JP2010232528A - Single wafer cleaning apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a single wafer cleaning apparatus reducing an uncleaned contact part of a to-be-cleaned object with a supporting body while preventing warpage and breakage of the object and preventing a cleaning liquid from infiltrating to a lower surface side of the object by cleaning while maintaining the flatness of the object. <P>SOLUTION: The single wafer cleaning apparatus has a sucking and floating table and a spin table. The sucking and floating table contains a plurality of spiral flow-forming part, having a cylindrical recessed part and a discharge port for discharging a gas along the inner wall surface of the cylindrical recessed part, on the top surface part thereof, and is arranged right under a to-be-cleaned object. The spin table is arranged in the periphery of the sucking and floating table, and has the supporting body which supports the side surface of the object right above the sucking and floating table to spin the object supported by the supporting body with a central axis. In the single wafer cleaning apparatus, while sucking and floating the object in a noncontact state, the side surface of the object is supported by the supporting body, and the object is spun with the central axis by the spin table, to clean the top surface. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a single wafer cleaning apparatus for cleaning an object to be cleaned such as a semiconductor silicon wafer, a wafer on which a device pattern is formed, or a photomask one by one.

  When processing objects such as silicon wafers and wafers and substrates used for semiconductor manufacturing such as photomasks in semiconductor manufacturing processes, particles such as organic matter, metal dust, and foreign matter are processed. If it adheres to the surface of the workpiece, uniform processing will not be performed on the surface of the object to be processed, and other wafers will be indirectly cross-contaminated from such wafers. Become. For this reason, particles or the like are usually removed from the object to be processed by cleaning with a cleaning device before processing the wafer or the like.

  For example, various patterns are formed on the surface of the wafer to form a plurality of elements. In the final stage of the subsequent process, the back surface of the wafer is ground (backlapped) to reduce the thickness of the wafer, and the polished back surface of the wafer is cleaned.

  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. 6 shows a schematic view of a conventional sheet style cleaning apparatus. This single wafer cleaning apparatus 101 includes a rotatable table 102, a rotation driving unit 107 for rotating the table 102 around its central axis, and a cleaning nozzle 106 for cleaning the upper surface of the object 105 to be cleaned. It has.
The table 102 is provided with a plurality of pins 103 for supporting the side surface of the object 105 to be cleaned on the arm 104.

In order to clean the upper surface of the cleaning object 105 using such a single wafer cleaning apparatus 101, the side surface of the cleaning object 105 is supported by the pin 103 of the table 102, and the table 102 is rotated by the rotation drive unit 107. Thus, the object 105 to be cleaned is rotated, and the cleaning liquid containing the chemical solution is discharged from the cleaning nozzle 106 to the upper surface side of the object 105 to be cleaned.
In such a single wafer cleaning apparatus, a 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 (Patent Document). 1).

JP 2006-95458 A

However, when the conventional cleaning apparatus as described above is used, since the lower surface and side surface of the object to be cleaned are in direct contact with the arm and the support, the object to be cleaned is damaged or contaminated at the contact point. There is a problem in that cross-contamination between objects to be cleaned is caused, or cleaning residue occurs because it is difficult to clean a contact portion of the objects to be cleaned.
In particular, it is difficult to maintain the flatness due to the distortion of the wafer itself and the laminated thin film on the wafer in the cleaning of the lap surface of the thin wafer after the back wrap as described above and the transport of the wafer before and after the cleaning. In some cases, the wafer is warped or damaged. Due to such distortion, deflection due to the weight of the wafer, damage to the side surface of the wafer, etc., it is impossible to transmit the rotational drive in the conventional spin structure using the outer peripheral support such as the pins supporting the side surface of the wafer. In some cases, cleaning could not be performed.

  Further, when performing cleaning with the back surface of the wafer having a patterned device surface on the upper side, the cleaning liquid enters the device surface side (front surface), that is, the lower surface side of the object to be cleaned 105, and affects the device surface. There was also a problem of giving.

  The present invention has been made in view of the above-described problems. Even if the object to be cleaned is thin, it is cleaned while maintaining its flatness, and warpage, breakage, and the lower surface side of the object to be cleaned. It is an object of the present invention to provide a single wafer cleaning apparatus capable of suppressing the occurrence of cleaning residue at a contact portion of an object to be cleaned with a support while suppressing the immersion of the cleaning liquid.

