JPH0338714Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention relates to a compound moving table device that is movable within a plane including at least the Z axis, and in particular prevents deterioration of parallelism when moving the moving table. This allows positioning to be performed with high precision.

[Conventional technology]

2. Description of the Related Art In the manufacturing process of semiconductor integrated circuits, an exposure apparatus is used to expose and print a circuit pattern on a wafer coated with photoresist. With the increase in the degree of integration of semiconductor integrated circuits, exposure apparatuses are required to have highly accurate positioning on the order of 0.1 micron.

It is difficult to perform such highly accurate positioning with a conventionally known moving table device in which the moving table is simply moved by a feed screw. For this purpose, a table moved by a feed screw is used as a coarse movement table, a fine movement table supported so as to be able to move minutely is provided on the coarse movement table, and the absolute position of this fine movement table is measured with a laser measuring device. , correct the movement error of the coarse movement table by slightly displacing the fine movement table,
It has been proposed to perform precise positioning.

As the exposure apparatus, a reduction projection type exposure apparatus is generally employed. This reduction projection type exposure equipment is a so-called step-and-repeat type that prints small integrated circuit patterns onto the wafer one by one, so it is necessary to maintain the parallelism of the light-receiving surface of the wafer with high precision. Therefore, the parallelism of the top surface of the table on which the wafer is placed must also be maintained with high precision.

As a conventional compound moving table device, there is one described, for example, in Japanese Utility Model Application Publication No. 58-196834.

In this conventional example, Z shown in FIG.
A method in which the axis table is provided on the uppermost stage side and a method in which the Z-axis table shown in FIG. 3 is provided in the lowermost stage are disclosed. Both use an inclined feeding method that uses an inclined surface to move the table in the Z-axis direction, and are configured to move in the Z-axis direction by moving the Z slider in the horizontal direction. .

[Problem that the invention attempts to solve]

However, in the conventional method shown in FIG. 2, the Z slider is placed on the top surface of the XY slider, so the weight of the Z slider is
The inertial mass applied to the slider increases when the Y slider operates, making it impossible to increase the operating speed.Furthermore, the load on the XY slider support is large, so the strength of the XY slider must be increased. There is a problem that the slider becomes large and heavy, making it impossible to make it smaller and lighter.Furthermore, the support section of the XY slider is independent, and it is necessary to make the XY movement plane and the top surface of the Z slider parallel. There is a problem in that Z-direction errors are likely to occur due to the operation of the slider, and that it cannot be applied to exposure apparatuses that require strict parallelism.

Furthermore, in the method shown in Figure 3, the XY slider is placed on top of the Z slider, so the Z slider does not take any part in the operation of the XY slider.
Moreover, when applied to an exposure device, when operating the Z slider, it is for focus adjustment, and the frequency of operation in the Z direction is not very high.
Even if the XY slider is mounted on the slider, it has the advantage of being able to eliminate the influence of inertia.
Since it is necessary to process the Z slider into a tapered shape, the problem still remains that it is difficult to strictly maintain parallelism.

Furthermore, the methods shown in FIGS. 2 and 3 above both move the Z slider in the horizontal direction to perform movement in the Z axis direction. Since the moving table is in surface contact with the inclined surface, the sliding friction resistance is large and a large amount of power is required to move the Z slider (especially in the method shown in Figure 3, when the XY slider is placed ), and the movement of the Z slider that acts on the table placed on the Z slider increases the force in the direction of movement, making it necessary to increase the supporting force of the table. Another problem is that stick slips are likely to occur. For this reason, it is possible to interpose a rolling element with a cage between the inclined guide surface of the Z slider and the table that is in contact with it, but since the surface on which the rolling element with a cage is interposed is an inclined surface, it is difficult to use it. If the holder is displaced below the inclined surface during the process, and the holder comes into contact with the fixed part and becomes immovable, a new problem arises in that smooth operation of the table cannot be guaranteed. In this case, although the amount of downward displacement of the retainer caused by the movement of the Z slider is small, it accumulates, and after long-term use, it comes into contact with the fixed part and becomes immovable. In order to solve this problem, a force may be applied to restrict the movement of the retainer, but this is not preferable from the standpoint of ensuring precise operation of the Z slider.

