JPH06345262A - Processing device - Google Patents

Abstract

PURPOSE:To smoothly deliver an object to be processed to a processing mechanism by eliminating inconvenience that the object to be processed is hardly separated from an arm due to the residue of processing liquid. CONSTITUTION:A plurality of projecting adsorption parts 14 which are contacted with the underside in the vicinity of the circumferential edge of an object to be processed are provided on an arm 8. Outside the adsorption parts 14, a residue receiving groove 12 for receiving the residue of processing liquid supplied to the object to be processed is formed. The object to be processed can be supported in the condition of not contacting its circumferential edge with the arm 8, and the residue falling down from the circumferential edge part of the object to be processed can be received in the residue receiving groove 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing apparatus for performing processing such as resist film formation and development processing on an object to be processed such as a semiconductor wafer.

[0002]

2. Description of the Related Art Generally, in a semiconductor device manufacturing process, a series of processes in which a semiconductor wafer is coated with a photoresist, a circuit pattern is reduced using a photolithography technique, transferred to the photoresist, and developed. Is applied.

When performing such processing, the processing system shown in FIG. 14 is used. This processing system
A loader unit 40 for loading and unloading a semiconductor wafer (hereinafter, simply referred to as a wafer) W as an object to be processed, a brush cleaning device 42 for cleaning the wafer W with a brush, and a jet water cleaning device for cleaning the wafer W with high-pressure jet water. 44 and an adhesion processing device 46 for hydrophobicizing the surface of the wafer W
And a cooling processing device 48 for cooling the wafer W to a predetermined temperature.
And a resist coating device 50 for coating the resist on the surface of the wafer W and side-rinsing to dissolve and remove the resist in the peripheral portion, and a heating device 52 for heating the wafer W after the resist coating to perform pre-baking or post-baking. Further, the developing device 54 and the like for performing the developing process of the exposed wafer W are integrated to improve the working efficiency.

A wafer transfer path 56 is provided along the longitudinal direction in the central portion of the processing system configured as described above, and the devices 40 to 54 are arranged on the wafer transfer path 56 with their front faces facing each other. The wafer transfer mechanism 58, which transfers the wafer W to and from each of the devices 40 to 54, has a wafer transfer path 56.
It is provided so as to be movable along. The wafer transfer mechanism 58 includes an arm 59 for holding the wafer W by vacuum suction or supporting the lower surface of the peripheral portion. For example, two arms 59 are arranged above and below, and can be independently moved to the wafer mounting positions of the respective devices 40 to 54 by a moving mechanism. Each arm 5
As shown in FIG. 15, a wafer support frame 60 is formed in a partially cut-out annular shape, and the wafer support frame 60 is mounted at three inner sides of the support frame 60 by engaging with the peripheral edge of the wafer W. A claw 61 that supports the shape is provided. These claws 61 are shown in FIG.
As shown in FIG.
The wafer W is prevented from being displaced during the transfer by dropping the wafer. By using two such arms 59, the loading and unloading of the wafer W can be performed in parallel with respect to the respective devices 40 to 54, and the processing efficiency can be improved. Then, for example, one unprocessed wafer W stored in a wafer cassette (not shown) of the loader unit 40 is taken out and conveyed, and cleaning, adhesion processing, cooling, resist coating, prebaking, and exposure (not shown) are sequentially performed. Exposure, development, and post-baking are performed by the apparatus, and the processed wafer W is transferred and stored in a wafer cassette (not shown) of the loader unit 40.

[0005]

By the way, in the above-mentioned apparatus, when the coating treatment is performed by using a high-viscosity treatment liquid such as polyimide, instead of the low-viscosity resist liquid which is usually used, Even if the side rinsing process is performed by the resist coating apparatus 50, the polyimide on the peripheral edge of the wafer is difficult to remove and remains. When the processing liquid residue 64 adheres to the claws 61 of the arm 59, the wafer W is transferred to the arm 59.
It becomes difficult to separate the wafers W from each other, and the wafer W cannot be carried into the respective devices 40 to 54 smoothly. In particular, the heat treatment apparatus 52 is for placing the wafer W on the heat plate 62 provided in each of the stacked blocks 52A to perform the heat treatment, and the transfer of the wafer W to the heat plate 62 is As shown in FIG. 17, since it is performed above the heat plate 62 by the three support pins 63 that are provided so as to vertically move through the heat plate 62, the processing liquid residue 64 is attached to the claw 61 of the arm 59. Then, when the wafer W is placed on the support pins 63, the wafer W may be displaced or dropped. There is also a problem that the polyimide remaining on the periphery of the wafer W is peeled off and adheres to the wafer W as particles.