  In order to achieve the above object, according to the present invention, a cleaning nozzle for cleaning an upper surface of an object to be cleaned with a cleaning liquid is provided, and the cleaning liquid discharged from the cleaning nozzle while rotating the object to be cleaned with a central axis is used. In the single wafer cleaning apparatus for cleaning the upper surface of the object to be cleaned, the upper surface portion has a plurality of swirl flow forming portions having at least a cylindrical recess and a discharge port for discharging gas along the inner wall surface of the recess, A suction levitation table disposed immediately below the object to be cleaned; a support disposed around the suction levitation table and supporting a side surface of the object to be cleaned immediately above the suction levitation table; A spin table for rotating the object to be cleaned supported by a support on a central axis, and discharging a gas from a discharge port of the swirl flow forming unit to thereby form a central part of a cylindrical recess of the swirl flow forming unit Negative to occur And the side surface of the object to be cleaned is supported by the support while the object to be cleaned is adsorbed and floated in a non-contact state by the gas released from the swirl flow forming portion into the gap with the object to be cleaned. The single wafer cleaning apparatus is characterized in that the upper surface is cleaned by rotating the object to be cleaned around a central axis by the spin table.

  As described above, the upper surface portion has a plurality of swirl flow forming portions each having at least a cylindrical recessed portion and a discharge port for discharging gas along the inner wall surface of the recessed portion, and is disposed immediately below the object to be cleaned. A suction levitation table; and a support that is disposed around the suction levitation table and supports a side surface of the object to be cleaned immediately above the suction levitation table, and the object to be cleaned supported by the support is centered. A negative pressure generated at the center of the cylindrical recess of the swirl flow forming unit by discharging gas from the discharge port of the swirl flow forming unit, and the swirl flow forming The side surface of the object to be cleaned is supported by the support while the object to be cleaned is adsorbed and floated in a non-contact state by the gas released from the inside to the object to be cleaned. Mainly to be cleaned If the surface to be cleaned is rotated in order to clean the object to be cleaned, the rotation drive can be reliably transmitted while extending in a non-contact state, even if it is thin. Warpage and breakage can be suppressed. In addition, since the object to be cleaned can be rotated at a high speed, it is possible to prevent the cleaning liquid discharged on the upper surface of the object to be cleaned from being blown outward by the centrifugal force of the rotation and soaking into the lower surface side of the object to be cleaned. Will be able to. Moreover, since the position of the side surface of the object to be cleaned that is supported by the support can be changed by adjusting the adsorption force of the object to be cleaned during the cleaning, the occurrence of cleaning residue can be suppressed.

At this time, it is preferable that the adsorption levitation table is movable up and down.
Thus, if the suction levitation table is movable up and down, the height position and suction force of the object to be cleaned can be easily controlled by adjusting the distance between the object to be cleaned and the suction levitation table, Cleaning can be performed while extending the object to be cleaned more reliably. Further, the height can be changed between the cleaning position of the cleaning object and the transfer position of the cleaning object to the suction floating table, so that the cleaning object can be easily transferred.

  Further, at this time, the suction levitation table is raised so that the contact force between the support of the spin table and the object to be cleaned is reduced or non-contacted, thereby making a difference in the number of rotations of the spin table and the object to be cleaned. It is preferable that the position of the side surface supported by the support of the object to be cleaned can be changed.

  In this way, the rotation speed of the spin table and the object to be cleaned is increased by lowering the contact force between the support of the spin table and the object to be cleaned by raising the suction levitation table. If the position of the side surface supported by the support for the object to be cleaned can be changed, the position of the side surface supported by the support for the object to be cleaned can be more reliably determined during cleaning. Therefore, it is possible to more reliably eliminate the cleaning residue at the side support portions.

Also, at this time, by rapidly accelerating the rotation of the spin table, a difference occurs in the rotation speed of the spin table and the object to be cleaned, and the position of the side surface supported by the support of the object to be cleaned is changed. It is preferable that it can be used.
Thus, by rapidly accelerating the rotation of the spin table, a difference is generated in the rotation speed of the spin table and the object to be cleaned, and the position of the side surface supported by the support of the object to be cleaned is changed. If possible, the position of the side surface supported by the support of the object to be cleaned can be changed more reliably during cleaning, and the cleaning residue at the side support portion can be more reliably eliminated. It becomes.

Further, at this time, it is preferable that the gas released from the swirl flow forming portion into the gap with the object to be cleaned further flows toward the outer periphery of the object to be cleaned.
As described above, if the gas released from the swirl flow forming portion into the gap with the object to be cleaned further flows out toward the outer periphery of the object to be cleaned, the gas flowing out toward the outer periphery is used. Therefore, it is possible to more reliably suppress the cleaning liquid from entering the lower surface side of the object to be cleaned.

Further, at this time, an object to be cleaned detection sensor for detecting presence / absence and breakage of the object to be cleaned can be further provided.
In this way, if there is an object detection sensor that detects the presence or absence and damage of the object to be cleaned, the presence or damage of the object to be cleaned is detected and the object to be cleaned is missing or damaged. In this state, it is possible to prevent the cleaning liquid from being discharged into the spin table by discharging the cleaning liquid. In particular, when a thin object to be cleaned is cleaned, cracks are likely to occur, and therefore it is effective to have such a sensor.

Further, at this time, it is possible to further include a liquid leakage detection sensor for detecting liquid leakage to the lower inner side of the spin table.
Thus, if it has a liquid leakage detection sensor for detecting liquid leakage to the lower inner side of the spin table, it can quickly detect that the cleaning liquid has leaked below the spin table. It becomes.

