JPH0471475B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a movement guide device, and more particularly, the present invention relates to a movement guide device, and more specifically, it moves a second member such as a sample transport stage along a trajectory set on a first member such as a support base. The present invention relates to a movement guide device for relatively moving members. The present invention provides a movement guide device suitable for a sample transport device for semiconductor wafers, etc., in a step-and-repeat reduction projection exposure apparatus that repeats high-speed and high-precision movement and stopping, especially when manufacturing semiconductor devices such as integrated circuits. It is.

[Prior Art] A reduction projection exposure apparatus used for manufacturing semiconductor devices such as LSIs regularly exposes a mask or reticle pattern on a semiconductor wafer in a grid pattern to improve positional accuracy with respect to the previously printed pattern. Of course, it is necessary to increase the speed of the step-and-repeat operation in order to improve the work efficiency. For this reason, the transport system of the wafer stage that moves the wafer within the XY two-dimensional coordinate plane is required to start and stop at high speed and to have high accuracy in stopping position.To this end, various improvements have been made to stage movement guide devices. .

In this type of transport system, generally called an XY stage, the basic method of the movement guide device is as follows:
Conventionally, the type shown in FIG. 10 has been used.

In the same figure, 101 is a top plate (slider), 1
02 is the stage surface, 103 is the bearing mounting plate, 104
105 is a static pressure bearing for guiding in the vertical and horizontal directions, which is attached to the bearing mounting plate 103, and 105 is a guide rail. As a result, the top plate 101 is guided to move smoothly along a trajectory perpendicular to the drawing. 106 is a resin semi-floating bearing for braking, 10
7 is a sliding plate that comes into sliding contact with the bearing 106, and 108 is a pressing roller unit. The pressing roller unit 108 uses its roller to support the braking bearing 106.
By sandwiching the sliding plate 104 between the brake bearing 106 and adjusting or controlling its pressing force,
The apparent coefficient of friction in the moving direction of the friction sliding portion between and the sliding plate 107 is set to a desired value or variably controlled. 109 indicates the center of gravity of the stage portion.

The stage transport system of an exposure apparatus consists of a moving table (stage) equipped with a movement guide device as shown in Fig. 10, a drive mechanism and a motion transmission mechanism, and multiple combinations of these to move at an XY right angle. It is designed to be movable in the X and Y directions of the coordinate system.

However, such a device has the following drawbacks.

As the height increases in the vertical direction, the device becomes larger.

As the height of the apparatus increases, the distance between the center of gravity 109 and the wafer surface becomes longer, and minute rotational vibrations around the center of gravity appear magnified on the wafer surface.

By flowing air through the hydrostatic bearing 104, force is applied to the bearing mounting plate 103, causing the mounting plate 103 to deform as shown in FIG. As a result, the inclination and clearance between the bearing surface and the guide are increased, the characteristics of the bearing 104 are deteriorated, and a predetermined rigidity cannot be obtained.

Dust generated by the sliding of the semi-floating bearing 106 enters the hydrostatic bearing, causing deterioration or damage to the bearing. Furthermore, dust adhering to the wafer causes printing defects.

Since the guide configuration is fully constrained, the guide 105
It is also necessary to adjust both the parallelism and perpendicularity of the hydrostatic bearing mounting plate 103, which takes time.

[Objective of the Invention] The object of the present invention is to solve the above-mentioned problems with the conventional type, to provide a structure that allows the device to be made thinner, and to further increase the rigidity of the bearing to improve posture against load and external force fluctuations. To reduce the amount of fluctuation and to minimize the deterioration of posture accuracy (progressing direction, horizontal direction, vertical direction, rolling, pitching, yawing), and at the same time to obtain effective damping force against vibrations in each posture. There is a particular thing.

[Description of Examples] Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is an external view showing the overall configuration of a movement guide device according to an embodiment of the present invention. Also, 2nd to 5th
The figure shows the configuration of each unit that makes up the device.