Therefore, this invention was devised by focusing on the problems of the conventional example, and when a rolling element with a cage is interposed between the top surface of the Z-axis slider and the horizontal movement table, It is an object of the present invention to provide a composite moving table device that can prevent misalignment and maintain parallelism with high accuracy.

[Means for Solving the Problems] In order to achieve the above object, this invention provides a compound movable table device movable in a plane including at least the Z axis, a base having an inclined guide portion, and a base having an inclined guide portion; A slope slider that is movable while being guided by a guide part and has a horizontal upper surface, a drive mechanism that drives the slope slider forward and backward along the slope guide part, and a rolling element with a cage on the horizontal upper surface of the slope slider. It is characterized in that it includes a horizontally movable moving table placed therebetween.

[Effect]

In this invention, by using the drive mechanism to move the slope slider having a horizontal upper surface along the slope guide part of the base, the slope slider and the slope slider placed on it are moved regardless of the movement of the slope slider. The distance between the movable table and the movable table can be maintained in a horizontal state, and the rolling element with a retainer interposed therebetween can be prevented from shifting. In addition, by ensuring the linearity of the inclined guide surface of the base and the parallelism of the horizontal upper surface of the inclined slider, the upper and lower surfaces of the movable table placed on the inclined slider via the rolling element with cage are If the surfaces are parallel, it is possible to ensure the parallelism of the top surface of the moving table without being affected by the movement of the slope slider.In this case, since the top and bottom surfaces of the moving table are parallel surfaces, precision machining is easy, and the overall accuracy can be improved.

〔Example〕

Hereinafter, embodiments of this invention will be described based on the drawings.

First, a reduction projection exposure apparatus to which this invention can be applied will be explained with reference to FIG.

In the figure, 101 is a reduction projection exposure apparatus, which includes a stage 103 on which a wafer 102 is placed, and a reduction lens 104 fixedly arranged opposite to the upper surface of the stage 103.
, a reticle mounting table 106 on which the reticle 105 is placed, and a light source section 107 arranged above the reticle mounting table 106 .
The circuit pattern formed on the reticle 105 is projected onto the wafer 102 in a reduced size.

The XYZ stage 103 is configured to be movable in three axes (X, Y, and Z axes), and performs focus adjustment by moving in the Z-axis direction.

At the lower end of the cylindrical body 108 that holds the reduction lens 104 facing the wafer, there is formed a through hole 109 through which the exposure light beam passes, and four air blowing nozzles 110 are formed around the through hole 109 at equal angular intervals. Each nozzle 110 has an aperture 112 connected to a common air supply 111.
and is connected to one input side of a common differential pressure converter 113. The other input side of the differential pressure converter 113 is connected to the air supply source 111 via a throttle 114 and communicated with the standby. These nozzles 11
0, an air supply source 111, apertures 112, 114, and a differential pressure converter 113 constitute an air micrometer 115.

Then, the detection signal of the differential pressure converter 113 is supplied to the focus adjustment control device 116, and this control device 11
At step 6, the target value setter 116a compares the target value with a predetermined target value and supplies the error signal, which is the difference value, to the drive circuit 116b composed of an amplifier or the like.
This forms an excitation current that operates an actuator such as a motor, which is then transferred to the XYZ stage 1.
13 to drive the Z-axis drive mechanism, and adjust the distance between the nozzle 110 and the wafer 102 to an appropriate value.

A specific example of the XYZ stage 103 is constructed as shown in FIGS. 2 to 8.

That is, in FIG. 2, reference numeral 1 denotes a coarse movement table as a base, which is configured to be movable within a horizontal plane by an XY drive mechanism (not shown).

