JP5156488B2 - Substrate cleaning apparatus and substrate cleaning method - Google Patents

Description

  The present invention relates to a semiconductor wafer, a glass substrate for photomask, a glass substrate for liquid crystal display, a glass substrate for plasma display, a substrate for FED (Field Emission Display), a substrate for optical disk, a substrate for magnetic disk, and a magneto-optical disk. The present invention relates to a substrate cleaning apparatus and a substrate cleaning method for ultrasonically cleaning a substrate for use.

  The manufacturing process of electronic components such as semiconductor devices and liquid crystal display devices includes a process step of forming a fine pattern by repeatedly performing processes such as film formation and etching on the surface of a substrate. Here, in order to perform fine processing satisfactorily, it is necessary to keep the substrate surface clean, and a cleaning process is performed on the substrate surface as necessary. Therefore, conventionally, in order to remove particles adhering to the substrate, a cleaning liquid is supplied to the substrate and ultrasonic vibration is applied to the cleaning liquid. Thereby, the particles are effectively detached from the substrate and removed by the ultrasonic vibration energy of the cleaning liquid.

  The following method has been proposed as such a substrate cleaning apparatus. For example, the apparatus described in Patent Document 1 cleans the substrate surface by spraying a cleaning liquid to which ultrasonic vibration is applied from the nozzle toward the substrate surface. In addition, the apparatuses described in Patent Documents 2 and 3 clean the substrate surface by forming a liquid film of a cleaning liquid on the surface of the substrate and applying ultrasonic vibration to the liquid film. Further, in the apparatus described in Patent Document 4, an ultrasonic transducer is disposed opposite to the substrate surface, and a cleaning liquid is introduced between the two to clean the substrate surface.

Japanese Patent Laid-Open No. 11-244796 (page 6) Japanese Patent No. 3493492 (FIGS. 6 and 7) Japanese Patent Laying-Open No. 2001-87725 (FIG. 2) Japanese Patent Laying-Open No. 2006-326486 (FIGS. 3 and 4)

  In the above-described cleaning method, ultrasonic wave application means (bar-shaped horn, probe, ultrasonic wave application head) for applying ultrasonic vibrations are arranged to face the substrate surface, and particles are removed by ultrasonic vibration at the opposite positions. Yes. For this reason, in order to increase the particle removal rate, it is effective to increase the output of ultrasonic vibration and decrease the frequency. However, as the output increases, the possibility of damaging the pattern on the substrate formed at the opposite position has increased. In addition, in the above cleaning method, the ultrasonic wave applying means is moved relative to the substrate surface in order to clean the entire substrate surface. Therefore, the damage is applied to the entire substrate surface. Conversely, if the output of ultrasonic vibration is reduced or the frequency is increased, damage can be suppressed, but the particle removal rate is greatly reduced. As described above, since the conventional cleaning method uses only ultrasonic vibration to remove particles, it has been difficult to simultaneously suppress substrate damage and remove particles.

  The present invention has been made in view of the above problems, and has as its first object to provide a substrate cleaning apparatus and method capable of efficiently removing particles on the substrate surface while suppressing damage to the substrate. To do.

  A second object of the present invention is to uniformly remove particles on the substrate surface.

In order to achieve the above object, the substrate cleaning apparatus according to the present invention provides ultrasonic applying means for applying ultrasonic vibration to the liquid film of the first cleaning liquid covering the surface of the substrate, and the ultrasonic vibration passes through the liquid film in the substrate. The supply means for supplying the second cleaning liquid to the liquid film at a second position different from the first position where the ultrasonic vibration is applied on the path propagating toward the surface, and the ultrasonic application means are operated. Control means for supplying the liquid film with an additional vibration different from the ultrasonic vibration by supplying the second cleaning liquid to the liquid film by the supply means while applying ultrasonic vibration to the liquid film, and the supply means discharges the second cleaning liquid The second cleaning liquid ejected from the nozzle is applied to the liquid film in the form of liquid droplets to give additional vibration .

In addition, in order to achieve the above object, the substrate cleaning method according to the present invention includes a first step of bringing an ultrasonic transducer into contact with the liquid film of the first cleaning liquid covering the substrate surface at a first position, and ultrasonic vibration. A second step of applying an additional vibration different from the ultrasonic vibration to the liquid film by supplying the second cleaning liquid to the liquid film at a second position different from the first position while operating the child to apply the ultrasonic vibration to the liquid film. The second step is characterized in that a droplet of the second cleaning liquid is dropped onto the liquid film .

  In the invention thus configured, ultrasonic vibration is applied to the liquid film of the first cleaning liquid covering the substrate surface at the first position, and the second cleaning liquid is applied to the liquid film at a second position different from the first position. And an additional vibration different from the ultrasonic vibration is applied to the liquid film. That is, when the second cleaning liquid is supplied to the liquid film, the surface of the liquid film undulates and vibrates the liquid film. This wave vibration is added to the liquid film as the “additional vibration” of the present invention. Applying wave vibration in this way greatly contributes to the improvement of the particle removal rate, as shown in the experimental results described in detail later.

  Here, the “liquid film of the first cleaning liquid covering the substrate surface” includes (a) a liquid film consisting only of the substrate-side liquid film region formed on the substrate surface by supplying the first cleaning liquid to the substrate surface; (b) The substrate-side liquid film region formed on the substrate surface by supplying the first cleaning liquid to the substrate surface, and the outer side formed on the plate surface by the first cleaning liquid flowing from the substrate surface to the plate surface. And a liquid film having a liquid film region.

  Among these, for the substrate on which the liquid film (a) is formed, both the first position and the second position can be set in the substrate-side liquid film region. In this case, as will be described in detail later, a region where the particle removal rate can be improved by the addition of wave vibration (hereinafter referred to as “good removal region”) is not spread over the entire surface of the substrate but is biased. Therefore, if the substrate rotating means for rotating the substrate is further provided and the ultrasonic vibration and the wave vibration are applied to the liquid film while the substrate is rotating at least once or more, the following effects can be obtained. That is, by adopting such a configuration, the relative relationship between the first position and the second position with respect to the substrate surface changes with time. Therefore, a good removal area can be expanded and the uniformity of particle removal can be improved. Also, according to the experimental results described in detail later, the good removal region is the substrate surface region at the second position and the substrate surface region opposite to the first position with respect to the second position. Therefore, when rotating the substrate, from the viewpoint of improving the uniformity of particle removal, (1) the second position is positioned closer to the rotation center of the substrate than the first position, or (2) the second position is It is preferable to set the rotation center of the substrate. In addition, the apparatus configuration can be simplified by fixedly arranging the ultrasonic wave applying means. Further, the first position can be arbitrarily set. For example, it is desirable to set the first position by removing the region where the particle removal should be satisfactorily performed on the substrate surface. This is because the surface peripheral portion of the substrate is usually a portion where a pattern or the like is not formed, and thus pattern damage can be prevented by arranging the ultrasonic wave imparting means on the surface peripheral portion.

  On the other hand, for the substrate on which the liquid film (b) is formed, the first position can be set to the outer liquid film region. Since this outer liquid film region is located outside the substrate surface, the ultrasonic vibration output from the ultrasonic wave application means propagates to the substrate side liquid film region through the outer liquid film region. It is possible to effectively prevent the substrate surface from being damaged. Further, the above-described effects can be obtained by adding wave vibration to the substrate-side liquid film region and the outer liquid film region in which ultrasonic vibration propagates toward the substrate surface. In this case, the entire substrate surface is a good removal region. Instead of adding the ripple vibration to the outer liquid film region, the ripple vibration may be added to the substrate side liquid film region.

