JP2501763B2 - Wafer polishing equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer polishing apparatus for polishing the outer periphery of a wafer-shaped work such as a silicon wafer.

[0002]

2. Description of the Related Art In a silicon wafer used as a material of a semiconductor chip, fine processing is performed more and more in a manufacturing process of the semiconductor chip, and therefore it is necessary to prevent fine dust generation from the outer periphery of the wafer. Therefore, it is necessary to chamfer the outer periphery of the wafer and polish the outer peripheral surface to a mirror surface, and a wafer polishing apparatus for that purpose has been developed.

There is a linear orientation flat (hereinafter referred to as an orientation flat) on the outer periphery of the wafer, and in order to efficiently and accurately polish the outer circumference of the wafer and the orientation flat, the polishing process may be divided. That is, in order to polish the outer circumference of the wafer, if the inner circumference polishing surface provided on the inner circumference of the cylindrical body is used, the contact portion between the outer circumference of the wafer and the polishing surface becomes wider, so that the polishing can be performed efficiently. can do.
Further, since the orientation flat cannot be polished on the inner peripheral polishing surface, the outer peripheral polishing surface provided on the outer periphery of the cylindrical body is used. Therefore, by dividing the wafer into a plurality of processing stations and simultaneously processing the outer circumferential portion and the orientation flat portion of the plurality of wafers, it is possible to improve the polishing efficiency as a whole.

In such a wafer polishing apparatus having a plurality of processing stations, in order to polish the outer periphery of the wafer 11 which is sequentially supplied, a transfer mechanism for transferring and transferring the wafer 11 between the plurality of processing stations is provided. be able to. An example of the wafer polishing apparatus is shown in FIG. A wafer loader unit 70 has a wafer positioning unit. Reference numeral 72 denotes a first wafer pressing device, which can press the outer circumference of the wafer 11 against the outer circumference of a rotary polishing section 74 having a cylindrical inner and outer circumference with polishing surfaces. The first wafer pressing device 72 is provided with the wafer 11 at one end of an arm rotatably provided on the base.
Is provided with a suction type holding device, which is rotationally driven by a cylinder connected to the other end of the arm. A second wafer pressing device 76 can press the outer circumference of the wafer 11 against the inner circumference of the rotary polishing section 74. The second wafer pressing device 76 is the same as the first wafer pressing device 76.
The wafer pressing device 72 is driven by the same mechanism.
Reference numeral 78 denotes a wafer unloader unit, from which the polished wafer 11 is discharged. Reference numeral 80 denotes a first transfer device, which is provided with a suction-type holding device for holding the wafer 11 at its tip, and the wafer 11 is received by the loader unit 70 by the holding device and passed to the holding device of the first pressing device 72. . Similarly, the second transfer device 82 transfers the wafer 11 from the first wafer pressing device 72 to the second wafer pressing device 76, and the third transfer device 84 transfers the wafer 11 to the second wafer pressing device 76. To the unloader unit 78. By handing over the wafer 11 and carrying it in this manner, the outer circumference of the sequentially supplied wafers can be automatically polished. By the way, the provision of such a plurality of transfer devices is nothing but the polishing of the wafer on the outer peripheral surface and the inner peripheral surface of the rotary polishing section at the same time to improve the polishing efficiency. That is, if polishing is performed individually, it is sufficient to provide one transport device.

[0005]

However, according to the above-mentioned wafer polishing apparatus, the wafer has to be delivered between the respective steps, which may cause a positional deviation of the wafer or contamination of the wafer, or the delivery of the wafer. Therefore, there was a problem that it took time and production efficiency was poor. Further, there is a problem that the structure of the transfer device and its operation control become complicated.

Therefore, an object of the present invention is to provide a wafer polishing apparatus capable of polishing the outer peripheral portion of a wafer with high accuracy and efficiency without complicating the structure of the apparatus and its operation control. .

