JP2010010652A - Single wafer cleaning apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a single wafer cleaning apparatus capable of preventing mutual contamination between cleaned objects which occurs when a backside of the cleaned object and a cleaning apparatus are in contact with each other, and suppressing reattachment of a cleaning liquid and cleaned dirt on the cleaned object. <P>SOLUTION: The single wafer cleaning apparatus includes at least a chuck pin for holding a side surface of the cleaned object, a flange arranged beneath the cleaned object and having a discharge port for discharging a liquid, and a liquid splash preventing plate arranged on an outer side of the flange for preventing splash of the liquid discharged from the flange. A backside of the cleaned object is floated with a liquid by the flange in a non-contact state, and the chuck pin holds the side surface of the cleaned object to clean the cleaned object. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a single wafer cleaning apparatus for cleaning a semiconductor silicon wafer, a substrate on which a device pattern is formed on a photomask, and the like one by one.

  When processing semiconductor substrates such as silicon wafers and photomasks in semiconductor manufacturing processes, if particles such as organic matter, metal dust, or foreign matter adhere to the substrate, In this case, uniform processing is not performed, and such a substrate is indirectly cross-contaminated from another substrate, resulting in a decrease in product manufacturing yield. Therefore, before processing a normal substrate, particles and the like are removed from the substrate by cleaning the substrate with a cleaning device.

  Conventionally, such a cleaning apparatus for cleaning an object to be cleaned includes a batch type cleaning apparatus capable of simultaneously cleaning a plurality of objects to be cleaned and a single wafer cleaning apparatus for cleaning objects to be cleaned one by one. is there. Batch type cleaning equipment has become difficult to handle multiple semiconductor substrates at the same time with the recent increase in size of semiconductor substrates, and the size of the equipment itself needs to be increased. Devices have become widely used.

FIG. 4 shows a schematic diagram of a conventional sheet-type washing apparatus. This single wafer cleaning apparatus 101 includes a rotatable table 102, a rotation driving unit 108 for rotating the table 102 around its central axis, and a surface nozzle 106 for cleaning the surface of an object 105 to be cleaned. , And a back surface nozzle 107 for cleaning the back surface of the object 105 to be cleaned.
The table 102 is provided with a plurality of pins 103 for hooking the object 105 to be cleaned on the arm 104 in order to hold the object 105 to be cleaned. The back nozzle 107 is installed so as to protrude from the center of the arm 104 and is not rotated.

In order to clean the front and back surfaces of an object to be cleaned using such a single wafer cleaning apparatus 101, the object to be cleaned 105 is held by the table 102, and the table 102 is rotated by the rotation drive unit 108 to be cleaned. The object 105 is rotated and, for example, the chemical solution is discharged from the front surface nozzle 106 to the front surface side of the object to be cleaned, and the back surface is cleaned by discharging a cleaning liquid such as ultrapure water from the discharge port formed in the back surface nozzle 107. .
Such cleaning is usually performed in a chamber or a clean room in which a downflow atmosphere gas is circulated.
In addition, a single wafer cleaning apparatus is disclosed in which ultrasonic waves are superimposed on a cleaning liquid by an ultrasonic vibrator (not shown), and the ultrasonic waves are propagated to an object to be cleaned for cleaning (see Patent Document 1).

However, when the object to be cleaned is cleaned with such an apparatus 101, the cleaning liquid scattered from the object to be cleaned 105 rises and adheres to the object to be cleaned 105 again due to the rotational wind pressure of the table 102 that rotates at a high speed. I couldn't. In addition, there is a problem that excess cleaning liquid that has fallen down from the nozzle 107 for the back surface is repelled and scattered by the rotating table 102 and the rotating mechanism, thereby reducing particles due to the cleaning liquid reattaching to the front and back surfaces of the object 105 to be cleaned. It was a challenge to make it happen.
In addition, there is also a problem that damage is generated on the surface of the object to be cleaned by superimposing ultrasonic waves on the cleaning liquid with a nozzle with an ultrasonic vibrator.

  For the problem of re-adhesion of the cleaning liquid to the object to be cleaned, a tapered umbrella as disclosed in Patent Document 2 is provided at the tip of the back surface nozzle to suppress the rising of the cleaning liquid due to the rotational wind pressure, and the object to be cleaned Although measures such as preventing re-adhesion of the cleaning liquid to the object have been taken, it is still insufficient, and it has been difficult to reduce the number of particles because the cleaning liquid has re-adhered to the object to be cleaned.

JP 2006-95458 A JP-A-2005-251806

  Furthermore, in the above prior art, since the back surface of the object to be cleaned 105 is in direct contact with the arm 104, the object to be cleaned is scratched or contaminated from the contact point, and mutual contamination between objects to be cleaned is caused. There was a problem of causing. In addition, it is difficult to clean the holding portion of the article 105 to be cleaned, and there is a problem that residues after cleaning are likely to adhere.

In addition, as described above, when ultrasonic waves are propagated to an object to be cleaned for cleaning, it is important that the ultrasonic vibrator and the object to be cleaned are kept in a parallel state. If the parallelism is slightly shifted, cleaning unevenness occurs in the surface.
For these reasons, maintaining the parallelism of the object to be cleaned with the ultrasonic vibrator has become an important issue.

