JPH0786462A - Moving stage device - Google Patents

Abstract

PURPOSE:To prevent tilting and oscillation of a base board by strengthening stiffness of a static pressure bearing means by respective prepressure means, where a prepressure means is a permanent magnet, and controlling a current of a coil generating magnetic force in the same direction with or in the opposite direction to the permanent magnet. CONSTITUTION:A magnetic circuit is formed by a guiding surface 1a, a permanent magnet 901 and both yokes 902, 903 and magnetic force of the magnetic circuit makes a moving base 4 to be sucked by a guiding surface of a base board 1 so as to give prepressure to the second static pressure bearing pads 7, 8. As to a prepressure unit coil 904 of the respective prepressure units 9, when the prepressure unit coil 904 is excited by a current to be fed from a controller, magnetic force of the magnetic circuit is changed to change prepressure. Thereby, oscillation and tilting to be generated at a moving time of a moving stage device can be prevented so as to improve throughput of a semiconductor exposure device, a precision machine tool and a precision measuring machine by speed-up of positioning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is intended for positioning a substrate such as a wafer exposed in a semiconductor exposure apparatus, a precision machine tool, a precision measuring machine or the like, an object to be processed, an object to be measured at a high speed and with high accuracy. Of the moving stage device.

[0002]

2. Description of the Related Art In semiconductor exposure apparatuses, precision machine tools, and precision measuring machines, it is required to position a substrate such as a wafer to be exposed, an object to be processed, an object to be measured, etc. at a high speed. It is supported in a non-contact manner on the bed by a hydrostatic bearing device, which reduces friction and enables high-speed driving with a linear motor, etc., while also preventing deterioration of positioning accuracy due to surface roughness of the bed and foreign matter. A moving stage device was developed.

FIG. 14 shows an example of a conventional moving stage device. This is a base 10 having a flat guide surface 101a.
1 and a pair of linear motors 102 and 103 along the guide surface 101a of the base 101 in a predetermined axial direction (hereinafter,
It is called "X-axis direction". ) Moving table 104 that is reciprocated
The base 101 includes a pair of guides 101b and 101c that guide the moving base 104 in the X-axis direction, and a linear coil 102 that is a fixed body of the linear motors 102 and 103.
a, 103a are supported, and the moving table 104 is a linear magnet 102 which is a moving body of each linear motor 102, 103.
Holds b and 103b. Each guide 10 of the moving table 104
A first hydrostatic bearing pad is supported on the surface facing the 1b and 101c so as to inject gas between the movable table 104 and the guides 101b and 101c and to support the two in a non-contact manner by its static pressure. On the surface 104c of the board 101 facing the guide surface 101a, the second static pressure bearing pads 107 and 108 for holding the two in a non-contact manner by jetting a gas between the movable table 104 and the guide surface 101a are held. Has been done.

A wafer, an object to be measured, and the like (not shown) are held on the moving table 104, and current is supplied to the linear coils 102a and 103a of the linear motors 102 and 103 to drive the linear motors 102 and 103. , Mobile platform 1
Reference numeral 04 moves to a predetermined position on the base 101 along the guides 101b and 101c to position the wafer and the like. As described above, the moving table 104 is supported in a non-contact manner with respect to the guide surface 101a of the table 101 and the guides 101b and 101c. Therefore, since there is no frictional resistance, the moving table 104 moves at an extremely high speed. You can do it, and base 1
Even if the guide surface 101a of No. 01 has unevenness, the moving table 104 is tilted by these and the flatness thereof is reduced, and there is no possibility of impairing the positioning accuracy.

