JP3292639B2 - Rotation holding device and method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for rotating and holding an object to be processed, and more particularly, to cleaning and wet etching with a chemical solution while rotating a plate-shaped object such as a wafer for semiconductor production while holding the object. The present invention relates to a rotation holding device for an object to be processed.

[0002]

2. Description of the Related Art In a semiconductor manufacturing process, there is a process for performing processing such as cleaning of a wafer with a chemical solution and wet etching. In order to perform such processing uniformly within the wafer surface, there is a method of performing processing while rotating the wafer.

FIG. 7 shows a conventional rotation holding device 1 for holding and rotating a wafer by vacuum suction. The conventional rotation holding device 1 includes a rotating body 3 having a chuck portion 2 for chucking a wafer W at an upper end, and a groove 5 is formed on a chuck surface 4 of the chuck portion 2. An exhaust passage 6 is formed inside the rotating body 3, and one end of the exhaust passage 6 forms a first opening 7 in the center of the chuck surface 4, and the other end is formed on a side peripheral surface of the rotating body 3. A second opening 8 is formed. The first opening 7 communicates with the groove 5 formed on the chuck surface 4. The rotating body 3 is rotatably supported by a bearing 10 via a seal member 9 and can be rotated by a rotation driving means (not shown). An annular groove 1 communicating with the second opening 8 is formed on an inner peripheral surface of the bearing 10.
1 are formed over the entire circumference. One end of a vacuum pipe 12 is attached to the outer peripheral surface of the bearing 10, and the vacuum pipe 12 communicates with the annular groove 11 through the opening 13. The other end of the vacuum pipe 12 is connected to a vacuum exhaust device (not shown).

In the conventional rotation holding device 1 having such a configuration, after the wafer W is mounted on the chuck surface 4, vacuum is evacuated by a vacuum exhaust device. Then, the air in the space formed by the back surface (holding surface) of the wafer W and the groove 5 is exhausted to be in a vacuum state, and the wafer W is suction-held on the chuck surface 4. In this state, the rotating body 3 is rotated by the rotation driving means to perform a cleaning process using a chemical solution or a wet etching process.

However, the above-described conventional rotation holding device 1 holds the wafer W in a state where the chuck surface 4 is in contact with the back surface of the wafer W.
There is a problem that the upper particles adhere to the back surface of the wafer W, and the problem is particularly serious in the cleaning process of the wafer because it is necessary to clean not only the front surface but also the back surface of the wafer.

Therefore, as a rotation holding device for holding the wafer W in a non-contact state, a rotation holding device applying the Bernoulli principle has been proposed. FIG. 8 shows a conventional rotation holding device 20 to which the Bernoulli principle is applied.
The rotation holding device 20 includes a rotating body 22 having a chuck portion 21 for chucking the wafer W at an upper end, and a chuck surface 23 of the chuck portion 21 has a diameter slightly smaller than the diameter of the wafer W and has a whole. A gas outlet 24 is formed around the circumference. A gas supply passage 25 is formed inside the rotating body 22, and one end of the gas supply passage 25 communicates with the gas ejection port 24 over the entire circumference thereof through a branch passage 26 that extends inclining upward. are doing. On the other hand, the other end of the gas supply passage 25 forms a gas supply port 27 on the side peripheral surface of the rotating body 22. The rotating body 22 is rotatably supported by a bearing 29 via a seal member 28, and can be rotated by a rotation driving means (not shown). An annular groove 30 communicating with the gas supply port 27 is formed on the inner peripheral surface of the bearing 29 over the entire circumference. One end of a gas supply pipe 31 is attached to the outer peripheral surface of the bearing 29, and the gas supply pipe 31 communicates with the annular groove 30 through the opening 32. The other end of the gas supply pipe 31 is connected to gas supply means (not shown) for supplying nitrogen gas.