[0007]

In order to achieve the above object, the present invention has the following constitution. That is, a wafer polishing apparatus according to the present invention includes a rotating base that intermittently rotates at a constant rotation angle, a plurality of swing arms arranged on the rotating base at regular intervals in the circumferential direction, and the swing base. A holding device provided on one end side of the arm for holding the wafer, a wafer loader station, a wafer polishing station having a rotary polishing section, which are arranged corresponding to the swinging arm at each stop position of the rotary substrate, At least three of the wafer unloader stations and the swing arm rotationally positioned at the polishing station in the polishing station are rotated to make the outer periphery of the wafer held by the holding device the polishing surface of the rotary polishing section. And an oscillating device of an oscillating arm for pressing.

Further, according to the present invention, a rotating base body which intermittently rotates at a constant rotation angle, a plurality of shaft mounting portions arranged at a constant interval in the circumferential direction on the rotating base body, and the shaft mounting portion as a center. A plurality of swing arms that are rotatably provided on the swing arm, and a holding device that is provided at one end of the swing arms and that holds a wafer;
At least three stations, a wafer loader station, a wafer polishing station having a rotary polishing section, and a wafer unloader station, which are arranged corresponding to the swinging arms at the respective stop positions of the rotary substrate, and at the polishing station. An oscillating device of the oscillating arm that rotates the oscillating arm rotatably located at the polishing station to press the outer periphery of the wafer held by the holding device against the polishing surface of the rotating polishing section, and the rotating base are intermittent. When rotating, for example, the swing arm is brought into contact with a stopper and the outer periphery of the wafer is pressed in a direction opposite to the rotation direction in which the polishing surface of the rotary polishing section is pressed, whereby the swing arm is rotated. There is also a wafer polishing apparatus characterized in that it is provided with a lock mechanism for preventing rotation of the wafer.

In the wafer polishing apparatus,
The polishing station has a first polishing station having an outer peripheral rotary polishing section having an outer peripheral surface provided with a polishing surface, and a second polishing station having an inner peripheral rotary polishing section having an inner peripheral surface provided with a polishing surface. With two stations, the production efficiency can be further improved.

A holding device provided at one end of the swing arm is composed of a suction device for sucking and holding a wafer, and a cleaning device for cleaning the wafer surface and the suction surface of the suction device at the unloader station. If the above is provided, the wafer after polishing and the suction surface of the suction device can be cleaned within one polishing step time required for each polishing station, and the productivity of the entire system can be improved.

[0011]

According to the wafer polishing apparatus of the present invention, the wafer once held by the holding apparatus is not transferred thereafter, and the wafer loader station, the polishing station on the outer periphery of the wafer having the rotary polishing unit, and the wafer Sequentially located to at least three of the unloader stations. For this reason, there is no fear of wafer misalignment, the time required for delivery can be omitted, and the working time for polishing the outer periphery of the wafer can be greatly shortened as a whole process, resulting in a significant improvement in production efficiency. Further, since the wafers are sequentially transferred only by intermittent rotation of the rotary base, the structure of the wafer transfer device and its operation control can be simplified. Then, the rocking device can rotate the rocking arm rotatingly located at the polishing station in the polishing station to press the outer periphery of the wafer held by the holding device against the polishing surface of the rotary polishing section. . At this time, since the rotation of the swing arm is restricted by one point of the shaft attachment portion, the outer periphery of the wafer can be pressed against the rotary polishing portion while preventing the error swing, and the outer periphery of the wafer can be accurately polished. You can

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. 1 is a plan view showing an embodiment of a wafer polishing apparatus according to the present invention, and FIG.
It is a side view of the Example of. Reference numeral 10 denotes a rotating base, which intermittently rotates at a constant rotation angle. As shown in FIG. 2, the rotary base 10 is provided with a shaft 12 extending downward from the central portion. The shaft 12 is rotatably fitted and rotatably mounted on a bearing portion 16 provided on the device base 14. Reference numeral 15 is a drive motor, the drive force of which is transmitted to the shaft 12 via a gear. A servo motor, a stepping motor, or the like can be used as the drive motor 15. As described above, the rotary substrate 10 constitutes the rotary portion of the rotary type transport device. . In addition, in the upper part of the rotary substrate 10, at equal intervals in the circumferential direction (intervals for equipping the same number of stations including a loader station and an unloader station, in this embodiment, a quarter is divided into four). As shown in FIG. 1, it has four support rods 18 extending outward. A shaft attachment portion 20 is provided at the tip of each of the support rods 18.