[0005]

However, according to the above-mentioned conventional technique, when the center of the driving force of the linear motor or the like and the center of gravity of the moving base do not match, the moving base is moving due to a moment resulting from this. However, there is a possibility that the vehicle may be tilted to lower the straight traveling accuracy and generate vibrations such as pitching. Therefore, there is a problem that the moving table cannot be moved at a sufficiently high speed and the time required for positioning cannot be shortened sufficiently.
Therefore, the gas supply pressure of the hydrostatic bearing pad is controlled (see Japanese Patent Laid-Open No. 58-25637), or the orifice of the jet port of the hydrostatic bearing pad is adjusted by using a driving means such as a piezoelectric element ( (See Japanese Laid-Open Patent Publication No. 63-151515) or a method of offsetting the tilt of the movable table by providing a hydrostatic bearing pad on the guide surface of the base and tilting the guide surface (Japanese Patent Laid-Open No. 4-27218). However, the method of adjusting the gas supply pressure or adjusting the orifice of the ejection hole has poor responsiveness, so the time required for positioning becomes long, and the hydrostatic bearing pad is attached to the guide surface of the base. The method of providing and inclining this lacks stability of the pedestal and may increase the size of the entire apparatus.

The present invention has been made in view of the above problems of the prior art, and provides a moving stage apparatus having a simple and responsive mechanism for preventing vibration and tilt of the moving table. That is the purpose.

[0007]

In order to achieve the above object, a moving stage apparatus of the present invention comprises a base having a guide surface, and a movable base supported by the static pressure bearing means in a non-contact manner on the guide surface. And a drive means for moving the movable table along the guide surface, a plurality of precompression means for urging the movable table toward the guide surface, and a control means for controlling each precompression means. Characterize.

Further, it is preferable that each of the preloading means is a permanent magnet, and the control means is a coil for generating a magnetic force in the same direction or a reverse direction to the permanent magnet and a controller for controlling the current of the coil.

[0009]

According to the above apparatus, the rigidity of the hydrostatic bearing means is enhanced by each preloading means, and tilting and vibration of the bed can be prevented by controlling each preloading means.
If the preload means is a permanent magnet and the control means is a coil that generates a magnetic force in the same direction as or a direction opposite to that of the permanent magnet and a controller that controls the current of the coil, the entire moving stage device may become large. In addition, it is extremely responsive.

[0010]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing a first embodiment,
The moving stage apparatus according to the present embodiment includes a base 1 having a flat guide surface 1a, a pair of linear motors 2 serving as driving means,
3 comprises a movable table 4 which is reciprocally moved along a guide surface 1a of the table 1 in a predetermined axial direction (hereinafter referred to as "X-axis direction"). The table 1 moves the movable table 4 in the X-axis direction. And a pair of guides 1b and 1c for guiding the linear motors and linear coils 2a and 3a which are fixed bodies of the linear motors 2 and 3, respectively, and a movable table 4 is a linear magnet 2b which is a movable body of the linear motors 2 and 3, Hold 3b.

As shown in FIG. 2, each guide 1 of the movable table 4 is
On the surfaces 4a, 4b facing b, 1c, there are first static pressure bearing pads 5, 6 for injecting a gas between the movable table 4 and the guides 1b, 1c and supporting the both in a non-contact manner by the static pressure. A surface 4c that is held and faces the guide surface 1a of the base 1.
The second hydrostatic bearing pads 7 and 8 which are hydrostatic bearing means for ejecting gas between the movable table 4 and the guide surface 1a and supporting the two in a non-contact manner by the static pressure thereof are held.

A wafer, an object to be measured, and the like (not shown) are held on the upper surface of the moving table 4, and current is supplied to the linear coils 2a and 3a of the linear motors 2 and 3 to drive the linear motors 2 and 3. Then, the moving table 4 moves to a predetermined position on the table 1 along the guides 2 and 3 to position the wafer and the like. As described above, the movable table 4 is supported in a non-contact manner with respect to the guide surface 1a of the platform 1 and the guides 1b and 1c. Therefore, since there is no frictional resistance, the movable table 4 can be moved at a very high speed. Even if the guide surface 1a of the base 1 has irregularities, the moving table 4a
There is no risk that the linearity accuracy is lowered due to the tilting of the shaft and the positioning accuracy is impaired.

As shown in FIG. 3, the movable table 4 holds preloading units 9 and 10 as preloading means on both end surfaces 4d and 4e in the X-axis direction, and each preloading unit 9 and 10 is shown in FIG. As shown, a permanent magnet 901, a pair of yokes 902 and 903 arranged so as to sandwich the permanent magnet 901, and each yoke 9
02,903 leg portions 902a, 903 projecting downward
Preload unit coil 904 which is a coil wound around a
905, and a permanent magnet 901 and each yoke 902, 9
03 is integrally coupled to the movable table 4 by a mounting member 906.

