JP2000317825A - Polishing apparatus including attitude control device for substrate holding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform polishing with the surface pressure distribution of a surface to be polished put in the optimum state by controlling the attitude of a top ring main body of the substrate holding device for holding a substrate which is an object to be polished and pressing the same to a polishing surface on a turn table by electromagnetic force. SOLUTION: A target value of attitude of a top ring and a displacement value of the top ring 6 which is detected by a sensor and converted by a coordinate converting part are input to a subtractor of a control part, and a difference between them is input as an error signal to a controller. The error signal is subject to inclination control and damping processing and further passed through a notch filter for eliminating vibration to be converted to a voltage command signal. It is converted to a control signal for an attitude control device by the coordinate converting part and supplied to a driving part. The control signal is supplied to each driving circuit 24, and converted to an exciting current for displacing an armature 14 in each driving circuit 24. The exciting current is supplied to electromagnetic coils 13a to d to control the attitude of the top ring 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate holding apparatus for holding a substrate such as a semiconductor wafer when polishing and flattening the substrate, and a polishing apparatus having the substrate holding apparatus.

[0002]

2. Description of the Related Art In recent years, as the degree of integration of semiconductor devices has increased, circuit wiring has become finer, and the distance between wirings has become smaller. In particular, in the case of optical lithography of 0.5 μm or less, the depth of focus becomes shallow, so that the image plane of the stepper needs to be flat. Therefore, it is necessary to flatten the surface of the semiconductor wafer. As one means of this flattening method, polishing is performed by a polishing apparatus.

Conventionally, this type of polishing apparatus has a turntable and a top ring, and the top ring applies a constant pressure to the turntable, and an object to be polished is interposed between the turntable and the top ring. ,
The surface of the object to be polished is polished flat and mirror-finished while supplying a polishing liquid.

In the above-described polishing apparatus, if the relative pressing force between the polishing object being polished and the polishing cloth is not uniform over the entire surface of the polishing object,
Under-polishing or over-polishing occurs depending on the pressing force of each part. Therefore, in the conventional polishing apparatus, as shown in FIG. 18, a spherical portion 52 is integrally formed at the tip of a top ring drive shaft 51, and the top surface of a top ring 54 for holding a semiconductor wafer 53 to be polished is formed. A spherical seat 55 for accommodating the spherical portion 52 is formed, the top ring 54 is configured to be tiltable with respect to the drive shaft 51, and the top ring 54 automatically follows the inclination of the turntable 16. Thereby, the parallelism between the wafer holding surface 54a of the top ring 54 and the upper surface of the turntable 16 is maintained, and the relative pressing force between the semiconductor wafer 53 and the polishing pad 57 stuck on the turntable 16 is reduced over the entire surface of the wafer. To be uniform. A top ring drive shaft and a spherical portion are separated into a top ring drive shaft and a ball bearing (ball), and a ball bearing is interposed between the top ring drive shaft and the top ring. JP-A-6-198561).

However, in the above-described apparatus, since the pressing force F is applied to the semiconductor wafer 53 from the drive shaft 51 via the top ring 54 during polishing, frictional force is applied to the contact surface between the semiconductor wafer 53 and the polishing cloth 57. μF (μ: coefficient of friction), and the tilt center O of the top ring 54 from the contact surface
Due to the height H, a rotational moment M = μFH for tilting the top ring 54 is generated, and a phenomenon that the semiconductor wafer 53 “thrusts” into the surface layer of the polishing pad 57 in the front portion in the polishing direction occurs. That is, there is a drawback that the entire surface of the semiconductor wafer cannot be pressed uniformly to the polishing cloth. In order to reduce the moment M to zero, it is necessary to set the height H of the tilt center to zero. Therefore, a device using a spherical bearing whose tilt center is located on the contact surface between the object to be polished and the polishing cloth is used. Has also been proposed.

If the tilting center is located on the contact surface between the object to be polished and the polishing cloth, the rotational moment M for tilting the top ring caused by the frictional force becomes zero,
Theoretically, the parallelism between the top ring and the turntable should be maintained. However, the upper surface of the polishing cloth that contributes to the polishing action, that is, the polished surface is not entirely flat, so that a slight undulation is formed on the polished surface by the rotation of the turntable. Since the top ring tries to tilt following the undulation of the polished surface, the top ring excessively tilts due to the inertia force at the time of tilting, or the movement of the top ring becomes unstable, As a result, there is a problem that a non-uniform surface pressure distribution state of the polishing pressure is generated on the object to be polished.

In order to solve the above-mentioned problems, the present applicant has disclosed in Japanese Patent Application Laid-Open No. 10-58308 a magnetic bearing device in which a rotating shaft of a top ring is supported by a thrust magnetic bearing and a radial magnetic bearing, We have proposed a polishing apparatus with attitude control means for controlling the attitude of the top ring with respect to the turntable by controlling the apparatus. Thus, by controlling the attitude of the top ring by applying the control mechanism of the magnetic bearing device, the polishing is performed with the surface pressure distribution of the polishing pressure on the surface to be polished of the object to be polished in an optimum state, and the flatness is reduced. It is intended to perform high polishing.

[0008]

However, the apparatus described in Japanese Patent Application Laid-Open No. H10-58308 employs a configuration in which the rotating shaft of the top ring is completely supported by a magnetic bearing device. There is a problem to do.

1) Since a pressing force for pressing the object to be polished against the polished surface of the turntable is supported by the axial magnetic bearing, it is necessary to generate a very large magnetic force. As a result, a large magnetic bearing is required. Become.

2) A drive motor for rotating the top ring must be accommodated in a casing containing a magnetic bearing device, and the drive motor must be capable of generating a large torque. Therefore, a considerably large mechanism is required including the above.

3) The vertical movement of the top ring is indispensable for attaching and detaching the object to be polished to and from the top ring, but it is necessary to vertically move the entire unit including the magnetic bearing device, the driving motor and the top ring. In addition, the mechanism itself for moving up and down requires a large one.

According to the present invention, there is provided a method of supporting a rotating shaft of a top ring by using a magnetic bearing device.
By solving the above problem and controlling the posture of the top ring for holding the substrate to be polished, polishing can be performed with the surface pressure distribution of the surface to be polished of the object to be polished in an optimum state. An object of the present invention is to provide a polishing apparatus provided with a substrate holding device.

[0013]

In order to achieve the above-mentioned object, a polishing apparatus according to the present invention comprises a turntable having a polished surface and a substrate to be polished, which is pressed against the polished surface on the turntable. A polishing apparatus, comprising: a top ring main body that holds the substrate; pressing means that presses the top ring main body against a polishing surface of a turntable; and the top ring main body. And posture control means for controlling the posture of the vehicle by electromagnetic force.

The pressing means may be a drive shaft for imparting rotation to the top ring, and the drive shaft and the top ring may be connected to each other via a joint so as to be tiltable.