In the conventional rotation holding device 20 having such a configuration, the nitrogen gas from the gas supply means is supplied to the gas supply passage 25 and the branch passage 26, and this nitrogen gas is injected from the gas outlet 24. . In this state, the wafer W is accurately positioned above the chuck surface 23 and transferred by the transfer means (not shown). Then, the wafer W is brought into a floating state by the jet pressure of the nitrogen gas injected on the back surface thereof, and at the same time, the central portion C of the gap between the back surface of the wafer W and the chuck surface 23 is brought into a negative pressure state by the flow rate of the nitrogen gas. Thus, the wafer W is held by suction. In this state, the rotating body 22 is rotated by the rotation driving means to perform a cleaning process using a chemical solution and a wet etching process.

[0008]

However, the conventional rotation holding device 20 to which the above-mentioned Bernoulli principle is applied,
The nitrogen gas introduced into the gas supply passage 25 is supplied to the branch passage 2
6, the gas is distributed and jetted over the entire circumference of the gas jetting port 24, so that the circumferential distribution of the pressure and flow rate of the nitrogen gas G toward the outer circumference of the wafer W is not as shown in FIG. There was a tendency to be uniform. If the distribution of the pressure and the flow rate of the nitrogen gas G in the circumferential direction becomes non-uniform in this way, the floating wafer W is inclined as shown in FIG. 9, so that accurate horizontality cannot be maintained. When the chemical liquid L is supplied from the nozzle 33 to the inclined surface of the wafer W, the chemical liquid L is deflected in the inclined direction as shown in FIG. 10, and the in-plane uniformity of processing such as cleaning and etching deteriorates. There was a problem.

Further, since the conventional rotation holding device 20 holds the wafer W only by the suction force due to the negative pressure generated according to Bernoulli's principle, the wafer W moves in the horizontal direction (wafer jumps out). ) Cannot be regulated, which causes a problem that the wafer W is displaced in the horizontal direction.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a rotation holding device for an object to be processed which can be lifted and rotated while maintaining good horizontality. is there. It is another object of the present invention to provide a rotation holding device for an object to be processed, which can restrict the horizontal displacement of the object to be rotated.

[0011]

According to the first aspect of the present invention,
By emitting gas toward the back side of the workpiece
A chuck surface for holding the object to be processed using the generated negative pressure is provided with a rotatable rotating body formed at an end portion, and the level of the object to be processed is held near the outer peripheral edge of the chuck surface when the object is held.
The gas residence groove circumference to set, the gas residence groove concentric to the chuck surface of the inner side than the inner peripheral edge of the gas pocket groove for,
A gas supply port for discharging a gas obliquely upward and outward is provided around the gas supply path, and a gas supply path having a branch passage that is in communication with the gas discharge port and is inclined with respect to the chuck surface is formed inside the rotating body; the shall be the feature.

According to a second aspect of the present invention, the gas outlet is formed by an opening which is continuous in a circumferential direction.

According to a third aspect of the present invention, the gas outlet is formed by a plurality of holes formed in a circumferential direction.

According to a fourth aspect of the present invention, the rotating body is provided with a holding means having a plurality of movable holding claws capable of holding an outer edge of the workpiece.

According to a fifth aspect of the present invention, the plurality of movable holding claws are urged in a holding direction when the rotating body is rotated.

According to a sixth aspect of the present invention, there is provided an apparatus for rotating and holding an object to be processed according to the fourth aspect of the present invention, wherein the object is rotated from the gas ejection port.
With the gas ejected obliquely upward and outward, the plurality of movable holding claws are set to a release position, the workpiece is transferred above the chuck surface, and the gas holds the workpiece holding surface. Utilizing the negative pressure generated between the chuck surface and the workpiece is held in a floating state without contacting the chuck surface, and the plurality of movable holding claws are moved to a holding position. The object is sandwiched, and the rotating body is rotated to rotate the object.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a rotation holding device 100 for an object to be processed according to the present embodiment. The rotation holding device 100 holds and rotates a wafer W by applying Bernoulli's principle.

