JPS5939027A - Precision xy stage - Google Patents

Abstract

PURPOSE:To execute step-feed at high speed with high accuracy by disposing a chromatotrunnion system self-centering mechanism with a ball ring to a feed screw constituting a feed-unit. CONSTITUTION:A rotary motion of a motor 13 is converted into a rectilineal motion by the feed screw 14 and a feed nut 20 through a shaft coupling 18, and a movable piece 15 is fed rectilinearly by connecting the nut 20 and the movable piece 15 through the duble trunnion self-aligning mechanism. A pair of pins 28 are formed in the V-V' direction of an intermediate seat 27 combined so as to be unified with the nut 20 in the mechanism, and the mechanism connects an internal holder 30 through the ball ring 29. The holder 30 has a pair of the pins 28 in the H-H' direction, and is connected to an external holder 31 through the ball ring 29. Even when the direction of rotation of the feed screw 14 has a slight displacement to the direction of guidance of a guide, the mutual functional interference of both the guide and the feed screw can be inhibited.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an XY stage that performs highly accurate step feeding, and particularly to a precision XY stage suitable for high-speed movement and highly accurate positioning.

For example, a reduction projection exposure apparatus, which is a part of semiconductor manufacturing equipment, has an optical system consisting of a light source 1 and a lens 2, as shown in FIG. It is something that is projected onto the surface and burned into it.
X to perform step feeding for each pattern of wafer 4
Y stage 5 is used.

For example, this XY stage 5 performs step feeding every 10 steps in a time of the order of Q, 18 ec, and requires a stopping accuracy of the order of 0.11 to 0.019 m and a guiding accuracy of the order of 10-frad.

The XY stage consists of a combination of a linear motion feed structure and a guide structure. Although not particularly shown, for example, in the linear motion feed structure, there are various feed screw methods, pinion & two screw methods, traction bar type, and linear motor. Various types of guide systems have been used in the past, such as the bef guide system, roller p guide system, static pressure guide system, suction-repulsion floating guide system, etc., which have various shapes. Among these, the configuration of an XY stage using a feed screw system related to the present invention is shown in FIGS. 2 to 6.

A first configuration example is shown in the plan view of FIG. 2 to the front view of FIG. 3.

In the configuration shown in Figures 2 and 3, the XY
A stage unit 7 is provided, which is driven and positioned by XY drive units 8.

The stage unit 7 has a lower stage 10 mounted on a stage base 9, and an upper stage 1 mounted on the lower stage 10.
1 is mounted, and a roller hook 12 is provided on each stage, which is connected to a drive unit 8.

The drive unit 8 transfers the rotation of the motor 13 to the feed screw 14.
The arm 16 is configured to convert the movable element 15 into linear motion by
The stage unit 7 is operated by connecting the roller hook 12 with a connector 17 fixed to the roller hook 12. The drive unit 8 is fixed to the ped 6 9, and the structural point is that as the lower stage 10 moves, the roller hook 12 on the upper stage 11 side moves laterally while engaging with the connector 17.

In the first configuration example shown in FIGS. 2 and 3, since the drive system and the guide system are separated, the structure of the stage unit 7 is simplified and a highly accurate guide surface can be easily obtained. Although it has the advantage of reducing disturbance factors such as vibration and heat of the motor 13, it occupies a large area on the bed 6.

On the other hand, as a configuration for reducing the area occupied on the bed 6, a second configuration example is shown in the plan view of FIG. 4 through the side view of FIG. 5 and the front view of FIG. 6.

In the second configuration example shown in FIGS. 4 to 6, a lower stage 10 is mounted on a stage base 9, and an upper stage 11 is mounted on the lower stage base,
Feed screw 1 is installed between stage base 9 and lower stage 10.
4 is built in to feed the lower stage. The feeding of the upper stage 11 is similar to the first configuration example.
A roller hook 12 is disposed on the drive unit 8 to perform the feeding.