The present invention has been made in view of the above circumstances, and an object thereof is that even when a treatment is performed using a high-viscosity treatment liquid such as polyimide, the object to be treated is separated from the arm by the residue of the treatment liquid. It is an object of the present invention to provide a processing apparatus that can smoothly transfer an object to be processed to each processing mechanism and efficiently perform a series of processing without causing inconvenience.

[0007]

In order to achieve the above object, the first processing apparatus of the present invention has a plurality of processing mechanisms for performing processing on an object to be processed, and these processing mechanisms including the object to be processed. Assuming a processing device having a transport mechanism for transporting and an arm movably provided on the transport mechanism for holding the object to be processed, the arm is brought into contact with the lower surface near the peripheral edge of the object to be processed. A plurality of projecting suction portions for supporting this are provided, and a slag receiving groove for receiving a residue such as a treatment liquid supplied to the object to be treated is formed outside the suction portions. is there.

Further, the second processing apparatus of the present invention includes a plurality of processing mechanisms for processing the object to be processed, a transfer mechanism for transferring the object to be processed to these processing mechanisms, and the transfer mechanism. Assuming a processing device having a movable arm for holding the object to be processed, the arm is provided with a plurality of claws for supporting several points in the circumferential direction of the object to be processed, and the upper surface of each claw. In addition, a plurality of projecting suction portions that abut on the lower surface near the peripheral edge of the object to be processed and support the same at several points are provided at several locations corresponding to the diameters of several kinds of objects to be processed.

In the second aspect of the invention, the operation of the projecting suction portions corresponding to the diameter of the object to be processed may be performed manually, but it is preferable that each projecting suction portion be covered. It is better to provide a detecting means for detecting the diameter of the object to be treated, and to operate the projecting suction portion of the portion supporting the object to be treated based on a signal from the detecting means.
In this case, for example, a vacuum sensor or a photoelectric sensor can be used as the detecting means.

[0010]

According to the first processing apparatus of the present invention configured as described above, a plurality of arms for holding the object to be processed are brought into contact with the lower surface near the peripheral edge of the object to be processed to support the same at several points. By providing the projecting suction portion, the object to be processed is held in a state in which the peripheral edge thereof is not in contact with the arm, so that there is no inconvenience that the object to be processed becomes difficult to separate from the arm due to the residue of the processing liquid. . Moreover, by forming a slag receiving groove for receiving a residue such as the processing liquid supplied to the object to be processed, on the outside of the adsorption portion that supports the vicinity of the peripheral edge of the object to be processed,
Even if the residue of polyimide falls from the peripheral edge of the wafer, it can be received by the residue receiving groove, so that the residue can be prevented from scattering in the apparatus, and the scattering of particles can be suppressed.

According to the second processing apparatus of the present invention, the arm for holding the object to be processed is provided with a plurality of claws for supporting several points in the circumferential direction of the object to be processed, and the upper surface of each claw is provided. By providing a plurality of projecting suction portions that abut on the lower surface near the peripheral edge of the object to be processed and support the same at several points in correspondence with the diameters of several kinds of objects to be processed, It is possible to hold the arm in a non-contact state and to handle several kinds of objects having different diameters without exchanging the arm.

[0012]

Embodiments of the present invention will be described in detail below with reference to the drawings. The overall apparatus configuration of the processing apparatus of the present invention can be the same as that of the semiconductor wafer coating / developing apparatus shown in FIG. 14. Therefore, the most characteristic constituent elements of the processing apparatus of the present invention will be described here. A transport mechanism for a certain object will be described.

First Embodiment FIG. 1 is a perspective view showing an arm portion of a carrying mechanism according to the first embodiment of the present invention, and FIG. 2 is a schematic front view of the carrying mechanism.

The transfer mechanism 57 includes a transfer path 56 (see FIG. 14).
(See) a traveling block 2 provided movably along the upper transport rail 1, and three traveling blocks 2 provided on the traveling block 2 with their positions vertically displaced via support shafts 3, 4, and 5, respectively. It has arms 6, 7 and 8. Below, upper arm 6
Is referred to as a first arm, the middle arm 7 is referred to as a second arm, and the lower arm 8 is referred to as a third arm.