The substrate holding device has a frame for supporting the drive shaft rotatably about its axis, and the attitude control device is fixed to the frame and an electromagnet device fixed to the top ring. And an armature driven by the armature.

Further, the electromagnetic attitude control device may detect the attitude of the top ring and perform feedback control of the attitude based on the detected attitude.

Further, a pressing ring is disposed around the top ring so as to be vertically movable, and pressing means for pressing the pressing ring with a variable pressing force against the polishing surface is provided. The pressing ring is attached to the top ring via a bearing. It is possible to allow the top ring to rotate while supporting the pressing ring in a non-rotating state.Also, the holding surface of the top ring that holds the substrate is hung on the top ring. Displaceable with respect to the polishing surface by fluid pressure, and having a retainer ring around the top ring, the retainer ring can be pressed against the polishing surface independently of the top ring. You can also.

According to the present invention, the surface pressure distribution of the pressing force applied to the surface to be polished is optimized by controlling the posture of the top ring holding the substrate to be polished by applying electromagnetic force. The polishing can be performed with high flatness.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a polishing apparatus according to the present invention will be described below with reference to FIGS.

FIG. 1 is a longitudinal sectional view showing the entire structure of a first embodiment of a polishing apparatus, and FIG. 2 is a sectional view of a principal part of a substrate holding device in the polishing apparatus.

As shown in FIGS. 1 and 2, the polishing apparatus is a turntable 1 having a polishing cloth 2 adhered to the upper surface thereof.
And a substrate holding device 5 for holding the semiconductor wafer 3 as a substrate and pressing the semiconductor wafer 3 against the polishing pad 2. The substrate holding device 5 includes a top ring 6 for holding the semiconductor wafer 3, a top ring drive shaft 7 that supports the top ring 6 and applies a pressing force and a rotational driving force to the top ring 6,
It comprises a universal joint portion 8 that transmits a pressing force while allowing the top ring drive shaft 7 to tilt from the top ring 6 and a posture control device 11 that controls the posture of the top ring 6. A polishing liquid supply nozzle 60 is provided above the turntable 1 so that the polishing liquid is supplied onto the polishing cloth 2 on the turntable 1 by the polishing liquid supply nozzle 60. The upper surface of the polishing cloth 2 forms a polishing surface that is in sliding contact with the surface to be polished of the semiconductor wafer 3.

As shown in FIG. 2, the top ring 6 includes a top ring main body 9 composed of a lower holding plate 9A and an upper upper plate 9B, and a retainer ring 10 fixed to an outer peripheral portion of the top ring main body 9. The top ring 6 holds the upper surface of the semiconductor wafer 3 by the substrate holding surface on the lower surface of the top ring main body 9, and holds the outer peripheral portion of the semiconductor wafer 3 by the retainer ring 10. An elastic mat 611 is attached to the lower surface of the top ring body 9.

As shown in FIG. 2, the top ring body 9 has a gap G between the holding plate 9A and the upper plate 9B, and the gap G is filled with a liquid such as vacuum, pressurized air, or water. Can be supplied. The top ring body 9 has a gap G
And a large number of communication holes (not shown) which are opened on the lower surface in communication with the communication port. The elastic mat 611 also has an opening at a position facing the communication hole. Thus, the upper surface of the semiconductor wafer 3 can be suctioned by vacuum, and a liquid or pressurized air can be supplied to the upper surface of the semiconductor wafer 3.

As shown in FIG. 1, the top ring drive shaft 7 is connected to a top ring air cylinder 22 fixed to a top ring head 21. 7 moves up and down, and presses the semiconductor wafer 3 held on the lower end surface of the top ring 6 against the turntable 1.

The top ring drive shaft 7 is connected to a rotary cylinder 23 via a key (not shown), and the rotary cylinder 23 has a timing pulley 24 on its outer periphery. The timing pulley 24 is connected via a timing belt 25 to a timing pulley 27 provided on a top ring motor 26 fixed to the top ring head 21. Therefore, when the top ring motor 26 is rotationally driven, the rotary cylinder 23 and the top ring drive shaft 7 rotate integrally via the timing pulley 27, the timing belt 25 and the timing pulley 24, and the top ring 6 rotates. The top ring head 21 is supported by a top ring head shaft 29 fixedly supported on a frame.

On the other hand, the universal joint portion 8 which transmits the pressing force while allowing the top ring drive shaft 7 to tilt from the top ring 6 to each other allows the top ring 6 and the top ring drive shaft 7 to tilt each other. It has a spherical bearing mechanism 40 and a rotation transmission mechanism 45 for transmitting the rotation of the top ring drive shaft 7 to the top ring body 9. The spherical bearing mechanism 40
A spherical concave portion 41a formed in the center of the lower surface of the drive flange 41 fixed to the lower end of the top ring drive shaft 7, a spherical concave portion 9a formed in the center of the upper surface of the upper plate 9B,
A bearing ball 42 made of a high-hardness material such as ceramics is interposed between the concave portions 41a and 9a.

The rotation transmitting mechanism 45 includes a driving pin (not shown) fixed to the driving flange 41 and a driven pin (not shown) fixed to the upper plate 9B, and the top ring body 9 is inclined. However, since the driven pin and the driving pin are relatively movable in the vertical direction, the driven pin and the driving pin are displaced from each other and engaged with each other, so that the rotational torque of the top ring drive shaft 7 is reliably transmitted to the top ring main body 9. .

Next, an attitude control device 11 for controlling the attitude of the top ring 6 will be described with reference to FIGS. FIG. 2 is a sectional view of a main part of the substrate holding device as described above.
FIG. 3 is a view taken along line III-III in FIG. 2, and FIG.
FIG. 4 is a sectional view taken along line IV.

As shown in FIGS. 2 and 3, the attitude control device 11 includes an electromagnet core 12 fixed to a top ring head 21 and four magnetic poles 12 a protruding radially outward from the electromagnet core 12. , 12b, 12c, 12d
And four electromagnetic coils 13a, 13b, 13c, 13d wound around these magnetic poles 12a to 12d, and a magnetic pole 12a.
And a cylindrical armature 14 opposed to 12-12d with a gap. The armature 14 is fixed to the top ring body 9.

As shown in FIG. 4, each of the magnetic poles 12a to 12d
Has a U-shaped cross section, and electromagnetic coils 13a to 13d are wound around the upper side of the U-shaped portion. In addition, the electromagnetic coil
A coil may be wound below the magnetic pole 12 as shown in FIG. The magnetic poles 12a to 12d and the armature 14 are made of a magnetic material such as Permalloy (registered trademark). The electromagnetic coil 13a is arranged on the X-axis positive direction side, and the electromagnetic coil 13b is arranged on the X-axis negative direction side. The electromagnetic coil 13c is arranged on the Y axis positive direction side, and the electromagnetic coil 13d is arranged on the Y axis negative direction side. On two axes P and Q inclined by 45 degrees with respect to the X axis and the Y axis, four pairs of displacement sensors
a1, 15a2; 15b1, 15b2; 15c1, 15
c2; 15d1 and 15d2 are arranged. Each displacement sensor pair is held by a sensor holder 17.