At this time, the cleaning nozzle can be an ultrasonic cleaning nozzle or a spray nozzle that applies ultrasonic vibration to the cleaning liquid.
Thus, if the cleaning nozzle is an ultrasonic cleaning nozzle that applies ultrasonic vibration to the cleaning liquid, the cleaning effect can be improved by ultrasonic waves, and if it is a spray nozzle, the cleaning liquid can be supplied softly. .

Further, at this time, a drainage cup for collecting the cleaning liquid discharged from the cleaning nozzle is provided, and the drainage cup is disposed around the spin table and is moved up and down according to the type of the chemical liquid of the cleaning liquid. By changing the above, it is possible to separate and collect the cleaning liquid.
As described above, the apparatus includes a drain cup that collects the cleaning liquid discharged from the cleaning nozzle, and the drain cup is arranged around the spin table and moves up and down according to the type of the chemical liquid of the cleaning liquid. If the cleaning liquid can be separated and recovered, the chemical liquid of the separated cleaning liquid can be reused, and the cost can be reduced.

At this time, the spin table can spin dry the object to be cleaned, and can rotate at a maximum rotation speed of 4000 rpm.
As described above, the spin table can spin dry the object to be cleaned. If the rotation speed can be rotated at a maximum of 4000 rpm, the object to be cleaned can be quickly dried by spin drying. It will be a thing.

Further, at this time, a robot hand for conveying the object to be cleaned can be provided, and the object to be cleaned on the suction floating table can be delivered in a non-contact manner by the robot hand.
As described above, if the robot hand for transporting the object to be cleaned is provided and the object to be cleaned on the suction floating table can be transferred in a non-contact manner by the robot hand, the object to be cleaned is not It can be cleaned by contact and transported in a non-contact manner, and even a thin object to be cleaned can be prevented from being damaged, and cross contamination between objects to be cleaned can also be suppressed.

  In the present invention, in the single wafer cleaning apparatus, the upper surface portion includes a plurality of swirl flow forming portions each having at least a cylindrical recess and a discharge port for discharging gas along the inner wall surface of the recess. An adsorbing levitating table disposed immediately below the adsorbing levitating table, and a support member disposed around the adsorbing levitating table for supporting a side surface of the object to be cleaned. A spin table that rotates the object to be cleaned about a central axis, and discharges gas from the discharge port of the swirl flow forming unit to generate a negative generated at the center of the cylindrical recess of the swirl flow forming unit. The side surface of the object to be cleaned is supported by the support while the object to be cleaned is adsorbed and floated in a non-contact state by the pressure and the gas released from the swirl flow forming portion into the gap with the object to be cleaned. And the spin table Then, the object to be cleaned is rotated around the central axis to clean the upper surface, so that the object to be cleaned can be reliably transferred by rotating while being extended in a non-contact state. However, warpage and breakage of the object to be cleaned can be suppressed. In addition, since the object to be cleaned can be rotated at a high speed, it is possible to prevent the cleaning liquid discharged on the upper surface of the object to be cleaned from being blown outward by the centrifugal force of the rotation and soaking into the lower surface side of the object to be cleaned. Will be able to. Moreover, since the position of the side of the object to be cleaned that is supported by the support can be changed by adjusting the adsorption force of the object to be cleaned, it is possible to suppress the occurrence of cleaning residue on the side of the object to be cleaned. It will be possible.

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 the schematic which expanded the upper part of the single wafer type washing | cleaning apparatus of FIG. It is explanatory drawing explaining a mode that a to-be-cleaned object adsorbs and floats. It is the schematic which shows an example of the adsorption | suction floating table and spin table which can be used with the single wafer type washing | cleaning apparatus which concerns on this invention. It is the schematic which shows another example of the spin table which can be used with the single wafer type washing | cleaning apparatus which concerns on this invention. (A) Side surface schematic diagram which shows an example of a support body of straight pin shape. (B) Schematic top view showing an example of a spin table having a straight pin-shaped support. It is the schematic which shows an example of the conventional single wafer type washing | cleaning apparatus.

Hereinafter, although an embodiment is described about the present invention, the present invention is not limited to this.
In the cleaning of an object to be cleaned using a conventional single wafer cleaning device, the object to be cleaned is damaged or contaminated at the contact point with the support of the object to be cleaned, or cross contamination between objects to be cleaned is caused. There is a problem that cleaning residue occurs because it is difficult to clean the contact portion of the object to be cleaned. For example, a wafer having a diameter of 200 mm usually has a thickness of about 725 μm, but may be processed to a thickness of, for example, about 30 to 150 μm by the above-described back wrap or the like. In such a thin object to be cleaned, it is difficult to maintain flatness due to distortion of the object to be cleaned, and the object to be cleaned may be warped or damaged. If the spin structure with the support that supports the side surface of the object to be cleaned cannot transmit rotation drive due to such distortion, deflection due to the weight of the object to be cleaned, damage to the object to be cleaned, etc. was there.