The first and second arms 6 and 7 are of the same general structure as those shown in FIG. 15 for transferring the wafer W to and from the respective devices 40 to 54 during the normal resist coating and developing process. The third arm 8 is an arm that is newly adopted in the processing apparatus of the present invention, and is used only when performing a coating process of a highly viscous processing liquid such as polyimide. It is a dedicated arm for transferring the wafer W from the apparatus 50 to the heat treatment apparatus 52. These first to third arms 6 to 8 can be independently moved by a moving mechanism (not shown), and the horizontal direction (X and Y directions), the vertical direction (Z direction) and the rotation direction (?
Direction) can be moved. As such an arm moving mechanism, for example, a rotating mechanism such as a stepping motor and a ball screw connected thereto, or a belt-driven slide mechanism is used.

As shown in FIGS. 3, 4 and 5, the third arm 8 has a wafer receiving portion 10 formed along the inner side wall 9a of the wafer supporting frame 9, and the inner peripheral edge of the wafer receiving portion 10 is formed. A stepped portion 11 is formed in a rim shape on the inner portion of the inner wall 9
A partially cut-out annular slag receiving groove 12 is formed on the inner side of the wafer support frame 9 by a, the wafer receiving portion 10 and the step portion 11. As shown in FIG. 4, closing walls 13 are formed at both ends of the slag receiving groove 12.

On the upper surface of the stepped portion 11 of the wafer receiving portion 10, projection-shaped wafer suction portions 14 are formed at both ends and an intermediate portion in total. Each of the suction portions 14 has a suction hole 15 in the shape of an elongated hole along the circumferential direction, and these suction holes 15 are formed by an air passage 16 formed inside the arm. It communicates with 17. The intake port 17 is connected to a vacuum suction device (not shown) via an air passage 18 formed inside the support shaft 5, and by driving this vacuum suction device, the three suction ports 15 simultaneously operate. Intake is performed. Stepped portion 11 in which these suction ports 15 are formed
The outer diameter of the wafer W is set to be slightly smaller than the diameter of the wafer W, for example, about 2 to 10 mm, and the projecting wafer suction portion 14 is brought into contact with the lower surface in the vicinity of the peripheral edge of the wafer W to suck and hold it. ing.

Further, the diameter of the inner wall 9a of the wafer receiving portion 10 is set to be slightly larger than the diameter of the wafer W, for example, about 2 to 10 mm, and the peripheral portion of the wafer W sucked and held by the suction portion 14 does not contact. It is like this. That is, the third arm 8 adsorbs three points on the lower surface near the peripheral edge of the wafer W by the wafer adsorption portions 14 provided at the three points and supports them at three points, and as shown in FIG. The wafer W can be held in a state in which the portion Wa is pushed out above the slag receiving groove 12.

Next, the operation of the transport mechanism constructed as described above will be described. First, when performing a normal resist coating / developing process, using the first and second two arms 6 and 7, the loading / unloading of the wafer W into / from each of the devices 40 to 54 is performed.
Carry out in parallel. This allows efficient processing.

Next, when a high-viscosity processing liquid such as polyimide is applied, most of the transfer process is performed using the first and second arms 6 and 7 also in this case. ,
In particular, the transfer step in which the residue 64 of the processing liquid adheres to the arm claw 61 is a problem, that is, only the transfer step of transferring the wafer W coated with the polyimide by the coating device 50 to the support pins 63 of the heat processing device 52 is the third step. Arm 8 of. At that time, the transport mechanism 57 first moves the traveling block 2 to the front of the coating device 50 and drives only the third arm 8 to insert the traveling block 2 into the coating device 50.

In the coating device 50, for example, the wafer W is lifted by a spin chuck for rotating the wafer W (not shown) provided with a wafer W spin-coated with a resist solution in a film shape so as to be lifted up and down. After waiting, the third arm 8 is inserted to a fixed position in the coating apparatus 50, and then a spin chuck (not shown) is lowered or the third arm 8 is raised to move the wafer receiving portion of the third arm 8. The wafer W is transferred to 10. As a result, the three suction portions 14 of the third arm 8 come into contact with the three lower surfaces of the wafer W in the vicinity of the peripheral edge thereof to suck and hold the wafer W.