In other words, the d-line motion of the lower stage 10 is obtained by the rotation of the lower stage 10 drive motor 13 fixed to the stage base 9 via the rotation AJhk shaft joint 18 at fs 72 and 14. Further, on the upper stage II side, the drive unit 8 is configured to convert the rotation of the motor 13 for driving the upper stage 11 into linear motion of the mover 15 by means of the feed screw 14. Connector 17 fixed to arm 16 arranged like a book and upper stage 1
By connecting it to the roller hook 12 fixed on the first side, the upper stage 11 is moved linearly.

The present invention e relates to a detailed structure for realizing the entire basic configuration described above. Hereinafter, examples of valley structures according to the prior art are listed in FIGS. 7 to 12.
FIG. 0 shows two types of prior art related to the structure for securing the feed screw and the movable part.

In the structure example of the first prior art shown in the front view of FIG. 7 to the plan view of FIG. The rotary motion of the feed screw 140 is received by the feed nut 20 and converted into linear motion, and the arm 16, which is integrally connected to the movable element 15, provides linear motion and driving force to the object to be operated.

In this type of linear motion mechanism, it is particularly important to match the guiding direction of the guide with the direction of the center of rotation of the feed jack.

That is, the virtual center line Gp-Gp' that is involved in the pitching of the guide 19 in FIG. 7, the center FPFp' of the feed screw 14, and the yawing of the guide 19 in FIG. If the virtual center line Gy-Gy' and the center Fy-F) of the feed screw 14 are not aligned at a much lower angle than the allowable elastic deformation of the component, the load torque will fluctuate and the guiding accuracy will be affected. If a gap is provided between the guides or between the feed screws in order to avoid a phenomenon in which the amount of feed is lowered, the required guidance accuracy and feed accuracy will be reduced, so consideration must be given to these.

In addition, the guide structure of the cross roller guide 190 is used with a preload applied, but if the amount of preload is uneven due to the precision of the component parts, it may cause misalignment in the row of rollers that transfer during repeated reciprocating movements. Since there are structural problems that arise, consideration must be given to these problems.

FIGS. 9 and 10 show a second prior art series relating to a structure for securing a feed screw and a movable part.

In the second structural technology series shown in the front view of FIG. 9 to the plan view of FIG. 10, the aim is to allow all deviations between the guiding direction of the guide and the rotating direction of the feed screw.

That is, in order to prevent rotation of the feed nut 20 for converting the rotational movement of the feed screw 140 into linear movement of the feed nut 20, the roller arm 21 and The tenth
It is possible to obtain linear motion with the rotation center direction FF' of the feed screw 14 shown in the figure as the moving direction. In the prior art shown in Figures 9 to 10, the deviation between the rotation center direction FF' of the feed screw 14 and the guide direction GG' of the horizontal rail 240 is absorbed as an incorrect rotating element of the feed nut 20. As a result, uneven feeding of the mover 15 occurs, and tilting and lateral vibration of the arm 16 due to unbalance of the point of action of the operating object directly acts on the joint between the feed screw 14 and the feed nut 20. , consideration must be given to large fluctuations in load torque and shortened service life of the feed mechanism. The plan view of FIG. 11 and the front view of FIG. 12 show examples of prior art relating to the engagement structure between the stage 7Q)jJ4v-ru 24, the slider 25, and the roller 23 with J9.

In Figures 11 and 12, the stage 7 is mounted on the stage base 9, the contact surfaces formed on the left and right sides form guides Gp-Gp' in the pitching direction, and the stage base 9 is mounted with a tightening screw. The contact surface between the horizontal rail 24, which is integrally fastened at 26, and the slider 25, which is integrally connected to the stage 7, is the guide Gy- in the yawing direction.
Gy', and in order to maintain contact between the horizontal rail 24 and the slider 25, the structure is such that they are pressed together by a 23ft lawn leaf spring 22. In the prior art shown in FIGS. 11 and 12, the guides in the pitching direction and yawing direction do not interfere with each other, but in the case of fast step feeding, the contact surface of the horizontal rail 24 Since it is perpendicular to Gp-Gp' and the structure is such that the contact of the guide in the pitching direction depends on the weight of the movable part, consideration must be given to suppressing the transient phenomenon of lifting of the guide in the pitching direction when starting and stopping at high speed. Become.