FIG. 5 is a block diagram showing a functional configuration of a control unit for controlling the attitude control device 11. As shown in FIG. As shown in the figure, the control unit includes a subtractor 30 and a controller 31. The subtractor 30 has a target value of the attitude of the top ring,
Sensors (displacement sensors 15a1, 15a2; 15b1, 1
5b2; 15c1, 15c2; 15d1, 15d2) 1
5, the displacement values α and β of the control target (top ring 6) converted by the coordinate conversion unit 35 are input, and the difference is input to the controller 31 as error signals eα and eβ. Here, α and β indicate the inclination around the X axis and the inclination around the Y axis, respectively, as shown in FIG. The X axis and the Y axis are located in a horizontal plane. In this case, the top ring 6 is tilted around the X axis around the bearing ball 42 and Y
It becomes a compound motion of tilting around the axis.

The error signals eα and eβ are subjected to tilt control and attenuation processing in a PID + local phase advance processing section 31-1, and are further converted to voltage command signals Vα and Vβ through a notch filter 31-2 for removing vibration. . Then, the control signals Vxu and Vyu for the attitude control device are output by the coordinate conversion unit 31-3.
And supplied to the drive unit 32.

The driving unit 32 includes the electromagnetic coils 13a, 13b,
13c and 13d and a drive circuit 24 for exciting them. Each of the signals Vxu and Vyu is supplied to each drive circuit 24, and in each drive circuit 24, the excitation currents Ixu +, Ixu-, and Iyu + for displacing the armature 14 in the positive and negative directions of the X and Y axes shown in FIG. , Iyu
To the electromagnetic coils 13a, 13b, 13c, 1
3d to control the attitude of the control object (top ring 6). In this case, since the center of rotation of the top ring 6 (the bearing ball 42) is separated from the X and Y axes of the armature 14 shown in FIG. 3 by a predetermined height (L), the armature 14 is moved away from the X and Y axes shown in FIG. When displaced in the positive and negative directions of the Y axis, the top ring body 9, that is, the top ring 6, can tilt in any direction with respect to the horizontal plane about the bearing ball 42.

Next, the operation of the polishing apparatus configured as shown in FIGS. 1 to 6 will be described. The semiconductor wafer 3 is held on the lower surface of the top ring, and the air cylinder 22 for the top ring is operated to press the top ring 6 toward the rotating turntable. 2 is pressed against the semiconductor wafer 3. In this case, the pressing force from the air cylinder 22 is transmitted to the top ring main body 9 via the top ring drive shaft 7 and the universal joint 8. On the other hand, the abrasive liquid supply nozzle 60
The polishing liquid is held in the polishing cloth 2 by flowing the polishing liquid from the polishing pad 2. Polishing is performed in a state where the polishing liquid is present between the polishing surface (lower surface) of the semiconductor wafer 3 and the polishing cloth 2. Will be The rotation of the top ring drive shaft 7 is performed via a drive pin fixed to the drive flange 41 and a driven pin fixed to the top ring body 9.
Conveyed to.

During the polishing, the attitude of the top ring body 9 holding the semiconductor wafer 3 is controlled by the attitude control device 11. In this case, as described above, the inclination of the top ring main body 9 is measured by the displacement sensor 15 (15a1, 15a2; 15).
b1, 15b2; 15c1, 15c2; 15d1, 15
The output of d2) is processed and detected, and the inclination of the top ring body 9 can be controlled to an arbitrary angle in an arbitrary direction with respect to the horizontal plane in accordance with the undulation of the upper surface of the turntable 1, ie, the polished surface, The parallelism between the substrate holding surface of the top ring body 9, that is, the polished surface of the semiconductor wafer and the upper surface of the polishing cloth 2, that is, the polished surface is maintained, and the distribution of the pressing pressure applied to the polished surface of the semiconductor wafer 3 is in-plane. It can be controlled uniformly. The distribution of the pressing pressure applied to the polished surface of the semiconductor wafer 3 is maintained by keeping the polished surface of the semiconductor wafer 3 and the polished surface of the turntable not parallel but slightly inclined. May be controlled in-plane uniformly.

According to the present embodiment, the pressing force for pressing the semiconductor wafer 3 against the polished surface of the turntable 1 is:
The pressing force of the air cylinder is transmitted to the top ring 6 as it is. Only the inclination of the top ring 6 is controlled by the attitude control device 11 using electromagnetic force. Therefore, the attitude control device 11 is reduced in size and has a simple structure. When controlling the attitude of the top ring 6, the state of the polished surface (such as undulation) of the upper surface of the turntable 1 is measured in advance and input to the controller, and the top ring 6 is determined based on the input value.
Find the best posture for you. Then, while detecting the posture of the top ring 6 by the displacement sensor 15, the posture control device 11 controls the posture of the top ring 6 to an optimal state.

According to the present embodiment, the semiconductor wafer 3
When the top ring 6 is attached to and detached from the top ring 6, the top ring 6 and the posture control device 11 having a compact and lightweight structure may be moved up and down integrally. Can be used.

Next, a polishing apparatus according to a second embodiment of the present invention will be described with reference to FIGS. FIG.
FIG. 8 is a vertical sectional view of the polishing apparatus, and FIG.
FIG. 9 is a sectional view taken along line II-VIII, and FIG. 9 is a sectional view taken along line IX-IX in FIG.

In the second embodiment, the configuration of the top ring unit including the top ring 6 and the attitude control device 11 is the same as that of the first embodiment, but the configuration of the turntable, that is, the attitude of the turntable is controlled. The difference is that you can do it.

As shown in FIG. 7, the turntable 101
And a rotating shaft 102 of a motor (not shown) are connected via upper and lower coupling members 103 and 104.
The lower coupling member 104 is fixed to the upper end of the rotating shaft 102 of the motor, and the upper coupling member 103 is fixed to the lower surface of the turntable 101. Then, the lower coupling member 104 and the upper coupling member 103
The self-aligning roller bearing 105 is disposed between the
The turntable 101 and the upper coupling member 103 can be tilted in all directions with respect to the lower coupling member 104 about the self-aligning roller bearing 105. A short columnar pin 106 is implanted in the lower coupling member 104, and the pin 106 engages with the engagement hole 103 a of the upper coupling member 103 so that the turntable 101 rotates. . A predetermined gap is formed between the engagement hole 103a and the pin 106 so as to absorb the inclination of the turntable 101.

In this embodiment, an attitude control device 111 for controlling the attitude of the turntable 101 is provided. The attitude control device 111 includes an electromagnet core 112 fixed to the frame 28, and four magnetic poles 112a, 112b, 112c, 112d provided on the electromagnet core 112.
And four electromagnetic coils 113a, 113b, 113c, 113d wound around these magnetic poles 112a to 112d.
And a circular and disk-shaped armature 114 facing the magnetic poles 112a to 112d with a gap. Armature 114 is turntable 101
It is fixed to.