In Fig. 1, 1 is the top plate (slider), 2 is the hydrostatic bearing mounting unit, 3 is the guide unit, and 4 is the top plate (slider).
5 is a feeding mechanism unit, and 5 is a sliding unit.

Figure 2 shows the bearing mounting unit 2 fixed to the top plate 1.
21 is a hydrostatic bearing mounting plate for vertical support, 22 is a hydrostatic bearing mounting plate for left and right support, and 6 is a hydrostatic porous bearing.

FIG. 3 shows the arrangement of guide rails of the guide unit 3, where 31 is a vertical guide and 32 is a horizontal guide.

FIG. 4 shows the stage feed mechanism unit 4, and 41 and 43 are ball bearing housings,
42 is a ball screw, and 44 is a leaf spring for absorbing whirling of the ball screw.

Fig. 5 shows the sliding unit 5, 51 is a sliding piece fixing block, 52 is a sliding piece that is a ceramic semi-floating bearing, 53 is a preload roller unit, 54 is a ceramic sliding plate, and 55 is a sliding piece. This is a plate spring for supporting the plate 54 and absorbing its displacement.

Further, FIG. 6 is a bearing arrangement diagram showing the arrangement of vertically supporting hydrostatic bearings for preventing displacement in the vertical direction, and FIG. 7 is a sectional view of the sliding unit of FIG. 5.

Next, the operation of this embodiment will be explained with reference to FIGS. 1 to 7.

First, the top plate 1 is moved to the upper and lower guides 3 by the hydrostatic bearings 6.
It floats higher than 1. At this time, since the bearing has a three-stage structure as shown in FIG. 6, the rigidity is increased compared to the conventional example, and deterioration of bearing characteristics due to deformation of the mounting plate can be prevented as shown in FIG. 11.
Further, in the lateral direction, rigidity is provided by disposing a hydrostatic bearing 6 between the left and right supporting hydrostatic bearing mounting plate 22 and the guide 32. Note that by embedding the bearing 6 in the mounting plate 21 as shown in FIG.
The device can be made thinner. Furthermore, by using a ceramic porous bearing for the static pressure bearing 6, the rigidity can be further increased and the amount of posture fluctuation can be reduced in response to load and external force fluctuations.

The top plate 1 floated by the hydrostatic bearing 6 is driven by the drive unit 4. The drive is performed by a ball screw 42 whose both ends are supported by ball bearings. Leaf springs 44 are arranged vertically and horizontally to absorb the swinging of the ball screw, and the connection to the top plate 1 applies thrust near the center of gravity 9 to reduce vibration.

Further, in order to efficiently damp the generated vibrations, a semi-floating unit (sliding unit) 5 for generating frictional force as shown in FIGS. 5 and 7 is arranged. The sliding piece 52 of this semi-floating unit 5 is made of ceramic to prevent dust generation, and the sliding piece 52 of the semi-floating unit 5 is
Air is now being taken in through the air. The frictional force is controlled by the preload applied to the pressing roller 53 and the suction pressure applied to the sliding piece. The ceramic sliding plate 54 is supported by a leaf spring 55 in order to prevent the magnitude of the preload from changing due to deformation of the sliding plate, the straightness of the guide, etc. and the fluctuation of the frictional force.

Although only one sliding piece 52 is shown in FIG. 7, the present invention is not limited to this, and a plurality of sliding pieces 52 may be set. For example, one in the front and one in the back,
It is also possible to provide a total of two and fix them to the top plate 1, and have their sliding surfaces come into sliding contact with the guide surface on the right side of the sliding plate 54. Furthermore, the sliding piece 52 may be integrally configured with a plurality of sliding surfaces.
In any case, it is preferable to configure the plurality of sliding surfaces to slide on the guide surface.