  Furthermore, when performing cleaning with the back side of the wafer having the patterned device surface on the top side, that is, when cleaning the top surface with the device side (front side) on the bottom side, the cleaning liquid is moved to the bottom side of the wafer. There was also a problem that would enter the device and adversely affect the device surface.

  Therefore, the present inventor has intensively studied to solve such problems. As a result, an adsorption levitation table having a plurality of swirl flow forming portions on the upper surface portion that generate a swirl flow inside is arranged immediately below the object to be cleaned, and the object to be cleaned is adsorbed and floated around the suction levitation table. If a spin table is provided, and the upper surface is cleaned while supporting the side surface of the object to be cleaned with the support of the spin table and rotating on the central axis thereof, the object to be cleaned is not warped in a non-contact state. Can be cleaned while maintaining flatness while extending, suppressing cross-contamination between objects to be cleaned, suppressing warpage and breakage even with thin objects to be cleaned, and rotating the object to be cleaned at a high speed It was conceived that it was possible to prevent the material from being swung to the bottom surface of the object to be cleaned. Furthermore, since the position of the side of the object to be cleaned that is supported by the support can be changed by adjusting the height position and suction force of the object to be cleaned, it is possible to suppress the occurrence of cleaning residue. As a result, the present invention has been 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 an adsorption levitation table 2 for adsorbing and levitating an object 5 to be cleaned, a spin table 3 that supports and rotates a side surface of the object 5 to be cleaned, and a cleaning liquid. And a cleaning nozzle 6 for discharging the liquid.
FIG. 2 is an enlarged schematic view of the upper part of the single wafer cleaning apparatus 1 of FIG. As shown in FIG. 2, the adsorption levitation table 2 has a plurality of swirl forming portions 4 on the upper surface. The swirl flow forming unit 4 is configured to form a swirl flow inside. Such a suction levitation table 2 is arranged directly under the object to be cleaned 5 so that the object to be cleaned 5 can be adsorbed and floated according to the principle described later.

  A spin table 3 is disposed around the suction levitation table 2. The spin table 3 is connected to a shaft 13 through a bearing, and the spin table 3 can be rotated around the shaft 13 by a rotary motor (not shown). The spin table 3 is provided with a support 9 for supporting the side surface of the object 5 to be cleaned. And the to-be-cleaned object 5 which is adsorbed and levitated by the adsorption levitating table 2 and whose side surfaces are supported by the support 9 can be rotated about its central axis. Here, the spin table 3 can make the object 5 to be cleaned spin dry. Further, the rotation speed can be set to be rotatable at a maximum of 4000 rpm, and this is preferable because the object to be cleaned 5 can be dried in a shorter time, but is not particularly limited. .

Here, in the single wafer cleaning apparatus 1 of the present invention, the principle of sucking and floating the object to be cleaned 5 will be described.
As shown in FIG. 3, the plurality of swirl flow forming portions 4 provided on the upper surface portion of the adsorption levitation table 2 have a cylindrical recess 7 and a discharge port 8 for discharging gas into the recess 7. A gas such as compressed air is discharged from the discharge port 8 into the recess 7 and swirls along the inner wall surface of the recess 7 to form a swirl flow. Due to this swirling flow, a large negative pressure is generated at the central portion of the recess 7 of the swirling flow forming portion 4, and a force for adsorbing the object 5 to be cleaned is generated. And since the gas which formed this swirl | vortex flow is discharge | released to the clearance gap between the swirl | vortex flow formation part 4 and the to-be-cleaned object 5, the to-be-washed | cleaned object 5 is adsorbed and floated maintaining a clearance gap between the adsorption | suction levitation tables 2. .

Here, when the distance between the object to be cleaned 5 and the adsorption floating table 2 is X [mm], the weight of the object to be cleaned 5 is m [kg], and the constant is α, the adsorption force Y is
Y = αX ² + m
It is represented by Also, in order to perform rotational driving when the total static friction of the support 9 is μ,
Y> μm
Y may be satisfied so that X is set so that the object to be cleaned 5 is extended and the bending or the like is minimized.
Here, although not particularly limited, for example, the distance X can be set to about 0 to 3 mm.

  An example of the adsorption levitation table 2 and the spin table 3 that can be used in the single wafer cleaning apparatus 1 of the present invention is shown in FIG. As shown in FIG. 4, the adsorption levitation table 2 has a dish shape, and a plurality of swirl flow forming portions 4 are arranged at equal intervals near the outer periphery of the upper surface portion. If the swirl flow forming portions 4 are arranged at equal intervals in this way, the force for adsorbing the object to be cleaned 5 can be made stronger and uniform, and the flatness of the object to be cleaned 5 can be reliably increased. It can be kept floating by adsorption. Further, as shown in FIG. 4, the shape of the support 9 of the spin table 3 can be a taper provided on the contact surface with the object 5 to be cleaned. If it does in this way, a contact part with the to-be-washed | cleaned object 5 will decrease, and a damage and contamination of a contact part can be suppressed more reliably, and it will be supported by the support body 9 of the to-be-washed | cleaned object 5 by making adsorption | suction power small. The position can be easily changed. However, in the present invention, the position is not particularly limited to this, and a conical trapezoidal shape or a pin shape without a taper may be used.

