JPH03296208A - Table feed controller - Google Patents

Abstract

PURPOSE:To obtain a table feed controller in which a yawing is controlled securely if it is generated while the table is fed by installing a yawing correction device to magnetize at least one electromagnet coil according to the yawing direction and amount which is detected by a yawing detector. CONSTITUTION:A feed controller 17 finds the location of each of plane mirrors 11 and 12 of a table 10 based on the location detection signals output from location detectors 14 and 15, finding out the yawing direction and amount of the table 10 on a basis of a difference in location of the plane mirrors. Then, finding an electromagnet coil 16-k to correspond to the location of the plane mirror 12 detected by the location detector 15, the feed controller 17 magnetizes the electromagnet 16-k by applying to it a current in proportion to the yawing amount in the direction according to the yawing direction, in other words, a current required for vanishing a difference in location of the plane mirrors 11 and 12. In this case, the table slopes in the direction shown by an arrow (). So, a current of such a current value as in proportion to the inclination of the yawing is applied to the electromagnet 16-k in the flow direction against a permanent magnet 13. By this method, the yawing of the table 10 is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a table feed control device that controls the feed of a table used in, for example, an exposure apparatus.

(Prior Art) FIG. 5 is a block diagram of an exposure apparatus using a reflection projection optical system. The exposure light emitted from the light source is formed into an arcuate slit-shaped illumination beam by an optical system (not shown) and is irradiated onto the mask 2. A predetermined pattern is formed on this mask 2, and the exposure light that has passed through this pattern is reflected by one surface of a trapezoidal mirror 3 and enters a reflection projection optical system 4. This reflective projection optical system 4 has a concave mirror 5 and a convex mirror 6 arranged with their optical axes aligned.The exposure light from the trapezoidal mirror 3 is reflected by the concave mirror 5 and sent to the convex mirror 6.
The exposure light reflected by the concave mirror 5 is reflected again by the concave mirror 5 and sent to the other surface of the trapezoidal mirror 3.

The exposure light reflected by the other surface of the trapezoidal mirror 3 is irradiated onto the wafer 7. Note that the wafer 7 is placed at the imaging position of the reflection projection optical system 4. Then, the mask 2 and the wafer 7 are synchronously fed in the direction of arrow (A) by an air bearing feeding table, and the entire pattern of the mask 2 is scanned. As a result, the pattern formed on the mask 2 is transferred to the wafer 7.

Incidentally, the mask 2 and the wafer 7 are attached to a feeding table and aligned before exposure processing, and in this state are fed by the feeding table in the direction of arrow (A). However, when yawing occurs between Mask 2 and Ueno\7,
Misalignment occurs between the mask 2 and the wafer 7. If this positional shift occurs, the pattern cannot be accurately transferred to the wafer 7. In this case, as the sizes of the mask 2 and the wafer 7 increase, the relative distance between the mask 2 and the wafer 7 increases, so even a slight yawing causes a large displacement between the mask 2 and the wafer 7. Therefore,
This displacement due to yawing is suppressed by adjusting the air pressure of the feed table.

However, although it is possible to suppress yawing by adjusting the air pressure in a static state, the responsiveness is low, so it becomes difficult to suppress yawing when the speed of the feed table is high and the yawing is fast.

(Problems to be Solved by the Invention) As described above, when yawing is suppressed by adjusting the air pressure, it is difficult to suppress yawing when the speed of the feed table is high.

Therefore, an object of the present invention is to provide a table feeding control device that can reliably suppress yawing even if yawing occurs during feeding.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a table feeding control device for a table fed in a linear direction, which includes a yawing detection means for detecting yawing of the table, and a magnetization device provided on the side surface of the table. a plurality of electromagnetic coils facing the magnetized body and arranged along the feeding direction of the table; and at least one of the electromagnetic coils according to the yawing direction and amount detected by the yawing detection means. This is a table feed control device that attempts to achieve the above object by including a yawing correction means that excites a coil.

Further, the present invention provides a table feeding control device for a table fed in a linear direction, including a yawing detection means for detecting yawing of the table, and electromagnets provided at respective positions in front and rear of the table with respect to the feeding direction. at least one of the electromagnetic coils according to the yawing direction and amount detected by the yawing detection means. This is a table feed control device that attempts to achieve the above object by including a yawing correction means that excites one coil.

(Function) By providing such means, when the yawing of the table is detected by the yawing detection means, at least one coil among the plurality of electromagnetic coils arranged along the table feeding direction is detected by the yawing detection means. The correction means excites the magnet according to the yawing direction and its amount. This excitation causes an electromagnetic force to act between the electromagnetic coil and the magnetized body provided on the side surface of the table, suppressing yawing.

Further, by providing the above means, when the yawing of the table is detected by the yawing detection means, at least one coil among the electromagnetic coils provided on the table is adjusted according to the yawing direction and amount by the yawing correction means. It is excited by This excitation causes an electromagnetic force to act between the electromagnetic coil and the longitudinal magnetic body arranged along the feeding direction of the table, thereby suppressing yawing.