As shown in FIG. 9, each of the magnetic poles 112a to 112a
2d has an inverted U-shaped cross section, and electromagnetic coils 113a to 113d are wound around the inside of the inverted U-shaped portion. Magnetic pole 1
12a to 112d and the armature 114 are made of a magnetic material such as permalloy. As shown in FIG. 8, the electromagnetic coil 113a is arranged on the X axis positive direction side, and the electromagnetic coil 113b is arranged on the X axis negative direction side. The electromagnetic coil 113c is arranged on the Y axis positive direction side, and the electromagnetic coil 113d is arranged on the Y axis negative direction side. Four displacement sensors 115a, 115b, 115 are provided on two axes R, S inclined at 45 ° with respect to the X axis and the Y axis.
c, 115d are arranged.

FIG. 10 is a block diagram showing a functional configuration of a control unit for controlling the attitude control device 111. As shown in the figure, the control unit for each of the turntable and the top ring has the same configuration as the control unit shown in FIG. 5, and an arithmetic unit for inputting the signals of the two and accurately outputting the relative positions of the two is added. It has a configuration.

As shown in FIG. 10, the control unit of the top ring includes a subtractor 30 and a controller 31. The subtractor 30 includes a target value of the attitude of the top ring,
, And converted by the coordinate converter 35, and further input by the calculator 36, the displacement values α and β of the control object corrected based on the tilt information of the turntable, and the difference between the displacement values α and β is output as error signals eα and eβ. Is input to

On the other hand, the control section of the turntable includes a subtractor 30 'and a controller 31'.
The target value of the attitude of the turntable and the sensor 115
(Displacement sensors 115a, 115b, 115c, 115
The displacement values α ′ and β ′ of the control target detected by d) and converted by the coordinate converter 35 ′ and corrected by the calculator 36 based on the tilt information of the top ring are input, and the difference between them is the error signal eα ′. , Eβ ′ to the controller 31 ′.

The arithmetic unit 36 calculates a relative error from the inclination information of the top ring and the turntable, and corrects the respective target values, thereby enabling highly accurate control. Normally, the accuracy can be improved by correcting the target position of the top ring based on the inclination of the turntable, so that the feedback R2 to the turntable can be omitted. Of course, each control is possible even in a configuration without an arithmetic unit. Here, α ′ and β ′ indicate the inclination around the X axis and the inclination around the Y axis, respectively, in FIG. In this case, the turntable 101 has a combined motion of tilting around the X axis and tilting around the Y axis around the self-aligning roller bearing 105.

The error signals eα ′ and eβ ′ are subjected to a tilt control and an attenuation process in a PID + local phase advance processing section 31 −1, and further passed through a notch filter 31 ′-2 to remove a vibration, so that a voltage command signal Vα ′, Vβ '. Then, the control signal V for the attitude control device is output by the coordinate conversion unit 31'-3.
x1 and Vy1 are supplied to the drive unit 32 '.

The driving section 32 'is provided with the electromagnetic coils 113a and 11a.
3b, 113c and 113d and a drive circuit 24 'for exciting these components. Each of the signals Vx1 and Vy1 is supplied to each driving circuit 24 ', and each of the driving circuits 2
At 4 ', exciting currents Ix1 +, Ix1 for displacing armature 114 in the positive and negative directions of the X and Y axes shown in FIG.
−, Iy1 +, Iy1-
a, 113b, 113c, and 113d to control the attitude of the control target (the turntable 101).

According to the embodiment shown in FIGS. 7 to 10,
In addition to the attitude control of the top ring 6, the turntable 10
1 attitude control can be performed. Therefore, the semiconductor wafer 3 can be polished while maintaining both the polished surface of the semiconductor wafer 3 and the polished surface on the turntable 101 in an optimum state.

FIGS. 11 and 12 show an example in which the attitude control device 11 as described above is applied to another type of polishing device.

That is, in this polishing apparatus, the holding plate 9A of the top ring main body 9 has flexibility, and the polishing device applies fluid pressure to the gap G between the holding plate 9A and the upper plate 9B. The holding plate 9A is capable of bending in the vertical direction, and the retainer ring 10 disposed around the top ring 9 is made movable relative to the top ring 9 in the vertical direction. A fluid pressure bag 88 is provided on the retainer ring 10 by introducing fluid pressure into the fluid pressure bag 88.
Is pressed against the polishing pad 2 with a variable pressing force. This apparatus is provided with the same attitude control device 5 as in the above-described embodiment. Therefore, in this embodiment, the holding plate 9A is not provided with a communication hole extending from the upper surface to the lower surface as in the above embodiment.

In FIGS. 11 and 12, the gap G is connected to a fluid source 85 via a regulator R1. The holding plate 9A is made thin as a whole, and is designed so that the entire surface of the wafer holding surface (the lower surface of the holding plate) is uniformly deformed when pressurized by the pressurized fluid introduced into the gap G or when negative pressure is applied. . Reference numeral 89 denotes a tube for connecting the gap G and the regulator R1.

As shown in FIG. 12, the retainer ring 10 is located at the lowermost position and is made of a resin material and is in contact with the polishing pad 2. The first retainer ring member 10a is located above the first retainer ring member 10a. 1 retainer ring member 10a
, And a second retainer ring member 10b having an L-shaped cross section. The second retainer ring member 10b is connected at the upper end to the upper plate 9B in the rotational direction by a pin 99, and the retainer ring 10 rotates integrally with the top ring 6. A fluid pressure bag 88 formed of an annular rubber tube is disposed between the retainer ring 10 and the top ring 6. The fluid pressure bag 88 is fixed to the holding plate 9A. The fluid pressure bag 88 is provided with a regulator R
2 is connected to a fluid source 85. Reference numeral 90 denotes a tube for connecting the fluid pressure bag 88 and the regulator R2.

The top ring 6 is connected via a universal joint 8 to a top ring drive shaft 7 having a drive flange 41, and the top ring drive shaft 7 is connected to a top ring fluid 21 fixed to a top ring head 21. Pressure (air)
It is connected to the cylinder 22. The top ring hydraulic cylinder 22 is connected to a fluid source 85 via a regulator R3.
It is connected to the. The universal joint 8 includes a top ring 6
Constitutes a tilting mechanism for tilting by following the tilting of the turntable 1.

The top ring drive shaft 7 is connected to a rotary cylinder 23 via a key (not shown). The rotary cylinder 23 has a timing pulley 24 on its outer periphery. The timing pulley 24 is connected via a timing belt 25 to a timing pulley 27 provided on a top ring motor 26 fixed to the top ring head 21. Therefore, when the top ring motor 26 is rotationally driven, the rotary cylinder 23 and the top ring drive shaft 7 rotate integrally via the timing pulley 27, the timing belt 25 and the timing pulley 24, and the top ring 6 rotates. The rotation of the top ring drive shaft 7 is transmitted to the top ring 6 by a rotation transmission mechanism 128 including a plurality of pins. The top ring head 21 is supported by a top ring head shaft 29 fixedly supported by a frame (not shown).