  The present invention has been made in view of the above-mentioned problems, and prevents the contamination of the rear surface of the object to be cleaned and the cross contamination between the objects to be cleaned, which are caused by the contact between the back surface of the object to be cleaned and the cleaning device, and is cleaned. An object of the present invention is to provide a single wafer cleaning apparatus that can prevent dirt such as residues from reattaching to an object to be cleaned and perform uniform cleaning in the surface.

  In order to achieve the above object, according to the present invention, a surface nozzle for cleaning the surface of an object to be cleaned with a cleaning liquid is provided, and the cleaning liquid discharged from the surface nozzle while rotating the object to be cleaned with a central axis is used. In a single wafer cleaning apparatus that cleans the surface of an object to be cleaned, at least a chuck pin that holds a side surface of the object to be cleaned, and a flange that is disposed immediately below the object to be cleaned and has a discharge port for discharging liquid The object to be cleaned is floated by the flange with the back surface being in non-contact state, and the object to be cleaned is cleaned by holding the side surface of the object to be cleaned with the chuck pin. A single wafer cleaning apparatus is provided.

  As described above, the single wafer cleaning apparatus of the present invention includes at least a chuck pin that holds a side surface of the object to be cleaned, a flange that is disposed immediately below the object to be cleaned, and has a discharge port that discharges liquid. The surface of the object to be cleaned is floated by the flange with the back surface being in a non-contact state, and the object to be cleaned is cleaned by holding the side surface of the object to be cleaned with the chuck pin. Generation | occurrence | production of the damage | wound by contact with a back surface and a flange, the reattachment to the to-be-cleaned object of contamination, such as the wash | cleaned residue, and the mutual contamination between to-be-cleaned objects can be suppressed. In addition, since the object to be cleaned floats horizontally with respect to the flange and the side surface is held by the chuck pin, mechanical stress is not applied to the object to be cleaned, and the level of the object to be cleaned is stabilized during cleaning. Even in the case of cleaning by superimposing ultrasonic waves on the cleaning liquid, it is possible to maintain the parallelism with the vibrator and prevent the occurrence of cleaning unevenness in the surface.

At this time, the flange may have a plurality of discharge ports.
As described above, the flange has a plurality of discharge ports, so that an object to be cleaned can be more stably floated on the flange during cleaning, and the levelness can be maintained.

At this time, the flange can be moved up and down.
Thus, if the flange is movable up and down, the height can be changed between the cleaning position of the object to be cleaned and the transfer position of the object to be cleaned on the flange, so that the object to be cleaned can be easily transferred. In addition, the cleaning liquid can be reliably prevented from being scattered at the cleaning position.

Further, at this time, a liquid splash preventing plate disposed outside the flange and preventing splash of the liquid discharged from the flange can be provided.
In this way, by providing the liquid splash prevention plate that is disposed outside the flange and prevents the splash of the liquid discharged from the flange, the cleaning liquid scattered by the rotational drive splashes and is cleaned. It can suppress reattachment to things

At this time, a cleaning liquid is used as the liquid discharged from the discharge port of the flange, and the back surface of the object to be cleaned can also be cleaned.
As described above, the back surface of the object to be cleaned can be cleaned by using a cleaning liquid as the liquid discharged from the discharge port of the flange, while maintaining the back surface of the object to be cleaned in a non-contact state. Can be efficiently cleaned.

At this time, vibration means for applying ultrasonic vibration to the liquid discharged from the flange is disposed on the flange, and the superimposed ultrasonic wave is propagated to the object to be cleaned to clean the object to be cleaned. be able to.
In this way, vibration means for applying ultrasonic vibration to the liquid discharged from the flange is disposed on the flange, and the superimposed ultrasonic wave is propagated to the object to be cleaned to clean the object to be cleaned. Therefore, the cleaning effect can be improved, and the object to be cleaned can be cleaned while maintaining the levelness of the object stably, so that the parallelism between the object to be cleaned and the vibration means is maintained, and uneven cleaning within the surface is suppressed. be able to. At this time, ultrasonic waves are propagated from the back surface of the object to be cleaned to the front surface side, and the front surface side can be ultrasonically cleaned at the same time.

At this time, when the wavelength of the ultrasonic wave applied to the liquid discharged from the flange is λ [mm], the flying height of the object to be cleaned is m [mm], and k is an arbitrary integer, the value of m is It is preferable to be within a range of ± 20% with respect to the value of λ / 2 × k.
Thus, when the wavelength of the ultrasonic wave applied to the liquid discharged from the flange is λ [mm], the flying height of the object to be cleaned is m [mm], and k is an arbitrary integer, the value of m is If within the range of ± 20% with respect to the value of λ / 2 × k, the ultrasonic wave can be reliably propagated from the back surface to the front surface side of the object to be cleaned, and the cleaning effect by the ultrasonic wave on the surface can be further improved. The object to be cleaned can be cleaned efficiently.

At this time, the amount of liquid discharged from the flange and the number of rotations for rotating the object to be cleaned are set so that the value of m is within ± 20% of the value of λ / 2 × k. Can be controlled.
In this way, by controlling the discharge amount of the liquid discharged from the flange and the number of rotations for rotating the object to be cleaned, the value of m is surely ± 20% with respect to the value of λ / 2 × k. Can be within the range.