  In addition, when the first position is set in the outer liquid film region in this way, it is desirable to arrange the rotation center of the substrate, the second position, and the first position in a straight line in this order. By adopting, the uniformity of particle removal can be improved.

  Note that, in order to reliably apply the wave vibration to the liquid film, it is desirable that the second cleaning liquid is applied to the liquid film in a droplet state to apply additional vibration. Further, the first cleaning liquid may be supplied from the nozzle to the substrate surface to form a liquid film. In this way, the supply means executes the liquid film forming operation and the droplet supplying operation, and the liquid film formation to the cleaning can be efficiently performed with a small number of components. Conversely, the first cleaning liquid may be supplied to the substrate surface from a nozzle different from this nozzle to form a liquid film. Further, when the ultrasonic vibrator is brought into contact with the liquid film of the first cleaning liquid covering the substrate surface at the first position, the substrate may be rotated, whereby particles are efficiently and uniformly removed. be able to. Furthermore, the same kind of treatment liquid may be used as the first and second cleaning liquids.

  According to the invention, the ultrasonic vibration is applied to the liquid film of the first cleaning liquid covering the substrate surface, and the addition is different from the ultrasonic vibration at the second position different from the first position where the ultrasonic vibration is applied. Since vibration is applied to the liquid film, even if the ultrasonic vibration output and frequency are set to such an extent that the substrate is not damaged, the particle removal rate can be improved by adding the wave vibration. That is, it is possible to achieve both suppression of substrate damage and improvement of particle removal.

  In the conventional apparatus, ultrasonic vibration is applied to the liquid film of the cleaning liquid formed on the substrate surface to remove particles from the substrate surface, and the present inventor intends to improve the ultrasonic cleaning technology. Then, the cleaning liquid was supplied under various conditions to the liquid film to which the ultrasonic vibration was applied, and the change in the particle removal rate due to the difference in the supply conditions was verified. As a result of the verification, it was found that the particle removal rate is improved by supplying the cleaning liquid to the liquid film to which the ultrasonic vibration is applied and applying the ripple vibration to the liquid film. Accordingly, the present inventor has created a substrate cleaning apparatus and method combining ultrasonic vibration and wave vibration based on such knowledge. Hereinafter, after describing the contents of knowledge of the present inventor, that is, “improvement of particle removal rate by vibration addition”, embodiments used for the knowledge will be described in detail.

<Improvement of particle removal rate by vibration addition>
The inventor conducted the following experiment. Nine silicon wafers (wafer diameter: 200 mm) are prepared, and wafers (substrates) W1 to W9 are forcibly contaminated using a single wafer processing apparatus (Dainippon Screen Manufacturing Co., Ltd., Spin Processor SS-3000). Let Specifically, a dispersion liquid in which particles (Si scraps) are dispersed on the wafer surface is supplied to the wafer while rotating the wafer. Here, the liquid amount of the dispersion, the wafer rotation speed, and the processing time are appropriately adjusted so that the number of particles adhering to the wafer surface is about 10,000. Then, the number (initial value) of particles (particle size: 0.08 μm or more) adhering to the wafer surface is measured. The number of particles is evaluated using a particle evaluation apparatus SP1-TBI manufactured by KLA-Tencor.

  Next, a liquid film of DIW (deionized water) is formed on the surface Wf of the wafer W using an apparatus having a schematic configuration shown in FIG. That is, a flow rate of 300 (mL / min) from the nozzle 41 arranged at a position separated from the wafer surface Wf by the nozzle height H while rotating the wafers W1 to W9 at 100 rpm in a horizontal posture with the surface Wf facing upward. Then, DIW is supplied to the wafer surface Wf. As a result, a DIW film of 2 to 3 mm is formed on the wafer surface Wf. Then, as shown in FIG. 4B, the ultrasonic wave application head 71 is positioned at the vibration application position P1 on the peripheral edge of the wafer to apply ultrasonic vibrations, and supply conditions (DIW flow rate) are set for each of the wafers W1 to W9. The wafer surface Wf is cleaned by supplying DIW to the wafer rotation center (position P2) while making the nozzle height H) different. Specifically, while the ultrasonic wave application head 71 is fixedly disposed at the vibration application position P1, the ultrasonic vibration oscillation output is set to 5 W and the oscillation frequency is set to 3 MHz, while the supply conditions for each of the wafers W1 to W9 are set. Settings are made as shown in FIG. Note that DIW supplied to the liquid film was imaged by an imaging device such as a digital camera in order to observe the supply state when DIW discharged from the nozzles 41 reached the liquid film under each supply condition.

  Spin drying is performed after the wafer cleaning process, and the number of particles adhering to the wafer surface is measured using the above-described particle evaluation apparatus. Then, by comparing the number of particles after the cleaning process with the number of particles before the cleaning process (initial value), the particle removal rate is calculated for the entire wafer surface and the evaluation target region (shaded area in FIG. 1C). To do.

In the above experiment, the DIW supply conditions are different, but depending on the supply conditions, the DIW supply state may be a rod shape (liquid column state) or a droplet state. That is, under the supply conditions for the wafers W2, W3, and W6 among the wafers W1 to W9, as shown in FIG. 3A, DIW supplied from the nozzle 41 to the liquid film has a rod shape that is a continuous flow. Thus, the DIW is supplied to the rotation center (position P2) of the wafer while the surface of the liquid film does not swell and remains almost stationary. On the other hand, under the supply conditions for the wafers W1, W2, W4, W5, and W7 to W9, as shown in FIG. 3B, DIW supplied from the nozzle 41 to the liquid film is a liquid droplet that is an intermittent separated flow. In this state, the surface of the liquid film is rippled by the liquid DIW.

  FIG. 4 shows the particle removal state for the wafers W1 to W9 cleaned under each supply condition. The black dots in the figure indicate the positions where the particles have been removed. Accordingly, the particle removal rate can be obtained from the number of black dots, while the bias of the cleaning effect can be obtained from the distribution of black dots. Here, the particle removal rate is calculated separately for the entire wafer surface and the evaluation target region. “Overall XX%” in the figure is the particle removal rate on the entire surface of the wafer, and the numbers for the semicircular broken line encircled portion are the particle removal rate in the evaluation target region. This evaluation target area means an area located on the opposite side of the vibration applying position P1 with respect to the droplet dropping position P2 on the wafer surface as shown in FIG. 1 (c) and FIG.

  From the above experimental results, it can be said that further application of cleaning liquid (DIW) in a droplet state to the liquid film to which ultrasonic vibration is applied is a very useful means for improving the particle removal rate. I understand. This is closely related to applying ripple vibration to the liquid surface of the liquid film by supplying droplets. It can also be seen that the cleaning effect is biased from the particle removal distribution. The region where the particle removal rate can be improved by the addition of the ripple vibration, that is, the good removal region is not spread over the entire surface of the wafer but is biased, and the relative positional relationship between the vibration applying position P1 and the droplet dropping position P2 is Accordingly, the good removal area is different. That is, the ultrasonic vibration applied to the liquid film at the vibration applying position P1 propagates through the liquid film toward the wafer surface Wf. For example, in the above experiment, the vibration applying position P1 is the wafer surface as shown in FIG. Since it is the left end peripheral portion of Wf, the ultrasonic vibration propagates from the left end peripheral portion side of the wafer W to the right end side. Then, although the ripple vibration is added on the propagation path, the wafer surface area opposite to the vibration applying position P1 with respect to the droplet dropping position P2 to which the ripple vibration is applied is a good removal area. Therefore, the good removal area can be controlled by adjusting the relative positional relationship. In particular, when the droplet dropping position P2 is set at the rotation center of the wafer W and the wafer W is rotated during the cleaning process, the good removal region moves as the wafer rotates. Therefore, if the wafer W is rotated once or more, particles can be uniformly and satisfactorily removed from the entire wafer surface. As described above, the vibration applying position P1 corresponds to the “first position” of the present invention, and the droplet dropping position P2 corresponds to the “second position” of the present invention.