On the other hand, the retainer ring 10 is connected to the top ring 6 via a pin 99 and a fluid pressure bag 88. The rotation of the top ring 6 is transmitted to the retainer ring 10 by the pin 99, and the retainer ring 10 is It is moved up and down by the pressure bag 88. That is, the retainer ring 10 is vertically movable with respect to the top ring 6 and is rotatable integrally with the top ring 6.

As described above, the gap G is the regulator R
1 is connected to a fluid source 85. By adjusting the fluid pressure of the fluid supplied to the gap G by the regulator R1, the curved shape (lower convex, upper convex, etc.) of the lower surface (wafer holding surface) of the holding plate 9A can be adjusted. The degree of curvature can be adjusted. The hydraulic cylinder 22 for top ring and the hydraulic bag 88 are respectively provided with regulators R3 and R2.
Is connected to the fluid source 85 via the. The gap G and the fluid pressure bag 88 are respectively connected to the top ring drive shaft 7.
Tubes 89 and 90 extending inside and a rotary joint 93 at the upper end of the top ring drive shaft 7 are connected to regulators R1 and R2. The pressure of the top ring 6 pressing the semiconductor wafer 3 against the polishing pad 2 can be adjusted by adjusting the fluid pressure of the pressurized fluid supplied to the top ring air cylinder 22 by the regulator R3. By adjusting the fluid pressure of the pressurized fluid supplied to the fluid pressure bag 88, the pressing force with which the retainer ring 10 presses the polishing pad 2 can be adjusted.

The regulators R1, R2, R3
Are connected to the controller 124 and are controlled according to the input values of the controller 124. in this case,
Regulator R1 is independently controlled by controller 124, while regulators R2 and R3 are controlled in relation to each other. That is, retainer ring 1
When 0 is pressed against the polishing pad 2, the retainer ring 10 receives a reaction force and affects the pressing force of the top ring 6. Therefore, the set values of the pressing force of the top ring 6 and the pressing force of the retainer ring 10 are input to the controller 124, and the controller 124 calculates the fluid pressure to be applied to the top ring fluid pressure cylinder 22 and the fluid pressure bag 88, thereby obtaining the regulator R1. , R2 to supply a fluid having a predetermined pressure to the top ring hydraulic cylinder 22 and the hydraulic bag 88, respectively. Thereby, the pressing force of the top ring 6 and the retainer ring 10
The desired values can be obtained as the pressing forces. That is, the pressing force of the top ring 6 and the pressing force of the retainer ring 10 can be independently changed without being affected during polishing.

As shown in FIG. 12, the holding plate 9A has a plurality of communication holes 3h opened on the lower surface, and the communication holes 3h are formed in the joint 126 and the communication holes formed in the upper plate portion 9B. It is connected to a vacuum source (not shown) such as a vacuum pump through 2h and the tube 127. As a result, the wafer holding surface of the holding plate 9A can suck the upper surface of the semiconductor wafer 3 by vacuum. The joint 126 is provided with O-rings 138 at the upper and lower outer peripheral portions, so that the gap G does not communicate with the communication holes 2h, 3h. Further, the joint 126 and the holding plate 9A are fitted by a clearance fit so that the deformation of the holding plate 9A is not hindered. The communication hole 3h is connected to a switching valve (not shown) via a tube 127 extending inside the top ring drive shaft 7 and a rotary joint 93, and the communication hole 3h is evacuated by appropriately switching the switching valve. It can be in communication with a source or a source of pressurized air or a liquid. Accordingly, the wafer holding surface of the holding plate 9A is polished by applying a vacuum to the communication hole 3h by a vacuum source to suck the semiconductor wafer 3 in vacuum and ejecting pressurized air from the communication hole 3h by a pressurized air source. A backside pressure can be applied to the semiconductor wafer 3 inside. By applying a slight backside pressure to the semiconductor wafer 3 during polishing, it is possible to remove the suction traces generated during the transfer of the semiconductor wafer by vacuum suction. Further, the semiconductor wafer 3 can be separated from the wafer holding surface by ejecting the liquid from the communication hole 3h by the liquid source.

A polishing liquid supply nozzle 60 is provided above the turntable 1 so that the polishing liquid Q is supplied onto the polishing cloth 2 on the turntable 1 by the polishing liquid supply nozzle 60. ing.

In the polishing apparatus having the above configuration, the semiconductor wafer 3 is held on the wafer holding surface of the top ring 6, and the top ring 6 is pressed toward the turntable 1 by operating the top ring fluid pressure cylinder 22 to rotate the top ring 6. The semiconductor wafer 3 is pressed against the polishing cloth 2 on the upper surface of the turntable 1. On the other hand, by flowing the polishing abrasive Q from the abrasive supply nozzle 60, the polishing abrasive Q is held on the polishing pad 2, and the surface of the semiconductor wafer 3 to be polished (lower surface)
The polishing is performed in a state where the polishing liquid Q exists between the polishing pad 2 and the polishing pad 2.

When a pressurized fluid such as compressed air is supplied from the fluid source 85 to the gap G during polishing, the wafer holding surface of the holding plate 9A is bent downwardly by the pressure of the pressurized fluid. As a result, the semiconductor wafer 3 is pressed against the polishing pad 2 at a higher pressure on the central portion side than on the outer peripheral portion side. Therefore, when the outer peripheral portion of the semiconductor wafer 3 tends to be polished from the central portion side, the insufficient polishing on the central portion side can be corrected by the deformation effect of the wafer holding surface of the holding plate 9A as described above. .

On the other hand, when the central portion of the semiconductor wafer 3 tends to be polished from the outer peripheral portion, the regulator R1
Is adjusted to reduce the pressure of the pressurized fluid supplied from the fluid source 85 to the gap G, or to zero to change the curved shape of the wafer holding surface of the holding plate 9A. As a result, the polishing pressure on the outer peripheral portion side of the semiconductor wafer 3 is made higher than the polishing pressure on the central portion side, the insufficient polishing on the outer peripheral portion side is corrected, and the entire surface of the semiconductor wafer 3 can be uniformly polished.

In this embodiment, the top ring 6
Has a variable pressing force F1 for pressing the semiconductor wafer 3 to be polished against the polishing cloth 2 on the turntable 1, and a variable pressing force F2 for the retainer ring 10 pressing the polishing cloth 2. The pressing force F1 and the pressing force F2 can be changed independently of each other. Therefore, the pressing force F2 of the retainer ring 10 pressing the polishing cloth 2 can be changed according to the pressing force F1 of the top ring 6 pressing the semiconductor wafer 3 against the polishing cloth 2.