  Further, at this time, the flange may be provided with a bank on the outer peripheral portion and the upper surface is formed in a shallow dish shape.

  In particular, the flange is provided with a bank on the outer peripheral portion and the upper surface is formed in a shallow dish shape, the wavelength of the ultrasonic wave applied to the liquid discharged from the flange is λ [mm], and the object to be cleaned When the flying height of m is mm [mm], the height of the flange bank is h [mm], and k is an arbitrary integer, the value of h + m is within ± 20% of the value of λ / 2 × k It is preferable to be within.

  Thus, when the flange is provided with a bank on the outer peripheral portion and the upper surface is formed in a shallow dish shape, the wavelength of the ultrasonic wave applied to the liquid discharged from the flange is λ [mm], When the flying height of the object to be cleaned is m [mm], the height of the flange bank is h [mm], and k is an arbitrary integer, the value of h + m is ± 20 with respect to the value of λ / 2 × k. %, The ultrasonic wave can be reliably transmitted from the back side to the front side of the object to be cleaned, and the cleaning effect by the ultrasonic wave on the surface can be further improved, and the object to be cleaned can be efficiently cleaned. it can.

At this time, the amount of liquid discharged from the flange and the number of rotations for rotating the object to be cleaned are controlled so that the value of h + m is within ± 20% of the value of λ / 2 × k. Can be.
In this way, by controlling the discharge amount of the liquid discharged from the flange and the number of rotations that rotate the object to be cleaned, the value of h + m is surely ± 20% with respect to the value of λ / 2 × k. Can be within the range.

Also, at this time, the robot hand for transporting the object to be cleaned is provided, and the robot hand can transfer the object to be cleaned on the flange without contacting the back surface of the object to be cleaned. Is preferred.
As described above, the robot hand for transporting the object to be cleaned is provided, and the robot hand passes the object to be cleaned on the flange with the back surface of the object to be cleaned in a non-contact state. The back side of the object to be cleaned can be cleaned and transported in a non-contact manner, preventing scratches and contamination on the back surface and suppressing cross-contamination between objects to be cleaned, so that dirt after cleaning reattaches to the object to be cleaned. The effect which suppresses can be show | played more effectively.

  In the present invention, the single wafer cleaning apparatus comprises at least a chuck pin that holds a side surface of the object to be cleaned, and a flange that is disposed directly below the object to be cleaned and has a discharge port for discharging liquid. The surface of the object to be cleaned is floated by the flange so that the surface of the object to be cleaned is floated in a non-contact state, and the side surface of the object to be cleaned is cleaned by the chuck pins. It is possible to prevent contamination due to scratches on the back surface due to contact with the substrate and residues after cleaning, and to prevent mutual contamination between objects to be cleaned. In addition, since the object to be cleaned is floated horizontally by the flange and the side surface is held by the chuck pin, the level of the object to be cleaned can be kept stable during cleaning, and ultrasonic waves are superimposed on the cleaning liquid. When cleaning, the parallelism with the vibrating means can be maintained and the occurrence of uneven cleaning within the surface can be suppressed.

It is a schematic sectional drawing which shows one Embodiment of the single wafer type washing | cleaning apparatus which concerns on this invention. It is a schematic explanatory drawing which shows a mode that the to-be-cleaned object on the flange of the single wafer type washing | cleaning apparatus which concerns on this invention is delivered with a robot hand. It is a schematic sectional drawing which shows another embodiment of the single wafer type washing | cleaning apparatus which concerns on this invention. It is the schematic which shows an example of the conventional single wafer type washing | cleaning apparatus. It is a schematic sectional drawing which shows another embodiment of the single wafer type washing | cleaning apparatus which concerns on this invention.

Hereinafter, although an embodiment is described about the present invention, the present invention is not limited to this.
Conventionally, for example, in a manufacturing process of a semiconductor or the like, a single wafer cleaning apparatus is used as a cleaning apparatus for cleaning a substrate used for semiconductor manufacture.
However, when cleaning is performed using a conventional single wafer cleaning device, the back surface of the object to be cleaned and the back surface of the object to be cleaned may be scratched, or dirt such as cleaning residues may be cleaned. There are problems such as reattachment to objects or mutual contamination between objects to be cleaned. Also, if the object to be cleaned is mechanically chucked and held as in the past, mechanical stress is applied, and if the object to be cleaned is warped or the substrate has a large diameter, deflection due to its own weight occurs, and the parallelism Since it was difficult to maintain the temperature, there was a problem that unevenness occurred in cleaning in the substrate surface when ultrasonic cleaning was performed.

  Therefore, the present inventor has intensively studied to solve such problems. As a result, the back surface of the object to be cleaned is cleaned while being held in contact with the cleaning device, so that scratches on the back surface of the object to be cleaned, mutual contamination between objects to be cleaned, It was conceived that reattachment to the object to be cleaned can be suppressed.

