JP5531489B2 - Wafer end face cleaning method and apparatus, and cleaning liquid supply apparatus - Google Patents

Description

  The present invention relates to a wafer end face cleaning method and apparatus using ultrasonic waves, and a cleaning liquid supply apparatus used in the method and apparatus.

  As semiconductor devices such as integrated circuits (ICs) and large scale integrated circuits (LSIs) are miniaturized, there is a problem in yield reduction due to the attachment of minute foreign matters during the manufacturing process. For this reason, not only a technique for removing adhered foreign substances in a semiconductor device formation region of a semiconductor wafer, but also a technique for cleaning a wafer end face (bevel part) for removing contaminants that cause the generation of the foreign substances has become important. .

  In order to manufacture a semiconductor device at a low cost, the diameter of a semiconductor wafer is generally increased to a diameter of 300 mm, and further studies on a 450 mm diameter have begun. Along with this, the manufacturing equipment in each manufacturing process has become larger and more expensive, and it is important to reduce costs comprehensively by simplifying the construction of the manufacturing equipment and improving the operating rate and running cost of the manufacturing equipment. It has become. This is also true for the wafer edge cleaning process, which is likely to be required more and more during the fine process of large diameter wafers.

  FIG. 1 schematically shows a typical wafer edge cleaning technique according to the prior art. The processing target wafer 1 is fixed with the suction pad 2 on the back surface with the front surface (pattern forming surface) facing up, and is rotated around the central axis of the wafer 1. A cleaning liquid (for example, pure water) supplied from a nozzle 3 disposed above the surface of the wafer 1 flows to the wafer end surface by centrifugal force due to the rotation of the wafer 1. One or more rotating brushes 4 are pressed against the wafer end surface, and the surface of the wafer end surface and / or the back surface side is subjected to physical scrubbing using the cleaning liquid flowing between the rotating brush and the wafer end surface. The rotating brush 4 is generally a sponge-like brush made of polyvinyl alcohol (PVA) and having elasticity. In such physical brush cleaning, since the brush is consumed, it is necessary to periodically replace or dispose of the brush, resulting in a decrease in the apparatus operating rate and an increase in running cost.

  In addition, if a chemical solution that performs chemical cleaning is used as the cleaning solution, the rotating brush may be omitted, but an expensive anti-corrosion material, an exhaust mechanism, and a safety protection mechanism for workers are avoided to avoid corrosion caused by the chemical solution. I need. Therefore, such chemical cleaning increases the size of the cleaning device and increases the manufacturing cost and running cost of the device. Furthermore, chemical cleaning requires the disposal of chemicals and has a problem that the environmental load is large.

  Under such circumstances, in recent years, a technique using ultrasonic waves for cleaning the wafer end face has been developed. For example, the cleaning liquid supplied with ultrasonic vibration is supplied onto the rotating wafer to improve the cleaning power, or the cleaning liquid is supplied onto the rotating wafer, and the cleaning liquid that has flowed into the ultrasonic excitation device disposed at the wafer end face position is used. A method of applying ultrasonic vibration using the excitation device is known.

JP 11-238713 A JP 2001-46985 A

  However, a known method for supplying ultrasonic vibration to the cleaning liquid supplied on the wafer or the supplied cleaning liquid is used for the attenuation of the ultrasonic vibration or because of the low efficiency of transmitting ultrasonic waves to the cleaning liquid. It is difficult to increase the degree of cleaning sufficiently. Therefore, there is still a demand for a cleaning technique that can sufficiently remove foreign substances adhering to the wafer end face while avoiding the use of rotating brushes that are consumables and chemicals having various problems.

  According to one aspect, a wafer end face cleaning method is provided. The cleaning liquid supply device has a groove-like wall surface that wraps around the edge of the wafer. In the method, the cleaning liquid supply device is disposed so that the wall surface of the device is close to the end surface of the wafer, and ultrasonic vibration is generated from the wall surface of the cleaning liquid supply device toward the end surface of the wafer during the rotation of the wafer. Discharging a given cleaning liquid.