  When the shape of the support body 9 is a straight pin shape as shown in FIG. 5A, the side surface of the object to be cleaned 5 is provided with a plurality of support bodies 9 in order to reliably transmit the rotational driving force to the object to be cleaned 5. It is desirable to provide a mechanism for chucking. At the time of delivery of the object 5 to be cleaned, the holding diameter formed by each of the straight pin-shaped supports 9 is made larger than the diameter of the object 5 to be cleaned, and is formed by each of the supports 9. The holding diameter can be reduced to chuck the side surface of the object 5 to be cleaned, and the cleaning can be performed while supporting the side surface.

Such a chuck mechanism by the support 9 can be configured as follows, for example.
That is, as shown in FIG. 5A, the straight pin-shaped support 9 is eccentrically disposed on the pin base 16 that can rotate about the central axis. Further, as shown in FIG. 5B, a plurality of pin bases 16 on which the support bodies 9 are arranged are arranged in the vicinity of the outer peripheral portion of the spin table 3 at equal intervals. A holding diameter for chucking and supporting the side surface is formed. Then, by rotating the pin base 16, the holding diameter can be reduced to chuck the side surface of the object 5 to be cleaned, or the holding diameter can be made larger than the diameter of the object 5 to be easily put in and out. Configure as you can.

  Further, the suction levitation table 2 can be moved up and down. In this way, the suction force can be controlled by adjusting the distance X between the object to be cleaned 5 and the suction levitation table 2 by the vertical movement of the suction levitation table 2, and the height position of the object to be cleaned 5 can be adjusted. Can be changed. In addition, 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 suction floating table 2, so that the cleaning object 5 can be easily transferred. preferable.

  In the single wafer cleaning apparatus 1 of the present invention, the object to be cleaned 5 is adsorbed and floated in a non-contact state by such an adsorption levitating table 2, and the object to be cleaned 5 is supported by the support 9 of the spin table 3 as described above. Since the upper surface is cleaned by supporting the side surface and rotating about its central axis, warping occurs due to distortion of the object 5 to be cleaned, such as distortion of the wafer itself or the laminated thin film on the wafer. The object 5 to be cleaned can be adsorbed and lifted in a non-contact state while extending so as not to warp, and the support 9 does not require a strong support force on the side surface of the object 5 to be cleaned. The upper surface of the object to be cleaned 5 can be cleaned while transmitting the rotational drive and maintaining the flatness. As a result, the object to be cleaned 5 such as a thin wafer of about 30 to 150 μm can be cleaned while suppressing warpage and breakage. Moreover, the damage | wound of the back surface of the to-be-cleaned object 5 by contact and the mutual contamination between the to-be-cleaned objects 5 can also be suppressed.

  Further, the object 5 to be cleaned is adsorbed with a strong force by the plurality of swirl flow forming portions 4 and the side surface of the object to be cleaned 5 is supported by the support 9, so that the object 5 to be cleaned can be rotated at high speed for cleaning. In addition, the cleaning liquid discharged on the upper surface of the object to be cleaned 5 can be swung out by the centrifugal force of the high-speed rotation to prevent the cleaning liquid from entering the lower surface side of the object to be cleaned 5.

Furthermore, since the position of the side surface of the cleaning object 5 supported by the support 9 can be changed by adjusting the suction force or height position of the cleaning object 5 during cleaning, the occurrence of cleaning residue is suppressed. Can do. In this case, specifically, the suction levitation table 2 is raised to reduce the distance X to reduce the suction force Y to Y <μm, and the contact force between the support 9 of the spin table 3 and the object 5 to be cleaned. Is lowered or brought into non-contact to cause a difference in the number of rotations of the spin table 3 and the object 5 to be cleaned, and then the spin table 3 is lowered and returned to its original state. The position of the side surface to be changed can be changed.
If it is such, it can change more reliably the position of the side surface supported by the support body 9 of the to-be-cleaned object 5 during washing | cleaning, and can eliminate the washing | cleaning residue of the part more reliably.

  Alternatively, by rapidly accelerating the rotation of the spin table 3 during cleaning, a difference occurs in the rotation speed of the spin table 3 and the object 5 to be cleaned, and the position of the side surface supported by the support 9 of the object 5 to be cleaned is changed. It is also possible to change the position of the side surface supported by the support 9 of the object to be cleaned 5 more reliably during cleaning, and it is possible to more reliably eliminate the cleaning residue at that portion. In this case, the rotation speed of the spin table 3 can be rapidly accelerated from 600 rpm to 1000 rpm in 0.1 seconds, for example.