The guide surface 1a of the base 1 is made of a magnetically permeable material such as iron. The guide surface 1a and the permanent magnet 9 are
01 and both yokes 902 and 903 form a magnetic circuit, and the moving table 4 is moved by the magnetic force of the magnetic circuit.
Suction toward the guide surface of the second hydrostatic bearing pad 7, 8
Give preload to. The preload unit coils 904 and 905 of the preload units 9 and 10 are connected to a controller (not shown), and when the preload unit coils 904 and 905 are excited by the current supplied from the controller, the magnetic force of the magnetic circuit is changed to preload the preload units. Is configured to change.

In the controller, at the same time as the driving force of each linear motor 2 and 3 is generated, a predetermined current is applied to the preload unit coils 904 and 90 of each preload unit 9 and 10.
The control program to be supplied to 5 is set.

That is, the movable base 4 when the drive current having the waveform shown in FIG. 5A is supplied to each of the linear motors 2 and 3.
Of the preloading units 9 and 10 necessary to prevent this is calculated in advance, and the preloading units 9 and 10 are calculated in synchronization with the driving of the linear motors 2 and 3.
If a control program to be supplied to the preload unit is created and set in the controller, the current having the waveform shown in FIG. 5B is automatically supplied to each preload unit 9 and 10 in each positioning cycle in which the moving table 4 moves. The preload is prevented from changing and the movable table 4 is prevented from tilting. As a result, the moving table 4 can be moved at a high speed to shorten the time required for positioning.

Next, a modification of this embodiment will be described.

FIG. 6 and FIG. 7 show a first modification of the present embodiment. In this modification, a pair of end faces 14d, 14e of a movable base 14 similar to the movable base 4 of the first embodiment are respectively paired. Each of the preload units 19 to 22 is provided, and an acceleration detector 23, which is an acceleration detecting means, is fixed to the upper surface of the moving table 14, and the acceleration of the moving table 14 is detected by the acceleration detector 23. This is configured so that it is input to a controller (not shown) similar to that of the embodiment to supply a predetermined current to each of the preload units 19 to 22.

FIGS. 8 and 9 show a second modified example. In this modified example, a pair of preload units are provided on both end surfaces 34d and 34e of a movable table 34 similar to the movable table 4 of the first embodiment. 39 to 42 are provided, and both end faces 34d,
A pair of non-contact displacement detectors (for example, electrostatic capacitance type displacement gauges) 43 and 44, which are a pair of displacement detecting means, are respectively arranged in 34e, and the vertical displacement of the movable table 34 is directly detected by these, and Preload units 39 to 42 based on the output
It is configured to supply a current to the. In this modification, since the inclination of the moving table 34 is directly detected to eliminate the inclination, when the moving table 34 is tilted due to the imbalance of the mass while the moving table 34 is stationary, the material of the moving table 34 or the like is changed. Even if the flatness is lowered due to deformation over time, there is an advantage that these can be detected immediately and the positioning accuracy can be prevented from lowering.

FIG. 10 is a perspective view showing a second embodiment. The moving stage apparatus of the present embodiment is similar to the first embodiment in that it has a base 51 having a guide surface 51a and an integrated body 51. A pair of guides 51b, 51c provided and a guide surface 51
The movable table 54 is movable along the guides 51b and 51c on a, and the pair of linear motors 52 and 53 is a driving means for moving the movable table 54.
Between the 1b and 51c and the guide surface 51a, as shown in FIGS. 11 and 12, a hydrostatic bearing pad 5 which is hydrostatic bearing means.
It is kept non-contact by 5 to 58. Instead of the preload units 9 and 10 of the first embodiment, two pairs of permanent magnet units 5 parallel to the guides 51b and 51c on the guide surface 51a.
9a to 62a are fixed, and the movable table 54 is fitted and inserted between each pair of permanent magnet units 59a to 62a, and together with these, the preload unit coils 59b to 62 constituting magnetic means.
Holds b.

