JPS63172988A - Moving mechanism - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field to which the invention pertains] The present invention relates to a movement guide device, and more particularly, the present invention relates to a movement guide device, and more specifically, a movement guide device that 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 an object. The present invention provides a movement guide device suitable for a sample withdrawal device for semiconductor wafers, etc., in a step-and-repeat reduction projection exposure apparatus that repeatedly moves and stops at high speed and with high precision, especially when manufacturing semiconductor devices such as integrated circuits. It is.

[Conventional technology]

Reduction projection exposure equipment used in the manufacture of semiconductor devices such as LSIs regularly exposes a mask or reticle pattern on a semiconductor wafer in a grid pattern, and of course improves the positional accuracy with respect to the previously printed pattern. In order to improve efficiency, it is necessary to speed up the step-and-repeat operation. 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, which is generally called an XY stage, the basic system of the movement guide device shown in FIG. 9 has conventionally been used.

In the figure, 101 is a top plate (slider), 102 is a stage surface, 103 is a bearing mounting plate, and 104 is a bearing mounting plate 1.
03 is a static pressure bearing for guiding in the vertical and horizontal directions, and 105 is a guide rail. Due to these, the top plate 101 is guided to move smoothly along a trajectory perpendicular to the drawing. 106 is a resin control phase semi-floating bearing;
107 is a sliding plate that comes into sliding contact with the bearing 106, and 108 is a pressing roller unit. For pressing, the roller unit 108 uses its rollers to sandwich the sliding plate 107 between it and the control bearing 106, and adjusts or controls the pressing force, thereby controlling the pressure between the braking bearing 106 and the sliding plate 107. The apparent friction coefficient in the moving direction of the friction sliding part is set to a desired value or variably controlled. 109 indicates the center of gravity of the stage portion.

The stage conveyance system of the exposure apparatus is a moving table (stage) equipped with a movement guide device as shown in FIG.
A drive mechanism and a motion transmission mechanism are added to the , and by combining a plurality of these, it is possible to move in the X direction and the Y direction of the XY orthogonal coordinate system.

By the way, in such a device, the frictional force between the control bearing 106 and the sliding plate 107 is constant both during movement and during stop control, and it is necessary to apply enough friction force to obtain sufficient vibration damping during stop control. Since it becomes difficult to move at high speed when moving, the frictional force cannot be increased very much, and there is a drawback that sufficient vibration damping cannot be obtained. Furthermore, the frictional force between the two cannot be reduced to zero unless the pressing roller unit 108 is removed and a gap is created between the two, and the frictional force will always work during movement, resulting in high-speed movement. It also had the disadvantage of inhibiting the

[Purpose of the invention]

An object of the present invention is to solve the above-mentioned problems of the conventional type and also to provide an effective damping force against vibrations.

(Explanation of Examples) Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1-A is an external view showing the overall configuration of a movement guide device according to an embodiment of the present invention, and FIG. 1-8 is a sectional view thereof. Further, FIGS. 2 to 5 show the configuration of each unit that constitutes the apparatus.

In FIG. 1-A, 1 is a top plate (slider), 2 is a hydrostatic bearing mounting unit, 3 is a guide unit, 4 is a feed mechanism unit, and 5 is a sliding unit. M is also -9 for yiri-kun, tsubo-yuni, and nodo 4-setsu.

Figure 2 shows the arrangement of 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 the guide rails of the guide unit 3, where 31 is a vertical guide and 32 is a horizontal guide.

FIG. 4 shows the stage feeding mechanism unit 4, 41.
43 is a ball bearing housing, 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 semi-floated ceramic bearing, 53 is a preloading static pressure bearing unit, 54 is a ceramic sliding plate,
55 is a leaf spring for supporting the sliding plate 54 and absorbing its displacement.

Further, FIG. 6 is a bearing arrangement diagram showing the arrangement of vertically supporting static pressure 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-A to 7.