(Example) Hereinafter, a first example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a table feed control device applied to an exposure apparatus with a reflection projection optical system. A mask and a wafer are mounted on the transfer table 10 in mutually positioned positions. This feeding table 10 is fed linearly in the direction of arrow (b) by a feeding mechanism (not shown). Further, a plane mirror 11 is provided on the side surface of the feeding table 10 perpendicular to the feeding direction. ．． 12 are provided. These plane mirrors], 1. , 12 are feeding tables provided at both ends of the side surfaces of the feeding table ]0. Further, a permanent magnet 13 is provided on a side surface of the feeding table 10 parallel to the feeding direction. This permanent magnet 13 is formed into a plate shape,
It is provided on the entire side surface of the feed table 10.

On the other hand, a position detector 14.15 is arranged at each position facing each plane mirror 11.12. Both of these position detectors 14 and 15 are connected to the feed table 10 in a non-contact manner.
For example, a laser length measuring device is used to measure the distance to.

Further, an electromagnet coil array 16 is arranged along the feeding direction of the feeding table 10 and at a position facing the permanent magnets 13. This electromagnet coil array 16 has a configuration in which a plurality of electromagnet coils 16-1, 16-2[deg.]-6-n are arranged.

Further, the feed control device 17 has the following functions in addition to the function of driving and controlling the feed mechanism. That is, each position detector 1
4. The feed table 10 receives the position detection signal from 15.
A yawing detection function that determines the yawing direction and amount thereof, and each electromagnet coil 16-1 to
It has a yawing correction function that excites electromagnetic coils corresponding to the surfaces of the position detectors 14 and 16n on the side of each position detector 14 and 15. In this case, if the feed table 10 is tilted in the direction of the arrow (c), the yawing correction function is activated in the flow direction that the electromagnetic coils 16-1 to 16-n and the permanent magnet 13 attract and that is proportional to the amount of yawing. A value, that is, a current of a value necessary to make the position difference of each plane mirror 11. If so, a current is required in the flow direction in which the electromagnetic coils 16-1 to 16-n and the permanent magnet 13 repel each other and whose value is proportional to the amount of yawing, that is, to make the position difference between each plane mirror 11 and 12 zero. A current of a certain value is supplied to the electromagnetic coils 6-1 to 16-n.

Next, the operation of the apparatus configured as described above will be explained.

When the feed mechanism is driven under the control of the feed control device 17, the feed table 10 is fed in the direction of the arrow (b). In this state, each position detector 14, 15 outputs a laser beam. These laser beams reach each plane mirror 11.12, are reflected, and enter each position detector 14.15 again. These position detectors 14 and 15 generate interference fringes between the output laser light and the incident reflected laser light, and output position detection signals each having a voltage level corresponding to the light intensity of the interference fringes. These position detection signals are sent to the feed control device 17.

The feed control device 17 determines each position of each plane mirror 11, 12 of the feed table 10 from each position detection signal, and determines the yawing direction and amount of the feed table 10 from the difference between these positions.

Next, the feed control device 17 determines the electromagnet coil 16-k corresponding to the position of the plane mirror 12 detected by the position detector 15 as shown in FIG.
6-k in a current direction corresponding to the yawing direction and a current value proportional to the yawing amount, that is, each plane mirror 11.1
It is excited by supplying a current of a value necessary to make the position difference between the two points zero. In this case, as shown in FIG.
is tilted in the direction of arrow (d), so electromagnet coil 1
6-k is supplied with a current having a current value proportional to the yawing inclination in the flow direction repelling the permanent magnet 13. Thus, the yawing of the feed table]0 is suppressed.

In this way, in the first embodiment, the feed table 1
0's yawing direction and its amount are determined, and one coil among the plurality of electromagnetic coil arrays 16 arranged along the feeding direction of the feeding table 10 is energized according to the yaw direction and its amount. Yawing of the feed table 10 can be suppressed with good response due to the electromagnetic force.

Moreover, by reducing the size of each of the electromagnetic coils 16-1 to 16-n, yawing can be corrected in minute sections, and the positioning state of the mask and wafer can be maintained with high precision. Furthermore, even if the feed table 10 is fed at high speed, yawing of the feed table 10 can be suppressed with good responsiveness.

Therefore, if applied to an exposure device, accurate pattern transfer can be performed without causing yawing.

In the first embodiment, one electromagnet coil is excited, but as shown in FIG.
−j may be excited. In this case, for example, if the feed table [0] is tilted in the direction of arrow (d), the electromagnetic coils 16-i to 16-j will have a flow direction that is repulsive to the permanent magnet 13, and the electromagnetic coil 16 -j～]6-J
Current is supplied with decreasing current value in the order of .

By performing such excitation, the responsiveness to yawing suppression of the feed table 10 can be further improved.