Next, the transport mechanism 57 is provided with the third arm 8
Was moved from the coating device 50 to a fixed position on the traveling block 2, the wafer W was transferred to the other wafer transfer mechanism 58 via the relay mechanism 56A, and the traveling block 2 was moved in front of the heat treatment device 52. After that, the third arm 8 is inserted into the heat treatment device 52, and the driving of the vacuum suction device is stopped.

In the heat treatment device 52, the third arm 8
Is inserted in a fixed position for delivery, the three support pins 63 shown in FIG. 17 are raised, and the wafer W is delivered from the third arm 8 to the support pins 63.

In this case, even if the polyimide residue 64 adheres to the peripheral edge Wa of the wafer W, the peripheral edge Wa of the wafer W is not in contact with the arm 8, so that the wafer W is The wafer W can be delivered and received smoothly without being attached to the arm 8 and becoming difficult to separate. Therefore, there is no risk that the wafer W will shift or drop during delivery. Further, even when the polyimide residue 64 drops from the peripheral edge Wa of the wafer W when the wafer W is transferred or delivered by the third arm 8, the polyimide residue 64 falls in the residue receiving groove 12 below the peripheral edge 18 of the wafer W. As it can be received, it prevents the residue 64 from scattering in the device,
Generation of particles can be suppressed. This leads to an improvement in yield.

In this first embodiment, a large number of conical suction ports 19 are scattered on the bottom 12a of the slag receiving groove 12 as shown in FIG. 6, or the bottom of the slag receiving groove 12 as shown in FIG. 12a is inclined toward the support frame 9 side to form the suction port 20 in some places, and the residue 64 received by the slag receiving groove 12 is sucked out by vacuum suction, thereby further effectively preventing the generation of particles. be able to.

In the first embodiment, for example,
As shown in FIG. 8, the claw member 2 is movable inward and backward inside the wafer support frame 9 in correspondence with the position of each wafer suction portion 14.
In the case of normal resist coating, the claw member 21 is moved forward and used to hold the wafer W and apply a high-viscosity processing liquid such as polyimide in the case of normal resist coating. When performing, the claw member 21 may be retracted and not used, and the wafer W may be suction-held by using the suction portion 14 as shown in FIG.

In the example of FIG. 8, a spring 23 is provided in the moving space 22 of the claw member 21 of the wafer support frame 9 to constantly urge the claw member 21 toward the protruding side, and the moving space 2
2 is connected to a vacuum suction device, and during the coating process of the high-viscosity processing liquid, the vacuum suction device is operated to reduce the pressure in the moving space 22, and the claw member 21 is moved against the urging force of the spring 23. It is configured to be pulled toward the support frame 9 side.

In such a configuration, the use of the suction portion 14 and the use of the claw member 21 are switched between the film thickness sensor of the optical interference type or the like for measuring the thickness of the film formed on the wafer W and the measurement thereof. The transfer mechanism 57 can be automated by providing a control device such as a microcomputer that determines the film type based on the result. For example, when the film thickness is as thick as about 10 μm, it is determined to be polyimide, and the wafer suction unit 14 is used. When the film thickness is 1 to 2 μm, it is determined to be a normal photoresist, and the claw member 21 is used. The determination of the film type is also effective when the first and second arms 6 and 7 and the third arm 8 are automatically used properly.

Second Embodiment FIG. 9 is a plan view showing a third arm of the transport mechanism according to the second embodiment of the present invention, and FIG. 10 is an enlarged plan view and a sectional view of the essential part of FIG. It is shown. In the second embodiment, the configuration other than the third arm 8 is the same as that of the first embodiment, and the description thereof will be omitted.

As shown in FIGS. 9 and 10, the third arm 8 of the second embodiment has a total of three positions on both ends and an intermediate part of the wafer support frame 9 formed in a partially cut-out annular shape. The claws 25 for supporting the wafer W are provided so as to project inward in the radial direction of the support frame 9, and the projections for abutting the upper surfaces of the claws 25 on the lower surface near the peripheral edge of the wafer W and supporting the same at three points. Of the three kinds of wafers WA, WB, W having three suction portions 26A, 26B, 26C
It is provided according to the diameter of C.