Reference numeral 22 is a swing arm, and each of the shaft mounting portions 2 is
It is rotatably attached to zero. A holding device 24 for holding the wafer 11 is provided on one end side of the swing arm 22. The holding device of this embodiment uses a suction type holding device 24 as will be described later.

A wafer loader station 26 corresponds to the swing arm 22 at the stop position of the rotary substrate 10 and is arranged so that the wafers 11 are sucked one by one by the holding device 24. Has been done. Further, in the loader station 26, the position of the orientation flat of the wafer is detected by the sensor, and the suction head 25 of the holding device 24 is rotated so that the orientation flat is positioned at a predetermined rotation position.

Reference numeral 28 denotes a first polishing station for polishing the outer periphery of the wafer, which corresponds to the swing arm 22 at the stop position of the rotary substrate 10 and includes an outer peripheral rotary polishing section 29 having a polishing surface on its outer periphery. Have. At the first polishing station 28, the orientation flat of the wafer 11 is polished in particular. An air cylinder device 30 rotates the swing arm 22 rotatably located at the first polishing station 28 to rotate the outer periphery of the wafer 11 held by the holding device 24 to the polishing surface of the outer peripheral rotation polishing unit 29. Swing arm 2 for pushing
2 rocking device is constituted. This air cylinder device 3
0 is fixedly provided on the base body 14 side of the apparatus so that the tip of the rod abuts the swing arm 22 when the swing arm 22 is located at the first polishing station 28. The protrusion causes the swing arm 22 to be pressed and rotated as shown in FIG. Reference numeral 32 is an air cylinder device for unlocking. Details will be described later.

Reference numeral 34 is a second polishing tool for polishing the outer periphery of the wafer 11.
The polishing station includes an inner peripheral rotary polishing section 35 corresponding to the swing arm 22 at the stop position of the rotary substrate 10 and having a polishing surface provided on the inner periphery of the cylindrical body. In this second polishing station 34, in particular, the circumferential outer periphery of the wafer 11 is polished. Note that, as shown in FIG. 2, the inner peripheral rotary polishing section 35 is provided so as to be rotated at a high speed by a motor 37, and is provided so as to be vertically movable along a guide 39. Reference numeral 36 denotes an air cylinder device, which rotates the swing arm 22 rotatably positioned at the second polishing station 34 to polish the outer periphery of the wafer 11 held by the holding device 24 by the inner rotation polishing unit 35. It constitutes a swinging device of the swinging arm 22 that is pressed against the surface.
The air cylinder device 36 is the same as the air cylinder device 3.
It is equivalent to 0. An air cylinder device 38 for unlocking is equivalent to the air cylinder device 32 for unlocking.

In the outer peripheral polishing of the wafer 11 of the present embodiment, the outer periphery of the wafer 11 is pressed against the polishing surface of the outer peripheral rotary polishing section 29 or the inner peripheral rotary polishing section 35 in the same manner as a usual polishing method, and slurry ( Polishing liquid) is supplied.
The polishing surfaces of the rotary polishing units 29 and 35 are formed by elastic buffs, and are compressed by pressing the outer periphery of the wafer 11. Therefore, the chamfering of the outer periphery of the wafer 11 and the polishing of the outer surface can be performed simultaneously.