That is, the pressing force F1 by which the top ring 6 presses the semiconductor wafer 3 against the polishing cloth 2 on the turntable 1 can be changed by the regulator R3, and the pressing force F2 by which the retainer ring 10 presses the polishing cloth 2 by the regulator R2. Can be changed (see FIG. 1). While appropriately adjusting the pressing force F2 with respect to the pressing force F1, the holding plate 9A
By appropriately adjusting the shape of the wafer holding surface, the distribution of the polishing pressure from the central portion of the semiconductor wafer 3 to the peripheral portion and further to the outer peripheral portion of the retainer ring 10 outside the semiconductor wafer 3 becomes continuous and uniform. . Therefore, it is possible to prevent the polishing amount at the central portion and the peripheral edge portion of the semiconductor wafer 3 from being excessive or insufficient.

When it is desired to intentionally increase or decrease the polishing amount of the peripheral portion of the semiconductor wafer 3 from the inner side, the pressing force F2 of the retainer ring 10 is reduced to the top ring 6
By selecting the optimum value based on the pressing force F1, the polishing amount of the peripheral portion of the semiconductor wafer 3 can be intentionally increased or decreased.

That is, the semiconductor wafer 3 is polished by the cooperative operation of the shape correction of the wafer holding surface 3a by controlling the pressure of the fluid supplied to the gap G and the shape correction of the polishing pad 2 by the retainer ring 10. . This makes it possible to correct insufficient polishing (eg, a central portion, an outer peripheral portion, etc.) of the semiconductor wafer. In addition, a local portion (for example, a central portion, an outer peripheral portion, or the like) of the semiconductor wafer 3 can be intentionally increased in polishing amount or conversely reduced in polishing amount.

Also, a measuring instrument such as a film thickness meter for measuring the amount of polishing of the semiconductor wafer 3 is provided on the turntable 1 to detect the profile (shape) of the surface to be polished during polishing, and the detection result is input to the controller 124. Thus, the shape of the wafer holding surface of the holding plate 9A can be changed.

The attitude control device 11 has substantially the same configuration as that of the above-described embodiment. The cylindrical armature 14 is provided on the upper plate 9B of the top ring 6, and the top ring head 21 has an electromagnet. A core 12 and electromagnetic coils 13a to 13d are provided, and the attitude of the top ring 6 is controlled in the same manner as in the above-described embodiment. FIGS. 13 to 15 show an example in which a posture control device 11 similar to that described above is attached to a polishing apparatus of another form.

That is, in this polishing apparatus, the bolt 31 is attached to the outer periphery of the holding plate 9A of the top ring 6.
A pressing ring 133 is provided on the outside of the retainer ring 10 which is detachably fixed with the pressing ring 133 so as to be vertically movable.

The holding plate 9A has a number of communication holes 135 communicating with the gap G and opening on the lower surface. Elastic mat 13
Similarly, 2 has a through hole at a position facing the communication hole 135. Thus, the upper surface of the semiconductor wafer 3 can be suctioned by vacuum, and a liquid or pressurized air can be supplied to the upper surface of the semiconductor wafer 3.

The pressing ring 133 provided around the top ring 6 is, as shown in FIG. 14, a first pressing ring member 133 made of alumina ceramic at the lowest position.
a and second and third pressing ring members 133b, 13 made of stainless steel above the first pressing ring member 133a.
3c. The second and third pressing ring members 133b, 133c are connected to each other by bolts (not shown), and the first pressing ring member 133a is provided.
Is fixed to the second pressing ring member 133b by bonding or the like. The lower end of the first pressing ring member 133a is a pressing surface 133f that presses the polishing pad 2.

A bearing receiving flange 136 is fixed to the top ring body 9A of the top ring 6.
Then, the bearing receiving flange 136 and the pressing ring 1
A pressure ring support bearing 137 for supporting the pressure ring 133 is interposed between the pressure ring 33 and the pressure ring 33. As shown in FIGS. 13 and 14, the pressure ring support bearing 137 includes a bearing case 137a fitted to the third pressure ring member 133c, and a large number of balls arranged over the entire circumference in two vertical rows. 137b, and a retainer (not shown) for holding the ball 137b in the bearing case 137a. The upper end of the pressing ring support bearing 137 is pressed by a bearing holder 150 fixed to the upper end of the pressing ring 133.

In the present embodiment, the top ring 6
No means such as a key for transmitting the rotation of the top ring 6 to the pressing ring 133 is provided between the pressing ring 133 and the pressing ring 133. Therefore, the top ring 6 rotates around the axis of the top ring drive shaft 7 during polishing, but the pressing ring 133 is configured to be non-rotating with respect to its own axis, that is, the top ring 6 and the pressing ring 133. , A relative rotation is generated between the two. However, at this time, the outer peripheral surface of the bearing receiving flange 136 fixed to the top ring 6 forms a bearing rolling surface 36R on which the ball 137b rolls. The pressing ring support bearing 137 has the functions of both a rotation support bearing and a vertical movement support bearing. The relative rotation of the top ring 6 and the pressing ring 133 is allowed by the rotation support bearing function of the pressing ring support bearing 137. The press ring 133 is allowed to move up and down with respect to the top ring 6 by the vertical movement support bearing function of the press ring support bearing 137.

The third pressing ring member 1 of the pressing ring 133
The lower end of the shaft 122a of the press ring air cylinder 122 is engaged with 33c. The press ring air cylinder 122 is fixed to the top ring head 9. A plurality (for example, three) of the pressure ring air cylinders 122 are arranged on the circumference. Also retainer ring 1
0 is made of metal such as stainless steel, and retainer ring 1
A tapered surface 10Bt that is inclined inward in the radial direction is formed in the lower part on the outer peripheral part of 0, and the lower part is formed thinner than the upper part. On the other hand, a tapered surface 133t inclined inward in the radial direction is formed at a position corresponding to the tapered surface 10Bt of the retainer ring 10 on the inner peripheral portion of the pressing ring 133, and the pressing surface 133f of the pressing ring 133 is held by the top ring 6. The semiconductor wafer 3 is brought as close as possible to the peripheral edge.

With the configuration of the retainer ring 10 and the pressing ring 133 described above, the pressing surface 13 of the pressing ring 133
Since the distance between the inner peripheral edge of the semiconductor wafer 3 and the peripheral edge of the semiconductor wafer 3 can be shortened, the pressing ring 133 can press the polishing cloth 2 near the peripheral edge of the semiconductor wafer 3.

As shown in FIG. 13, the air cylinder 22 for the top ring and the air cylinder 122 for the pressing ring are
Compressed air source 2 via regulators R1 and R2, respectively
4 is connected. The pressure of the top ring 6 pressing the semiconductor wafer 3 against the polishing pad 2 can be adjusted by adjusting the air pressure supplied to the top ring air cylinder 22 by the regulator R1, and the pressure ring air can be adjusted by the regulator R2. Cylinder 122
By adjusting the air pressure supplied to the pressing ring 13
The pressing force by which 3 presses the polishing cloth 2 can be adjusted.