Next, a second embodiment of the present invention will be described with reference to a block diagram of a table feed control device shown in FIG. Note that the same parts as those in the present invention are given the same reference numerals, and detailed explanation thereof will be omitted.

The feed table 20 runs on rails 21.22. Electromagnetic coils 23 and 24 are provided on one side of the feed table 20 parallel to the feed direction (e).

These electromagnetic coils 23 and 24 are installed at each end of the side surface of the feed table 20.

2. Further, a long and rigid magnetic body, for example, an iron plate 25, is arranged at a position facing each electromagnetic coil 23, 24 and along the feeding direction (E) of the feeding table 20.

On the other hand, the feed control device 26 has the following function in addition to the function of driving and controlling the feed mechanism of the feed table 20. That is, a yawing detection function receives position detection signals from each position detector 1.4.15 and determines the yawing direction and amount of the feed table 20, and a yawing detection function detects the yawing direction and amount determined by this yawing detection function. It has a yawing correction function of exciting one of the electromagnetic coils 23 and 24 among the electromagnetic coils 23 and 24. In this case, if the feed table 20 is tilted in the direction of the arrow (c), the yawing correction function controls the electromagnetic coil 23 to a current value proportional to the amount of yawing, that is, the position difference between the plane mirrors 1.1' and 12 is zeroed out. It has a function of exciting the electromagnetic coil 24 with a current of a value necessary for the yawing amount, and, if the feed table 10 is tilted in the direction of arrow (d), exciting the electromagnet coil 24 with a current of a value proportional to the amount of yawing. .

Next, the operation of the apparatus configured as described above will be explained. When the feed mechanism is driven under the control of the feed control device 26, the feed table 20 is fed in the direction of the arrow (E). In this state, each of the position detectors 4 and 15 outputs a laser beam and outputs a position detection signal for each plane mirror 11 and 12 in the same manner as described above. These position detection signals are sent to the feed control device 26.

The feed control device 26 determines the positions of the plane mirrors 11, 12 on the feed table 20 from each position detection signal, and determines the yawing direction and amount of the feed table 20 from the difference between these positions. Next, feed control device 2
6, if the feed table 20 is tilted in the direction of arrow (c), the electromagnet coil 23 is excited with a current value proportional to the amount of yawing, and if the feed table 20 is tilted in the direction of arrow (d), the electromagnet coil 23 is excited. The coil 24 is excited with a current value proportional to the amount of yawing. In this way, yawing of the feed table 20 is suppressed.

4 In this manner, in the second embodiment described in Section 1, the yawing of the feed table 20 is detected, and at least one of the electromagnetic coils 23 and 24 provided on the feed table 20 is activated depending on the direction and amount of yawing. Since the yaw is suppressed by the electromagnetic force between the feed table 20 and the iron plate 25 disposed along the feed direction by exciting the feed table 20, the same effects as in the first embodiment can be achieved.

Note that the present invention is not limited to the above embodiments, and may be modified without departing from the spirit thereof. For example, although the yawing of the feed table is detected by a laser length measuring device, it may also be detected by using a linear encoder, especially any device that can detect the position of each end of the feed table. Furthermore, the electromagnetic coil array and the iron plate may be arranged on both sides of the feed table, in which case permanent magnets or electromagnetic coils are provided on both sides of the feed table.

[Effects of the Invention] As detailed above, according to the present invention, it is possible to provide a table feeding control device that can reliably suppress yawing even if yawing occurs during feeding.

[Brief explanation of drawings]

1 to 3 are diagrams for explaining a first embodiment of a table feed control device according to the present invention, in which FIG. 1 is a configuration diagram, FIG. 2 is a schematic diagram showing a yawing suppressing effect, FIG. 3 is a diagram showing another excitation method, FIG. 4 is a configuration diagram showing a second embodiment of the apparatus of the present invention, and FIG. 5 is a configuration diagram of an exposure apparatus. 10.20...Feeding table, 11. ．． 12 - Plane mirror 13... Permanent magnet, 14, 1.5... Position detector, 16... Coil array for electromagnet, 17.26...
・Feed control device, 23.24... Electromagnetic coil, 2
5... Iron plate.

Claims (2)

[Claims] (1) In a table feed control device for a table fed in a linear direction, a yawing detection means for detecting yawing of the table, a magnetized body provided on a side surface of the table, and a magnetized body provided on a side surface of the table, and A plurality of electromagnetic coils arranged along the feeding direction, and a yawing correction means for exciting at least one of the electromagnetic coils according to the yawing direction and amount detected by the yawing detection means. A table feed control device characterized by: (2) A table feeding control device for a table fed in a linear direction, including yawing detection means for detecting yawing of the table, and electromagnets provided at respective positions in the front and rear of the table with respect to the feeding direction. a longitudinal magnetic body facing the electromagnetic coils and arranged along the feeding direction of the table; A table feed control device comprising: yawing correction means for exciting at least one of the coils.