A guide stand 2 is attached to the center of the coarse movement table 1, as shown in FIGS. 3, 4, and 5. This guide stand 2 has a wide recess 3 on the upper surface side that slopes forward and downward, and is formed in a U-shape in cross section, and the opposing inner surface forming the recess 3 has a wide recess 3 that slopes forward and downward as an inclined guide section. Slanted guide grooves 4a and 4b are formed.

Then, a slope slider 5 is placed in the recess 3 of the guide table 2.
are arranged so as to be slidable along the inclined guide grooves 4a and 4b. This slope slider 5 has a lower surface 5
a is an inclined surface parallel to the recess 3, and the upper surface 5b
is formed into a trapezoidal shape on a horizontal surface, and inclined guide grooves 6a, 6b are formed on the side faces opposite to the inclined guide grooves 4a, 4b, and these guide grooves 6a, 6b
A cross roller 7 with a cage is interposed between the roller and the inclined guide grooves 4a and 4b. As shown in an enlarged view in FIG. 5, this cross roller 7 includes a number of cylindrical rollers 7a held in a retainer 7b with their rotational axes alternated by 90 degrees in the direction of their extension.
These rollers 7a are connected to the inclined guide grooves 4a, 4b and 6.
It alternately contacts the opposing surfaces of a and 6b. In this case, since a preload is applied to the cross roller 7, cage displacement hardly occurs, but if necessary to reduce cage displacement, use spring force at both ends of the cage 7b to prevent cage displacement. A means may be provided. In this way, even if the retainer displacement prevention means is provided, the guide table 2 and the inclined slider 5
The sliding resistance between the two does not affect the movement of the slope slider 5. In other words, if the sliding resistance between the guide platform 2 and the slope slider 5 is approximately constant, the absolute value of the sliding resistance can be adjusted by adjusting the output of the DC motor 9, which will be described later. It can be absorbed by. Here, a cross roller guide CG is formed by the inclined guide grooves 4a, 4b and 6a, 6b and the cross roller 7 with a cage.

A ball nut 8 is fixed to the rear end surface of the slope slider 5, and a ball screw 11 connected to the rotating shaft of a DC motor 9 constituting a drive mechanism is screwed into the ball nut 8 to rotate the DC motor 9. , are moved in the direction of extension of the inclined guide grooves 4a, 4b.

A movable table 14 is mounted on the horizontal upper surface 5b of the slope slider 5 via a rolling element 13 with a retainer so as to be movable within a horizontal plane. Here, the rolling element 13 with a cage is composed of a large number of highly precisely finished balls 13a and a cage 13b that holds the balls 13a. In addition, 13c is the rolling element 13 with cage.
This is a guide that prevents the device from being pulled out.

On the other hand, on the coarse movement table 1, support stands 16a and 16b are fixed to the left and right sides of the U-shaped part 15a and support stands 16a and 16b extending in the front and back direction from the lower ends of both sides of the U-shaped part 15a, respectively. A movable table 17 movable in the XY-axis directions is supported so as to be movable in the XY-directions via silicone grease as a damping agent.

As shown in FIGS. 5 and 7, the movable table 17 includes a square portion 17a, a supporting portion 17c extending outward by forming step portions 17b from the left and right sides of the square portion 17a,
17d are integrally constructed, and a substantially square through hole 17e is formed in the center of the square portion 17a, and the support portions 17c,
Rectangular through holes 17f and 17g are formed in the holes 17d, respectively, and as shown in FIG. The movable table 14 is inserted into the through hole 17e. A leaf spring 20 is bridged between the upper surface of the movable table 17 and the upper surface of the movable table 14 as shown in FIG. This leaf spring 20
is formed into a substantially trapezoidal shape, and is divided into both side parts 20b and a central part 20c by forming parallel slits 20a at symmetrical positions across the center line at the base thereof,
The center portion 20c is fixed to the movable table 14, and the side portions 20b are fixed to the movable table 17 with screws, respectively, to urge the movable table 14 downward.