The rotation holding device 100 includes a rotating body 1 having a chuck portion 101 for chucking a wafer W at an upper end.
02 and the chuck surface 10 of the chuck portion 101.
3 has a circular shape having a diameter slightly larger than the diameter of the wafer W as shown in FIGS. On the chuck surface 103, a gas retaining groove 105 is formed slightly inward from the outer peripheral edge 104, continuously over the entire circumference,
The outer peripheral edge 106 of the gas retaining groove 105 is located slightly inside the outer peripheral edge Wa of the wafer W. On the inner periphery 107 of the gas retaining groove 105, a gas outlet 108 is formed continuously over the entire circumference, and the circumferential gas outlet 108 has a diameter of about half the diameter of the wafer W. have. A gas supply passage 109 is formed inside the rotator 102, and an end of the gas supply passage 109 on the chuck surface 103 side extends through a branch passage 110 that extends inclining upward and a gas ejection port 108. To the entire circumference. On the other hand, the gas supply passage 109
The other end of the gas supply port 1
11 are formed.

The rotating body 102 is rotatably supported by a bearing 113 via a sealing material 112, and can be rotated by a rotation driving means 114 and its transmission mechanism 115. On the inner peripheral surface of the bearing 113, an annular groove 116 communicating with the gas supply port 111 is formed over the entire circumference. Gas supply pipe 11 is provided on the outer peripheral surface of bearing 113.
7 is attached to the gas supply pipe 11.
7 is a gas inlet 11 formed on the outer peripheral surface of the bearing 113
8 communicates with the annular groove 116. The other end of the gas supply pipe 117 is connected to gas supply means (not shown) for supplying nitrogen gas.

FIG. 3 schematically shows a wafer processing apparatus 200 in which the above-described rotation holding apparatus 100 is incorporated. This wafer processing apparatus 200 accurately positions a wafer W above the chuck surface 103 of the rotation holding apparatus 100. A transport means 201 for positioning, transporting, and unloading is provided. Further, the wafer processing apparatus 200 includes a chemical solution supply system 202.
The chemical solution supply system 202 has a nozzle 203 for supplying a chemical solution to the surface of the wafer W.
03 is driven by a nozzle drive mechanism 205 having a motor 204. The nozzle 203 is connected to a chemical tank 207 via a chemical supply pipe 206, and a valve 208 and a transport pump 209 are provided in the middle of the chemical supply pipe 206.
Is interposed. The chemical tank 207 is connected to a chemical storage tank 211 via a pipe 210.

Next, the operation and effect of this embodiment will be described. First, nitrogen gas from a gas supply means (not shown) is supplied to the gas supply passage 109 and the branch passage 110, and this nitrogen gas is ejected from the gas ejection port.
Here, since the branch passage 110 has an upward slope from the center of the rotating body 102 toward the outside, the nitrogen gas is blown obliquely upward and outward from the gas injection port 108. The flow rate of the nitrogen gas injected from the gas injection port 108 is, for example, 30 to 50 liters / minute.

With the nitrogen gas injected from the gas injection port 108 in this manner, the wafer W is transported by the transfer means 201.
Is accurately positioned above the chuck surface 103 and transferred. Then, the nitrogen gas blown out from the gas injection port 108 collides with the back surface of the wafer W, and the wafer W floats without contacting the chuck surface 103 due to the injection pressure of the nitrogen gas. The vicinity of the center of the gap between the back surface of the wafer W and the chuck surface 103 is in a negative pressure state, and the wafer W is suction-held. Here, the flow rate of the nitrogen gas flowing out from the gap between the back surface (holding surface) of the wafer W and the chuck surface 103 is set to 3 m / min or more.

In the state where the wafer W is held by suction in this manner, the nitrogen gas blown out from the gas ejection port 108 collides with the middle part in the radial direction of the back surface of the wafer W, and is thereafter formed on the chuck surface 103. Gas retention groove 105
Flow into The nitrogen gas flowing into the gas retaining groove 105 flows out through a narrow gap d formed between the outer peripheral end of the back surface of the wafer W and the outer peripheral end of the chuck surface 103. As described above, the nitrogen gas blown out from the gas ejection port 108 collides with the middle portion in the radial direction of the back surface of the wafer W, flows into the gas retaining groove 105, and then flows out through the gap d. For example, the pressure and the flow rate of the nitrogen gas are stabilized in the gas retaining groove 105, and the pressure difference between the pressure in the gas ejection port 108 and the pressure in the gas retaining groove 105 is also stabilized. Nitrogen gas is sprayed uniformly and the chuck surface 103
The pressure and flow rate of the nitrogen gas flowing out from the gap d between the wafer W and the back surface of the wafer W are also stabilized and become uniform in the outer peripheral direction, so that the wafer W is held above the chuck surface 103 with extremely good horizontality.

