JPH0332206B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a movement stage mechanism for moving a sample in an electron beam exposure apparatus used for manufacturing semiconductor devices.

As a conventional device of this type, there is one shown in FIG. 1, for example.

In the figure, 1 is an X table on which a sample is placed and can be moved back and forth in the X direction, 2a and 2b are X guides parallel to each other to ensure linearity when moving the X table 1, and 3 is an X table that can be moved back and forth in the X direction. The Y tables 4a and 4b are connected to the X guides 2a and 2b and are movable back and forth in the Y direction perpendicular to the X direction. The guide 5 is a base for fixing the Y guides 4a and 4b.

In order to move the moving stage with such a configuration in the Y direction, linear motion is applied to the Y drive rod 6a connected to the Y table 3, like a feed screw nut connected to a rotary motor or a hydraulic cylinder. A method is used in which possible driving sources are connected and thrust is applied to the Y table 3 via the Y drive rod 6a. In this case, a rectangular frame 7 is provided at the tip of the X drive rod 6b, and a roller 8 that can roll in the Y direction inside the rectangular frame 7 is connected to the X table 1. This allows the X table 1 to move in the Y direction even when the X drive rod 6b remains stationary. Further, when moving in the X direction, a drive source such as the above-mentioned hydraulic cylinder is connected to the X drive rod 6b, and a thrust is applied to the X table 1 with the rectangular frame 7 pressed against the rollers 8.

In the conventional moving stage structure described above, the table on which the sample is placed is always mechanically coupled to at least the drive source in either the X or Y direction, so the vibrations generated in the drive source affect the drive rod. Therefore, even after the movement of the sample table has stopped, the vibration is slow to settle, and furthermore, even while the movement of the sample table is stopped, vibrations with an amplitude on the order of 1/10 to 1/100 μm are transmitted from the drive source. As a result, when incorporated into an electron beam exposure apparatus, there were disadvantages in that productivity was reduced due to the extra waiting time for vibration settling, and writing accuracy was reduced due to vibration during stoppage.

In order to eliminate these drawbacks, the present invention arranges a piece of electrostrictive material at the joint between the drive rod and the stage, and expands the piece of electrostrictive material arranged in the moving direction while the stage is moving. By eliminating the mechanical gap at the joint, and when the stage is stopped, the electrostrictive material piece is contracted to create a gap at the joint, breaking the connection between the stage and the drive rod. This is to remove vibrations transmitted from the drive source to the stage through the drive rod when the stage is stopped, and will be described in detail below with reference to the drawings.

FIG. 2 shows an embodiment of the present invention. In the figure, 11
Place the sample 11a and make X and Y2 perpendicular to each other.
The sliders 12a and 12b, which move in the direction, are connected to the platform 11, and the sliders 13a and 13b, which are arranged parallel to the X and Y directions, respectively, hold the sliders 12a and 12b, and the slider 12a , 12b have a linear motion guide function during axial movement of the guides 14a, 14b, drive rods 15 connected to the guides 13a, 13b.
Reference numerals a and 15b are linear guides for ensuring motion accuracy during reciprocating movement of the drive rods 14a and 14b. 16a and 16b are linear motion guides 15, respectively.
Hydraulic cylinder 17 is connected to drive rods 14a and 14b via a and 15b and provides thrust to drive the stage 11 in the Y and X directions, respectively. This base has a plane guiding function to suppress vertical fluctuations when the base moves in two-dimensional directions.

Next, FIG. 3 is a sectional view taken along the line A-A' in FIG. 2, showing in detail the relative positional relationship between the slider 12a and the guide 13a. Guide 13a
An electrostrictive material piece 22 is fixed to the side surface facing the slider 12a via an insulating material 21, and both sides of the electrostrictive material piece 22 parallel to the slider 12a are coated with a conductive material 24. The opposing surface is covered with an insulating material 23. When fixing the electrostrictive material piece 22, when an external voltage is applied to the electrostrictive material piece 22 and an electric field is applied, the direction in which the material piece 22 is deflected is the thickness direction, that is, the Y drive rod 14.
Arrange it so that it matches the moving direction of a. Further, the dimensions of the electrostrictive material piece 22 are such that when an external voltage is applied and it expands in the thickness direction, the mechanical gap between the slider 12a and the guide 13a is completely removed, and conversely, the application of the external voltage is canceled. At times, it is set so that it shrinks in the thickness direction and returns to its original size, creating a mechanical gap between the slider 12a and the guide 13a. In FIG. 3, only the Y direction has been described, but the slider 12 in the X direction
The relative positional relationship between guide 13b and guide 13b is also equivalent.

Next, the operation of the moving stage having such a configuration will be explained with reference to FIGS. 3 and 4.