  In the above experiment, ultrasonic vibration and wave vibration are applied to the liquid film (corresponding to the “substrate-side liquid film region” of the present invention) formed on the wafer surface Wf. As will be described in the second embodiment and the third embodiment, the same experimental results as described above can be obtained even if the position for applying ultrasonic vibration and wave vibration is changed. For example, when using the apparatus according to the second or third embodiment, as shown in FIGS. 5 and 6, the substrate-side liquid film region LF1 formed on the wafer surface Wf and the wafer surface periphery are outward. A liquid film LF having an outer liquid film region (corresponding to the “outer liquid film region” of the present invention) LF2 formed so as to protrude can be formed. As described above, when the wafer surface Wf is covered from above by the liquid film LF having the substrate side liquid film region LF1 and the outer liquid film region LF2, ultrasonic vibration can be applied to the outer liquid film region LF2. Most of the ultrasonic vibration propagates toward the wafer surface Wf. Then, by applying ripple vibration on the propagation path, particles adhering to the wafer surface region on the opposite side of the vibration application position P1 with respect to the droplet dropping position P2 to which the ripple vibration is applied are applied in the same manner as the above experimental result. It was successfully removed. For example, as shown in FIG. 5, in the outer liquid film region LF2, the vibration is applied so that the vibration application position P1 is opposite to the substrate-side liquid film region LF1 (left side in the figure) with respect to the droplet dropping position P2. When applied to the outer liquid film region LF2, the entire wafer surface Wf is on the side opposite to the vibration applying position P1 with respect to the droplet dropping position P2, and becomes a good removal region. For example, as shown in FIG. 6, by applying ultrasonic vibration to the outer liquid film region LF2, the ultrasonic vibration propagates from the left end portion of the wafer surface Wf to the entire wafer surface Wf. In this state, the substrate side When ripple vibration is added to an arbitrary position in the liquid film area LF1, the wafer surface area opposite to the vibration application position P1 with respect to the droplet dropping position P2 to which the ripple vibration is applied becomes a good removal area.

<First Embodiment>
FIG. 7 is a diagram showing a first embodiment of a substrate cleaning apparatus according to the present invention. FIG. 8 is a cross-sectional view showing a configuration of an ultrasonic wave application head used in the substrate cleaning apparatus of FIG. Further, FIG. 9 is a block diagram showing an electrical configuration of the substrate cleaning apparatus shown in FIG. This substrate cleaning apparatus is a single wafer type substrate cleaning apparatus used for a cleaning process for removing contaminants such as particles adhering to the surface Wf of a substrate W such as a semiconductor wafer. More specifically, after a treatment liquid such as DIW is supplied as a cleaning liquid to the substrate surface Wf on which the device pattern is formed to form a liquid film of the cleaning liquid, ultrasonic vibration and wave vibration are applied to the liquid film. An apparatus for applying and cleaning the substrate W. In the present embodiment, both the first cleaning liquid and the second cleaning liquid use the same type of processing liquid.

  The substrate processing apparatus includes a spin base 11 having a slightly larger planar size than the substrate W. A plurality of support pins 12 are arranged on the periphery of the upper surface of the spin base 11. Each support pin 12 comes into contact with the end of the substrate W, so that the substrate W is supported in a substantially horizontal state with the substrate surface Wf of the substrate W facing upward. Note that the configuration for holding the substrate is not limited to this, and for example, the substrate W may be held by an adsorption method such as a spin chuck.

  As shown in FIG. 7, a rotation shaft 31 is connected to the spin base 11. The rotating shaft 31 is connected to an output rotating shaft 34 of a motor 33 via a belt 32. And if the motor 33 act | operates based on the control signal from the control unit 2, the rotating shaft 31 will rotate with the motor drive. As a result, the substrate W held by the support pins 12 above the spin base 11 rotates around the rotation axis Pa together with the spin base 11. Thus, in the present embodiment, the “substrate rotating means” of the present invention is configured by the rotating shaft 31, the belt 32, and the motor 33, and the substrate W can be rotationally driven.

  A supply unit 4 is provided to supply the cleaning liquid to the surface Wf of the substrate W thus rotationally driven. In the supply unit 4, the nozzle 41 is disposed on the rotation axis Pa and above the spin base 11. A cleaning liquid supply unit 43 is connected to the nozzle 41 via a flow rate adjustment unit 42 so that the cleaning liquid can be supplied to the rotational center position of the substrate surface Wf. Thus, in the present embodiment, the rotation center position of the substrate surface Wf and the droplet dropping position (second position) P2 coincide. Then, in a state where the cleaning liquid supply unit 43 is operated, the flow rate adjustment unit 42 is operated according to the control signal from the control unit 2 to adjust the supply of the cleaning liquid from the cleaning liquid supply unit 43 to the nozzle 41. More specifically, the flow rate adjusting unit 42 has a function of supplying and stopping the cleaning liquid to the nozzle 41 and adjusting the flow rate when supplying the cleaning liquid. One of the main purposes of adjusting the flow rate of the cleaning liquid is to selectively execute a liquid film forming operation and a droplet dropping operation by a single nozzle 41, as will be described in detail later. Of course, as in the second and third embodiments described later, two types of nozzles are provided, a liquid film is formed by ejecting the first cleaning liquid from one liquid film forming nozzle, and the other droplet. Alternatively, the second cleaning liquid may be discharged from the nozzle for applying a ripple vibration to the liquid film.

  The upper end of the nozzle 41 is connected to the nozzle lifting / lowering drive mechanism 52 by a horizontal beam 51. Then, the nozzle 41 is moved up and down together with the horizontal beam 51 by operating the nozzle lifting drive mechanism 52 according to the control signal from the control unit 2. Therefore, when a height position command related to the height position of the nozzle 41 from the substrate surface Wf is given from the control unit 2 to the nozzle lifting drive mechanism 52, the nozzle 41 moves up and down in accordance with the height position command. Positioned at the height position. Therefore, by adjusting the height H from the substrate surface Wf to the tip (discharge port) of the nozzle 41, the liquid landing state of the cleaning liquid discharged from the nozzle 41 is changed to a liquid column state or a droplet state. Can be controlled.

  In addition, in order to prevent the cleaning liquid discharged from the nozzle 41 from scattering, a splash prevention cup 61 is provided around the spin base 11. That is, when the cup raising / lowering drive mechanism 62 raises the cup 61 according to the control signal from the control unit 2, the cup 61 moves the substrate W held by the spin base 11 and the support pins 12 to the side as shown in FIG. The cleaning liquid that surrounds the position and scatters from the spin base 11 and the substrate W can be collected. On the other hand, a transfer unit (not shown) places an unprocessed substrate W on the support pins 12 on the spin base 11, receives a processed substrate W from the support pins 12, and an ultrasonic wave application unit to be described next When the head 71 of 77 is moved between the vibration applying position and the retracted position, the cup raising / lowering driving mechanism 62 drives the cup 61 downward in accordance with a control signal from the control unit 2.