With the wafer W held horizontally in this manner, the rotation driving means 114 is driven to rotate the rotating body 102 via the transmission mechanism 115, and the wafer W is rotated integrally with the rotating body 102. And the nozzle drive mechanism 2
The motor 204 is operated to supply a chemical solution from the nozzle 203 to the central portion of the surface of the wafer W. The chemical supplied to the central portion of the surface of the wafer W is diffused toward the outer peripheral edge of the wafer W by the rotation of the wafer W. Here, as described above, since the wafer W is held at an extremely good level, the chemical liquid is uniformly diffused from the center of the wafer W to the outer peripheral edge, and therefore, the cleaning of the surface of the wafer W with the chemical liquid. And processing such as etching can be performed with extremely high in-plane uniformity. Further, the chuck surface 103 and the wafer W
If the distance of the gap d from the back surface of the wafer W is, for example, 0.5 to 1 mm, the chemical liquid that is going to flow around the back surface of the wafer W can be blown off by the nitrogen gas blown out of the gap d. It is possible to prevent contamination by chemicals and unnecessary etching.

Further, the gas ejection port 10 according to the present embodiment is
Although 8 is formed continuously over the entire circumference, the configuration of the gas injection port is not limited to this. For example, a plurality of holes are formed at equal intervals over the entire circumference to form the gas injection port. Can also. The rotation holding device provided with the gas ejection port having such a configuration can also achieve the same operation and effect as those of the first embodiment. Second Embodiment Next, a second embodiment of a rotation holding device for a workpiece according to the present invention will be described with reference to the drawings. In the present embodiment, a means for preventing horizontal movement (protrusion) of the wafer W is added to the above-described first embodiment. Therefore, in the following description,
The same members as those in the first embodiment are denoted by the same reference numerals, and detailed description is omitted.

FIG. 4 shows a rotation holding device 300 for an object to be processed according to this embodiment.
Includes a rotating body 102 having a chuck portion 101 for chucking the wafer W at an upper end. Chuck unit 1
5, three rotating plates 301, 301, 301 are rotatably provided at equal intervals as shown in FIG. 5, and the upper surface of each rotating plate 301, 301, 301 The holding claws 302, 302, 302 are decentered from the center of rotation.
Is erected. On the back surface of each rotating plate 301, 301, 301, each link mechanism 30 is decentered from its center of rotation.
One end of each of the link mechanisms 303, 303, 303 is connected, and the other end of each of the link mechanisms 303, 303, 303 is attached to each of the mounting pieces 305, 305 of the rotary cylinder 304 rotatably fitted on the outer periphery of the rotary body 102. , 305. Each of the rotating plates 301, 301, 301 is provided with a respective holding claw 302, 302,
The urging means (not shown) presses and urges the wafer 302 to rotate in the direction of holding the wafer W. A pressing piece 306 protrudes from the rotary cylinder 304, and the pressing piece 306 can be pressed by the tip of the output shaft 308 of the cylinder 307.

Next, the operation and effect of this embodiment will be described. First, as shown in FIG.
To cause the output shaft 308 to advance in the direction of arrow A in the figure, and press the pressing piece 306 at its tip against the urging force of the urging means (not shown). Then, the rotating cylinder 30
4 rotates in the direction of arrow B in FIG.
03, 303 are simultaneously pulled in the direction of arrow C in the figure, and the rotating plates 301, 301, 301 connected to the link mechanisms 303, 303, 303 simultaneously rotate in the direction of arrow D in the figure. Then, the holding claws 302, 302, 302 provided on the upper surfaces of the rotary plates 301, 301, 301 move in the direction of releasing the wafer W (release position direction), and the holding state of the wafer W is released. In this released state, the wafer W processed by the transfer means 201 shown in FIG.
And the unprocessed wafer W is floated above the chuck surface 103 and held horizontally by the method described in the first embodiment.

