out the processed substrate W from the apparatus, and a series of substrate processing for one substrate W is completed. Then, the same processing as described above is performed for the next substrate W.

  As described above, according to the present embodiment, after the rinsing liquid is supplied to the substrate surface Wf at the first flow rate (2 (L / min)) and the initial rinsing process is performed, the second flow rate lower than the first flow rate is obtained. Since the rinsing liquid is supplied to the substrate surface Wf at a flow rate (1.5 (L / min)) and the intermediate rinsing process is performed, the amount of the rinsing liquid used can be suppressed. In addition, since the liquid film of the rinsing liquid is formed on the entire substrate surface Wf using the rinsing liquid having a large flow rate before the flow rate of the rinsing liquid is reduced, the rinsing is performed even in the intermediate rinsing process in which the rinsing liquid flow rate is reduced. Since the liquid can be spread over the entire substrate surface Wf to cover the entire substrate surface Wf, the substrate surface Wf can be favorably rinsed by preventing partial exposure of the substrate surface Wf.

  Further, since the flow rate of the rinse liquid in the liquid filling step is larger than the flow rate of the rinse liquid (second flow rate) in the intermediate rinse step (third flow rate), the time required for the liquid filling process is shortened. be able to. Further, since the flow rate of the rinsing liquid in the liquid filling process is increased, it is possible to reliably prevent the rinsing liquid from spreading over the entire substrate surface Wf and exposing a part of the substrate surface Wf.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in the above embodiment, the liquid supply unit 20 is configured so that the flow rate of the rinsing liquid can be dynamically changed, and the rinsing liquids having different flow rates are discharged from one nozzle 4, but is configured as follows. May be. FIG. 5 is a diagram showing another embodiment of the substrate processing method according to the present invention. In this embodiment, in addition to the liquid supply unit 20, a DIW supply unit 48 that supplies a rinsing liquid at a constant flow rate (for example, a rinsing liquid flow rate during an intermediate rinsing process) is provided. A nozzle 52 is connected to the DIW supply unit 48 via a pipe 50. A valve 54 is inserted in the pipe 50, and when the valve 54 is opened in response to an opening command from the control unit 14, the rinse liquid from the DIW supply unit 48 is sent to the nozzle 52, and a constant flow rate is supplied from the nozzle 52. Thus, the rinse liquid is discharged onto the substrate surface Wf. In the apparatus configured as described above, the rinse liquid is supplied from the nozzle 4 to the substrate surface Wf at a large flow rate and the initial rinse process is performed. Then, the valve 18 is closed and the discharge of the rinse liquid from the nozzle 4 is stopped simultaneously. Alternatively, the intermediate rinsing step can be performed by supplying the rinsing liquid to the substrate surface Wf from the nozzle 52 at a low flow rate after the stop. When the rinse liquid is discharged from the nozzle 52 after the rinse liquid discharge from the nozzle 4 is stopped, the time from the stop of the rinse liquid discharge from the nozzle 4 to the start of the rinse liquid discharge from the nozzle 52 is set to a certain time, for example, 0. It is desirable to prevent exposure of a part of the substrate surface Wf by setting it within 3 seconds.

  In the above embodiment, the substrate W is rotated at the same rotational speed in the initial rinsing process and the intermediate rinsing process. However, the rotational speed of the substrate W in the intermediate rinsing process is the rotational speed of the substrate W in the initial rinsing process. You may comprise so that it may become smaller. By reducing the rotational speed in this way, it is possible to effectively prevent mist generation in the intermediate rinsing process. In addition, the rotation speed of the substrate W in each process can be set as appropriate according to the processing content in each process, and in particular, the rotation speed of the substrate in the initial rinsing process is the intermediate rinsing process, the liquid filling process, and It is preferable to set so as to be higher than the rotation speed of the substrate W in the liquid swing-off process (liquid removal process). For example, even when the substrate surface Wf becomes a hydrophobic surface due to the hydrofluoric acid solution, the rinsing liquid is surely spread over the entire substrate surface Wf by increasing the rotation speed of the substrate W and increasing the flow rate of the rinsing liquid in the initial rinsing process. Thus, it is possible to prevent a part of the substrate surface Wf from being exposed. This provides excellent process performance.