  FIG. 8 is a cross-sectional view showing the configuration of the ultrasonic wave application head. The ultrasonic wave application unit 77 includes an ultrasonic wave application head 71, an arm member 72 that holds the ultrasonic wave application head 71, and a head drive mechanism 73 that moves the ultrasonic wave application head 71.

  In the ultrasonic wave imparting head 71, a vibration plate 712 is attached to a bottom side opening of a main body portion 711 made of a fluororesin such as Teflon tetrafluoride (registered trademark). The diaphragm 712 has a disk shape in plan view, and the bottom surface thereof is a vibration surface VF. A vibrator 713 is attached to the upper surface of the diaphragm 712. Then, when a pulse signal is output from the ultrasonic oscillator 714 to the vibrator 713 based on the control signal from the control unit 2, the vibrator 713 vibrates ultrasonically.

  The ultrasonic wave application head 71 is held at one end of the arm member 72. A head driving mechanism 73 is connected to the other end of the arm member 72. The head drive mechanism 73 has a rotary motor 731. Then, the rotation shaft 732 of the rotation motor 731 is connected to the other end of the arm member 72, and when the rotation motor 731 is actuated according to the control signal from the control unit 2, the rotation center as shown in FIG. The arm member 72 swings around Pb, and the ultrasonic wave application head 71 is reciprocated between the vibration application position P1 and the retreat position P0. Here, the setting of the vibration applying position P1 is arbitrary, but in this embodiment, the vibration applying position P1 is set to the peripheral edge of the surface of the substrate W in order to suppress damage due to ultrasonic vibration. During the cleaning process, the ultrasonic wave application head 71 is fixedly disposed at the vibration application position P1.

  The elevating base 734 on which the rotation motor 731 is mounted is slidably fitted to an upright guide 735 and is screwed to a ball screw 736 provided side by side with the guide 735. The ball screw 736 is linked to the rotating shaft of the lifting motor 737. The lifting motor 737 operates in response to a control signal from the control unit 2 and rotates the ball screw 736 to move the nozzle 41 up and down. Thus, the head drive mechanism 73 is a mechanism that moves the ultrasonic wave application head 71 up and down and reciprocates to position it at the vibration application position P1.

  Further, when the ultrasonic wave application head 71 is positioned at the vibration application position P 1 by the head drive mechanism 73, the distance between the vibration surface VF and the substrate surface Wf, that is, the substrate facing distance D is accurately controlled by driving control of the lifting motor 737. Done. That is, as shown in FIG. 8, the substrate facing distance D is equal to or less than the film thickness of the liquid film LF of the cleaning liquid, and the space (gap space K) sandwiched between the vibration surface VF and the substrate surface Wf is the cleaning liquid. The interval is filled. When the control unit 2 operates the ultrasonic wave application head 71 in the liquid contact state, ultrasonic vibration is applied to the liquid film LF and the substrate W.

  The control unit 2 that controls the entire apparatus mainly includes a CPU (Central Processing Unit) 21, a RAM (Random Access Memory) 22, a ROM (Read Only Memory) 23, and a drive control unit 24. Yes. Among these, the ROM 23 is a so-called nonvolatile storage unit, and stores a program for controlling each unit of the apparatus. Then, when the CPU 21 controls each part of the apparatus according to the program stored in the ROM 23, the apparatus executes a substrate cleaning operation described below.

  Next, the operation of the substrate cleaning apparatus configured as described above will be described. In this substrate cleaning apparatus, an unprocessed substrate W is transported onto the support pins 12 by a transport unit (not shown) and held on the support pins 12. Then, after the transfer unit is retracted from the substrate cleaning apparatus, the CPU 21 of the control unit 2 controls each part of the apparatus and executes a cleaning process. At this time, the ultrasonic wave application head 71 is positioned at the retracted position P0.

  First, the rotation of the substrate W is started. Subsequently, the cleaning liquid is discharged from the nozzle 41 in the form of a liquid column and supplied to the substrate surface Wf. As a result, a liquid film LF of the cleaning liquid is formed on the substrate surface Wf (liquid film forming operation). At this time, the film thickness of the liquid film LF is adjusted with high accuracy by adjusting the rotation speed of the substrate W. For example, when the rotation speed of the substrate W is set to 100 rpm and DIW is supplied as a cleaning liquid from the nozzle 41 to the substrate surface Wf at a flow rate of 300 (mL / min), a liquid film LF of a cleaning liquid of 2 to 3 mm is formed on the substrate surface Wf. Can be formed. In the first embodiment, the liquid film LF is formed on the substrate surface Wf only by the liquid film region LF1, and the substrate surface Wf is covered from above by the liquid film LF.

  After the liquid film is formed, the ultrasonic wave application head 71 is moved from the retracted position P0 to the vibration application position P1 and positioned. As a result, the vibration surface VF comes into contact with the liquid film LF. Subsequently, a pulse signal is output from the ultrasonic oscillator 714 to the vibrator 713, and the vibrator 713 vibrates ultrasonically. Accordingly, ultrasonic vibration is applied to the liquid film LF at the vibration applying position (surface peripheral edge portion of the substrate W) P1. In this embodiment, while applying the vibration described below, it is fixedly arranged at the vibration applying position P1, and at that time, the oscillation output of the ultrasonic vibration is 5 W and the oscillation frequency is 3 MHz. Is set.

  In this embodiment, in addition to the above ultrasonic vibration, the cleaning liquid is dropped from the nozzle 41 in the form of droplets to give the vibration vibration to the liquid film LF. That is, the control unit 2 controls the flow rate adjusting unit 42 to adjust the flow rate of the cleaning liquid from the nozzle 41, and also controls the nozzle lifting / lowering drive mechanism 52 to adjust the height position of the nozzle 41. By adjusting the (cleaning liquid flow rate and nozzle height H), a droplet of the cleaning liquid is supplied to the rotation center of the substrate W on the liquid film LF (droplet dropping operation).

  In this way, ultrasonic vibration is applied to the liquid film LF on the substrate surface Wf at the vibration applying position P1, and a droplet of the cleaning liquid is supplied to the liquid film LF at a droplet dropping position P2 different from the vibration applying position P1. Thus, a wave vibration different from the ultrasonic vibration is applied to the liquid film LF. Thereby, the particles adhering to the substrate surface Wf are remarkably improved as compared with the case where the ultrasonic vibration is simply applied. This effect is as shown in the above experimental results, and even if the ultrasonic vibration output and frequency are set to such an extent that the substrate W is not damaged by using this effect, the effect of the particles by the ripple vibration is effective. Thus, the substrate surface Wf can be satisfactorily cleaned.

  When the cleaning process for the substrate surface Wf is completed as described above, the supply of the cleaning liquid to the nozzle 41 is stopped and the ultrasonic vibration is stopped. Further, the rotational speed of the substrate W is increased to apply a centrifugal force to the cleaning liquid remaining on the substrate W to remove the cleaning liquid from the substrate W and dry it (spin drying). When the series of processing is completed, the substrate W processed by the transport unit is unloaded from the substrate cleaning apparatus.