  Then, if the object to be cleaned is floated and the side surface of the object to be cleaned is held by the chuck pin in that state, the object to be cleaned can be held in a non-contact manner with the cleaning device, and the object to be cleaned is not lifted by the conventional liquid Since the mechanical stress that occurs when holding the side and back surfaces is not applied and the object to be cleaned is difficult to bend, compared to the conventional case where only the side surface of the object to be cleaned is held without floating the liquid. By lifting the cleaning object with liquid, the holding force of the chuck pin in that state can be weakened, so that the object to be cleaned is less likely to bend, and the object to be cleaned can be kept stable and level. I came up with it. And when wash | cleaning using an ultrasonic wave, it discovered that a washing | cleaning nonuniformity generate | occur | produced within the surface of a to-be-washed | cleaned object can be suppressed maintaining a parallelism with a vibration means. And the best form for implementing these was scrutinized and the present invention was completed.

FIG. 1 is a schematic cross-sectional view showing an embodiment of the single wafer cleaning apparatus of the present invention.
As shown in FIG. 1, a single wafer cleaning apparatus 1 according to the present invention includes a chuck pin 3 that holds a side surface of an object to be cleaned 5, a surface nozzle 6 that discharges a cleaning liquid for cleaning the surface of the object to be cleaned 5, and an object to be cleaned. A flange 2 for levitation of an object is provided. A bank 8 is provided on the outer peripheral portion of the flange 2, and is formed in a shallow dish shape whose upper surface is recessed. Further, a discharge port 7 for discharging a liquid is provided at the bottom of the shallow dish-shaped upper surface of the flange 2.

The object 5 to be cleaned is floated by the flange 2 having the above-described configuration, the back surface thereof is not in contact with the flange 2, and the suction force to the object 2 to be cleaned acts on the flange 2 side. 2 can be held horizontally while maintaining parallelism.
Further, the chuck pin 3 is installed on the top of the bank 8 of the flange 2.

  A cylindrical member 16 that supports the flange 2 and extends downward is connected to the flange 2. The cylindrical member 16 is connected to the shaft 11 by a bearing, and the hollow motor 9 allows the cylindrical member 16 and the flange 2 to rotate around the shaft 11. And the to-be-cleaned object 5 floated by the flange 2 and the side surface of which is held by the chuck pin 3 can be rotated about its central axis.

Here, for example, as shown in FIG. 1, rail-like members facing the outer peripheral lower portion of the flange 2 and the upper portion of the main body fixing member 12 can be combined. By doing so, it is possible to prevent the liquid from entering the shaft portion or the like inside the cleaning apparatus 1. However, it is not particularly limited to this.
Further, a cup 14 for preventing the cleaning liquid discharged mainly from the surface nozzle 6 from being scattered is provided on the upper outer periphery of the single wafer cleaning apparatus 1. That is, the cleaning liquid that has fallen off and scattered from the surface side of the object to be cleaned 5 is mainly received by the cup 14, and the cleaning liquid downstream from the back surface side of the object to be cleaned 5 is not mainly scattered by the liquid splash prevention plate 4. To be accepted. Therefore, in the present invention, even the cleaning liquid scattered from the front surface side, the back surface side, and the side surface is received, and can be prevented from floating and reattaching to the object 5 to be cleaned.

When the object to be cleaned 5 is cleaned by the single wafer cleaning apparatus 1 of the present invention, the object to be cleaned 5 is floated by the flange 2, and the back surface of the object 5 is not in contact with the flange 2 by the chuck pin 3. The surface of the object to be cleaned 5 is cleaned with the cleaning liquid discharged from the surface nozzle 6 while being rotated around the central axis by the rotational driving force of the hollow motor 9 holding the side surface of the object 5 to be cleaned.
By cleaning the object to be cleaned 5 in this way, it is possible to prevent the back surface of the object 5 to be cleaned due to contact from being contaminated by scratches or residues after cleaning, or causing mutual contamination between objects to be cleaned. can do.

At this time, the flange 2 can be moved up and down. For example, the flange 2 can be moved up and down using a cylinder 10 for moving up and down as shown in FIG.
Thus, if the flange 10 is movable up and down, the cleaning position of the cleaning object 5 (the position shown in FIG. 1) and the transfer position of the cleaning object 5 to the flange 2 (the flange is raised, the cup 14), the height of the object to be cleaned 5 can be easily transferred, and the cleaning liquid can be reliably prevented from being scattered at the cleaning position.

Further, a liquid splash preventing plate 4 can be disposed outside the flange 2 so as to surround the flange 2.
As described above, by providing the liquid splash prevention plate 4, the liquid discharged from the discharge port 7 of the flange 2 is sprinkled by the rotating mechanism or the like and scattered and flies up, or the member of the cleaning device 1. It can be prevented from being repelled and adhering to the object 5 again, and the liquid can be discharged through the cleaning liquid discharge line 13.

At this time, the cleaning liquid is used as the liquid discharged from the discharge port of the flange 2, and the back surface of the article 5 to be cleaned can also be cleaned.
In this way, if the cleaning liquid is used as the liquid discharged from the discharge port of the flange 2, the back surface of the object to be cleaned 5 can be cleaned at the same time, while keeping the back surface of the object to be cleaned 5 in a non-contact state, The front and back surfaces can be cleaned efficiently. Further, since the object to be cleaned 5 is floated and held, the entire back surface can be easily cleaned.

  When the object to be cleaned 5 is often in direct contact between the processing apparatus and the back surface of the substrate in a subsequent processing step, such as a semiconductor substrate, the back surface of the substrate is cleaned to prevent cross-contamination between the substrates. The present invention for cleaning the back surface of the object to be cleaned in a non-contact manner is particularly useful.