Further, U-shaped support stands 21a and 21b are fixed to the ends of the coarse movement table 1 in the front-rear direction, respectively.
Leaf springs 22 are attached to the legs of these support stands 21a and 21b.
U-shaped block 2 that can be moved in the X direction via
3a and 23b are connected. Support portions 24f and 24r on both sides of these blocks 23a and 23b
is extended upward to the vicinity of the stepped portion 17b of the movable table 17, and is connected to the front end side of the strut portion 24f, the rear end side of the strut portion 24r, and the square 1 of the movable table 17.
7a are connected by a leaf spring 25.

Electromagnets 26a each having an excitation coil wound around a U-shaped core are mounted on the support stands 21a and 21b, respectively.
26b is arranged, and these electromagnets 26a, 26b
both ends of which face the magnetic plates 27a, 27b fixed to the front and rear edges of the moving table 17 with a predetermined distance therebetween, and support stands 16a, 1 of the coarse moving table 1.
Electromagnets 28a and 28b each having an excitation coil wound around a similar U-shaped core are arranged below 6b, and both ends of these electromagnets 28a and 28b are connected to blocks 23a and 23b.
Magnetic plates 29a, 29 fixed to the center of 23b
b and are opposed to each other with a predetermined distance therebetween. Therefore, by adjusting the amount of excitation current supplied to the excitation coils of the electromagnets 28a and 28b, the block 2
3a and 23b are slightly moved in the X direction against the leaf spring 22, thereby causing the movable table 17 to be slightly moved in the X direction via the leaf spring 25. In addition, the electromagnet 26
By adjusting the amount of excitation current applied to the excitation coils a and 26b, the movable table 17 is slightly moved in the Y direction against the leaf spring 25.

Further, a wide chuck mounting plate 30 is fixed to the upper surface of the moving table 17, and a disc-shaped jig chuck 31 is fixed onto this chuck mounting plate 30. This jig chuck 31 has fan-shaped recesses 32 formed at predetermined intervals on the upper surface, and
A positioning pin 33 is implanted, and a positioning annular frame 34 is fixed to the outer periphery of the frame. The air passage 34 has an open air passage 34 and an air passage 35 formed in a U-shape surrounding the air passage 34.
5 are communicated with each of the recesses 32. and,
A chuck 37 on which a wafer or reticle is placed is placed on the jig chuck 31. This chuck 37 is vacuum-adsorbed to the jig chuck 31, and has an air passage 38 extending upward from the center of the lower surface, and an air passage 39 extending outward from its upper end at a 90 degree interval. Suction ports are opened at predetermined intervals between the air passage 39 and the top surface.

Further, an L-shaped reflecting mirror 41 is fixed to the outer peripheral edge of the chuck mounting plate 30, as shown in FIG. This reflecting mirror 41 reflects laser beams from X- and Y-axis laser length measuring devices (not shown), and these laser length measuring devices accurately detect the position of the fine movement table, and based on this, the electromagnet The chuck 37 is positioned by controlling the amount of current supplied to the chucks 26a, 26b, 28a, and 28b.

In FIGS. 4 to 6, 42 is a photodetecting element for detecting unevenness in the amount of light from the exposure light source, and is attached to an L-shaped support member 43 fixed to the support part 17c of the moving table 17. By sequentially moving the coarse movement table 1 and measuring the amount of light at a plurality of locations, pattern recognition is performed based on the measured positions and the amount of light, and the exposure light source is aligned.
Further, in FIG. 4, 44 is a temperature detector which measures the temperature at the chuck 37 position and controls an air conditioner (not shown) to maintain the temperature at the chuck 37 position at a predetermined value based on the measured value. . Furthermore, in FIG. 4, 45 is a detector that uses magnetism to detect three points, the control origin (neutral position) and its upper and lower limit positions in the Z-axis direction, and its magnetic body 45a is attached to the chuck mounting plate. 30, a detection section 45b is attached to the support base 21a, and the origin is set by supplying a detection signal output from the detection section 45b to the drive circuit 116b of the focus adjustment control device 116.