In the polishing apparatus having the above-described structure, the semiconductor wafer 3 is held on the lower surface of the top ring 6, and the top ring 6 is pressed toward the turntable 1 by operating the top ring air cylinder 22, and is rotated. The semiconductor wafer 3 is pressed against the polishing cloth 2 on the upper surface of the turntable 1. On the other hand, by flowing the polishing abrasive Q from the abrasive supply pipe 25, the polishing abrasive Q is held in the polishing cloth 2, and the polishing surface (lower surface) of the semiconductor wafer 3 and the polishing cloth 2
Polishing is performed in a state in which the polishing liquid Q is present.

The semiconductor wafer 3 is polished by appropriately adjusting the pressing force of the pressing ring 133 against the polishing cloth 2 by the pressing ring air cylinder 122 in accordance with the pressing force of the top ring 6 by the top ring air cylinder 22. During the polishing, the pressing force F1 by which the top ring 6 presses the semiconductor wafer 3 against the polishing cloth 2 on the turntable 1 can be changed by the regulator R1, and the pressing force F2 by which the pressing ring 133 presses the polishing cloth 2 can be changed by the regulator R2. (See FIG. 1). Therefore, during polishing, the pressing ring 1
33 is a pressing force F2 for pressing the polishing pad 2, and the top ring 6 is a pressing force F1 for pressing the semiconductor wafer 3 against the polishing pad 2.
It can be changed according to. By appropriately adjusting the pressing force F2 with respect to the pressing force F1, the distribution of the polishing pressure from the central portion of the semiconductor wafer 3 to the peripheral portion, and further to the outer peripheral portion of the pressing ring 133 outside the semiconductor wafer 3 is continuous and uniform. become. Therefore, it is possible to prevent the polishing amount at the peripheral portion of the semiconductor wafer 3 from being excessive or insufficient.

When it is desired to intentionally increase or decrease the polishing amount at the peripheral portion of the semiconductor wafer 3 from the inner side, the pressing force F2 of the pressing ring is changed to the pressing force F2 of the top ring.
By selecting an optimal value based on 1, the polishing amount of the peripheral portion of the semiconductor wafer 3 can be intentionally increased or decreased.

In the present embodiment, the pressing ring 13
Since the support ring 3 is supported by the top ring 6 via the press ring support bearing 137, the press ring 133 has high rigidity, that is, is sufficiently firmly supported. Further, since the pressing ring 133 is allowed to move up and down with respect to the top ring 6 by the vertical movement supporting bearing function of the pressing ring supporting bearing 137, the sliding resistance of the pressing ring 133 during the vertical movement is extremely small. 133 moves up and down smoothly.

The pressing ring 133 has a pressing ring support bearing 13 arranged concentrically with the axis of the top ring 6.
7, the concentricity between the pressing ring 133 and the top ring 6 can be ensured with high accuracy. As a result, the distance between the pressing ring 133 and the top ring 6, that is, the distance between the inner peripheral edge of the pressing ring 133 and the outer peripheral edge of the semiconductor wafer 3 supported by the top ring 6 can be kept uniform over the entire circumference. . Furthermore, since the wafer can be polished uniformly to a position closer to the periphery of the polished surface of the wafer, the number of semiconductor device products obtained from one wafer has increased, and operating conditions such as the pressing force of a pressing ring during polishing have been changed. Responsiveness at the time is improved.

The attitude control device 11 is mounted on the polishing device configured as described above. The configuration is substantially the same as that described above, and the armature mounted on the upper end of the pressing ring 133 is provided. 14 and the top ring head 2
The electromagnetic core 12 and the electromagnetic coils 12a to
12d.

FIGS. 16 and 17 show an example in which a posture control device 11 similar to that described above is attached to a polishing apparatus of still another embodiment. That is, in this polishing apparatus, the rotation support bearing function and the vertical movement support bearing function of the pressing ring support bearing 137 in the embodiment shown in FIGS. 13 and 14 are divided and the respective functions are separated into individual bearings 138 and 139. It is made to share. That is, a bearing receiving ring 140 is provided on the outer peripheral portion of the top ring main body 9 of the top ring 6 via a rotation supporting bearing 138, and a vertical movement supporting bearing 139 is provided between the bearing receiving ring 140 and the pressing ring 133. Is interposed. The rotary support bearing 138 is a normal radial bearing. As shown in FIGS. 16 and 17, three vertically movable support bearings 139 are provided on the circumference, and each vertically movable support bearing 139 is
3, an outer raceway member 139a fixed to the third roller 3, four short columnar rollers 139b in two rows and two columns, and a roller 139.
b of the inner raceway member 139c. The inner raceway member 139c is fixed to a bearing receiving ring 140, and a bearing retainer 169 is fixed to the bearing receiving ring 140.

A pressing ring stopper 170 is fixed to the upper end of the pressing ring 133, and a cover 171 is fixed to the upper end of the top ring body 9. The rotation support bearing 138 and the vertical movement support bearing 13
9 and three labyrinths 175,176,1
77 are formed. That is, the bearing retainer 16
9, a pressing ring stopper 170, and a cover 171 are formed with a labyrinth 175, a labyrinth 176 is formed between the bearing receiving ring 140 and the top ring body 9A, and a third pressing ring member of the pressing ring 133 is formed. A labyrinth 177 is formed between 133c and retainer 10.

In this polishing apparatus, FIG.
In addition, the position of the support of the bearing can be made closer to the polished surface as compared with that shown in FIG. As a result, the support stability of the pressing ring 133 can be further ensured. Also, the top ring 6 and the pressing ring 1
The relative rotation with respect to 33 is supported by the rotation support bearing 138, and the vertical movement of the pressing ring 133 with respect to the top ring 6 is supported by the vertical movement support bearing 139, which also contributes to the improvement of the life of the bearing. It is possible.

When the above-described structure is employed, it is not preferable that foreign substances enter the bearing installation portion, for example, liquids such as water and polishing liquid and solids such as polishing waste. Therefore, it is necessary to prevent the above-mentioned liquid or solid matter from entering the periphery of the bearing. As a means, the periphery may be mechanically sealed with a contact-type seal or covered with a structure such as a labyrinth. A method is conceivable. For example,
When mechanically sealed, a considerable amount of wear occurs at the contact portion, and the seal itself may become a consumable member. In addition, abrasion leads to the generation of foreign matter due to the wear, and may itself be a source of foreign matter. On the other hand, since the above-mentioned labyrinth structure is non-contact, there is no such concern. Furthermore, by arranging a plurality of labyrinths 175, 176, and 177, it is possible to improve the accuracy of preventing foreign matter from entering. Unnecessary entry of foreign matter into the polished surface is also undesirable, and the use of the labyrinth structure can be expected to have an effect of preventing foreign matter generated at a portion above the polished surface from falling.

The attitude control device 11 is mounted on the polishing device configured as described above, and the configuration thereof is substantially the same as that described above, and the armature mounted on the upper end of the pressing ring 133 is provided. 14 and the top ring head 2
The electromagnetic core 12 and the electromagnetic coils 12a to
12d.