  According to another aspect, there is provided a wafer end surface cleaning device having a wafer rotation mechanism for holding and rotating a wafer and a cleaning liquid supply device. The cleaning liquid supply device has a groove-shaped wall surface that wraps around the edge of the wafer, and discharges the cleaning liquid to which ultrasonic vibration is applied from the wall surface toward the wafer end surface while the wafer is rotating.

  According to still another aspect, there is provided a cleaning liquid supply apparatus that includes an ultrasonic oscillator and an ultrasonic horn that transmits ultrasonic waves emitted from the ultrasonic oscillator. The ultrasonic horn has a groove-like wall surface that wraps around the edge of the wafer to be cleaned. The cleaning liquid supply device also has a cleaning liquid conduit extending inside the ultrasonic horn, and the cleaning liquid conduit propagates the ultrasonic wave transmitted by the ultrasonic horn to the cleaning liquid to generate the ultrasonic cleaning liquid. The cleaning liquid supply device further has a conduit outlet extending between the cleaning liquid conduit and the wall surface of the ultrasonic horn, and discharges the ultrasonic cleaning liquid from the conduit outlet toward the wafer end surface.

  According to the disclosed technique, it is possible to efficiently supply the cleaning liquid to which the ultrasonic vibration is propagated to the wafer end surface, and to increase the cleaning degree of the wafer end surface without using a rotating brush that contacts the wafer end surface.

It is a perspective view which shows schematically the wafer end surface cleaning method and apparatus which concern on a prior art. 1 is a perspective view schematically showing a wafer end surface cleaning method and apparatus according to a first embodiment. It is a perspective view which illustrates the internal structure of an ultrasonic cleaning fluid supply unit. FIG. 4 is a cross-sectional view showing, in an enlarged manner, a portion close to the wafer end surface of the ultrasonic cleaning liquid supply unit along a straight line A-A ′ in FIG. 3, schematically showing a water film formed on the wafer end surface. It is a perspective view which shows schematically the wafer end surface cleaning method and apparatus which concern on 2nd Embodiment. FIG. 6 is a cross-sectional view similar to FIG. 4, schematically showing a water film formed on the wafer end surface of FIG. 5. It is a top view which shows roughly an alternative example of a wafer rotation mechanism. It is a side view of the wafer rotation mechanism of FIG. It is a side view which expands and shows the wafer contact part of the wafer rotation mechanism of FIG. It is a flowchart which illustrates the processing flow of a wafer end surface cleaning process.

  Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. In the drawings, various components are not necessarily drawn to the same scale. Throughout the drawings, the same or corresponding components are denoted by the same or similar reference numerals.

  First, a wafer end surface cleaning method and a wafer end surface cleaning apparatus including a cleaning liquid supply device according to the first embodiment will be described with reference to FIGS.

  As shown in FIG. 2, the cleaning apparatus according to the embodiment includes a wafer rotation mechanism 10 and a cleaning liquid supply apparatus (hereinafter referred to as an ultrasonic cleaning liquid) that generates a cleaning liquid (also referred to as an ultrasonic cleaning liquid in this application) to which ultrasonic vibration is applied. 20) (also referred to as a sonic cleaning liquid supply unit). The wafer rotation mechanism 10 holds a wafer 1 such as a semiconductor wafer and rotates it around a rotation axis. For example, the wafer rotating mechanism 10 vacuum chucks the back surface of the wafer 1 with the front surface (pattern forming surface) of the wafer 1 facing up, and rotates the wafer 1 around its central axis. The ultrasonic cleaning liquid supply unit 20 is disposed close to and non-contact with the wafer 1 and directly discharges the ultrasonic cleaning liquid toward the end face of the rotating wafer 1.