  As described above, according to the present embodiment to which the wave vibration is added, not only the ultrasonic vibration is added to the liquid film LF on the substrate W such as a silicon wafer, but also the wave vibration is added. The particle removal rate can be improved. Therefore, it is possible to suppress damage only by adding ultrasonic vibration at the oscillation output and frequency as described above, but particles cannot be removed well, but the addition of wave vibration improves the particle removal rate. Can do. That is, it is possible to achieve both suppression of substrate damage and improvement of particle removal.

  Further, in the above-described embodiment, the vibration applying position P <b> 1 is provided on the peripheral edge portion of the surface of the substrate W. Since this surface peripheral part is a site | part which does not form a pattern etc. normally, most ultrasonic vibrations which propagate the liquid film LF and are transmitted to the board | substrate W concentrate on a non-pattern site | part. As a result, pattern damage can be effectively prevented by ultrasonic vibration.

  Furthermore, when the ripple vibration is applied, a bias is generated in the good removal region. In this embodiment, the droplet dropping position P2 is set at the rotation center of the substrate W, and the cleaning process is performed while rotating the substrate W one or more times. Therefore, particles can be removed uniformly and satisfactorily over the entire substrate surface Wf.

  In the first embodiment, the droplet dropping position P2 is set as the rotation center of the substrate W. However, the droplet dropping position P2 is not limited to this, and is different from the vibration applying position P1. It is possible to efficiently remove particles on the substrate surface Wf while suppressing the damage to the substrate W by setting the wave vibration to the liquid film LF. Further, if the droplet dropping position P2 is positioned on the rotation center side of the substrate W with respect to the vibration applying position P1, particles can be uniformly removed from the entire substrate surface Wf.

Second Embodiment
By the way, in the substrate cleaning apparatus according to the first embodiment, the ultrasonic wave application head 71 is positioned at the vibration application position P1 of the liquid film region (hereinafter referred to as “substrate-side liquid film region”) LF1 formed on the substrate surface Wf. However, as described below, a liquid film region may be formed outside the periphery of the substrate W, and the ultrasonic vibration may be applied to the outer liquid film region. Hereinafter, a second embodiment of the present invention will be described in detail with reference to FIG. 5, FIG. 10, and FIG.

  FIG. 10 is a view showing a second embodiment of the substrate cleaning apparatus according to the present invention. FIG. 11 is a block diagram showing an electrical configuration of the substrate cleaning apparatus shown in FIG. The second embodiment is greatly different from the first embodiment in that the introduction portion 8 for forming the outer liquid film region is provided and the nozzle 41a in which the first cleaning liquid and the second cleaning liquid are different from each other. , 41b, and the vibration applying position P1 and the droplet dropping position P2 are in the outer liquid film region, and other configurations and operations are basically the same as those in the first embodiment. Therefore, in the following description, differences will be mainly described, and the same components as those in the first embodiment will be denoted by the same or corresponding reference numerals, and description thereof will be omitted.

  In the second embodiment, the supply unit 4 has two types of nozzles 41a and 41b. The nozzle 41a is disposed on the rotational axis Pa and above the spin base 11 as in the first embodiment. A first cleaning liquid supply unit 43a is connected to the nozzle 41a via a first flow rate adjustment unit 42a, and the first cleaning liquid can be supplied to the rotational center position of the substrate surface Wf. Then, the first cleaning liquid supply unit 43a and the first flow rate adjustment unit 42a are operated in accordance with a command from the control unit 2, whereby the first cleaning liquid is supplied from the first nozzle 41a to the central portion of the substrate surface Wf. At this time, the film thickness of the liquid film LF is adjusted with high accuracy by adjusting the rotation speed of the substrate W. In the second embodiment, as will be described below, the plate 81 of the introducing portion 8 can be arranged in the vicinity of the peripheral portion of the substrate W and substantially parallel to the substrate surface Wf, and is introduced from the substrate surface Wf. The first cleaning liquid flows into the surface of the plate 81 of the section 8 so that the outer liquid film region LF2 can be formed on the plate 81.

  As shown in FIGS. 5 and 10, the introduction portion 8 includes a plate 81 that can be disposed substantially parallel to the main surface of the substrate W in the vicinity of the peripheral portion of the substrate W, and fixes the plate 81 to the ultrasonic wave application head 71. And a side plate 82 to be used. That is, in this embodiment, one side (left hand side in FIG. 5) of the plate 81 is connected to the ultrasonic wave applying head 71 by the side plate 82 and attached in a so-called cantilever state. For this reason, the other side (the right-hand side in the figure) of the plate 81 is the free end side and extends to the substrate side. Then, when the head driving mechanism 73 is actuated in accordance with an operation command from the control unit 2 and the ultrasonic wave application head 71 moves to a predetermined vibration application position P1, the plate 81 moves to the vicinity of the peripheral edge of the substrate W and is positioned. Is done. The plate 81 is formed of a material (for example, quartz) having a higher hydrophilicity than the surface Wf of the substrate W to be cleaned. When the plate 81 is arranged near the peripheral edge of the substrate W by the head driving mechanism 73, the peripheral edge of the substrate surface Wf and the free end of the plate 81 are partially viewed from above as shown in FIG. The first cleaning liquid supplied from the nozzle 41a to the substrate surface Wf is introduced from the substrate W side to the plate 81 side due to the difference in surface tension. As a result, an outer liquid film region LF2 continuous with the substrate side liquid film region LF1 is formed on the plate 81, and the substrate surface is formed by the liquid film LF composed of the substrate side liquid film region LF1 and the outer liquid film region LF2. Wf is covered from above.

  In the present embodiment, when the plate 81 is disposed at the cleaning processing position (near the peripheral edge of the substrate W), the plate 81 can continuously have the substrate-side liquid film region LF1 and the outer liquid film region LF2. It is arranged close to the peripheral edge and the lower surface of the substrate W to such an extent. Therefore, when the second cleaning liquid is supplied from the other nozzle 41b to the liquid film LF to give the ripple vibration, the plate 81 and the substrate W can be prevented from coming into contact with each other and being damaged.

  A second cleaning liquid supply unit 43b is connected to the second nozzle 41b via a second flow rate adjustment unit 42b, and the second cleaning liquid can be supplied to the outer liquid film region LF2. In the second embodiment, the vibration applying position P1 is on the opposite side of the substrate-side liquid film region LF1 with respect to the droplet dropping position P2, and the rotation center of the substrate W, the droplet dropping position P2, and the vibration applying position P1 are the same. The droplet dropping position P2 is set so as to be on a straight line (one-dot chain line in FIG. 5B). Then, in a state where the second cleaning liquid supply unit 43b is operated, the second flow rate adjusting unit 42b is operated according to the control signal from the control unit 2, and the second cleaning liquid is supplied from the second cleaning liquid supply unit 43b to the nozzle 41b. Adjust.

  The upper end of the second nozzle 41b is connected to the second nozzle lifting / lowering drive mechanism 52b by a horizontal beam 51b. Then, the nozzle 41b is moved up and down together with the horizontal beam 51b by the operation of the second nozzle lifting drive mechanism 52b according to the control signal from the control unit 2. Therefore, when a height position command related to the height position of the nozzle 41b from the substrate surface Wf is given from the control unit 2 to the second nozzle lifting / lowering drive mechanism 52, the nozzle 41b moves up and down to the height position command. It is positioned at the corresponding height position. Therefore, by adjusting the height H from the substrate surface Wf to the tip (discharge port) of the nozzle 41b, the liquid deposition state of the second cleaning liquid discharged from the nozzle 41b on the outer liquid film region LF2 is changed to the liquid column. The state and the droplet state can be controlled.