On the upper surfaces of the suction portions 26A, 26B and 26C, there are formed suction holes 15 each having a long hole extending in the circumferential direction. In each air passage 27 connecting these suction ports 15 and the vacuum suction device, each suction portion 26A, 26B, 26C is provided.
Open / close valves 28A, 28 for switching the suction operation for each
B and 28C are provided, and the wafer W can be suction-held by using one of the three suction portions 26A, 26B, and 26C of each claw 25 according to the size of the wafer W. ing. For example, when a large-diameter wafer WC is suction-held, each claw 25 can be opened by opening the opening / closing valve 28C.
The sucking portions 26C of the wafers start sucking, and the sucking portions 26C suck and hold the wafer WC at three locations in the vicinity of the peripheral edge thereof.
Support three points. In this case, even if the polyimide residue 64 is attached to the peripheral edge Wa of the wafer WC, the peripheral edge Wa of the wafer WC is not in contact with the arm 8, so that the wafer W is attached to the arm 8. The wafer W can be delivered and received smoothly without being attached and becoming difficult to separate. Even when the medium and small diameter wafers WB and WA are transferred, the opening and closing valves 28B and 28A are opened to suck and hold the wafer W as in the case of the wafer WC.
The wafer W can be delivered and received smoothly.

In the second embodiment, as shown in FIG. 11, the suction portions 26A, 26B and 26C have the highest height of the suction portion 26C for holding the large-diameter wafer WC. By setting the portions 26C, 26B, and 26A so that they become lower in order, for example, a large-diameter wafer W
When C is held, it is possible to prevent particles such as polyimide residue 64 attached to the periphery of the adsorption portions 26B and 26A from adhering to the lower surface of the wafer WC.

Further, in the construction of the second embodiment as described above, the switching of the use of the adsorption portions 26A, 26B and 26C is performed by using solenoid valves as the on-off valves 28A, 28B and 28C and shown in FIG. Thus, the vacuum degree sensors 29A, 29B, 29C as detection means are provided in the middle of each air passage 27.
Is provided to measure the degree of vacuum in each air passage 27, the wafer W is received with all the opening / closing valves 28A, 28B, 28C initially opened, and based on the change in degree of vacuum immediately after that,
For example, it can be automated by keeping the open / close valve of the air passage 27 in which the measured value of the vacuum degree sensors 29A, 29B, 29C is higher than a predetermined value and keeping the other two closed. . In addition, the vacuum sensor 29A,
Instead of 29B, 29C, each suction part 26A, 26B, 2
In the vicinity of 6C, for example, photoelectric sensors 30A, 30B, 3
0C is installed upward to detect the presence or absence of the wafer W,
By opening only the opening / closing valve of the outermost suction portion in which the wafer W is detected, each suction portion 26A, 26B, 2 is opened.
The switching of use of 6C can be automated.

In the above embodiments, the case where the object to be processed is a semiconductor wafer has been described, but the object to be processed is not necessarily limited to the semiconductor wafer, and may be, for example, an LCD substrate, a ceramics substrate, a compact disc, a printed circuit board,
The same applies to substrates coated with coating materials, optical filter substrates, and the like, which are coated with the treatment liquid.

In the above embodiment, the case where the processing apparatus is applied to the resist coating / developing apparatus has been described. However, other than this, for example, an apparatus for performing etching solution coating processing or magnetic liquid coating processing, a coating apparatus for coating material, etc. Of course, it is also applicable.

[0036]

In summary, according to the processing apparatus of the present invention, the following excellent effects can be exhibited.

1) According to the processing apparatus of the first aspect, the arm for holding the object to be processed is provided with a plurality of protrusion-like suction portions that abut on the lower surface near the peripheral edge of the object to be supported and support the same at several points. As a result, the object to be processed is held in a state where its peripheral edge is in non-contact with the arm, so that the object to be processed is not easily separated from the arm due to the residue of the processing liquid,
Wafers can be delivered and received smoothly. Further, by forming a slag receiving groove for receiving a residue such as a processing liquid supplied to the object to be processed outside the adsorption portion that supports the vicinity of the periphery of the object to be processed, the residue of the polyimide from the peripheral edge of the wafer is formed. Even if the shavings fall, they can be received by the slag receiving groove, so that the slag can be prevented from scattering into the apparatus, and the generation of particles can be suppressed.