40 is an unloader station,
At this position, the suction of the wafer by the holding device 24 is released, and the wafer 11 whose peripheral polishing has been completed is discharged. Further, in the unloader station 40, the wafer surface, particularly the surface on which the wafer is not sucked by the suction head 25 (hereinafter referred to as the wafer suction back surface), and the suction surface of the suction head 25 which is the suction device constituting the holding device 24. A cleaning device is provided for cleaning.

The cleaning device may be, for example, a brush device for cleaning by brushing. Although this brush device is not shown, when the wafer 11 is moved to the unloader station 40 while being sucked by the suction head 25 of the swing arm 22, the back surface of the wafer suction is first cleaned by the brush device. After that, the brush device moves laterally from below the suction head 25. Then, the suction of the wafer 11 is released and the wafer 1 is released.
After 1 is discharged in the carrier direction of the wafer, the brush device moves again below the suction head 25 to wash the suction surface of the suction head 25 this time. By providing the cleaning device in the unloader station 40 in this way, the wafer after polishing and the suction surface of the suction device can be cleaned within one polishing process time required for each polishing station, while maintaining the process balance. The productivity of the entire system can be improved.

As shown in FIG. 3, reference numeral 42 denotes a lock mechanism, which is used when the swing arm 22 is positioned at the loader station 26 and the unloader station 40, when the rotary base 10 rotates intermittently, and the like. Prevent the rotation of. A stopper 44 is formed by fixing a pin that abuts a side surface of the swing arm 22 in the vicinity of the holding device 24 to a protruding portion protruding from the supporting rod 18. The stopper 44 prevents the swing arm 22 from rotating clockwise as shown in FIG. That is, the swing arm 22 is restricted from rotating in the opposite direction to the rotation direction in which the outer periphery of the wafer 11 is pressed against the polishing surface of the outer peripheral rotary polishing section 29 (or the inner peripheral rotary polishing section 35). There is.

Reference numeral 46 denotes a stopper arm, which is a support rod 18
It is provided so as to be rotatable around a rotation shaft 48 provided in the. The swing arm 2 is attached to one end of the stopper arm 46.
An abutting portion 50 that comes into contact with the side surface of 2 is provided. A pin is fixed to the contact portion 50, and the tip of the pin contacts the swing arm 22. On the other hand, a spring 52 is stretched between the other end of the stopper arm 46 and the rotating base 10. That is, the stopper arm 46 is biased by the spring 52 so as to rotate clockwise. Therefore, the swing arm 22 is in a direction (clockwise direction) opposite to the rotation direction in which the outer periphery of the wafer is pressed against the polishing surface of the outer peripheral rotary polishing section 29 by the stopper arm 46.
Be urged by. In this way, the stopper 44 and the stopper arm 46 form the lock mechanism 42 that prevents the swing arm 22 from rotating.

Next, the operation of unlocking the lock mechanism 42 will be described. As the rod of the air cylinder device 32 projects as shown in FIG. 4, the tip of the rod abuts on one end of the stopper arm 46, and the stopper arm 46 is rotated counterclockwise. This allows the swing arm 22 to rotate counterclockwise within a predetermined range. As a result, the outer periphery of the wafer 11 is pressed against the polishing surface of the outer periphery rotary polishing section 29, and the wafer 1
The outer periphery of 1 is preferably polished. In addition, the wafer 11 is also similarly removed by the second polishing station.
It is pressed against the polishing surface of No. 5, and its outer periphery is polished. In addition,
The swinging range of the swing arm 22 may be a range for pressing the wafer, and is usually limited as shown in FIGS. 3 and 4. Further, the pressing means is not limited to the air cylinder device 32, and needless to say, a weight, a motor, a spring, or the like may be used.

Next, an example of the swing arm 22 and a holding device 24 provided at one end thereof will be described in detail with reference to FIG. The swing arm 22 has a shaft 23 erected upright in the middle thereof, which is rotatably attached to a bearing portion 19 provided at the tip of a support rod 18 extending from the rotary base 10. .