  As described above, since the splashing prevention plate 4 can prevent the cleaning liquid that has flowed down from the object to be cleaned 5 from being scattered, the cleaning liquid for cleaning the back surface of the object to be cleaned and the dirt of the cleaning liquid are reattached to the object to be cleaned 5. Can be suppressed.

Here, ultrasonic cleaning may be performed by applying ultrasonic waves to the cleaning liquid discharged from the surface nozzle 6 and propagating the ultrasonic waves superimposed on the cleaning liquid to the object to be cleaned 5.
In this case, an ultrasonic vibrator may be provided on the surface nozzle, and ultrasonic waves may be applied to the cleaning liquid discharged from the surface nozzle 6 by the vibrator.

  The cleaning effect can be improved by cleaning with the cleaning liquid on which the ultrasonic waves are superimposed. Further, the single wafer cleaning apparatus 1 of the present invention holds the side surface with the chuck pin in a state in which the object to be cleaned 5 is kept level by the flange 2, so that the object to be cleaned stably stabilizes the level during cleaning. Since it can maintain, it can suppress that the cleaning nonuniformity generate | occur | produces in the surface at the surface side of the to-be-cleaned object by ultrasonic cleaning.

At this time, the flange 2 can have a plurality of discharge ports 7.
As described above, the flange 2 has the plurality of discharge ports 7, so that the object to be cleaned 5 can maintain the levelness more stably during the cleaning.
Further, it is desirable that the liquid discharged from the flange 2 is pressure-controlled and supplied in a state where the fluctuation of the flow rate is reduced.

At this time, a robot hand that conveys the object to be cleaned 5 is provided, and the robot hand can deliver the object to be cleaned 5 on the flange while keeping the back surface of the object to be cleaned 5 in a non-contact state. .
FIG. 2 is a schematic explanatory view showing a state in which the object 5 to be cleaned on the flange 2 is delivered by the robot hand 31.
As shown in FIG. 2A, the robot hand 31 includes a hand 32 for holding the object to be cleaned 5 and a guide pin 33 for guiding the position of the object to be cleaned 5 when the object to be cleaned 5 is delivered. The arm 34 is configured to support the hand 32. Although the method of holding the object 5 to be cleaned by the hand 32 is not particularly limited, for example, an edge clip method can be used.

  When the object 5 to be cleaned is transferred to the flange 2 using such a robot hand 31, as shown in FIG. 2 (B), the robot hand 31 moves forward to just above the flange 2 and then reaches a predetermined position. At the same time, the flange 2 also rises to a delivery position where the distance from the robot hand 31 is a predetermined distance, and the liquid is discharged from the discharge port 7.

Next, when the holding of the object 5 to be cleaned by the hand 32 is released, the object to be cleaned 5 is attracted to the flange 2 side with the back surface being in non-contact state.
Thereafter, the flange 2 is lowered to a position where the position of the cleaning object 5 becomes the cleaning position, and the side surface of the cleaning object is held by the chuck pins 3.

Further, when receiving the object 5 to be cleaned from the flange 2, the robot hand 31 similarly advances to a position directly above the flange 2, the flange 2 is raised, and the robot hand 31 holds the cleaned object 5. Lower to position.
Next, after the object to be cleaned 5 is held by the hand 32, the liquid discharge is stopped from the discharge port 7 of the flange 2, and the object to be cleaned 5 is conveyed by the robot hand 31.

  In this way, by passing the object 5 to be cleaned on the flange 2 with the robot hand 31, the back surface of the object 5 to be cleaned can be transferred in a non-contact state.

FIG. 3 is a schematic sectional view showing another embodiment of the single wafer cleaning apparatus of the present invention.
As shown in FIG. 3, the single wafer cleaning device 21 of the present invention includes a flange 2 having the same configuration as that described above, and a chuck pin 3 for holding the side surface of the object 5 to be cleaned. . A liquid splash prevention plate 4 is disposed outside the flange 2.
In this embodiment, the chuck pin 3 is installed on the liquid splash prevention plate 4.

  The liquid splash preventing plate 4 is continuously provided with a cylindrical member 16 having a tapered end. The cylindrical member 16 is connected to the shaft 11 by a bearing, and the hollow motor 9 rotates the cylindrical member 16 and the liquid splash preventing plate 4 around the shaft 11. Then, the object 5 to be cleaned which is floated by the flange 2 and whose side surface is held by the chuck pin 3 installed on the upper part of the liquid splash prevention plate 4 can be rotated about its central axis. In this form, the flange 2 does not rotate.

In addition, the flange 2 includes a vibration unit 15 that applies ultrasonic vibration to the liquid discharged from the discharge port 7 of the flange 2. The liquid on which the ultrasonic wave is superimposed acts as an ultrasonic wave propagation film and propagates the ultrasonic wave to the object to be cleaned.
In the single wafer cleaning device 21 of the present invention, the object 5 to be cleaned is floated by the flange 2 while maintaining the level, and the side surface of the object 5 to be cleaned is held by the chuck pins 3. 5 can stably maintain the levelness.
Further, since the vibration means 15 is installed so as to be parallel to the upper surface of the flange 2, it is parallel to the rear surface of the object 5 to be cleaned, which is held immediately above the flange 2, and transmits ultrasonic waves evenly. Can be done.