  3 and 4 show the configuration of the ultrasonic cleaning liquid supply unit 20 in more detail. FIG. 3 is a perspective view showing the internal structure of the ultrasonic horn, and FIG. 4 is a cross-sectional view taken along the line A-A ′ in FIG. 3. The ultrasonic cleaning liquid supply unit 20 includes an ultrasonic oscillator 21 and an ultrasonic horn 22 to which the ultrasonic oscillator 21 is attached. Further, the ultrasonic cleaning liquid supply unit 20 is provided with a cleaning liquid conduit 23 disposed in the horn 22, a supply port 24 for supplying the cleaning liquid into the conduit 23 from the outside of the apparatus 20, and a plurality of cleaning liquids in the conduit 23. A conduit outlet 25.

  The ultrasonic oscillator 21 includes, for example, a piezoelectric transducer (PZT) that converts an electrical signal having an ultrasonic frequency of several tens of kHz to several MHz into mechanical vibration.

  The ultrasonic horn 22 includes a main body portion 22a to which the ultrasonic oscillator 21 is attached and an arc portion 22b that forms a hollow structure together with the main body portion 22a along a certain fixed portion on the outer periphery of the wafer 1 to be processed. Have. Moreover, the circular arc part 22b has the wall surface 22c which has the groove shape fitted to the end surface 1a of the process wafer 1, in the cross section, as shown in FIG. Specifically, it has the wall surface 22c which has the groove shape which wraps the edge part 1b of the process wafer 1. FIG. Here, the end portion 1 b is a portion including at least the end surface 1 a of the processing wafer 1. The cross-sectional shape of the wall surface 22c is adapted so that a substantially uniform distance d exists between the wall surface 22c and the wafer end 1b during processing of the wafer 1. The distance d preferably has a value in the range of 1 mm to 3 mm so that the liquid film 26 is stably formed by the ultrasonic cleaning liquid discharged from the conduit outlet 25 communicating with the wall surface 22c.

  The material of the ultrasonic horn 22 is not particularly limited as long as it is stable to the cleaning liquid, but may be a metal, particularly an alloy such as stainless steel or titanium alloy having rust prevention properties. Alternatively, the ultrasonic horn 22 may comprise quartz. Furthermore, the ultrasonic horn 22 may have a plurality of materials such as having an alloy such as stainless steel at the joint with the ultrasonic oscillator 21 and having quartz as a whole.

  The conduit 23 propagates the ultrasonic wave radiated from the ultrasonic oscillator 21 and transmitted by the ultrasonic horn 22 to the cleaning liquid, and guides the generated ultrasonic cleaning liquid along the arc portion 22 b of the ultrasonic horn 22. It extends like so. The conduit 23 includes first and second extending portions 23a and 23b in FIG. 3, but the shape of the conduit 23 is not limited to this. However, the angle 23 formed with respect to the propagation direction of the ultrasonic wave radiated from the ultrasonic oscillator 21 is preferably 45 ° ≦ θ ≦ 90 ° in the conduit 23 like the second extending portion 23b of FIG. And have a portion that extends. This is because the ultrasonic vibration is efficiently propagated to the cleaning liquid flowing in the conduit 23. The conduit | pipe 23 contains the alloy which has rust prevention property, for example.

  The conduit outlets 25 are preferably provided at a plurality of locations along the arc portion 22 b of the ultrasonic horn 22 and the conduit 23. More preferably, in order to uniformly supply the ultrasonic cleaning liquid to the end surface 1 a of the rotating wafer 1, the conduit outlets 25 are arranged at equal intervals along the arc portion 22 b of the ultrasonic horn 22. Further, in FIG. 4, the conduit outlet 25 is drawn so as to extend in the horizontal direction directly beside the wafer 1, but the arrangement position and angle of the conduit outlet 25 are not limited thereto. Since the wall surface 22c is adapted to the end portion 1b of the wafer 1 and the distance between them is within the range of 1 mm to 3 mm, the formation of a stable liquid film 26 is ensured. The cleaning liquid may be discharged from a shifted vertical position and / or a shifted angle. The conduit outlet 25 preferably comprises the same material as the ultrasonic horn 22 and / or the conduit 23.