Next, as shown in FIG.
The output shaft 308 of FIG. 7 is retracted in the direction of arrow E in the figure, and the pressing of the pressing piece 306 is released. Then, the rotating cylinder 304 is rotated in the direction F in the figure by the urging force of the urging means (not shown), and the link mechanisms 303, 303, 303 are simultaneously moved in the direction G as viewed in the figure, and each rotating plate 301 is rotated. , 301, 30
1 rotate simultaneously in the direction of arrow H in the figure. Each rotating plate 30
When 1, 301 and 301 rotate in the direction of arrow H, the holding claws 302, 302 and 302 provided on their upper surfaces move in the direction for holding the wafer W (holding position direction), and the wafer W is held. You. Note that the output shaft 308 of the cylinder 307 is retracted to a position sufficiently distant from the rotating body 102 so that the pressing piece 306 does not contact the output shaft 308 when the rotating body 102 rotates.

While the wafer W is held horizontally in this way, the rotation driving means 114 shown in FIG. 1 is driven, and the rotating body 102 is rotated via the transmission mechanism 115. Then, the rotating cylinder 304 also rotates together with the rotating body 102,
Each rotating plate 301, 301, 30 holding the wafer W
1 also rotates together with the wafer W in the direction of arrow I in FIG. Here, since the wafer W is held by the holding claws 302, 302, 302 of the rotary plates 301, 301, 301, the movement in the horizontal direction is restricted, and the wafer W may jump out during rotation. There is no. Also, as can be seen from FIG. 6, by the rotation in the direction of arrow I, each link mechanism 303 causes each of the rotating plates 301, 301,
It is urged in a direction to rotate 301 in the direction of arrow H in the figure. Therefore, the rotating wafer W is held by each of the holding claws 302,
302, 302 securely clamps.

Then, the nozzle driving mechanism 20 shown in FIG.
5 is operated to supply a chemical solution from the nozzle 203 to the central portion of the surface of the wafer W rotating. The chemical supplied to the central portion of the surface of the wafer W
Is diffused toward the outer peripheral edge of the wafer W.
Here, since the wafer W is held at an extremely good level, the chemical liquid is uniformly diffused from the center of the wafer W toward the outer peripheral edge, and therefore, the cleaning of the surface of the wafer W with the chemical liquid, etching, etc. Processing can be performed with extremely high in-plane uniformity. If the distance of the gap d between the chuck surface 103 and the back surface of the wafer W is, for example, 0.5 to 1 mm,
The nitrogen gas blown out from the gap d can blow off the chemical liquid that is going to go to the back surface of the wafer W, thereby preventing the back surface of the wafer W from being stained by the chemical liquid and unnecessary etching.

[0031]

As described above, according to the present invention, a gas retaining groove is provided around the outer peripheral edge of the chuck surface, and the gas retaining groove is concentric with the gas retaining groove on the inner side of the inner peripheral edge of the gas retaining groove. A gas supply port is provided around the rotator, and a gas supply passage having a branch passage that communicates with the gas discharge port and is inclined with respect to the chuck surface is formed inside the rotating body. Therefore, the chemical solution is uniformly supplied to the entire object to be processed, and the processing such as cleaning and etching of the surface of the object to be processed with the chemical solution can be performed with extremely high in-plane uniformity. In addition, the gas that is blown out from the gap between the chuck surface and the holding surface of the workpiece can blow off the chemical liquid that is going to reach the holding surface of the processing object. Necessary etching can be prevented.

According to the present invention, the rotating body is provided with a holding means having a plurality of movable holding claws capable of holding the outer edge of the object to be processed. Preferably, the holding means is provided with a plurality of holding means when the rotating body is rotated. The movable gripping claw is biased in the gripping direction, so that the moving of the workpiece is restricted by the movable gripping claw in the horizontal direction, so that the rotating workpiece does not pop out, and The object to be processed is more reliably held by the holding claws urged in the holding direction with the rotation of the body.