2) According to the processing apparatus of claims 2 and 3, the arm for holding the object to be processed is provided with a plurality of claws for supporting several points in the circumferential direction of the object to be processed, and the upper surface of each claw is provided. In addition, by providing a plurality of projecting suction portions that abut the lower surface near the peripheral edge of the object to be processed and support the same at several points in correspondence with the diameter of the object to be processed, the object to be processed has its peripheral edge armed. It can be held in a non-contact state with respect to the above, and can cope with several kinds of objects having different diameters without exchanging the arm.

[Brief description of drawings]

FIG. 1 is a perspective view showing an arm portion of a transfer mechanism according to a first embodiment of the present invention.

FIG. 2 is a schematic front view of the transport mechanism according to the first embodiment of this invention.

3 is a plan view of an arm showing a main part of FIGS. 1 and 2. FIG.

FIG. 4 is an enlarged perspective view of part A of FIG.

5 is a sectional view taken along line VV of FIG.

FIG. 6 is a partial perspective sectional view showing another embodiment of the first embodiment of the present invention.

FIG. 7 is a partial perspective sectional view showing another embodiment of the first embodiment of the present invention.

FIG. 8 is a schematic side view showing another embodiment of the first embodiment of the present invention.

FIG. 9 is a plan view showing an arm of the transfer mechanism according to the second embodiment of the present invention.

10 is an enlarged plan view and side view of a claw portion showing the main part of FIG. 9. FIG.

FIG. 11 is a schematic side view of a claw portion showing another embodiment of the second embodiment of the present invention.

FIG. 12 is a schematic configuration diagram of adsorption switching means showing another embodiment of the second embodiment of the present invention.

FIG. 13 is a schematic configuration diagram of adsorption switching means showing another embodiment of the second embodiment of the present invention.

FIG. 14 is a perspective view showing a resist coating and developing treatment apparatus.

15 is a plan view showing an arm of a conventional transfer mechanism incorporated in the processing apparatus of FIG.

16 is a cross-sectional view taken along line BB of FIG.

FIG. 17 is a diagram for explaining the transfer operation of the object to be processed in the processing apparatus of FIG.

[Explanation of symbols]

 6 1st arm 7 2nd arm 8 3rd arm (arm which concerns on this invention) 9 Wafer support frame 10 Wafer receiving part 12 Slag receiving groove 14 Wafer adsorption | suction part 15 Adsorption port 16 Air passage 25 Claw 26A-26C Protrusion Adsorption section 28A to 28C open / close valve 29A to 29C vacuum degree sensor (detection means) 30A to 30C photoelectric sensor (detection means)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Teru Kanbayashi 2655 Tsukyu, Kikuyo-cho, Kikuchi-gun, Kumamoto Prefecture Tokyo Electron Kyushu Co., Ltd. Kumamoto Plant (72) Inventor Masaaki Murakami 2655 Tsukyu, Kikuyo-cho, Kikuchi-gun, Kumamoto Prefecture Kumamoto Office of Tokyo Electron Kyushu Co., Ltd.

Claims (3)

[Claims] 1. A plurality of processing mechanisms for performing processing on an object to be processed, a transfer mechanism for transferring the object to be processed to these processing mechanisms, and the object to be processed provided movably on the transfer mechanism. In a processing apparatus having a holding arm, the arm is provided with a plurality of projecting suction portions that abut on a lower surface in the vicinity of the peripheral edge of the object to be processed and support several points of the lower surface. A processing apparatus comprising: a slag receiving groove for receiving a residue such as a processing liquid supplied to an object to be processed. 2. A plurality of processing mechanisms for processing an object to be processed, a transfer mechanism for transferring the object to be processed to these processing mechanisms, and the object to be processed provided movably on the transfer mechanism. In the processing device having an arm for holding, a plurality of claws for supporting several points in the circumferential direction of the object to be processed are provided on the arm, and the upper surface of each claw is provided on the lower surface near the peripheral edge of the object to be processed. A processing apparatus comprising: a plurality of projecting suction portions, which abut and support several points of the workpiece, in correspondence with the diameter of the object to be processed. 3. A detection means for detecting the diameter of the object to be processed is provided on each of the projecting suction parts, and the projecting suction part of the portion supporting the object to be processed is operated based on a signal from the detecting means. The processing device according to claim 2, wherein the processing device is configured to perform.