  2 and 3 show one ultrasonic horn 22 having an arc portion 22b equal to about ¼ of the outer circumference of the wafer 1, the present embodiment is not limited to this. For example, the size of the arc portion 22 b may be smaller than ¼ of the outer periphery of the wafer 1. Conversely, the size of the arc portion 22 b may be larger than ¼ of the outer periphery of the wafer 1, and the ultrasonic cleaning liquid supply unit 20 may have a plurality of cleaning liquid supply ports 24. Further, the wafer end surface cleaning apparatus has a plurality of ultrasonic cleaning liquid supply units, such as four ultrasonic cleaning liquid supply units 20 arranged in a ring shape so as to substantially surround the entire circumference of the wafer 1. May be.

  Further, the number of rotations of the wafer 1 by the rotation mechanism 10 can be preferably in a range of 30 to 100 rpm, such as 50 rpm. If the rotational speed is higher than 100 rpm, bubbles may be mixed into the liquid film 26 and the ultrasonic vibration may disappear or attenuate, and the cleaning liquid may scatter in the center direction of the wafer 1 and reattachment of foreign matters is likely to occur. On the other hand, if the rotational speed is lower than 30 rpm, sufficient centrifugal force does not work and the formation of the liquid film 26 tends to become unstable. In addition, it is preferable to perform the drying process which shakes off the washing | cleaning liquid adhering to the wafer edge part 1b with a centrifugal force after washing | cleaning of a wafer end surface. In this drying process, after the ultrasonic cleaning liquid supply unit 20 is separated from the wafer 1 using a drive mechanism such as an arm, the rotation speed of the rotation mechanism 10 is increased to, for example, 1000 rpm or more. Therefore, the wafer rotation mechanism 10 is preferably controllable in a relatively low speed range including at least 30 rpm-100 rpm, and more preferably rotates in both the low speed range and a relatively high speed range of, for example, 1000 rpm-3000 rpm. It can be controlled.

  According to the present embodiment, since ultrasonic waves are efficiently propagated to the cleaning liquid and the ultrasonic cleaning liquid thereby is supplied directly to the wafer end surface from the proximity position, even when pure water is used as the cleaning liquid. A sufficient cleaning power for removing foreign substances on the wafer end surface can be obtained. Therefore, it is possible to avoid the use of consumables such as a rotating brush and chemicals that increase the running cost and / or the manufacturing cost of the apparatus. Further, it is possible to shorten the time for cleaning the edge of each wafer by supplying ultrasonic cleaning liquid from a plurality of conduit outlets or using a plurality of ultrasonic cleaning liquid supply units.

  Next, with reference to FIGS. 5 and 6, a wafer end surface cleaning method according to the second embodiment and a wafer end surface cleaning apparatus including an ultrasonic cleaning liquid supply device will be described.

  As shown in FIG. 5, the cleaning apparatus according to this embodiment includes a wafer rotation mechanism 10, a cleaning liquid supply apparatus 20, and a further cleaning liquid supply apparatus 30. The wafer rotation mechanism 10 is, for example, a vacuum chuck for the back surface of the wafer 1 with the front surface of the wafer 1 such as a semiconductor wafer facing up, and rotates the wafer 1 around its central axis. It may have the same configuration as the rotation mechanism 10. Further, the cleaning liquid supply device 20 is disposed close to and non-contact with the wafer 1 and directly discharges the ultrasonic cleaning liquid toward the end surface of the rotating wafer 1. The ultrasonic cleaning liquid supply unit 20 shown may have the same configuration. Therefore, only the matter relevant to the further cleaning liquid supply apparatus 30 is demonstrated here.

  The cleaning liquid supply device 30 is, for example, a cleaning liquid nozzle and is disposed above the surface of the wafer 1 and discharges a cleaning liquid such as pure water toward the vicinity of the center of the rotating wafer 1. The discharged cleaning liquid moves in the direction of the wafer end surface by the centrifugal force generated by the rotation of the wafer 1, and at least a part of the cleaning liquid flows into the outer peripheral portion where the ultrasonic cleaning liquid supply unit 20 is disposed. Therefore, as shown in FIG. 6, the cleaning liquid supplied from the cleaning liquid nozzle 30 to the surface of the wafer 1 is mixed with the ultrasonic cleaning liquid from the conduit outlet 25 of the ultrasonic cleaning liquid supply unit 20 in the vicinity of the wafer end 1b. Thereby, the ultrasonic vibration is also propagated to the cleaning liquid from the cleaning liquid nozzle 30, and the water film 36 that ultrasonically vibrates is formed.