  Here, the cleaning liquid is not particularly limited. For example, hydrofluoric acid, hydrochloric acid, acetic acid, hydrogen peroxide, or mixed acids thereof, acidic cleaning liquid such as SC-2, alkaline cleaning liquid such as NaOH, KOH, or SC-1, Alternatively, pure water can be used. The cleaning process in the present invention includes, for example, a process by rinsing the object to be cleaned 5 with pure water, etching using hydrofluoric acid, or the like.

Further, in the present invention, not only the upper surface of the object to be cleaned 5 but also the side surface of the object to be cleaned 5 and the bevel portion on the lower surface side of the object to be cleaned 5 may be cleaned as described above. As described above, the single wafer cleaning apparatus of the present invention can suppress the intrusion of the cleaning liquid into the main surface on the lower surface side of the object 5 to be cleaned, and at the same time, the cleaning liquid can be applied to the lower surface side of the object 5 to be cleaned. It is possible to control which part of the bevel part is inserted. Such control can be performed according to conditions such as a gas flow rate, the number of rotations of the object 5 to be cleaned, a cleaning time, and a cleaning liquid concentration (viscosity of the cleaning liquid). That is, the cleaning width of the bevel portion on the lower surface side of the object to be cleaned 5 can be controlled by these conditions.
Alternatively, the cleaning width of the bevel portion on the lower surface side of the object to be cleaned 5 can be controlled by changing the shape of the upper surface of the spin table 3 immediately inside the support 9.

  In addition, a drainage cup 12 for preventing and recovering the cleaning liquid discharged from the cleaning nozzle 6 can be provided on the outer peripheral portion of the single wafer cleaning apparatus 1. That is, the cleaning liquid splashed and scattered from the surface side of the object 5 to be cleaned is received by the drain cup 12. Most of the cleaning liquid is shaken off from the surface side of the object to be cleaned 5 and received by the drain cup 12, but the cleaning liquid flowing down from the cleaning liquid discharge line 15 as shown in FIG. 2 can also be recovered. Yes.

Further, at this time, as shown in FIG. 3, it is preferable that the gas released from the swirl flow forming portion 4 into the gap with the object to be cleaned 5 flows out further toward the outer periphery of the object to be cleaned 5. .
Thus, if the gas released from the swirl flow forming portion 4 into the gap with the object to be cleaned 5 further flows out toward the outer periphery of the object to be cleaned 5, the gas flows out toward the outer periphery. Thus, it is possible to more reliably suppress the cleaning liquid discharged from the cleaning nozzle 6 toward the surface of the object to be cleaned 5 from entering the lower surface side of the object to be cleaned 5. Thereby, for example, even when the lower surface of the object to be cleaned 5 is the device surface of the wafer on which the pattern is formed, the influence on the device surface such as destruction of the pattern by the chemical liquid of the cleaning liquid is more reliably suppressed. be able to. As shown in FIGS. 4 and 5B, the support 9 that supports the side surface of the object 5 is the circumference of the spin table 3 so that the gas flows out in the outer peripheral direction of the object 5 to be cleaned. Each is formed at intervals in the direction, and gas can flow out from the gap between these supports.

  Further, if the support 9 has a straight pin shape as shown in FIG. 5A and the distance between the upper end of the pin base 16 and the object 5 to be cleaned is made small, the object 5 to be cleaned and the suction levitation table are used. Since the distance X to 2 is also reduced, and the outflow speed of the gas flowing out toward the outer peripheral direction of the object to be cleaned 5 is increased, the effect of suppressing liquid immersion on the lower surface side of the object to be cleaned 5 can be enhanced. Here, the distance between the upper end of the pin base 16 and the article 5 to be cleaned can be set to, for example, about 0.2 mm.

Further, at this time, as shown in FIG. 1, it is possible to further include an object detection sensor 10 for detecting presence / absence and damage of the object 5 to be cleaned. The object to be cleaned detection sensor 10 can be, for example, a CCD camera. The object to be cleaned detection 10 can check the object to be cleaned 5 at all times or when necessary, and can detect the presence or absence of the object to be cleaned 5 and damage. it can.
If the cleaning object detection sensor 10 for detecting the presence or absence and damage of the cleaning object 5 is provided, the cleaning liquid is discharged from the cleaning nozzle 6 in a state where the cleaning object 5 is absent or damaged. It is possible to prevent the cleaning liquid from leaking into the spin table 3 and, for example, the chemical liquid of the leaked cleaning liquid from being vaporized and affecting the lower surface of the object to be cleaned 5. In particular, when a thin object to be cleaned is cleaned, it is effective to have such a sensor because cracks are likely to occur.