An object of the present invention is to provide a precision XY stage tfE that can perform high-speed step feeding with high accuracy.

The present invention has a linear 4MJJ guide rock structure and has a cross trunnion between the feed screw and the linear motion movable part of an XY stage whose basic configuration is to convert the rotary motion of the motor into linear motion by a full-speed screw. The aim is to perform high-speed step feeding with high precision by installing a cross-trunnion type self-aligning mechanism that uses multiple contact rollers via spheres on both the inner and outer trunnions. be.

Examples of the present invention will be described below.

In the plan view shown in FIG. 13, the side view shown in FIG. 14, and the front view shown in FIG. By connecting the feeder nut 20 and the mover 15 via a double trunnion self-aligning mechanism, the mover 15 can be linearly fed.

Automatic alignment Iso, rI! t is a spacer 27 that is integrally connected to the feed nut 20, as shown in a partial cross section in FIG.
A pair of pins 28 are formed in the v/force direction, and a sphere 29 is formed.
It engages with the inner holder 30 via. Furthermore, the inner holder 30
has a pair of pins 28 in the H-H' force direction, and has a ball 3J29 (
(The spherical ring 29 engages with the outer holder 31 through the holder 31. As shown in FIG. Therefore, even if there is a slight deviation in the rotation direction of the feed screw with respect to the guiding direction of the guide, mutual functional interference between the two can be suppressed. (Automatic alignment function) In other words, the feed screw I/20 is Spacer 27 and inner holder 30
0, rotation around v-v' and movement in the v-v' force direction are smoothly performed via the ballpark 29, and furthermore, the inner holder 3
Rotation around H-H' between 0 and outer holder 31 and H
- Since the movement in the H' direction is performed smoothly via the ball ring 29, eccentricity and inclination (including curvature) are automatically compensated for, and an unbalanced load acts on the feed nut 20. It is possible to dramatically eliminate factors such as an increase in load torque and a decrease in service life, as well as a decrease in guide accuracy and feed position accuracy due to improper loading on the guide mechanism. The effective characteristic sound of this embodiment can be further exhibited by providing an appropriate amount of negative clearance (preloading) in the dimensional relationship (fitting) between the inner ring and the outer ring with respect to the ball field 29.

In the front view of FIG. 17 to the side view of FIG. 14 and the feed nut) 20 converts it into linear motion, and moves between the feed nut 2o and the stage 7 as a double trunnion! gl
l By connecting with the alignment mechanism via the connector 34,
Obtain stage 7 linear feed.

The self-aligning mechanism is partially shown in cross section in Fig. 17 and Fig. 18.
As shown in the figure showing the front shape of the connector 34, the feed nut 2
It has a pair of pins 28 in the v and -v' force directions of the spacer 27 which are integrally connected to the inner holder 3 through a spherical ring 29.
o. Furthermore fj3 Hol fi-30UH-H'
It has a pair of pins 28 in the force direction and engages with a connector 34 via a radial ball bearing 35, and the connector 34 is fixed to the stage 7. With the above configuration, even if there is a slight deviation in the guiding direction of the guide, mutual functional interference between the two can be suppressed. (Automatic alignment function) 20 (self-aligning function) 20 smoothly rotates around v-v' and moves in the v-v' force direction between the inner seat 27 and the inner holder 300 via the ballpark 29. Furthermore, between the inner holder 30 and the outer holder 31, rotation around ll-H' and movement in the H-H' force direction are smoothly performed via the radial ball bearing 35, resulting in eccentricity. The system automatically compensates for tilts (including curvature) and prevents an increase in load torque and shortened service life due to unbalanced loads acting on the feed lug (20), as well as a decrease in guide accuracy and feed position accuracy due to incorrect loads on the guide mechanism. The factors causing the decline can be dramatically eliminated. In addition, the dimensional relationship (fit) between the inner ring and the outer ring with respect to the ballpark 29 should be a suitable amount of negative clearance (preloading), and the fit between the outer ring of the radial ball bearing 35 and the connector 34 should be a blind fit. By providing a slight loose fit, the effective features of this embodiment can be further exhibited.