  Next, the operation of the substrate cleaning apparatus according to the second embodiment configured as described above will be described. In this substrate cleaning apparatus, an unprocessed substrate W is transported onto the support pins 12 by a transport unit (not shown) and held on the support pins 12. Then, after the transfer unit is retracted from the substrate cleaning apparatus, the CPU 21 of the control unit 2 controls each part of the apparatus and executes a cleaning process. At this time, the ultrasonic wave application head 71 is positioned at the retracted position P0.

  First, the rotation of the substrate W is started. Subsequently, the first cleaning liquid is ejected in a liquid column shape from the nozzle 41a and supplied to the substrate surface Wf. As a result, a liquid film LF of the cleaning liquid is formed on the substrate surface Wf (liquid film forming operation). At this time, as in the first embodiment, the film thickness of the liquid film LF is adjusted with high accuracy by adjusting the rotation speed of the substrate W.

  After the liquid film is formed, the rotation of the substrate W is stopped. Then, the height position of the anti-scattering cup 61 is set to the lowered position, and the plate 81 and the ultrasonic wave applying head 71 swing from the retracted position P0 toward the vibration applying position P1 (position shown in FIGS. 5 and 10). And is arranged near the outer edge of the substrate W. At this time, the free end side (the right hand side in FIG. 5) of the plate 81 opposite to the connection side of the side plate 82 to the ultrasonic wave application head 71 enters the lower surface side of the substrate W. Then, the upper surface of the end portion on the free end side of the plate 81 is disposed so as to face and close to the lower surface of the peripheral edge of the substrate W. Thereby, most of the upper surface of the plate 81 is arranged in parallel in the radial direction AR1 from the peripheral edge of the substrate W and is not covered by the substrate W.

  Thereby, a part of the first cleaning liquid accumulated on the substrate W is introduced from the substrate W onto the plate 81 by surface tension. As a result, an outer liquid film region LF2 is formed on the plate 81. Thus, in the second embodiment, not only the liquid film region LF1 is formed on the substrate surface Wf but also introduced from the substrate W side to the plate 81 side by the first cleaning liquid supplied to the substrate surface Wf. Thus, an outer liquid film region LF2 continuous with the substrate side liquid film region LF1 is formed. Thus, the substrate surface Wf is covered with the liquid film LF composed of the substrate side liquid film region LF1 and the outer liquid film region LF2, and the vibration surface VF of the diaphragm 712 is in contact with the outer liquid film region LF2.

  Further, in parallel with the swinging operation of the plate 81 and the ultrasonic wave applying head 71, the nozzle 41b swings from the retracted position toward the droplet dropping position (second position) P2 by driving the nozzle lifting / lowering driving mechanism 52b. However, the swinging operation of the nozzle 41b is not limited to this timing, and the swinging operation of the nozzle 41b may be started after the swinging operation of the introduction plate 81 and the ultrasonic wave application head 71 is completed. . Further, the swinging operation of the plate 81 and the ultrasonic wave application head 71 may be started after the swinging operation of the nozzle 41b is completed. The same applies to the swing timing of the nozzle 41b in the third embodiment described later.

  Here, as shown in FIGS. 5 and 10, when the plate 81 and the ultrasonic wave application head 71 are arranged near the peripheral edge of the substrate W, the vibration plate 712 of the ultrasonic wave application head 71 is viewed from the nozzle 41b. Are disposed on the far side of the substrate W in the radial direction AR1.

  Next, the control unit 2 operates the ultrasonic wave application unit 70 so that the ultrasonic vibration is applied to the vibration application position P1 of the outer liquid film region LF2, and vibrations different from the ultrasonic vibrations (wave vibrations). The second cleaning liquid is supplied from the second cleaning liquid supply unit 43b to the outer liquid film area LF2 so as to be applied to the droplet dropping position P2 of the outer liquid film area LF2. More specifically, the flow rate adjustment valve 42b is opened, and the second cleaning liquid is supplied to the droplet dropping position P2 in the outer liquid film region LF2. In parallel with the supply of the second cleaning liquid, a pulse signal is output from the ultrasonic oscillator 714 to the vibrator 713, and ultrasonic vibration is applied to the vibration applying position P1 of the outer liquid film region LF2. The vibration applying position P1 is on the far side of the substrate W as viewed from the droplet dropping position P2 of the second cleaning liquid supplied from the second cleaning liquid supply unit 43b. In addition, the center of rotation of the substrate W, the droplet dropping position P2, and the vibration applying position P1 are arranged on a straight line (one-dot chain line in FIG. 5B).

  As described above, in the second embodiment, the droplet-shaped second cleaning liquid can be dropped onto the outer liquid film region LF2 so as to satisfactorily impart the ripple vibration. In the cleaning process, since the ultrasonic vibration is applied and the second cleaning liquid is supplied to the outer liquid film region LF2, the damage to the substrate W caused by them is reduced and the substrate W adheres to the substrate W. The removal rate of particles to be improved can be improved in each stage.

  In addition, the application of the ultrasonic vibration alone does not damage the substrate W. On the other hand, the ultrasonic vibration can be detected within the ultrasonic vibration output range and the oscillation frequency range in which particles on the substrate W cannot be removed well. By using in combination with the wave vibration, the particles can be favorably removed from the substrate W. Therefore, compared with the case where only the ultrasonic vibration is applied to the outer liquid film region LF2 for cleaning, the removal rate of particles adhering to the substrate W is improved, and the wiring pattern formed on the substrate W is improved. Damage can be reduced.

  Further, as shown in FIGS. 5 and 10, the second cleaning liquid supply unit 43b can supply the second cleaning liquid at a position outside the substrate W and from one nozzle 41b toward the outer liquid film region LF2. Has been. Thereby, the range in which the second cleaning liquid discharged from the nozzle 41b collides with the outer liquid film region LF2 can be minimized. Therefore, the influence of substrate damage can be reduced.

  In this embodiment, the oscillation output of ultrasonic vibration by the ultrasonic wave application head 71 is 1 W or more and 10 W or less (preferably 3 W or more and 6 W or less), and the oscillation frequency is 1 MHz or more and 6 MHz or less (preferably 2 MHz or more and 3 MHz). The following are set: Thereby, it can prevent that the wiring pattern etc. which were formed on the board | substrate W and the board | substrate W receive the damage resulting from an ultrasonic vibration.

  When the removal of particles is completed as described above, the flow rate adjustment valve 42b is closed to stop the dropping of the second cleaning liquid droplets, and the application of ultrasonic waves by the ultrasonic application head 71 is stopped. Then, the ultrasonic wave application head 71 is retracted, and the substrate W is rotated at a high speed. Thereby, the first and second cleaning liquids adhering to the substrate W are shaken off by the rotational centrifugal force, the substrate is dried (spin drying), and the cleaning process is completed. When the series of processing is completed, the substrate W processed by the transport unit is unloaded from the substrate cleaning apparatus.

  As described above, according to the second embodiment, not only ultrasonic vibration is added to the liquid film LF on the substrate W such as a silicon wafer, but also ripple vibration is added, so the first embodiment As with, the particle removal rate can be improved. In the second embodiment, since the vibration application position P1 is set in the outer liquid film region LF2, the ultrasonic vibration output from the ultrasonic wave application head 71 is transmitted to the substrate side via the outer liquid film region LF2. Since it propagates to the liquid film region LF1, it is possible to effectively prevent the substrate surface Wf from being damaged due to ultrasonic vibration. Further, in the second embodiment, in the outer liquid film region LF2, the ripple vibration is added at the position P2 where the ultrasonic vibration propagates from the vibration applying position P1 toward the substrate side liquid film region LF1 and the substrate surface Wf. Therefore, particles can be removed with an excellent removal rate for the entire substrate surface Wf. That is, particles on the substrate surface Wf can be more efficiently removed while suppressing damage to the substrate W.