A holding device 24 for holding the wafer 11 rotatably with the outer periphery thereof being exposed is provided on the lower surface side at one end of the swing arm 22. Although there are various methods for holding the wafer, the holding device 24 of this embodiment has an air suction port 54 and a V-ring 56 that surrounds the suction port 54 in a circular shape, as shown in FIG. , That V-
A suction head 25 is used which holds the wafer 11 by bringing the ring 56 into close contact with the surface of the wafer and depressurizing the inside thereof to adsorb the wafer 11. The V-ring 56 is an airtight member formed of an elastic material such as synthetic rubber and having a spatula-shaped portion and having a substantially V-shaped cross section, and the spatula-shaped portion is provided on the surface of the holding device 24. It is mounted in a circular groove provided along the outer circumference of the suction head member 57 so as to be exposed.

Further, as shown in FIG. 5, the rotary drive device 58 for rotationally driving the suction head 25 includes a swing arm 2
It is fixed to the upper surface side of 2. The rotary shaft of the rotary drive device 58 is connected in series in the holding device 24 via the speed reducer 60 and the rotary shaft 62. The speed reducer 60 and the rotary shaft 62 are mounted on a bearing portion 64 provided at the tip of the swing arm 22 so as to extend in a direction orthogonal to the swing arm 22 via a bearing and a seal member. ing.

A servo motor or a stepping motor capable of controlling a rotation condition is used as the rotation drive device 58, and the suction head 25 can be rotated in both forward and reverse directions at a desired rotation speed via a speed reducer 60. it can. By the rotating mechanism of the suction head 25, the portion to be polished on the outer peripheral portion of the wafer 11 can be sequentially fed so as to come into contact with the rotating outer peripheral rotary polishing portion 29 or the inner peripheral rotary polishing portion 35.

Further, since the rotary drive device 58 is disposed on the swing arm 22, it does not affect the driving force of the pressing device (air cylinder device 30) for rotating the swing arm 22. . This is because the rotation driving device 58 rotates together with the swing arm 22 so that the wafer 11 is rotated.
The holding device 24 for contacting the rotary polishing section with an appropriate pressing force.
This is because the rotational force of the rotary drive device 58 does not adversely affect the driving force that moves the swing arm 22 by the rotation of the swing arm 22. Therefore, it is possible to accurately control the pressing force that presses the outer periphery of the wafer 11 against the rotary polishing section 58.
The outer periphery of the wafer 11 can be polished with high accuracy while preventing uneven polishing.

The rotation drive device 58 need not be coaxial with the rotation shaft 62 of the suction head 25 as in the present embodiment as long as it is disposed on the swing arm 22. . That is, the swing arm 22 is rotated by transmitting the rotation driving force of the rotation driving device 58 that rotates the wafer 11.
It suffices that the rotation drive device 58 be provided on the swing arm 22 so as not to be affected by the rotation of the.

By the way, the air cylinder devices 30 and 36 and the air cylinder devices 32 and 38 for unlocking are fixed to the device base 14, and do not rotate together with the rotary base 10. Therefore, there is no concern that the piping of the cylinder device will become entangled, and the device can be simplified. Also,
As the polishing member of the outer peripheral rotary polishing unit 29 or the inner peripheral rotary polishing unit 35 in this embodiment, a buff made of hard foam urethane mixed with abrasive grains such as silica can be used.

In the above embodiment, the case where the polishing stations are provided at two locations has been described, but the present invention is not limited to this, and only the polishing station having the outer peripheral rotation polishing section may be provided, or three locations. It is also possible to provide the above polishing station. Further, it is not limited to the cylindrical outer peripheral rotary polishing section or the inner peripheral rotary polishing section shown in the present embodiment, and other rotary polishing sections can be used. Although various embodiments of the present invention have been described above, the present invention is not limited to these embodiments.
Of course, many modifications can be made without departing from the spirit of the invention.