In the plan view of FIG. 19 to the front view of FIG. 20, the stage 7 is mounted on the stage base 9, and the contact surfaces formed on the left and right sides form a guide G in the pitching direction. The contact surface between the horizontal rail 24, which is integrally fastened to the stage base 9 with a tightening screw 26, and the slider 25, which is integrally connected to the stage 7, forms a guide 07G7' in the yawing direction, and the horizontal In order to maintain contact between the rail 24 and the slider 25, the roller 23 is pressed by a leaf spring 22, and the left and right guide surfaces of the horizontal rail 24 are formed at an inclination angle θ with respect to the vertical direction as shown in FIG. The inclination angle θ is set within 45 degrees so as to provide a horizontal guidance component and a vertical guidance component. At this time,
A filler corresponding to the horizontal rail 24 is also applied to the slider 25 and the pressing roller 23.

With the above configuration, it is possible to suppress the floating transient phenomenon at the time of high-speed start and stop.

In the plan view of FIG. 1i21 to the front view of FIG. ) 20 and the movable element 15 via a double trunnion self-aligning mechanism, the linear movement of the movable element 15 is obtained.

At this time, as a linear motion guide mechanism, four V
A letter-shaped roller follower 36 is arranged, and a pair of letter-shaped rails 3 are disposed at a position where it touches the outer ring of the letter-shaped roller 7 follower 36.
7 gold is placed. 4 more V-shaped rollers 7 oror 36
Of these, 36c and 36d are attached to the movable element 15 by elastic coupling (for example, an elastic lever portion 15ar is formed on the movable element 15). To assemble this linear motion guide mechanism, first fix the V-shaped rail 37a on the reference side with the tightening screw 26,
The V-shaped roller 7 on the reference side is brought into contact with the lowers 36a and 36b'i. Next, V-shaped roller followers 36c, 3 on the following side
The V-shaped rail 37b on the follower side is arranged via the V-shaped rail 37b, and after applying an appropriate amount of preload with the set screw 38, it is fixed with the tightening screw 26.

With the above structure and assembly, the left and right V-shaped rails 3
The V-shaped roller follower 36 rolls on the rail surfaces of 7a and 37b, and slight deviations in the distance between the left and right guides due to manufacturing precision etc.
Since 5a absorbs the energy, a smooth linear motion guide mechanism can be obtained.

In the embodiment shown in FIG. 21, the guide rigidity of the linear motion guide mechanism can be set by designing the spring constant of the elastic lever portion 15a of the movable element 15 to a required number. , to further strengthen the guide rigidity, the second
A specific embodiment of the present invention as shown in FIG. 3 will be used.

In Figure 23, the overall external configuration is shown in Figures 21 to 2.
Although it is similar to FIG. 2, the difference is in the shape of the elastic lever portion 15a that supports the V-shaped roller follower 36 and in that an adjustment screw 39 is provided.

That is, as a concrete implementation structure of the linear motion guide mechanism, four V-shaped roller followers 36 are arranged on the movable element 15, and a pair of V-shaped rails 37 are arranged at a position where they are in contact with the outer ring of the V-shaped roller followers 36. Cast. 4 more Vs
In addition to attaching 36d of the letter-shaped roller followers 36 to the movable element 15 by elastic coupling, for example, forming the elastic lever part 15a on the movable element 15, it acts to suppress the deflection displacement of the elastic lever part 15a. Adjustment screw 3 in position
Place 9. To assemble this linear motion guide mechanism, first, the V-shaped rail 37a on the reference side is fixed with the tightening screw 26, and the V-shaped roller followers 36a and 36b on the reference side are brought into contact with each other. Next, the V-shaped rail 37b on the following side is placed through the ■-shaped roller follower 36c on the following side, and the pair of V-shaped rails 37a, 3 are inserted and removed by the push screw 3B.
7b is parallelized. (If there is local load fluctuation when the three V-shaped roller followers 36a, 36b, and 36c are in contact with the rail surface, it is due to poor precision of the component parts.) After that, the three roller followers 36a to 36c
The fourth V-shaped roller follower 36d is brought into contact with the rail surface by rotating the adjustment screw 39 until it reaches the 100-wire motion load resistance during parallelization.