First, the top plate 1 is lifted up from the upper and lower guides 31 by the hydrostatic bearings 6. The hydrostatic bearing 6 is provided with a bulge that blows out air substantially in the direction of the opposing surface. At this time, since the bearing has a three-stage structure as shown in Figure 6, the rigidity is higher than that of the conventional example, and the bottom static pressure bearing 6 is attached to the mounting plate, which is caused by other static pressure bearings. Since the bearing is restrained in a direction that prevents deformation, deterioration of bearing characteristics due to this deformation can be prevented.

In addition, in the lateral direction, the left and right support hydrostatic bearing mounting plates 22 and guides 3
Rigidity is provided by arranging a static pressure bearing 6 between the two.

The upper and lower guides and the left and right guides have separate configurations.

The vertical restraint guide must have sufficient guide rigidity to stabilize the moving body in the vertical direction, and the vertical guide 31 and bearing mounting plate 103 must have a certain degree of wall thickness in the height direction. Must be. However, since the guide for lateral restraint does not receive force in the vertical direction, it does not require much guide rigidity, and only needs a height equal to the length of the hydrostatic bearing 6, which is large enough to provide the necessary air supply. I don't. Also, this height is greater than the required wall thickness of the upper and lower guides. The upper and lower guides and the left and right guides are separated, and the static pressure bearings 6 for the left and right guides are positioned at a height within the required wall thickness for the upper and lower guides, so the entire stage can be fixed better than when using a guide for full restraint. The height of the can be lowered.

In addition, since a static pressure bearing is provided that restrains the mounting plate in a direction that prevents it from deforming, the rigidity of the mounting plate 21 does not need to be increased so much, and the thickness of the mounting plate can be reduced, which also reduces the overall height of the stage. can be lowered. Note that by embedding the bearing 6 in the mounting plate 21 as shown in FIG. 6, the device can be made thinner. Further, by using a ceramic porous bearing as the hydrostatic bearing 6, the rigidity can be further increased and the amount of posture fluctuation can be reduced in response to changes in load and external force.

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. In order to absorb the whirling of the ball screw, leaf springs 44 are arranged on the top, bottom, left and right sides, and the connection to the top plate 1 is such that a thrust is applied near the center of gravity 9 to reduce vibrations, that is, the ball screw passes near the center of gravity 9. There is. Since the top plate 1 and the center of gravity 9 are close to each other, vibrations are less likely to occur.

Further, in order to efficiently damp vibrations generated by elastic vibrations in the axial direction of the ball screw, etc., a semi-floating unit (sliding unit) 5 for generating frictional force is arranged as shown in FIG. 5-7. The sliding piece 52 of this semi-floating unit 5 is made of ceramic to prevent dust generation, and has a hole in its sliding surface so that the air supply passage 51a in the mounting block 51 is passed through the sliding surface of the sliding plate 54. Air is supplied. The frictional force is controlled by the supply pressure to the ceramic porous hydrostatic bearing 56 and the supply pressure to the sliding piece.

When the stage starts moving, the CPU 73 controls the air supply path 51a.
The air supply pump 72 is controlled to increase the supply pressure to the sliding piece 52 through the air supply path 56a, or the air supply pump 75 is controlled to decrease the supply pressure to the static pressure bearing 56 through the air supply path 56a. The sliding piece 52 and the sliding plate 54 are brought into a non-contact state by the pressurized fluid. At this time, the static pressure bearing 56 and the sliding plate 5
The air supply pump 72 is configured to supply sufficient air supply pressure to prevent contact between the air supply and the air supply pump 72.

Since the stage is no longer subject to frictional resistance, high-speed movement becomes possible. Furthermore, at the start of the stop control, for example, when the stage reaches the vicinity of the target stop position and the stage control is switched from speed servo control to position servo control, the air supply bomb 2 is simultaneously operated to lower the supply pressure to the sliding piece 52.
Alternatively, the air supply bomb 75 is controlled to increase the supply pressure to the static pressure bearing 56, and the sliding piece 52 and the sliding plate 54 are brought into contact with each other so that sufficient frictional force is generated between them.