  Here, the water film 36 covers not only the groove-shaped wall surface 22c of the ultrasonic horn 22 of the ultrasonic cleaning liquid supply unit 20 and the wafer end 1b but also the surface of the wafer 1, so that the water film 36 is added to the wafer end face. It may also be possible to clean the wafer surface. However, since the ultrasonic vibration of the water film 36 is attenuated toward the center of the wafer 1, the foreign matter attached to the region is removed without damaging the fine pattern formed in the semiconductor device formation region of the wafer 1. Can do.

  In the present embodiment, the cleaning liquid supplied near the center of the rotating wafer 1 flows into the wafer end 1b by centrifugal force, so that even if foreign matter scatters in the wafer center direction during the cleaning process, it adheres again. It is discharged with the cleaning solution without any problems. Therefore, even if the number of rotations of the wafer 1 by the rotation mechanism 10 is set higher than that of the first embodiment, for example, 100 rpm, the influence of scattering of foreign matters can be suppressed. In addition, it is preferable to perform the drying process which shakes off the washing | cleaning liquid adhering to the surface and the edge part 1b of the wafer 1 with a centrifugal force after wafer washing | cleaning. In this drying process, after the ultrasonic cleaning liquid supply unit 20 is separated from the wafer 1 using a drive mechanism such as an arm, the rotation speed of the rotation mechanism 10 is increased to, for example, 1000 rpm or more.

  A cleaning liquid nozzle similar to the cleaning liquid nozzle 30 may be provided on the back surface side in addition to the front surface side of the wafer 1.

  Also in the present embodiment, as in the first embodiment, ultrasonic waves are efficiently propagated to the cleaning liquid, and the obtained ultrasonic cleaning liquid is supplied to the wafer end surface from the proximity position. Therefore, pure water was used as the cleaning liquid. Even in this case, sufficient cleaning power can be obtained to remove foreign substances on the wafer end face. Therefore, it is possible to avoid the use of consumables such as a rotating brush and chemicals that increase the running cost and / or the manufacturing cost of the apparatus. Further, it is possible to shorten the time for cleaning the edge of each wafer by supplying ultrasonic cleaning liquid from a plurality of conduit outlets or using a plurality of ultrasonic cleaning liquid supply units.

  Next, an alternative example of the back surface chuck type wafer rotating mechanism 10 shown in FIGS. 2 and 5 will be described with reference to FIGS. The wafer rotation mechanism can take various forms. FIG. 7 is a top view schematically showing a wafer end surface cleaning apparatus including a wafer rotating mechanism 40 according to an alternative example, and FIG. 8 is a side view thereof. However, in FIG. 8, the ultrasonic cleaning liquid supply unit 20 is omitted, and only two of the four rotation rollers 41 described later are shown.

  The wafer rotation mechanism 40 holds and rotates the wafer 1 to be subjected to the edge cleaning process by three or more (four in the illustrated example) rotation rollers 41. As an example, as shown in an enlarged view in FIG. 9, each rotating roller 41 includes a rotating shaft 41 a inclined with respect to the vertical direction, a first cylindrical portion 41 b, and a second diameter larger than the first cylindrical portion 41 b. It has a cylindrical portion 41d and a connecting portion 41c between the first and second cylindrical portions 41b and 41d. The inclination angle of the rotating shaft 41a with respect to the vertical direction is preferably 45 °. The wafer 1 is held and rotated in a state where the back surface side of the end surface 1a is in point contact with the first cylindrical portion 41b. Specifically, each rotating roller 41 is rotated at the same rotational speed by the power of one motor 42, and the wafer 1 is rotated by the frictional force of the point contact portion between each rotating roller 41 and the wafer 1.