  When the object to be cleaned 5 is cleaned by the single wafer cleaning device 21 of the present invention, the object to be cleaned 5 is floated by the flange 2 so that the back surface thereof is not in contact with the flange 2, and the chuck pin 3 The side surface of the object to be cleaned 5 is held by the rotary motor 9 and rotated around the central axis by the rotational driving force of the hollow motor 9, and ultrasonic vibration is applied to the liquid discharged from the discharge port of the flange 2 by the vibration means 15. It is possible to propagate the ultrasonic wave superimposed on the object to be cleaned 5 and ultrasonically clean the back surface of the object to be cleaned 5. Further, the ultrasonic wave propagates from the back surface to the front surface side of the object to be cleaned 5, and the surface of the object to be cleaned 5 can be ultrasonically cleaned with the cleaning liquid discharged from the surface nozzle 6.

By cleaning the object to be cleaned 5 in this way, the back surface of the object 5 to be cleaned due to contact may be damaged or the cross-contamination between objects to be cleaned may occur while improving the cleaning effect by ultrasonic waves. Can be suppressed. Further, it is possible to suppress the dirt such as the washed residue from being reattached to the object 5 to be cleaned.
Further, the liquid splash prevention plate 4 can prevent the liquid discharged from the discharge port 7 of the flange 2 from scattering, and the downstream liquid can be prevented from reattaching to the object to be cleaned.

  Here, when cleaning an object that is easily damaged by ultrasonic cleaning, such as a semiconductor substrate having a device pattern on the surface or a photomask, the ultrasonic wave is not directly applied to the cleaning liquid discharged from the surface nozzle. As the ultrasonic wave to be applied from the back surface, an ultrasonic wave that is permeable to the object to be cleaned 5 is used. The ultrasonic wave is applied to the liquid discharged from the flange 2 and the ultrasonic wave superimposed on the liquid is generated. The surface to be cleaned is indirectly ultrasonically cleaned by passing through the object to be cleaned 5 and propagating to the cleaning liquid discharged from the surface nozzle 6 on the surface side of the object to be cleaned 5. It is possible to suppress the occurrence of damage on the surface, and to obtain a cleaning effect with high ultrasonic vibration.

  As described above, when the object to be cleaned 5 is cleaned by applying ultrasonic waves to improve the cleaning effect, the ultrasonic wave is applied to the object to be cleaned 5 by maintaining the parallelism of the object to be cleaned with the vibration means 15. It is important that the object to be cleaned 5 is stably leveled with respect to the flange 2 so that the parallelism with the vibration means 15 can be maintained. The single wafer cleaning device 21 is particularly effective.

At this time, the wavelength of the ultrasonic wave applied to the liquid discharged from the flange 2 is λ [mm], the flying height of the cleaning object 5 is m [mm], the height of the bank 8 of the flange 2 is h [mm], When k is an arbitrary integer, the value of h + m is preferably within a range of ± 20% with respect to the value of λ / 2 × k, and more preferably satisfies h + m = λ / 2 × k.
As described above, the wavelength of the ultrasonic wave applied to the liquid discharged from the flange 2 is λ [mm], the flying height of the cleaning object 5 is m [mm], and the height of the bank 8 of the flange 2 is h [mm]. When k is an arbitrary integer, if the value of h + m is within ± 20% of the value of λ / 2 × k, the ultrasonic wave that reaches the back surface of the object to be cleaned is reliably It can be efficiently cleaned without propagating and causing damage on the surface side. Furthermore, if h + m = λ / 2 × k is satisfied, this action can be achieved more effectively. Therefore, the cleaning effect by ultrasonic waves can be further improved, and the object to be cleaned can be cleaned efficiently.

  At this time, by controlling the discharge amount of the liquid discharged from the flange 2 and the number of rotations for rotating the object 5 to be cleaned, the value of h + m is surely within ± 20% of the value of λ / 2 × k. Can be inside.

  Here, the height h of the bank 8 of the flange 2 may be a height that satisfies the above-described conditions, and does not cause generation or influence of stagnation or turbulence on the upper surface of the flange 2 because the shallow dish-shaped depression is too deep. desirable. Such adjustment of the height of the bank 8 is performed in the prior processing stage of the flange. And the value of k can be changed and it can adjust to the height of the bank which can be processed. For example, when the frequency is 1 MHz, the height h can be adjusted so that k = 2 and the sum of the height h and the flying height m of the cleaning object 5 is 1.5 mm.

At this time, the flange 2 can be moved up and down. For example, the flange 2 can be moved up and down using a cylinder 10 for moving up and down as shown in FIG.
Thus, if the flange 10 is movable up and down, the height can be changed between the cleaning position of the cleaning object 5 and the transfer position of the cleaning object 5 to the flange 2. The cleaning liquid can be reliably prevented from being scattered at the cleaning position.
Further, in this case, the flange 2 moves up and down, and the thickness of the liquid as the propagation film can be adjusted by changing the distance from the object 5 to be cleaned.
Further, the flange 2 is lowered and the distance between the flange 2 and the object to be cleaned 5 is increased to a predetermined distance or more, so that it is kept away from the liquid remaining on the upper surface of the flange 2 at the time of drying. Can be done efficiently.