Next, the operation of the above embodiment will be explained. First, a wafer or reticle is placed on the chuck 37 and held by suction. Next, focus adjustment is performed. In this focus adjustment, pressurized air is supplied from the air supply source 111 to the nozzle 110 through the aperture 112 to activate the air micrometer 115, and in this state, the focus adjustment control device 116 is activated.

When the focus adjustment control device 116 is activated in this way, an error is generated due to the difference between the focus adjustment target value preset by the target value setter 116a and the differential pressure detection signal output from the differential pressure converter 113. A signal is provided to the drive circuit 116b, which drives the drive circuit 116b.
The excitation current output from b is output to the DC motor 9 that constitutes the Z-axis drive mechanism. Therefore, when the differential pressure detection signal is smaller than the target value, the distance between the nozzle 110 and the wafer 102 is wider than the reference value, so for example, the DC motor 9 is reversed. When the DC motor 9 reverses in this manner, its rotational force is transmitted to the slope slider 5 via the reducer 10 and the pole screw 11, so that the slope slider 5 is guided by the cross roller guide 7 and retreats. , With this retreat, the slope slider 5 itself moves upward. At this time, the slope slider 5 moves while keeping its upper surface 5b in a horizontal plane, so that the rolling elements 13 with cages disposed on the upper surface 5b are not displaced, and the slope slider 5 can be smoothly retreated. can be ensured. Furthermore, by ensuring the linear movement of the slope slider 5 by the cross roller guide 7 in this state, there is no distortion in the parallelism of the upper surface of the slope slider 5. can be manufactured with high precision, and the moving table 14, chuck mounting plate 30, jig chuck 31, and chuck 37 can also be precisely finished in parallel with their upper and lower surfaces. Also, it is possible to prevent the parallelism of the upper surface of the chuck 37 on which the wafer 102 is placed from becoming distorted.

Then, as the upper surface 5b of the slope slider 5 moves upward, the moving table 14 placed thereon via the cage-equipped rolling element 13 moves upward, and the moving table 14 is placed on this moving table 14. Chuck mounting plate 30, jig chuck 31 and chuck 3
7 also rises, so the wafer 102 and nozzle 110
When the distance between the two points narrows and matches the reference value, the ascent is stopped and the focus adjustment is completed. Conversely, when the value of the differential pressure detection signal is larger than the target value, the control device 116 outputs an excitation current that drives the DC motor 9 in normal rotation, causing the DC motor 9 to rotate in the normal direction and advance the slope slider 5. Moving table 14, chuck mounting plate 30, jig chuck 31 and chuck 3
7 is lowered to widen the distance between the wafer 102 and the nozzle 110, and when it reaches the reference position, the lowering is stopped and focus adjustment is completed.

After completing this focus adjustment, the wafer 102
In order to adjust the position of the wafer 102, if the moving distance of the wafer 102 is large, the coarse movement table 1 is moved at high speed by a drive mechanism to near the target position.
Next, the electromagnets 26a, 26b and/or the excitation coils of the electromagnets 28a, 28b of the fine movement table are energized to move the moving table 17 slightly in the XY directions, and the absolute value of this fine movement is accurately measured using a laser length measuring device (not shown). Based on this detected value, the electromagnet 2 vibrates in the horizontal plane.A vibration damping section 19 is formed on the movable table 17, and the damping surface 18 is connected to the support base 16a through high viscosity silicone grease. ,16b
Since it is supported on the upper surface of the holder, a large vibration damping effect can be obtained.

Furthermore, when adjusting the mounting position of the mercury lamp when replacing the mercury lamp, etc. of the light source section 107, first mount the mercury lamp in a predetermined position, turn it on in this state, and direct the exposure light to the top surface of the stage 103. Irradiate on top. In this exposure light irradiation state, the coarse movement table 1 is moved by the drive mechanism, the light amount detectors 42 at multiple locations are moved within the exposure light irradiation range, and the light amount detection output of the light amount detectors 42 at each position is By supplying the mercury lamp to a processing device (not shown), the light amount distribution of the exposure light beam is detected, and this is displayed on a display device, for example, in a different color for each light amount, and the mounting position of the mercury lamp is adjusted according to this display. , the mounting accuracy of mercury lamps can be improved.