It becomes possible to efficiently damp the vibrations of the stage and reduce the time it takes for the stage to stop. Ceramic sliding plate 5
4 is the deformation of the sliding plate.

In order to prevent the friction force from fluctuating due to changes in the magnitude of preload due to the straightness of the guide, etc., the guide is supported by a leaf spring 55 so as to be movable in a substantially horizontal direction perpendicular to the direction of travel.

Although only one sliding piece 52 appears in Fig. 7,
It is not limited to this, and multiple settings may be made. For example, it is also possible to provide two in total, one in the front and one in the back, and fix them to the top plate 1, so that the sliding surface thereof can be brought into sliding contact with the guide surface on the right side of the sliding plate 54. Furthermore, the sliding piece 52 may be constructed integrally and provided with a plurality of sliding surfaces.

In any case, it is preferable to configure a plurality of sliding surfaces to slide on the guide surface.

For pressing, by using a static pressure bearing instead of a roller as the member that applies force, it is possible to prevent the generation of dust from the roller part and the generation of frictional force in the sliding (up and down) direction of the roller.

The lateral bearing arrangement may be as shown in FIG.

As shown in the figure, the lateral static pressure bearing can also be formed into a two-layer structure to prevent deformation of the mounting plate and increase rigidity.

(Effects of the Invention) As explained above, the present invention enables high-speed movement when moving the stage, enables high-speed stopping with sufficient vibration damping when controlling the stage to stop, and furthermore provides great stopping stability when stopping. is now possible.

[Brief explanation of the drawing]

Figure 1-A is an external view showing the overall configuration of a movement guide device according to an embodiment of the present invention, Figure 1-B is a cross-sectional view of the same, and Figure 2 is a layout diagram of a bearing mounting unit fixed to a top plate. , Fig. 3 is a guide rail layout, Fig. 4 is an external view of the stage feed mechanism unit, Fig. 5 is an external view of the sliding unit, Fig. 6 is a vertical bearing arrangement, and Fig. 7 is a sectional view of the sliding unit, FIG. 8 is a sectional view showing a modified example of the configuration of the lateral bearing, FIG. 9 is a sectional view showing the overall configuration of the conventional movement guide device, 1... Top plate ( slider), 2... hydrostatic bearing mounting unit, 3... guide unit, 4... feed mechanism unit,
5...Sliding unit, 6...Static pressure bearing, 21...
Vertical bearing mounting plate, 22... Horizontal bearing mounting plate, 31... Vertical guide, 32... Left and right guide, 41.42... Bearing unit, 42... Ball screw, 44... Board Spring, 51... Ceramic semi-floating bearing mounting plate, 52... Ceramic semi-floating bearing, 54... Ceramic sliding plate, 55... Leaf spring for supporting sliding plate, 56... Ceramic hydrostatic bearing.

Claims (5)

[Claims] (1) a first sliding surface provided on a first member; a second sliding surface provided on a second member that is movable relative to the first member and sliding on the first sliding surface; A moving mechanism characterized by having a control means for variably controlling the distance between the first sliding surface and the second sliding surface. (2) The control means controls the distance between the first sliding surface and the second sliding surface so that they are in a contact state and a non-contact state. Moving mechanism. (3) The moving mechanism according to claim 2, wherein the control means includes a fluid supply hole provided in the second sliding surface and a fluid supply means for supplying fluid to the fluid supply hole. (4) The control means further includes a pressurizing means for applying pressure to the first member in a direction to bring the first sliding surface and the second sliding surface into contact with each other, and the pressure of the pressurizing means and the fluid supply. 4. The moving mechanism according to claim 3, further comprising pressure control means for variably controlling at least one of the fluid supply pressures of the means. (5) The pressure control means brings the first sliding surface and the second sliding surface into a non-contact state when moving the second member, and the pressure controlling means brings the first sliding surface and the second sliding surface into a non-contact state when the second member is stopped. 5. The moving mechanism according to claim 4, wherein at least one of the fluid supply pressure of the fluid supply means and the pressure of the pressurizing means is controlled so as to bring the sliding surface into contact with the sliding surface.