At this time, the cleaning liquid is used as the liquid discharged from the discharge port of the flange 2, and the back surface of the article 5 to be cleaned can also be cleaned.
In this way, if the cleaning liquid is used as the liquid discharged from the discharge port of the flange 2, the back surface of the object to be cleaned 5 can be cleaned at the same time, while keeping the back surface of the object to be cleaned 5 in a non-contact state, The front and back surfaces can be cleaned efficiently.
Alternatively, degassed water can be used as the liquid discharged from the discharge port of the flange 2 and can be used as propagation water during application of ultrasonic waves.

At this time, the flange 2 can have a plurality of discharge ports 7.
As described above, the flange 2 has the plurality of discharge ports 7, so that the object to be cleaned 5 can maintain the levelness more stably during the cleaning.
Further, it is desirable that the liquid discharged from the flange 2 is pressure-controlled and supplied in a state where the fluctuation of the flow rate is reduced.

  Further, in the same manner as described above, the back surface of the cleaning object 5 can be transferred in a non-contact manner by transferring the cleaning object 5 on the flange 2 with the robot hand 31.

FIG. 5 is a schematic sectional view showing another embodiment of the single wafer cleaning apparatus of the present invention.
As shown in FIG. 5, the single wafer cleaning apparatus 41 of the present invention includes a flange 2 having a flat upper surface. Further, a liquid splash preventing plate 4 is disposed outside the flange 2, and a chuck pin 3 for holding the side surface of the object 5 to be cleaned is provided on the liquid splash preventing plate 4.
The liquid splash preventing plate 4 is continuously provided with a cylindrical member 16 having a tapered end. The cylindrical member 16 is connected to the shaft 11 by a bearing, and the hollow motor 9 rotates the cylindrical member 16 and the liquid splash preventing plate 4 around the shaft 11.

  Then, like the single wafer cleaning device 21 shown in FIG. 3 described above, the object 5 to be cleaned is floated by the flange 2 while maintaining the level, and the side surface of the object 5 to be cleaned is held by the chuck pins 3. Then, the object 5 to be cleaned is rotated about its central axis, so that the object 5 to be cleaned can stably maintain the level.

When cleaning is performed by applying an ultrasonic wave to the liquid discharged from the flange 2 in this embodiment, the wavelength of the ultrasonic wave applied to the liquid discharged from the flange 2 is λ [mm], and the flying height of the object 5 to be cleaned is set. When m [mm] and k are arbitrary integers, the value of m is preferably within a range of ± 20% with respect to the value of λ / 2 × k.
Thus, when the wavelength of the ultrasonic wave applied to the liquid discharged from the flange 2 is λ [mm], the flying height of the object 5 to be cleaned is m [mm], and k is an arbitrary integer, the value of m is If it is within the range of ± 20% with respect to the value of λ / 2 × k, the ultrasonic wave that has reached the back surface of the object to be cleaned is reliably propagated to the surface side, and it is efficient without causing damage to the surface side. Can wash well. Furthermore, if m = λ / 2 × k is satisfied, this action can be more effectively achieved. Therefore, the cleaning effect by ultrasonic waves can be further improved, and the object to be cleaned can be cleaned efficiently.

Further, by controlling the discharge amount of the liquid discharged from the flange 2 and the rotation speed for rotating the cleaning object 5, the value of m is surely within ± 20% of the value of λ / 2 × k. Can be.
Table 1 shows how to clean a silicon wafer while controlling the amount of liquid discharged from the flange 2 and the number of rotations to rotate the cleaning object 5 using the single wafer cleaning apparatus 41 of the present invention as shown in FIG. The flying height m at the time of floating is shown.

As shown in Table 1, it can be seen that the flying height m is changed by changing the discharge amount and the rotational speed. In order to adjust the flying height m to the above range with respect to the ultrasonic wave applied to the liquid discharged from the flange 2, the discharge amount and the rotational speed may be controlled based on the relationship shown in Table 1, for example, When an ultrasonic wave having a frequency of 1 MHz is used, when k = 1, the value of λ / 2 × k is 0.742, and ejection is such that m is within a range of ± 20% with respect to this value. Cleaning may be performed with the amount and the number of rotations.
The other members in FIG. 5 are the same as those in FIG.

  In the embodiment of the single wafer cleaning device 41 of the present invention shown in FIG. 5, the chuck pin 3 is installed on the upper part of the liquid splash prevention plate 4, the flange 2 does not rotate, the cylindrical member 16, and the liquid By rotating the splash prevention plate 4 about the shaft 11, the object 5 whose side surface is held by the chuck pin 3 can be rotated about its central axis. 5 has a flat top surface, and as shown in FIG. 1, the chuck pin 3 is installed on top of the flange 2, and the flange 2 rotates about the shaft 11 by the chuck pin 3. It can also be set as the structure which can rotate the to-be-cleaned object 5 by which the side surface was hold | maintained with the central axis.

  In the embodiment of FIG. 5, the upper surface of the flange 2 is flat, so that the upper surface of FIG. 1 can be easily and easily polished compared to a shallow dish, and the object 5 to be cleaned can be cleaned. There is an advantage that a certain substrate can be easily dried.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples of the present invention, but the present invention is not limited to these.