<Third Embodiment>
In the substrate cleaning apparatus according to the second embodiment, both the ultrasonic vibration and the wave vibration are applied to the outer liquid film region LF2. For example, as illustrated in FIG. 6, the wave vibration is applied to the substrate side liquid film region LF1. You may comprise as follows. Hereinafter, a third embodiment of the present invention will be described with reference to FIG. Since the basic configuration of the apparatus is the same as that of the second embodiment, description of the configuration is omitted.

  In the third embodiment, similarly to the second embodiment, the first cleaning liquid from the nozzle 41a is supplied to the substrate surface Wf to form the liquid film LF composed of the substrate side liquid film region LF1 and the outer liquid film region LF2. To do. In parallel with the swinging operation of the plate 81 and the ultrasonic wave application head 71, the nozzle 41b is driven by the nozzle lifting / lowering drive mechanism 52b from the retracted position to the droplet dropping position (second position) P2 of the substrate side liquid film region LF1. Swing toward The nozzle 41b thus positioned is positioned on the substrate side (right hand side in FIG. 6) with respect to the diaphragm 712 of the ultrasonic wave application head 71.

  Next, the control unit 2 operates the ultrasonic wave application unit 70 so that the ultrasonic vibration is applied to the vibration application position P1 of the outer liquid film region LF2, and vibrations different from the ultrasonic vibrations (wave vibrations). The second cleaning liquid is supplied from the second cleaning liquid supply unit 43b to the substrate side liquid film area LF1 so that is applied to the droplet dropping position P2 of the substrate side liquid film area LF1. In parallel with the supply of the second cleaning liquid, a pulse signal is output from the ultrasonic oscillator 714 to the vibrator 713, and ultrasonic vibration is applied to the vibration applying position P1 of the outer liquid film region LF2. The relative relationship between the vibration applying position P1 and the droplet dropping position P2 is the same as in the second embodiment when the vibration applying position P1 is viewed from the droplet dropping position P2 of the second cleaning liquid supplied from the second cleaning liquid supply unit 43b. Thus, the relationship is located on the far side of the substrate W. In addition, the rotation center of the substrate W, the droplet dropping position P2, and the vibration applying position P1 are arranged in this order on a straight line (one-dot chain line in FIG. 6B).

  As described above, also in the third embodiment, as in the second embodiment, since the ultrasonic vibration is applied to the outer liquid film region LF2, in the cleaning process, the substrate W resulting from the application of the ultrasonic vibration. Damage to the can be reduced. Further, by dropping the second cleaning liquid in the form of liquid droplets onto the substrate-side liquid film region LF1, ultrasonic vibration and wave vibration are applied to the substrate-side liquid film region LF1, and as a result, as shown in the above experimental results In addition, the removal rate of particles adhering to the substrate W can be improved in each stage.

  In the third embodiment, as shown in FIG. 6, the second cleaning liquid is supplied to the position corresponding to the peripheral portion of the substrate surface Wf in the substrate-side liquid film region LF1 to give the ripple vibration. That is, the droplet dropping position P2 is provided on the peripheral edge of the surface of the substrate W. Since the peripheral portion of the surface is usually a portion that does not form a pattern or the like, most of the vibration vibration generated when the second cleaning liquid is supplied to the liquid film LF is concentrated on the non-pattern portion. As a result, damage to the pattern can be effectively prevented by wave vibration. Further, as is clear from the figure, since the droplet dropping position P2 is set at a position closest to the vibration applying position P1 in the substrate-side liquid film region LF1, the removal excellent region is the substrate surface excluding the non-pattern portion. It spreads over the entire surface of Wf, and particles can be uniformly removed from the entire substrate surface Wf.

<Others>
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 second embodiment and the third embodiment, the rotation center of the substrate W, the droplet dropping position P2, and the vibration applying position P1 are on a straight line (the chain line in FIGS. 5B and 6B). The vibration applying position P1 and the droplet dropping position P2 are set so that the vibration applying position P1 and the droplet dropping position P2 are not limited to this. That is, a position different from the vibration application position (first position) P1 to which the ultrasonic vibration is applied is on a path through which the ultrasonic vibration propagates in the liquid film LF toward the substrate surface Wf. 2 position) P2. For example, as shown in FIGS. 12 and 13, the droplet dropping position P2 may be arranged at a position away from a straight line connecting the rotation center of the substrate W and the vibration applying position P1.

  In the second and third embodiments, the first cleaning liquid from the nozzle 41a is supplied onto the substrate surface Wf for forming a liquid film on the substrate surface Wf, and the second cleaning liquid from the nozzle 41b Although explained as what is supplied on plate 81 for introduction for grant, the supply method of the 1st and 2nd cleaning fluid is not limited to this. For example, when the first and second cleaning liquids are the same type of processing liquid, the cleaning liquid may be supplied from one nozzle. In this case, when the substrate-side liquid film region LF1 is formed, the nozzle is moved above the rotation center of the substrate W, and when the ripple vibration is applied, the nozzle is moved above the droplet dropping position P2. .

  In the second and third embodiments, the introduction plate 81 is driven by the head drive mechanism 73, and the nozzle 41b capable of discharging the second cleaning liquid can be swung and lifted by the nozzle lift drive mechanism 52b. However, the method of swinging and raising / lowering the introduction plate 81 and the nozzle 41b is not limited to this. For example, the nozzle 41 b may be attached to the ultrasonic wave application head 71 similarly to the introduction plate 81. In this case, the swinging and lifting mechanism can be shared. Therefore, the number of parts can be reduced and the footprint of the substrate cleaning apparatus can be reduced.

  In the second embodiment and the third embodiment, the ultrasonic wave application head 71 and the introduction plate 81 are configured to be movable integrally. However, they may be configured to be independently movable. In this case, the height position of the introduction plate 81 and the height position of the vibration plate 712 of the ultrasonic wave application head 71 can be independently positioned, and the position accuracy of each part can be improved. This makes it possible to deal with the recipes and enhance versatility.

  In the second and third embodiments, the substrate W has been described as being held on the spin base 11 by the support pins 12. However, the present invention is not limited to this. For example, a suction chuck smaller than the substrate W is used. The substrate W may be attracted and held. In this case, the substrate W may be rotated by rotating the suction chuck while the introduction plate 81 is disposed while the substrate W is being cleaned. Specifically, if the cleaning time is 60 seconds, at least one rotation (1 rpm) may be performed during this time. Thereby, the uniformity of the cleaning effect on the entire surface of the substrate W can be improved. Further, in the embodiment in which the substrate W is held by the support pins 12 as in the second embodiment and the third embodiment, the introduction plate 81 contacts the support pins 12 as the spin base 11 rotates during the cleaning process. The substrate W may be rotated while being retracted at the contact position and controlled to enter when the support pin 12 goes too far.