Further, at this time, as shown in FIG. 1, a liquid leakage detection sensor 11 for detecting liquid leakage to the lower inner side of the spin table 3 can be further provided.
In this way, if the liquid leakage detection sensor 11 that detects liquid leakage to the lower inner side of the spin table 3 is further provided, it is possible to quickly detect that the cleaning liquid has leaked below the spin table 3. Thus, the influence of the leaked cleaning liquid on the lower surface of the object to be cleaned 5 can be minimized. It is possible to prevent an undesirable situation such as corrosion caused by the cleaning liquid from occurring in the lower device mechanism.

At this time, the cleaning nozzle 6 may be an ultrasonic cleaning nozzle or a spray nozzle that applies ultrasonic vibration to the cleaning liquid.
Thus, if the cleaning nozzle 6 is an ultrasonic cleaning nozzle that applies ultrasonic vibration to the cleaning liquid, the cleaning effect can be improved by ultrasonic waves, and if it is a spray nozzle, the cleaning liquid can be supplied softly. it can. Here, the frequency of ultrasonic vibration applied to the cleaning liquid is not particularly limited, and may be a so-called megasonic nozzle that applies high-frequency ultrasonic waves such as 1 MHz.

At this time, as shown in FIG. 2, the drainage cup 12 for collecting the cleaning liquid discharged from the cleaning nozzle 6 is moved up and down in accordance with the type of the chemical liquid of the cleaning liquid to change the position, thereby separating the cleaning liquid. It can also be retrievable. That is, the drainage cup 12 is configured such that the left and right members 12a and 12b can be moved up and down independently. For example, when the cleaning liquid is received and collected inside 12b, 12b is lowered and 12a is increased. Thus, the liquid can be separated and recovered as in the case of moving up and down and receiving and recovering the cleaning liquid inside 12a. In addition, when delivering the object 5 to be cleaned, if the members 12a ′ and 12b ′ have a lower height than the object 5 to be cleaned as in the drain cup 12 ′ shown on the right side of FIG. The cup won't get in the way.
In such a case, the draining process is easy, and the chemical liquid of the separated cleaning liquid can be reused, and the cost can be reduced.

At this time, as shown in FIG. 2, a robot hand 14 that transports the object 5 to be cleaned is provided, and the object 5 to be cleaned on the suction levitation table 2 can be transferred without contact by the robot hand 14. It can be. Then, the above-described swirl flow forming portion may be formed on the robot hand 14.
In this way, if the robot hand 14 that transports the object 5 to be cleaned is provided and the object 5 to be cleaned on the suction levitation table 2 can be delivered in a non-contact manner by the robot hand 14, the object to be cleaned 5 can be cleaned in a non-contact manner and transported in a non-contact manner, and even a thin object to be cleaned 5 can be prevented from being damaged while preventing cross-contamination between objects to be cleaned 5 It is possible to suppress reattachment to the object 5 to be cleaned.

And when passing the to-be-cleaned object 5 to the adsorption | suction floating table 2 using such a robot hand 14, it can be performed as follows, for example.
First, a swirl flow is formed by the swirl flow forming unit of the robot hand 14 and the object to be cleaned 5 is sucked and held without contact. Then, after the robot hand 14 has advanced to just above the suction levitation table 2, it is lowered to a predetermined position. At the same time, the suction levitation table 2 is also raised to a delivery position where the distance from the robot hand 14 is a predetermined interval. The swirl flow is formed by the swirl flow forming unit 4. At this time, all the drainage cups 12, 12 'are lowered downward.

Next, when the suction of the object 5 to be cleaned by the robot hand 14 is released, the object 5 to be cleaned is sucked and floated by the suction and floating table 2 with its lower surface being in non-contact.
Thereafter, the suction levitation table 2 is lowered to the position where the object 5 to be cleaned becomes the cleaning position, and the side surface of the object 5 to be cleaned is supported by the support 9.

Similarly, when receiving the object 5 to be cleaned from the suction levitation table 2, the robot hand 14 advances to just above the suction levitation table 2, the suction levitation table 2 rises, and the robot hand 14 has been cleaned. The cleaning object 5 is lowered to a position where it is held.
Next, after the object 5 to be cleaned is sucked and held by the robot hand 14, the discharge of gas from the swirl flow forming unit 4 of the suction floating table 2 is stopped, and the object 5 to be cleaned is transported by the robot hand 14.

  In this way, by passing the object 5 to be cleaned on the suction levitation table 2 with the robot hand 14, the lower surface of the object 5 to be cleaned can be transferred in a non-contact state.

  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 pieces of silicon wafers having a diameter of 150 mm and a thickness of 90 μm were cleaned using a single wafer cleaning apparatus as shown in FIG. 1 equipped with an adsorption levitation table and a spin table as shown in FIG. Here, the distance X between the adsorption levitation table and the silicon wafer was 2.5 mm, and the rotation speed of the spin table during cleaning was 2000 rpm. The cleaning nozzle was a megasonic nozzle, and cleaning was performed by applying 1 MHz ultrasonic waves to the cleaning liquid. In addition, the suction levitation table was raised during cleaning, a difference was generated in the rotation speed of the spin table and the silicon wafer, and the position of the side surface supported by the silicon wafer support was changed twice.