  The application target of the present invention is not limited to the apparatus described in the above embodiment, and the rinse treatment and the drying treatment are performed on the substrate while rotating the substrate having the surface treated with the treatment liquid. The present invention can be applied to an apparatus. For example, as described in Japanese Patent Application Laid-Open No. 2006-278654, an apparatus using a so-called umbrella nozzle, or as described in Japanese Patent Application Laid-Open No. 2003-17547, a rinsing process is performed on chuck pins and nozzles in addition to the substrate. The present invention may be applied to an apparatus or the like. However, in these apparatuses, when performing the chuck rinsing process or the umbrella nozzle rinsing process, it is necessary to reduce the rotation speed of the substrate W or the spin chuck 2 to a rotation speed suitable for the same process. It is desirable to execute processing. That is, in the initial rinsing process, a rinsing liquid having a relatively high rotational speed and a large flow rate is supplied to the substrate in the same manner as in the above-described embodiment. After the substrate is supplied to the substrate and a sufficient rinsing effect is obtained, the rotation speed of the substrate W can be reduced to a rotation speed suitable for chuck rinsing (for example, 250 rpm for chuck rinsing and 50 rpm for umbrella nozzle rinsing).

  In the above embodiment, the substrate surface Wf is etched using the hydrofluoric acid solution as the “treatment liquid” of the present invention. However, the application target of the present invention is not limited to this, and the treatment liquid is not limited thereto. The present invention can be applied to all substrate processing methods in which a substrate is subjected to a rinsing process on a substrate that has been subjected to a predetermined process.

  The present invention generally relates to substrates including semiconductor wafers, photomask glass substrates, liquid crystal display glass substrates, plasma display glass substrates, FED substrates, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, and the like. The present invention can be applied to a substrate processing method in which a rinsing liquid is supplied onto the substrate surface to rinse the substrate surface.

It is a figure which shows an example of the substrate processing apparatus suitable for execution of the substrate processing method concerning this invention. It is a block diagram which shows the electric constitution of the apparatus shown in FIG. It is a graph which shows one Embodiment of the substrate processing method concerning this invention. It is a schematic diagram which shows one Embodiment of the substrate processing method concerning this invention. It is a figure which shows other embodiment of the substrate processing method concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 8 ... Chuck rotation mechanism 12 ... Spin base 14 ... Control unit 20 ... Liquid supply unit 24 ... Hydrofluoric acid supply source 34 ... DIW supply source 38 ... Flow controller for DIW 40 ... Flow control valve 42 ... Flow meter 48 ... DIW supply unit Wf ... Substrate surface W ... Substrate

Claims (5)

An initial rinsing step of supplying a rinsing liquid to the substrate surface at a first flow rate while rotating the substrate having a surface treated with the treatment liquid;
An intermediate rinsing step of supplying a rinsing liquid to the substrate surface at a second flow rate lower than the first flow rate while rotating the substrate after the initial rinsing step;
A liquid filling step of forming a liquid film of the rinse liquid on the substrate surface by supplying a rinse liquid to the substrate surface at a third flow rate larger than the second flow rate after the intermediate rinsing step;
A substrate processing method comprising: a liquid removal step of stopping the supply of the rinse liquid after the liquid filling step and rotating the substrate to remove the rinse liquid on the substrate surface.   The substrate processing method according to claim 1, wherein the initial rinsing step is a step of replacing the entire surface of the substrate with the rinsing liquid.   The substrate processing method according to claim 1, wherein a rotation speed of the substrate in the intermediate rinsing process is equal to or lower than a rotation speed of the substrate in the initial rinsing process. In the liquid filling step, the substrate is rotated,
The substrate processing method according to claim 1, wherein a rotation speed of the substrate in the initial rinsing process is higher than a rotation speed of the substrate in the intermediate rinsing process, the liquid filling process, and the liquid removal process.   The initial rinsing step, the intermediate rinsing step, and the liquid filling step are continuously performed, and the rinsing liquid is continuously supplied to the substrate surface from the initial rinsing step to the liquid filling step. The substrate processing method according to claim 1, wherein the flow rate of the rinsing liquid is changed.

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