[0089]

As described above, according to the present invention,
By applying the electromagnetic force to control the attitude of the top ring that holds the substrate to be polished, the surface pressure distribution on the surface to be polished is optimized, and the polishing is performed with high flatness. Can be.

According to the present invention, the pressing force for pressing the substrate to be polished against the polishing surface of the turntable is obtained by transmitting the pressing force of the air cylinder to the top ring as it is. Only the inclination of the top ring is controlled by a posture control device using electromagnetic force. Therefore, the attitude control device is reduced in size and has a simple structure.

According to the present invention, when the substrate to be polished is attached to and detached from the top ring, the top ring and the attitude control device having a compact and lightweight structure may be moved up and down integrally. Therefore, a simple vertical movement mechanism, for example, an air cylinder can be used.

Further, in the embodiment shown in FIGS. 11 and 12, the polishing pressure is prevented from becoming uneven at the central portion or the peripheral portion of the polishing object during polishing, and the polishing pressure is reduced. Of the polishing target can be prevented from being excessively or insufficiently polished at the central portion or the peripheral portion of the object to be polished. Therefore, the entire surface of the object to be polished can be polished flat and mirror-finished. Further, higher quality polishing can be performed in a semiconductor manufacturing process or the like, and the product can be provided to the peripheral portion of the semiconductor wafer, thereby contributing to an improvement in the yield of the semiconductor wafer.
Further, since there is a demand to intentionally increase or decrease the polishing amount of the peripheral portion of the polishing object from the inner side depending on the polishing object such as a semiconductor wafer,
The polishing amount at the peripheral portion of the object to be polished can be intentionally increased or decreased so as to be able to meet this demand. Furthermore, not only the periphery of the polishing object,
Polishing can be performed so as to increase or decrease the amount of polishing of a target region (for example, a central portion, an outer peripheral portion, etc.) of the polishing surface.

In the case shown in FIGS. 13 to 17, by adjusting the pressing force of the pressing ring and the object to be polished against the polishing surface, the object to be polished is appropriately polished as required. be able to.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an overall configuration of a polishing apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a main part of the substrate holding device according to the present invention.

FIG. 3 is a sectional view taken along line III-III of FIG. 2;

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;

FIG. 5 is a block diagram illustrating a functional configuration of a control unit that controls the attitude control device of the top ring.

FIG. 6 is a diagram illustrating the relationship between the inclination α of the top ring around the X axis and the inclination β around the Y axis.

FIG. 7 is a longitudinal sectional view showing an overall configuration of a polishing apparatus according to a second embodiment of the present invention.

8 is a sectional view taken along line VIII-VIII in FIG.

9 is a sectional view taken along line IX-IX of FIG.

FIG. 10 is a block diagram showing a functional configuration of a control unit that controls the attitude control device of the turntable.

FIG. 11 is a view showing another embodiment of the polishing apparatus according to the present invention.

FIG. 12 is a partially enlarged view of the polishing apparatus of FIG. 11;

FIG. 13 is a view showing still another embodiment of the polishing apparatus according to the present invention.

FIG. 14 is a partially enlarged view of the polishing apparatus of FIG.

FIG. 15 is a sectional view taken along line XIIII-XIIII of FIG. 14;

FIG. 16 is a view showing another embodiment of the polishing apparatus according to the present invention.

FIG. 17 is a sectional view taken along line XVII-XVII in FIG. 16;

FIG. 18 is a schematic view of a conventional polishing apparatus.

[Explanation of symbols]

1, 56, 101 Turntable 2, 57 Polishing cloth 3, 53 Semiconductor wafer 5 Substrate holding device 6, 54 Top ring 7, 51 Top ring drive shaft 8 Universal joint 9 Top ring main body 9a, 41a Recess 9B Upper plate 10 Retainer Ring 11, 111 Attitude control device 12, 112 Electromagnetic core 12a, 12b, 12c, 12d, 112a, 112
b, 112c, 112d Magnetic poles 13a, 13b, 13c, 13d, 113a, 113
b, 113c, 113d Electromagnetic coil 14, 114 Armature 15, 15a1, 15a2; 15b1, 15b2; 15
c1, 15c2; 15d1, 15d2, 115a, 11
5b, 115c, 115d Displacement sensor 21 Top ring head 22 Air cylinder for top ring 23 Rotating cylinder 24 Timing pulley, drive circuit 25 Timing belt 26 Motor for top ring 27 Timing pulley 29 Top ring head shaft 30 Subtractor 31 Controller 31-1 Processing unit 31-2 Notch filter 31-3 Coordinate conversion unit 32 Drive unit 40 Spherical bearing mechanism 41 Flange 42 Bearing ball 52 Spherical part 54a Wafer holding surface 55 Spherical seat 60 Abrasive liquid supply nozzle 102 Rotating shaft 103 Lower coupling member 104 Upper part Coupling member 104a Engagement hole 105 Self-aligning roller bearing 106 Pin

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Norio Kimura 11-1 Haneda Asahimachi, Ota-ku, Tokyo Ebara Corporation (72) Inventor Katsuya Okumura 8 Shinsugita-cho, Isogo-ku, Yokohama-shi Toshiba Yokohama Office F-term (reference) 3C058 AA07 AB04 BB02 BB03 BB04 BC01 CB01 DA17

Claims (6)

[Claims] 1. A polishing apparatus comprising: a turntable having a polishing surface; and a substrate holding device having a top ring for holding a substrate to be polished and pressing the substrate against the polishing surface on the turntable. A polishing apparatus, comprising: pressing means for pressing a top ring against a polishing surface of a turntable; and attitude control means for controlling the attitude of the top ring by electromagnetic force. 2. The method according to claim 1, wherein the pressing means is a drive shaft for giving rotation to the top ring, and the drive shaft and the top ring are connected to each other via a joint so as to be tiltable. The polishing apparatus according to claim 1. 3. An electromagnet device fixed to the frame, wherein the substrate holding device has a frame for supporting a drive shaft rotatably about the axis thereof,
The polishing apparatus according to claim 2, further comprising an armature fixed to the top ring and moved by a magnetic force of the electromagnet apparatus. 4. The attitude control device according to claim 2, wherein the attitude control device detects the attitude of the top ring and feedback-controls the attitude based on the detected attitude.
A polishing apparatus according to claim 1. 5. A pressing ring is disposed around the top ring so as to be vertically movable, and pressing means for pressing the pressing ring with a variable pressing force against the polishing surface is provided, and the pressing ring is connected via a bearing. The polishing apparatus according to any one of claims 1 to 4, wherein the top ring is supported so as to allow rotation of the top ring while maintaining the pressing ring in a non-rotating state. 6. A holding surface for holding a substrate of the top ring is displaceable with respect to the polishing surface by a fluid pressure applied to the top ring, and has a retainer ring around the top ring; The polishing apparatus according to any one of claims 1 to 4, wherein the retainer ring can be pressed against the polishing surface independently of the top ring.