(Example)
100 semiconductor substrates were cleaned using a single wafer cleaning apparatus as shown in FIG.
In addition, the robot hand as shown in FIG. 2 was used to deliver the object to be cleaned on the flange. Cleaning was performed by providing three outlets on the flange and discharging a cleaning liquid from the outlet. It dried immediately after washing | cleaning, the number of particles adhering to the surface of 100 board | substrates was measured with the particle counter, and the average value for 100 sheets of the residual rate of the particle | grains before washing | cleaning and after washing | cleaning was compared, respectively.
As a result, the average value of the residual ratio of the particles after cleaning was 4%, which was confirmed to be improved as compared with a comparative example described later.
In addition, when the number of particles on the outer periphery of the back surface of the substrate was evaluated, there was no increase in the number before the cleaning, and there was no contamination due to scratches on the back surface or residue after cleaning. It was also confirmed that the influence of cross contamination between 100 substrates could be suppressed.

(Comparative example)
Using a conventional single wafer cleaning apparatus as shown in FIG. 4, 100 semiconductor substrates similar to those of the example were cleaned, and evaluation similar to that of the example was performed.
As a result, it was confirmed that the average value of the residual ratio of the cleaned particles was about 20%, which was larger than that of the example.
In addition, when the number of particles on the outer periphery of the back surface of the substrate was evaluated, it was confirmed that some of the particles in particular on the substrate were in contact with the table. I was able to confirm that I received it.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits the same effects. Are included in the technical scope.

1, 21, 41 ... single wafer cleaning device, 2 ... flange, 3 ... chuck pin,
4 ... Liquid splash prevention plate, 5 ... Object to be cleaned, 6 ... Surface nozzle,
7 ... discharge port, 8 ... bank, 9 ... hollow motor, 10 ... cylinder for flange vertical movement,
11 ... shaft, 12 ... fixing member, 13 ... cleaning liquid discharge line,
14 ... cup, 15 ... vibrating means, 16 ... cylindrical member, 31 ... robot hand,
32 ... hand, 33 ... guide pin, 34 ... arm.

Claims (12)

In a single wafer cleaning apparatus comprising a surface nozzle for cleaning a surface of an object to be cleaned with a cleaning liquid, and cleaning the surface of the object to be cleaned with a cleaning liquid discharged from the surface nozzle while rotating the object to be cleaned around a central axis ,at least,
A chuck pin for holding a side surface of the object to be cleaned;
A flange having a discharge port for discharging liquid disposed immediately under the object to be cleaned;
A single wafer characterized in that the object to be cleaned is floated with the flange in a state where the back surface is not in contact, and the object is cleaned by holding the side surface of the object to be cleaned with the chuck pins. Type cleaning device.   2. The single wafer cleaning apparatus according to claim 1, wherein the flange has a plurality of discharge ports.   The single wafer cleaning apparatus according to claim 1 or 2, wherein the flange is movable up and down.   The liquid splash prevention board which is arrange | positioned on the outer side of the said flange and prevents the liquid splash of the liquid discharged from the said flange is comprised, The any one of Claim 1 thru | or 3 characterized by the above-mentioned. Single wafer cleaning device.   The single wafer cleaning apparatus according to any one of claims 1 to 4, wherein a cleaning liquid is used as the liquid discharged from the discharge port of the flange and the back surface of the object to be cleaned is also cleaned. .   Vibrating means for applying ultrasonic vibration to the liquid discharged from the flange is disposed on the flange, and the superposed ultrasonic wave can be propagated to the object to be cleaned to clean the object to be cleaned. The single wafer cleaning device according to any one of claims 1 to 5, wherein   When the wavelength of the ultrasonic wave applied to the liquid discharged from the flange is λ [mm], the flying height of the object to be cleaned is m [mm], and k is an arbitrary integer, the value of m is λ / 2 × The single wafer cleaning apparatus according to claim 6, wherein the single wafer cleaning apparatus is within a range of ± 20% with respect to a value of k.   The amount of liquid discharged from the flange and the number of revolutions for rotating the object to be cleaned are controlled so that the value of m is within ± 20% of the value of λ / 2 × k. The single wafer cleaning apparatus according to claim 7, wherein the single wafer cleaning apparatus is provided.   The single-wafer type cleaning apparatus according to any one of claims 1 to 6, wherein the flange is provided with a bank on an outer peripheral portion and has an upper surface formed in a shallow dish shape.   The flange is provided with a bank on the outer periphery and the upper surface is formed in a shallow dish shape. The wavelength of the ultrasonic wave applied to the liquid discharged from the flange is λ [mm], and the surface of the object to be cleaned is floated When the amount is m [mm], the height of the flange bank is h [mm], and k is an arbitrary integer, the value of h + m is within ± 20% of the value of λ / 2 × k. The single wafer cleaning apparatus according to claim 6, wherein the single wafer cleaning apparatus is provided.   The amount of liquid discharged from the flange and the number of rotations for rotating the object to be cleaned are controlled so that the value of h + m is within a range of ± 20% with respect to the value of λ / 2 × k. The single wafer cleaning apparatus according to claim 10, wherein the single wafer cleaning apparatus is provided. It comprises a robot hand that conveys the object to be cleaned, and the robot hand can deliver the object to be cleaned on the flange in a non-contact manner on the back surface of the object to be cleaned. The single wafer cleaning apparatus according to any one of claims 1 to 11.

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