Note that in the above embodiment, the slope slider 5
Although the explanation has been made on the case where the guide table 2 on the coarse movement table 1 is supported via the cross roller guide CG, the present invention is not limited to this. may be brought into surface contact.

Furthermore, the drive mechanism for the slope slider 5 is not limited to the above embodiment, and a pulse motor can be used instead of the DC motor, and a speed reducer can also be installed as necessary. , various drive mechanisms such as a feed screw method, a cam drive method, etc. can be applied.

Further, in the above embodiment, the case where the movable table 14 placed on the slope slider 5 moves in the X and Y directions has been described, but this invention can also be applied to the case where the movable table 14 placed on the slope slider 5 moves only in the X direction or the Y direction. In this case, not only balls but also rollers can be used as the cage-equipped rolling elements 13.

Furthermore, in the above embodiment, the case where this invention is applied to a reduction projection exposure apparatus has been described, but it is not limited to this, and may be applied to any XYZ table such as the XYZ table of other machine tools. Of course.

[Effect of idea]

As explained above, according to this invention, a slope slider having a horizontal upper surface is arranged movably along the slope guide part by a drive mechanism on a base having a slope guide part. Since the configuration has a moving table that can be moved in a horizontal plane via rolling elements with a cage on the top surface, the load when moving the moving table by the rolling elements with a cage is significantly reduced, and it is easy to hold the table. Since the rolling element is interposed between the horizontal upper surface of the slope slider and the movable table, it does not cause positional deviation even when the movable table or the slope slider moves, and ensures smooth movement of both. In addition, it is possible to prevent variations in parallelism due to movement of the slope slider or moving table,
Effects such as being able to provide a highly accurate moving table device can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram showing an example of a reduction projection exposure apparatus to which this invention can be applied, Fig. 2 is a schematic perspective view showing an embodiment of this invention, Fig. 3 is an exploded perspective view of Fig. 2, Fig. 4 is a plan view of the stage, Fig. 5 is a sectional view taken along the - line of Fig. 4, Fig. 6 is a sectional view taken along the - line of Fig. 4, and Fig. 7 is a sectional view taken along the - line of Fig. 5. 8 are plan views of a jig chuck applicable to this invention. In the figure, 1 is a coarse movement table (base), 2 is a guide table,
5 is a slope slider, 7 is a cross roller guide, 9
1 is a DC motor, 10 is a speed reducer, 11 is a ball screw, 13 is a rolling element with a cage, 14, 17 are moving tables, 19 is a vibration damper, 20, 22, 25 are leaf springs, 26a, 26b, 28a, 28b is an electromagnet,
31 is a jig chuck, 37 is a wafer chuck, 1
01 is a reduction projection exposure apparatus, 102 is a wafer, 10
3 is a stage, 104 is a reduction lens, 107 is a light source, 115 is an air micrometer, and 116 is a focus adjustment control device.

Claims (1)

[Claims for Utility Model Registration] 1. A compound movable table device movable within a plane including at least the Z-axis, comprising: a base having an inclined guide portion; a drive mechanism for driving the slope slider forward and backward along the slope guide portion; and a horizontally movable moving table placed on the horizontal upper surface of the slope slider via a rolling element with a retainer. A composite moving table device comprising: 2. By controlling the amount of current applied to the excitation coils of the composite moving tables 6a, 26b and/or the electromagnets 28a, 28b as set forth in claim 1, wherein the inclined guide portion is constituted by a cross roller guide. , it is possible to perform positioning on the submicron order. In this way, XY
By adopting an electromagnet as the drive mechanism for fine movement in the axial direction, vibrations are not generated unlike when using a motor, and when moving the moving tables 14 and 17 in the XY direction, It is possible to prevent the positional shift of the Also,
When the coarse movement table 1 is moved at high speed by the drive mechanism, the moving tables 14, 17, the chuck mounting plate 30, the jig chuck 31, and the chuck 3
Due to the inertia of 7th grade, these are devices.