And it evaluated about the damage of the silicon wafer after washing | cleaning, and the immersion of the washing | cleaning liquid to the lower surface side of the wafer under washing | cleaning.
As a result, it was confirmed that there was no damage after cleaning and no immersion of the cleaning liquid on the lower surface side, which was improved compared to the comparative example described later.
In addition, no scratches on the back surface or residual cleaning of the side surface occurred, and when the number of particles on the outer peripheral portion of the back surface of the substrate was evaluated, no increase was seen from before the cleaning, and between 100 substrates It was confirmed that the effects of cross-contamination can be suppressed.

(Comparative example)
Using a conventional single wafer cleaning apparatus as shown in FIG. 6, 100 silicon wafers similar to those in the example were cleaned, and evaluation similar to that in the example was performed.
As a result, warpage and breakage occurred in about 20% of the cleaned wafer, and the wafer could not be held and rotated. In addition, the washed liquid was also infiltrated into the lower surface even with the washed one.
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.

DESCRIPTION OF SYMBOLS 1 ... Single wafer type washing | cleaning apparatus, 2 ... Adsorption floating table, 3 ... Spin table,
4 ... swirl flow forming section, 5 ... object to be cleaned, 6 ... cleaning nozzle,
7: Recessed portion of the swirl flow forming portion, 8 ... Discharge port of the swirl flow forming portion, 9 ... Support,
10 ... object to be cleaned detection sensor, 11 ... leak detection sensor, 12, 12 '... drainage cup,
13 ... axis, 14 ... robot hand, 15 ... cleaning liquid discharge line, 16 ... pin base.

Claims (11)

In a single wafer cleaning apparatus comprising a cleaning nozzle for cleaning an upper surface of an object to be cleaned with a cleaning liquid, and cleaning the upper surface of the object to be cleaned with a cleaning liquid discharged from the cleaning nozzle while rotating the object to be cleaned around a central axis. ,at least,
An adsorption levitation table having a plurality of swirl flow forming portions on the upper surface portion having a cylindrical recess and a discharge port for discharging gas along the inner wall surface of the recess, and disposed immediately below the object to be cleaned,
A spin that is arranged around the suction levitation table and supports a side surface of the object to be cleaned immediately above the suction levitation table, and rotates the object to be cleaned supported by the support on a central axis. A table,
By discharging the gas from the discharge port of the swirl flow forming portion, the negative pressure generated in the central portion of the cylindrical recess of the swirl flow forming portion and the discharge from the swirl flow forming portion to the object to be cleaned are released. The side surface of the object to be cleaned is supported by the support while the object to be cleaned is adsorbed and floated in a non-contact state by the gas, and the upper surface is rotated by the spin table about the central axis. Single-wafer type cleaning device, characterized in that   The single wafer cleaning apparatus according to claim 1, wherein the suction floating table is movable up and down.   Raising the suction levitation table to reduce or non-contact the contact force between the spin table support and the object to be cleaned, thereby causing a difference in the rotation speed of the spin table and the object to be cleaned, The single wafer cleaning apparatus according to claim 2, wherein a position of a side surface supported by a support of the object to be cleaned can be changed.   By rapidly accelerating the rotation of the spin table, the rotational speed of the object to be cleaned can be changed, and the position of the side surface supported by the support of the object to be cleaned can be changed. The single wafer cleaning device according to any one of claims 1 to 3, wherein the single wafer cleaning device is.   5. The gas discharged from the swirl flow forming portion into the gap with the object to be cleaned flows out further toward the outer peripheral direction of the object to be cleaned. The single wafer cleaning apparatus according to Item 1.   6. The single wafer cleaning apparatus according to claim 1, further comprising an object detection sensor for detecting presence / absence and breakage of the object to be cleaned.   The single wafer cleaning apparatus according to any one of claims 1 to 6, further comprising a liquid leakage detection sensor that detects liquid leakage to a lower inner side of the spin table.   The single wafer cleaning apparatus according to any one of claims 1 to 7, wherein the cleaning nozzle is an ultrasonic cleaning nozzle or a spray nozzle that applies ultrasonic vibration to the cleaning liquid.   A drainage cup for collecting the cleaning liquid discharged from the cleaning nozzle is provided, and the drainage cup is arranged around the spin table and moves up and down according to the type of the chemical liquid of the cleaning liquid to change the position. The single wafer cleaning apparatus according to any one of claims 1 to 8, wherein the cleaning liquid can be separated and collected.   The sheet according to any one of claims 1 to 9, wherein the spin table is capable of spin drying the object to be cleaned, and is capable of rotating at a maximum rotation speed of 4000 rpm. Leaf cleaning device.   The robot hand for transporting the object to be cleaned is provided, and the object to be cleaned on the suction levitation table can be delivered in a non-contact manner by the robot hand. The single wafer cleaning apparatus according to any one of 10.

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