  In the second embodiment and the third embodiment, one ultrasonic wave application head 71 is arranged. However, as shown in FIG. 14, for example, the ultrasonic wave application head 71 is provided near the outer edge of the substrate W. A plurality of them may be arranged. In this embodiment, in the apparatus for performing the cleaning process on the substrate W held by the three support pins 12, the three introduction plates 81 and the ultrasonic wave application head 71 are adjacent to each other when viewed from the circumferential direction of the substrate W. It arrange | positions so that it may become between the support pins 12 to perform. Further, the respective ultrasonic wave applying heads 71 are arranged at substantially equal intervals (angle R1 interval: approximately 120 ° interval) along the circumferential direction of the substrate W. Thereby, the uniformity of the cleaning effect on the entire surface of the substrate W can be improved.

  Furthermore, in the first to third embodiments, the first cleaning liquid and the second cleaning liquid have been described as being DIW (same type of processing liquid), but the present invention is not limited to this. For example, the first and second cleaning liquids may be chemical liquids used for wafer cleaning such as SC1 solution (mixed aqueous solution of ammonia water and hydrogen peroxide water). Further, the first and second cleaning liquids may be different processing liquids.

  The present invention relates to a semiconductor wafer, a glass substrate for photomask, a glass substrate for liquid crystal display, a glass substrate for plasma display, a substrate for FED (Field Emission Display), a substrate for optical disk, a substrate for magnetic disk, a substrate for magneto-optical disk, etc. The present invention can be applied to a substrate cleaning apparatus and a substrate cleaning method for performing a cleaning process on an entire substrate including ultrasonic vibrations.

It is a figure which shows the experimental content regarding the particle removal by vibration addition. It is a figure which shows the supply conditions set by experiment. It is a figure which shows the supply state of the cleaning liquid supplied to a liquid film from a nozzle during a washing process. It is a figure which shows the particle removal state after a washing process. It is a figure which shows the relationship between the vibration provision position in 2nd Embodiment, and a droplet dripping position. It is a figure which shows the relationship between the vibration provision position in 3rd Embodiment, and a droplet dripping position. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows 1st Embodiment of the board | substrate cleaning apparatus concerning this invention. It is sectional drawing which shows the structure of the ultrasonic provision head used with the board | substrate cleaning apparatus of FIG. FIG. 8 is a block diagram showing an electrical configuration of the substrate cleaning apparatus shown in FIG. 7. It is a figure which shows 2nd Embodiment of the board | substrate cleaning apparatus concerning this invention. FIG. 11 is a block diagram showing an electrical configuration of the substrate cleaning apparatus shown in FIG. 10. It is a figure which shows the relationship between the vibration provision position in 4th Embodiment, and a droplet dripping position. It is a figure which shows the relationship between the vibration provision position in 5th Embodiment, and a droplet dripping position. It is a figure which shows 6th Embodiment of the board | substrate cleaning apparatus concerning this invention.

Explanation of symbols

2 ... Control unit (control means)
4 ... Supply unit (supply means)
7: Ultrasonic wave applying unit 31: Rotating shaft (substrate rotating means)
32 ... Belt (substrate rotation means)
33 ... Motor (substrate rotating means)
41, 41a, 41b ... nozzle 71 ... ultrasonic wave application head 81 ... introduction plate LF ... (cleaning liquid) liquid film LF1 ... substrate side liquid film area LF2 ... outer liquid film area P1 ... vibration application position (first position)
P2: Droplet dropping position (second position)
W ... Substrate Wf ... Substrate surface

Claims (17)

Ultrasonic application means for applying ultrasonic vibration to the liquid film of the first cleaning liquid covering the substrate surface;
A second cleaning liquid is applied to the liquid film on a path where the ultrasonic vibration propagates in the liquid film toward the substrate surface and at a second position different from the first position to which the ultrasonic vibration is applied. Supply means for supplying;
While supplying the ultrasonic vibration to the liquid film by operating the ultrasonic wave applying means, the second cleaning liquid is supplied to the liquid film by the supplying means to give an additional vibration different from the ultrasonic vibration to the liquid film. Control means ,
Substrate cleaning characterized in that the supply means has a nozzle for discharging the second cleaning liquid, and the second cleaning liquid discharged from the nozzle is applied to the liquid film in a droplet state to give additional vibration. apparatus. The liquid film has a substrate-side liquid film region formed on the substrate surface by supplying the first cleaning liquid to the substrate surface;
The substrate cleaning apparatus according to claim 1, wherein both the first position and the second position are in the substrate-side liquid film region. Comprising substrate rotating means for rotating the substrate;
3. The substrate cleaning apparatus according to claim 1, wherein the control unit applies the ultrasonic vibration and the additional vibration to the liquid film while the substrate is rotated at least once or more. 4.   The substrate cleaning apparatus according to claim 3, wherein the second position is located on a rotation center side of the substrate with respect to the first position.   The substrate cleaning apparatus according to claim 4, wherein the second position is a rotation center of the substrate.   The substrate cleaning apparatus according to claim 2, wherein the ultrasonic wave applying unit is fixedly disposed.   The substrate cleaning apparatus according to claim 6, wherein the ultrasonic wave applying unit is disposed to face a peripheral edge portion of the surface of the substrate. Further comprising a plate that can be disposed substantially parallel to the substrate surface near the periphery of the substrate;
The liquid film includes a substrate-side liquid film region formed on the substrate surface by supplying the first cleaning liquid to the substrate surface, and the first cleaning liquid flows from the substrate surface to the surface of the plate. An outer liquid film region formed on the plate surface,
The first position and the second position are both in the outer liquid film region,
The substrate cleaning apparatus according to claim 1, wherein the first position is opposite to the substrate-side liquid film region with respect to the second position. Comprising a plate that can be arranged substantially parallel to the substrate surface near the periphery of the substrate;
The liquid film includes a substrate-side liquid film region formed on the substrate surface by supplying the first cleaning liquid to the substrate surface, and the first cleaning liquid flows from the substrate surface to the surface of the plate. An outer liquid film region formed on the plate surface,
The substrate cleaning apparatus according to claim 1, wherein the first position is in the outer liquid film region, while the second position is in the substrate side liquid film region.   The substrate cleaning apparatus according to claim 8, wherein the ultrasonic wave applying unit is fixedly disposed on the plate. Further comprising a substrate rotating means for rotating the substrate,
The rotation center of the substrate, the second position, and the first position are arranged in the order of the rotation center of the substrate, the second position, and the first position. The substrate cleaning apparatus according to the item. It said supply means substrate cleaning apparatus according to any one of claims 1 to 11 to form the liquid film by supplying the first cleaning liquid to the substrate surface from the nozzle. It said supply means substrate cleaning apparatus according to any one of claims 1 to 11 to form the liquid film by supplying the first cleaning liquid from a nozzle different from the nozzle to the substrate surface. Wherein the first cleaning liquid and the second cleaning liquid, a substrate cleaning apparatus according to any one of claims 1 to 13 is a processing liquid of the same kind. A first step of bringing the ultrasonic vibrator into contact with the liquid film of the first cleaning liquid covering the substrate surface at a first position;
While applying the ultrasonic vibration to the liquid film by operating the ultrasonic vibrator, the second cleaning liquid is supplied to the liquid film at a second position different from the first position to add vibration different from the ultrasonic vibration. the a second step of providing the liquid film,
In the second step, the second cleaning liquid droplet is dropped onto the liquid film . The substrate cleaning method according to claim 15 , wherein the first step is performed while rotating the substrate. 17. The substrate cleaning method according to claim 15 or 16, wherein the first and second cleaning liquids are the same kind of processing liquid.