Further, although only one pressing roller unit 53 is shown in FIG. 7, the present invention is not limited to this, and a total of two pressing roller units 53 may be provided, one at the front and one at the back of the figure. In addition, as a modified example, two sliding pieces 5
It is also possible to adopt a configuration in which only one pressing roller unit 53 is disposed at a location corresponding to an intermediate position between the two. Further, three or more pressing roller units 53 may be installed.

Furthermore, in FIG. 8, the pressing roller 53 of the sliding unit is provided with a hydrostatic bearing 56. This can prevent the generation of dust from the roller portion and the generation of frictional force in the sliding (up and down) direction of the roller.

Further, the lateral bearing structure may be as shown in FIG. 9. As shown in the figure, by making the horizontal static pressure bearing also have a two-layer structure, deformation of the mounting plate can be prevented and rigidity can be increased.

[Effects of the Invention] As explained above, according to the present invention, the upper and lower guides and the left and right guides are separated and all have a static pressure structure, the bearing structure of the upper and lower guides is a three-stage structure, and the semi-floating static pressure structure made of ceramic is used. Since it is equipped with bearings, it has the following effects.

(1) By using a static pressure guide, it is possible to prevent the generation of dust due to contact such as sliding or rolling.

(2) The height of the stage can be lowered by separating the upper and lower and left and right guides. Further, adjustment in the orthogonal direction is not required.

(3) The three-stage bearing structure of the upper and lower guides prevents deformation of the bearing mounting plate.

(4) Appropriate vibration damping force can be obtained by the friction force generated by the ceramic semi-floating bearing.

(5) Ceramic semi-floated bearings prevent dust from being generated during sliding.

(6) By using porous material for the hydrostatic bearing, it has higher rigidity (approximately 1.5 times) and lower flow rate (approximately 1/10) than conventional bearings.
realized.

[Brief explanation of drawings]

FIG. 1 is an external view showing the overall configuration of a movement guide device according to an embodiment of the present invention, FIG. 2 is a layout diagram of a bearing mounting unit fixed to a top plate, and FIG. 3 is a layout diagram of a guide rail. 4 is an external view of the stage feed mechanism unit, FIG. 5 is an external view of the sliding unit, and FIG. 6 is an arrangement view of the bearings in the vertical direction.
7 is a cross-sectional view of the sliding unit, FIG. 8 is a cross-sectional view showing a modified example of the sliding unit, FIG. 9 is a cross-sectional view showing a modified example of the configuration of the lateral bearing, and FIG.
This figure is a sectional view showing the overall configuration of a conventional movement guide device, and FIG. 11 is a diagram showing a state of deformation of a conventional bearing mounting plate. 1... Top plate (slider), 2... Hydrostatic bearing mounting unit, 3... Guide unit, 4... Feeding mechanism unit, 5... Sliding unit, 6... Static pressure bearing, 21... Vertical direction bearing mounting plate, 22... Left and right directional bearing mounting plate,
31...Upper and lower guide, 32...Left and right guide, 41,4
2...Bearing unit, 42...Ball screw, 4
4... Leaf spring, 51... Ceramic semi-floating bearing mounting plate, 52... Ceramic semi-floating bearing, 53... Preload roller, 54... Ceramic sliding plate, 55... Leaf spring for supporting sliding plate.

Claims (1)

[Scope of Claims] 1. A movement guide device for relatively moving a second member along a trajectory set on a first member, comprising: three bearing surfaces provided between the first and second members; a first guide means having a guide having a static pressure structure on each surface and preventing relative displacement of the first and second members in a direction perpendicular to the moving surface; and a first guide means having a static pressure structure separated from the first guide means. a second guide means which is a guide and prevents relative change of the first and second members in a direction perpendicular to the direction of movement in the plane of movement; and a ceramic half that slides between the first and second members in the direction of movement. A movement guide device comprising a floating hydrostatic bearing. 2. The movement guide device according to claim 1, wherein the first guide means and the second guide means use ceramic porous bearings as hydrostatic bearings.