Therefore, according to this embodiment, the rigidity is large in the feeding direction,
Furthermore, it is possible to obtain a linear feed device that can compensate for the deviation between the linear motion guide direction and the rotation center of the feed screw.

Further, according to this embodiment, it is possible to obtain a linear feed device that can provide an appropriate amount of clearance in the feed direction and compensate for the deviation between the linear motion guide direction and the center of rotation of the feed screw.

Furthermore, according to this embodiment, a linear feed device can be obtained that can suppress the floating phenomenon of the guide surface due to high-speed step feed or the like.

Furthermore, according to this embodiment, it is possible to eliminate the phenomenon of deviation from the guide surface due to improper sliding due to protrusion of the rolling elements in rolling guides.

Although a general XY stage is used as a linear feed device in the detailed explanation of the present invention, embodiments of the present invention also include one stage, three or more stacked stages, or multi-stage stages that are not perpendicular to each other. .

As explained above, according to the present invention, high-speed step feeding can be performed with high accuracy.

[Brief explanation of drawings]

FIG. 1 is a conceptual configuration diagram showing an example of the object to which the present invention is applied, FIG. 2 is a plan view showing the first basic structure of the object of the invention, and FIG. 3 is a front view showing the first basic structure of the object of the invention. Figure 4 is a plan view showing the second basic configuration of the subject of the invention, Figure 5 is a side view of the second basic configuration of the subject of the invention, and Figure 6 is the second basic configuration of the subject of the invention.
7 is a front view showing the first prior art example, and FIG. 8 is a plan view showing the first prior art example.
FIG. 9 is a front view showing the second prior art example, FIG. 10 is a plan view showing the second prior art example, FIG. 11 is a plan view showing the third prior art example, and FIG. 12 is a top view showing the third prior art example. 13 is a plan view showing the first embodiment according to the present invention, FIG. 14 is a side view showing the first embodiment according to the present invention, and FIG. 15 is a front view showing the prior art example No. 3. A front view showing the first embodiment according to the present invention, FIG. 16 is a component diagram of the first embodiment according to the present invention,
FIG. 17 is a front view showing a second embodiment of the present invention, and FIG. 18 is a side view showing a second embodiment of the present invention.
FIG. 9 is a plan view showing the third embodiment of the present invention, and FIG.
The figure is a front view showing a third embodiment of the invention, FIG. 21 is a plan view of a fourth embodiment of the invention, and FIG. 22 is a front view of a fourth embodiment of the invention. 23 are plan views showing a fifth embodiment of the present invention. 13...Motor, 20...Feed nut, 28...
Bin, 29...Baseball stadium. No. IM Dream / M I ω' Su / 41J Author / j; fZJV

Claims (1)

[Claims] 1. At least the upper side of the XY stage, which converts the rotation of a motor into linear motion using a feed screw, is separated into a stage with a precision guide and a drive unit with a feed screw, etc., and separated from this feed unit. Precision X subjected to linear motion
A precision XY stage characterized in that the Y stage is provided with a chroma trunnion type self-aligning mechanism equipped with a ball on the feed screw constituting the feed unit. 2. In the invention as set forth in claim 1, the inner trunnion of the chromato 2-nion is constituted by a sphere that engages with the bottle, and the outer trunnion is constituted by a ball bearing that is completely attached to the pin, and the outer ring of the ball bearing is connected to the connector. A precision XY stage characterized by a structure that engages in a shape that wraps around the body.