  In order to transmit the rotation from the motor 42 to the rotating roller 41, each rotating roller 41 has a gear 43 fixed to each rotating shaft 41 a, and a further gear meshing with the gear 43 is attached to each rotating roller 41. A pulley 45 to which 44 is fixed is provided. Each pulley 45 is rotated by the timing belt 46 at the same rotational speed as the other pulleys 45. In order to transmit the rotation from the motor 42 to the timing belt 46, in the example shown in FIG. 8, one pulley 45 and a gear 44 associated therewith are directly connected to the motor 42. However, for transmission of rotation to the timing belt 46, a separate pulley that is directly connected to the motor 42 and that contacts the timing belt 46 may be provided.

  The rotational speed of the motor 42 is preferably controlled so that the rotational speed of the wafer 1 falls within the range of 30 rpm to 100 rpm as described above. Since the load applied to the contact portions of the wafer 1 with the respective rotating rollers 41 is dispersed also in the center direction of the wafer 1, an effect of keeping the wafer 1 horizontal can be obtained. Further, even if the wafer 1 is likely to lose its horizontal balance, the peripheral portion of the connecting portion 41c of each rotating roller 41 is raised substantially vertically as shown in FIG. The wafer 1 can be returned to the horizontal level before the direction balance is lost. Therefore, it is possible to clean the entire periphery of the wafer end surface while keeping the wafer 1 horizontal by using its own weight and avoiding the wafer end surface from contacting the ultrasonic cleaning liquid supply unit 20.

  Further, when the wafer rotation mechanism 40 is used, for example, in the second embodiment shown in FIG. 5, an apparatus similar to the cleaning liquid nozzle 30 is arranged near the center of the back surface of the wafer 1 to supply the cleaning liquid. The entire wafer 1 including the end face can be cleaned.

  In addition, after performing the wafer end face cleaning process by the wafer rotation mechanism 40, when performing swing-off drying by high-speed rotation such as 1000 rpm, the wafer 1 may be transferred to another wafer rotation mechanism or the like by a transfer arm or the like. Alternatively, another rotation mechanism that is in the retracted position below the wafer 1 in the same processing space as that of the wafer rotation mechanism 40 may be raised and the rotation mechanism may be used.

  Next, with reference to FIG. 10, the process flow of the wafer edge cleaning process will be described.

  In step S1, a wafer end face cleaning process recipe is set using, for example, an operation panel of the wafer cleaning apparatus. The recipe includes the processing time of the cleaning step (S8), the number of wafer rotations, and the ultrasonic power. In addition, the recipe may include other processing parameters such as the processing time of the drying step (S12) and the number of wafer rotations.

  In step S2, the wafer to be processed is transferred to a predetermined processing position for end face cleaning by, for example, a transfer arm, and the wafer is sucked to the wafer rotating mechanism by a vacuum chuck or the like in step S3 as necessary. Let

  Next, in step S4, rotation of the wafer is started in accordance with the wafer rotation speed (preferably 30 rpm-100 rpm) set in step S1. In step S5, for example, the cleaning liquid supply device which is the above-described ultrasonic cleaning liquid supply unit 20 is moved to an operating position close to the wafer end face. Further, if necessary, for example, a further cleaning liquid supply device which is the above-described cleaning liquid nozzle 30 is moved to an operating position above the wafer. Furthermore, if necessary, for example, a cleaning liquid nozzle similar to the above-described cleaning liquid nozzle 30 may be moved to an operating position below the wafer. Note that step S5 may be performed before step S4.

  Next, in step S6, the ultrasonic cleaning liquid supply unit starts discharging a cleaning liquid that is, for example, pure water. Further, the cleaning liquid nozzle as required starts to discharge the cleaning liquid, for example, pure water. In step S7, the ultrasonic cleaning liquid supply unit starts ultrasonic oscillation by the ultrasonic oscillator according to the ultrasonic power set in step S1. Thereby, the process flow moves to the cleaning step of Step S8. Then, after elapse of a set processing time, for example, 1 minute, the ultrasonic cleaning liquid supply unit stops the ultrasonic oscillation by the ultrasonic oscillator in step S9, and stops the discharge of the cleaning liquid in step S10. Further, the cleaning liquid nozzle as required also stops the discharge of the cleaning liquid. Thereafter, in step S11, the ultrasonic cleaning liquid supply unit and the cleaning liquid nozzle as necessary are moved to a retracted position separated from the processing target wafer.