[0031]

According to the wafer polishing apparatus of the present invention,
The wafer once held by the holding device is not transferred thereafter, and is positioned at least in three stations: a wafer loader station, a wafer outer polishing station having a rotary polishing section, and a wafer unloader station. For this reason, there is no concern that the wafer will be displaced, and the time required for delivery can be omitted. Further, since the wafers are sequentially transferred by the intermittent rotation of the rotary substrate, the structure of the wafer transfer device and its operation control can be simplified. When the outer periphery of the wafer is pressed against the polishing surface of the rotary polishing section at the polishing station, the swing arm is restricted from rotating by a single point, so that it can be pressed to prevent error shake and the wafer can be accurately moved. The outer circumference can be polished. Therefore, the wafer polishing apparatus of the present invention has the remarkable effect that the outer peripheral portion of the wafer can be polished accurately and efficiently without complicating the structure of the apparatus and its operation control.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

2 is a side view of the embodiment of FIG. 1. FIG.

3 is a plan view showing details of a lock mechanism of the embodiment of FIG. 1. FIG.

FIG. 4 is a plan view showing an operating state of FIG.

5 is a cross-sectional view showing details of the holding device of the embodiment of FIG. 1. FIG.

FIG. 6 is an explanatory diagram showing a conventional technique.

[Explanation of symbols]

 10 Rotating Base 18 Support Rod 20 Shaft Attachment 22 Swing Arm 24 Holding Device 25 Suction Head 26 Loader Station 28 First Polishing Station 29 Peripheral Rotating Polishing Unit 30 Air Cylinder Device 32 Air Cylinder Device for Unlocking 34 Second Polishing Station 35 Inner circumference rotary polishing unit 36 Air cylinder device 38 Air cylinder device for unlocking 40 Unloader station 42 Lock mechanism 58 Rotation drive device

Claims (4)

(57) [Claims] 1. A rotary base body that intermittently rotates at a constant rotation angle, a plurality of swing arms arranged on the rotary base body at equal intervals in the circumferential direction, and a wafer provided on one end side of the swing arm for mounting a wafer. A holding device for holding, and at least three stations, a wafer loader station, a wafer polishing station having a rotary polishing section, and a wafer unloader station, which are arranged corresponding to the swinging arms at respective stop positions of the rotary substrate. A swinging device of a swinging arm that rotates a swinging arm that is rotationally positioned in the polishing station in the polishing station to press the outer periphery of the wafer held by a holding device against the polishing surface of the rotary polishing section. A wafer polishing apparatus comprising: 2. A rotary base body that intermittently rotates at a constant rotation angle, a plurality of shaft attachment portions that are arranged on the rotary base body at equal intervals in the circumferential direction, and are rotatably provided around the shaft attachment portion. A plurality of swing arms, a holding device provided on one end side of the swing arms for holding a wafer, and a wafer loader station arranged corresponding to the swing arms at respective stop positions of the rotary substrate. A wafer polishing station having a rotary polishing section, a wafer unloader station, and at least three stations, and a swinging arm rotatingly positioned at the polishing station in the polishing station is rotated and held by a holding device. A swinging device of a swinging arm that presses the outer periphery of the wafer against the polishing surface of the rotary polishing unit, and the swinging arm when the rotating base body rotates intermittently, And a lock mechanism for preventing rotation of the swing arm by abutting against the stopper and pressing the outer periphery of the wafer in a direction opposite to the rotating direction in which the polishing surface of the rotary polishing section is pressed. A wafer polishing apparatus characterized in that 3. A first polishing station, wherein the polishing station has an outer peripheral rotary polishing section having a polishing surface provided on the outer periphery of a cylindrical body, and an inner peripheral rotating polishing having a polishing surface provided on the inner periphery of the cylindrical body. 2. The wafer polishing apparatus according to claim 1, which is two stations including a second polishing station having a section. 4. A holding device provided on one end side of the swing arm is configured by a suction device that sucks and holds a wafer, and the unloader station cleans the wafer surface and the suction surface of the suction device. The wafer polishing apparatus according to claim 1, further comprising a cleaning device.