First, when the stage 11 is stopped, the voltage applied to the electrostrictive material piece 22 is released, and the electrostrictive material piece 22 remains contracted in the thickness direction, and the slider 12a and guide 13a are is in a non-contact state. As shown in FIG. 4, the moving distance of the stage 11 in the X and Y directions is constantly measured by laser length measuring devices 31a and 31b having high length measurement resolution, and is converted into a digital signal. The signal is sent to the comparator 32. On the other hand, data 35 corresponding to the target moving distance of the stage 11 is input to the comparator 32, and within the comparator 32, the input data is compared with the length measurement data of the laser length measuring device 31a or 31b. Therefore, at the same time that an input signal is applied to the hydraulic cylinder 16a and the drive is started, a timing pulse is sent from the comparator 32 in synchronization with the input signal to turn on the switch 33.
As a result, a voltage is applied to the electrostrictive material piece 22 from the DC power supply 34, and the electrostrictive material piece 22 is expanded in the thickness direction, removing the gap between the slider 12a and the guide 13a, and expanding both sides of the slider 12a. The electrostrictive material pieces 22 are sandwiched together. In this state, the stage 11 is connected to the drive rod 14a via the slider 12a and the guide 13a, and is driven to a desired position by the hydraulic cylinder 16a.
During this operation, the guide 13b remains stopped,
In addition, no voltage is applied to the electrostrictive material piece mounted on the guide 13b, so that the guide 13
b and the slider 12b are maintained in a mechanically non-contact state, and the movement of the document table 11 in the Y direction is not hindered in any way.

Next, when the stage 11 stops at the target position and the vibration after the stop settles to about 1/10 to 1/100 μm, the comparator 32 generates a timing pulse and the switch 33 is turned off. Ba,
The electrostrictive material piece 22 returns to its original size when the voltage is removed, and a mechanical gap is created again between the slider 12a and the guide 13a, so that the hydraulic cylinder 16
Vibration from a is not transmitted to the slider 12a. Therefore, the vibrations after the stage 11 stops are stabilized very quickly.

In addition, in the explanation so far, Guide 13
Although a configuration has been adopted in which the electrostrictive material piece 22 is coupled to the sliders 12a and 13b, a configuration in which the electrostrictive material piece 22 is coupled to the sliders 12a and 12b is functionally equivalent. Furthermore, even if an electrostrictive material is used that contracts when a voltage is applied, the same purpose can be achieved if the switch 33 is turned off when driving and turned on when stopped. can.

As explained above, according to the movable stage structure of the present invention, the mechanical connection between the stage on which the sample is placed and the drive sources in the X and Y directions can be released when the stage is stopped. Therefore, the vibrations generated in the drive source are not transmitted to the workpiece table, so the vibrations of the workpiece table are quickly stabilized after stopping, and it is also possible to completely eliminate vibrations during stoppage. becomes. Therefore, when this moving stage is applied to an application such as moving a sample in an electron beam exposure system, it speeds up vibration stabilization after moving the sample, improving the productivity of the exposure system. Since vibrations during pattern drawing are completely eliminated, there is an advantage that pattern drawing accuracy can be improved.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a conventional moving stage, Fig. 2 is a perspective view showing an embodiment of the present invention, and Fig. 3 is a perspective view of a conventional moving stage.
FIG. 4 is a sectional view showing details of the combination of the slider and guide shown in the figure, and FIG. 4 is a diagram showing a method of releasing the voltage applied to the electrostrictive material piece of FIG. 3. 1: X table, 2a, 2b: X guide, 3:
Y table, 4a, 4b: Y guide, 5: base,
6a: Y drive rod, 6b: X drive rod, 7:
Rectangular frame, 8: Roller, 11: Stage, 11a: Sample, 12a, 12b: Slider, 13a, 13
b: Guide, 14a: X drive rod, 14b: Y
Drive rod, 15a, 15b: linear guide, 16
a, 16b: Hydraulic cylinder, 17: Base, 21,
23: Insulating material, 24: Conductive material, 22: Electrostrictive material piece, 31a, 31b: Laser length measuring device, 32: Comparator, 33: Switch, 34: DC power supply, 3
5: Data according to target movement distance.

Claims (1)

[Claims] 1. A mounting stage on which a sample is mounted and movable in two directions at right angles in a plane parallel to the mounting surface; Two sliders whose axial directions are perpendicular to each other serve as a guided mechanism for one movement direction of the table, and serve as a driving force receiving mechanism for a movement direction perpendicular to that direction. A moving stage having two guides that are fitted together and serve as a drive force transmission mechanism in the direction of the drive force and guide the movement of the stage in the direction perpendicular to the drive direction. One surface is fixed to either the guide or the slider, and when a voltage is applied to the opposing surfaces of the slider fitted with the guide, it expands in a direction perpendicular to the opposing surfaces of the guide and slider. The slider is characterized by having an electrostrictive material attached thereto having a thickness such that the guide and the slider are held together and the slider can move using the guide as a guide without being held in place when no voltage is applied. moving stage.