  Next, in step S12, the cleaning liquid is dried. This drying step may use, for example, swing-off drying by high-speed rotation of the wafer so that the cleaning liquid does not remain on the end surface, front surface, and / or back surface of the wafer to be processed to generate new contamination. In the example of swing-off drying, in step S12-1, the wafer rotation mechanism rotates the wafer according to the wafer rotation speed and time set in step S1, such as 1000 rpm. The wafer rotation mechanism used in the drying step S12 may be the same as or different from the mechanism in step S8 depending on the form of the wafer rotation mechanism used in the cleaning step S8 and the desired number of rotations. In step S12-2, the rotation of the wafer is stopped.

  Next, in step S13 as necessary, the wafer rotation mechanism releases the wafer suction by a vacuum chuck or the like. Finally, in step S14, the processed wafer is unloaded.

  If there are a plurality of wafers to be processed using the same recipe, for example, for one lot, steps S2 to S14 may be repeated.

  Although the embodiment has been described in detail above, the present invention is not limited to the specific embodiment, and various modifications and changes can be made within the scope of the gist described in the claims. For example, the further cleaning liquid supply device 30 of the second embodiment may be a so-called ultrasonic nozzle to increase the cleaning degree of the front surface and / or back surface of the wafer.

Regarding the above description, the following additional notes are disclosed.
(Appendix 1)
Arranging the cleaning liquid supply device so that the wall surface of the device is close to the end surface of the wafer;
During the rotation of the wafer, a cleaning step of discharging a cleaning liquid to which ultrasonic vibration is applied from the wall surface of the cleaning liquid supply device toward the end surface of the wafer;
Have
The wall surface has a groove-like cross-sectional shape that wraps around the edge of the wafer,
Wafer edge cleaning method.
(Appendix 2)
The wafer end surface cleaning method according to claim 1, wherein, in the cleaning step, the cleaning liquid is discharged from a plurality of discharge ports provided on the wall surface toward the end surface of the wafer.
(Appendix 3)
3. The wafer end surface cleaning method according to appendix 1 or 2, wherein in the cleaning step, a cleaning liquid is further supplied to the surface of the wafer using a further cleaning liquid supply device.
(Appendix 4)
The wafer end surface cleaning method according to any one of appendices 1 to 3, wherein the rotation speed of the wafer is within a range of 30 rpm to 100 rpm.
(Appendix 5)
A wafer rotation mechanism for holding and rotating the wafer;
A cleaning liquid supply device having a groove-shaped wall surface that wraps around an edge of the wafer, and supplying a cleaning liquid that discharges a cleaning liquid to which ultrasonic vibration is applied from the wall surface toward the end surface of the wafer during rotation of the wafer Equipment,
A wafer end surface cleaning apparatus.
(Appendix 6)
6. The wafer end surface cleaning apparatus according to appendix 5, further comprising a cleaning liquid supply apparatus that discharges a cleaning liquid onto the surface of the rotating wafer.
(Appendix 7)
The wafer rotating mechanism has three or more rotating rollers in which each rotating roller contacts the wafer on the back side of the end surface of the wafer, and the rotating rollers move the wafer by its own weight. The wafer end surface cleaning apparatus according to appendix 5 or 6, which is maintained in a horizontal direction.
(Appendix 8)
An ultrasonic oscillator,
An ultrasonic horn that transmits ultrasonic waves radiated from the ultrasonic oscillator, and an ultrasonic horn having a groove-like wall surface that wraps around an end of a wafer to be cleaned;
A conduit that extends inside the ultrasonic horn and guides the cleaning liquid; a conduit that propagates the ultrasonic wave transmitted by the ultrasonic horn to the cleaning liquid to generate the ultrasonic cleaning liquid;
A conduit outlet extending between the conduit and the wall surface of the ultrasonic horn and discharging the ultrasonic cleaning liquid toward an end surface of the wafer;
A cleaning liquid supply apparatus.
(Appendix 9)
The cleaning liquid supply apparatus according to appendix 8, wherein the ultrasonic horn has an arc portion having the wall surface along the outer periphery of the wafer to be cleaned, and a plurality of the conduit outlets are provided along the arc portion. .
(Appendix 10)
The cleaning liquid supply apparatus according to appendix 8 or 9, wherein the groove-shaped wall surface is adapted to have a uniform distance from the wafer end surface during cleaning of the wafer end surface.
(Appendix 11)
The cleaning liquid supply apparatus according to any one of appendices 8 to 10, wherein at least a part of the conduit forms an angle of 45 ° or more and 90 ° or less with respect to a propagation direction of the ultrasonic wave radiated from the ultrasonic oscillator. .