Further, according to the present invention, in the state where the gas is jetted from the gas ejection port by using the rotation holding device for the object to be processed according to the fourth aspect, the holding surface of the object to be processed is formed by the gas. The workpiece is held in a floating state without contacting the chuck surface by utilizing the negative pressure generated between the chuck surface and the holding surface of the workpiece by contact with the chuck surface. Not only is not contaminated by particles or the like, but also the object to be treated can be held at an extremely good level, so that the chemical is uniformly supplied to the whole object to be treated and Processing such as cleaning and etching of the surface of the processed object can be performed with extremely high in-plane uniformity. In addition, the gas that is blown out from the gap between the chuck surface and the holding surface of the workpiece can blow off the chemical liquid that is going to reach the holding surface of the processing object. Necessary etching can be prevented. Further, the movement of the object to be processed in the horizontal direction is restricted by the movable holding claw, so that the object to be processed during rotation can be prevented from jumping out.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of a rotation holding device for a workpiece according to the present invention.

FIG. 2 is an exemplary plan view showing a main part of the embodiment;

FIG. 3 is a schematic view showing a processing apparatus incorporating the embodiment.

FIG. 4 is a longitudinal sectional view showing a second embodiment of a rotation holding device for a workpiece according to the present invention.

FIG. 5 is a plan view showing the same embodiment.

FIG. 6 is an exemplary plan view showing a wafer holding state according to the embodiment;

FIG. 7 is a longitudinal sectional view showing a conventional rotation holding device.

FIG. 8 is a longitudinal sectional view showing another conventional rotation holding device.

FIG. 9 is an explanatory diagram showing a state of blowing out nitrogen gas from the rotation holding device.

FIG. 10 is an explanatory view showing an inclined state of a wafer held by the rotation holding device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100, 300 rotation holding device 101 chuck portion 102 rotating body 103 chuck surface 104 outer peripheral edge of chuck surface 105 gas retaining groove 107 inner peripheral edge of gas retaining groove 108 gas ejection port 109 gas supply passage 110 branch passage 114 rotation driving means 200 wafer processing Apparatus 201 Conveying means 202 Chemical supply system 203 Nozzle 301 Rotating plate 302 Nipping claw 303 Link mechanism 304 Rotating cylinder 305 Mounting piece 306 Pressing piece 307 Cylinder

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Company Hajime Ura 25-1, Ekimae Honmachi, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Toshiba Microelectronics Corporation In-house (56) References JP-A-7-7070 (JP, A) JP-A-6-37003 (JP, A) JP-A-2-253637 (JP, A) JP-A-62-196342 (JP, U) JP-A-63-43428 (JP, U) JP-B-62-40853 (JP, A) , B1) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01L 21/68 B65G 49/07

Claims (6)

(57) [Claims] 1. Injecting a gas toward a back surface of an object to be processed
A chuck surface for holding the object to be processed by utilizing the negative pressure generated by the rotation is provided with a rotatable rotating body formed at the end, and the chuck surface is held near the outer peripheral edge of the chuck surface when the object to be processed is held.
A gas retaining groove for increasing the degree of horizontality is provided around the gas retaining groove, and the gas is ejected obliquely upward and outward on the chuck surface inside the inner peripheral edge of the gas retaining groove, concentrically with the gas retaining groove. A gas supply passage having a branch passage communicating with the gas discharge port and inclined with respect to the chuck surface is formed inside the rotating body. Rotation holding device. 2. The apparatus according to claim 1, wherein the gas outlet is formed by an opening that is continuous in a circumferential direction. 3. The gas outlet according to claim 1, wherein the gas outlet is formed by a plurality of holes formed in a circumferential direction.
A rotation holding device for an object to be processed as described in the above. 4. The object according to claim 1, wherein said rotating body is provided with a holding means having a plurality of movable holding claws capable of holding an outer edge of said object to be processed. Rotation holding device for processed material. 5. The rotation of an object to be processed according to claim 4, wherein said holding means urges said plurality of movable holding claws in a holding direction when said rotating body is rotated. Holding device. 6. The plurality of movable parts in a state in which gas is ejected obliquely upward and outward from the gas ejection port using the rotation holding device for the object to be treated according to claim 4. With the holding claw in the release position, the workpiece is transferred above the chuck surface, and the negative pressure generated between the holding surface of the workpiece and the chuck surface by the gas is used to remove the workpiece. The processing object is held in a floating state without contacting the chuck surface, the plurality of movable holding claws are moved to a holding position to hold the processing object, and the rotating body is rotated to rotate the processing object. A method for holding an object to be rotated, characterized by rotating the object.