That is, as shown in FIG. 13, each of the preload unit coils 59b to 62b is attached to the mounting member 59c.
The preload unit coils 59b to 62b are fixed to the moving table 54 by means of a coil and are wound around an axis perpendicular to the moving direction of the moving table 54 in the horizontal plane.
Reference numerals 9a to 62a denote two permanent magnets 59d and 59e, which are vertically stacked, and are arranged such that their magnetic poles are opposite to each other. Both permanent magnets 59d, 59
e is integrated by a yoke 59f, and the thickness of each permanent magnet 59d, 59e in the vertical direction is not more than half the diameter of each preload unit coil 59b to 62b.

When current is supplied to each of the preload unit coils 59b to 62b, a Lorentz force is generated perpendicularly to the guide surface 51a, whereby the movable table 54 is attracted to the guide surface 51a and the same as in the first embodiment. Generate preload. Further, the preload by each of the preload unit coils 59b to 62b can be changed by controlling the current supplied to them by a controller (not shown) which is a control means. Since the other points are the same as those in the first embodiment, the description thereof will be omitted.

[0024]

Since the present invention is configured as described above, it has the following effects.

Since it is possible to prevent vibrations and tilts that occur when the moving stage apparatus moves, it is easy to speed up the positioning and improve the throughput of semiconductor exposure apparatuses, precision machine tools, precision measuring machines and the like.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment.

FIG. 2 is a schematic side view of the first embodiment.

FIG. 3 is a schematic plan view of the first embodiment.

FIG. 4 is an enlarged partial perspective view showing a portion surrounded by a frame A in FIG. 2 in an enlarged manner.

FIG. 5 is a diagram for explaining a program for controlling the preload unit of the first embodiment, (a) is a time chart of signals for driving a linear motor, and (b) shows a current waveform applied to the preload unit coil. It is shown.

FIG. 6 is a schematic side view showing a first modification of the first embodiment.

FIG. 7 is a schematic plan view showing a first modification of the first embodiment.

FIG. 8 is a schematic side view showing a second modification of the first embodiment.

FIG. 9 is a schematic plan view showing a second modification of the first embodiment.

FIG. 10 is a perspective view showing a second embodiment.

FIG. 11 is a schematic side view showing a second embodiment.

FIG. 12 is a schematic plan view showing a second embodiment.

13 is an enlarged partial perspective view showing an enlarged portion surrounded by a frame B in FIG.

FIG. 14 is a perspective view showing a conventional example.

[Explanation of symbols]

1,51 Platform 1a, 51a Guide surface 1b, 1c, 51b, 51c Guide 2,3,52,53 Linear motor 4,14,34,54 Moving base 5-8,55-58 Hydrostatic bearing pad 9,10 , 19 to 22, 39 to 42 Preload unit 23 Acceleration detector 43 Displacement detector 59a to 62a Permanent magnet unit 59b to 62b, 904, 905 Preload unit coil 901 Permanent magnet

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location H01L 21/68 K 23/31 H02P 3/00 9178-5H

Claims (6)

[Claims] 1. A pedestal having a guide surface, a movable table supported by the hydrostatic bearing means in a non-contact manner with the guide surface, and a drive means for moving the movable table along the guide surface, respectively. A moving stage device comprising a plurality of preloading means for urging the moving table toward the guide surface and a control means for controlling each preloading means. 2. The preload means is a permanent magnet, and the control means is a coil for generating a magnetic force in the same direction or a reverse direction to the permanent magnet and a controller for controlling the current of the coil. Item 1. A moving stage device according to item 1. 3. The moving stage apparatus according to claim 1, wherein each preloading means is a magnetic means for generating a Lorentz force, and the control means is a controller for changing the Lorentz force. 4. The moving stage apparatus according to claim 1, wherein the control unit is configured to be driven in synchronization with the driving unit. 5. The acceleration detecting means for detecting the acceleration of the moving table is provided, and the control means is driven based on the output of the acceleration detecting means. 3. The moving stage device according to any one of 3 to 3. 6. A plurality of displacement detection means for detecting the inclination of the moving table are provided, and the control means is driven based on the output of each displacement detection means. Item 5. The moving stage device according to any one of items 1 to 3.