DESCRIPTION OF SYMBOLS 1 Wafer 1a Wafer edge 1b Wafer edge 10 Wafer rotation mechanism 20 Ultrasonic cleaning liquid supply unit (cleaning liquid supply apparatus)
DESCRIPTION OF SYMBOLS 21 Ultrasonic oscillator 22 Ultrasonic horn 22a Ultrasonic horn main body 22b Ultrasonic horn circular arc part 22c Wall surface of ultrasonic horn circular arc part 23 Cleaning liquid conduit 24 Cleaning liquid supply port 25 Conduit outlet (cleaning liquid discharge port)
26 Liquid film 30 Cleaning liquid nozzle (further cleaning liquid supply device)
36 Liquid film 40 Wafer rotating mechanism 41 Rotating roller 42 Motor 43, 44 Gear 45 Pulley 46 Timing belt

Claims (5)

Arranging the cleaning liquid supply device so that the wall surface of the device is close to the bevel portion of the wafer;
During the rotation of the wafer, a cleaning step of discharging a cleaning liquid to which ultrasonic vibration is applied from the wall surface of the cleaning liquid supply device toward the bevel portion of the wafer;
Have
The wall has a groove-like cross-sectional shape that wraps the ends of the wafer, the groove-like cross-sectional shape has a uniform gap between the bevel portion of the wafer during cleaning of the bevel portion of the wafer Have been adapted as
Wafer edge cleaning method.   The wafer end surface cleaning method according to claim 1, wherein in the cleaning step, a cleaning liquid is further supplied to the surface of the wafer using a further cleaning liquid supply device.   The wafer end surface cleaning method according to claim 1, wherein the rotation speed of the wafer is within a range of 30 rpm to 100 rpm. A wafer rotation mechanism for holding and rotating the wafer;
A cleaning liquid supply device having a groove-shaped wall surface that wraps around an edge of the wafer, and discharges a cleaning liquid to which ultrasonic vibration is applied from the wall surface toward the bevel portion of the wafer during rotation of the wafer. A feeding device;
Have
The groove-like wall surface is adapted to have a uniform spacing with the bevel portion of the wafer during cleaning of the bevel portion of the wafer;
Wafer edge cleaning equipment. An ultrasonic oscillator,
An ultrasonic horn that transmits ultrasonic waves radiated from the ultrasonic oscillator, and an ultrasonic horn having a groove-like wall surface that wraps around an end of a wafer to be cleaned;
A conduit that extends inside the ultrasonic horn and guides the cleaning liquid; a conduit that propagates the ultrasonic wave transmitted by the ultrasonic horn to the cleaning liquid to generate the ultrasonic cleaning liquid;
A conduit outlet extending between the conduit and the groove-like wall surface of the ultrasonic horn and discharging the ultrasonic cleaning liquid toward the bevel portion of the wafer;
Have
The groove-like wall surface is adapted to have a uniform spacing with the bevel portion of the wafer during cleaning of the bevel portion of the wafer;
Cleaning liquid supply device.

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