KR19990001540A - Vertical displacement and leveling of the stage - Google Patents

Abstract

Disclosed is a vertical displacement and leveling device for a stage which enables precise position control.

The disclosed vertical displacement and horizontal adjusting device of the stage is hinged to the measuring means for measuring the vertical position and the horizontal state of the stage to be installed on the base, and the projection is formed between the stage and the base hinged to support the stage A lever member, a drive unit for driving the lever member up and down, and a position control means configured to detect and control a change in the up and down position of the lever member, the position control means being installed on a base and generating light and outputting light. And a slit member disposed on an optical path between the light source and the lever member, the slit member having a plurality of transmission regions adapted to pass incident light, and selectively reflecting light incident on the lever member and passing through the slit member. A reflecting member having a plurality of alternating reflecting and non-reflecting regions formed alternately, and a reflecting member Depending on which light-receives the reflected light up and the light receiving portion, a detection signal of the detection signal and the measurement of the light receiving means and a circuit unit for controlling the vertical displacement of the stage.

Description

Vertical displacement and leveling of the stage

The present invention relates to a displacement and leveling device of a stage, and more particularly, to a vertical displacement and leveling device of a stage which enables precise position control.

In general, a stage used in an exposure process during a manufacturing process of a stage such as a liquid crystal display device, a plasma display panel, a printed circuit board, and a semiconductor device requires ultra-precision control of vertical displacement and horizontal state.

1 is a perspective view schematically showing a vertical displacement and horizontal adjustment device of a general stage.

As shown, the vertical displacement and horizontal adjustment device of the stage includes driving means 10 for driving the stage 1 on which the substrate to be exposed is mounted up and down, and measurement means 50 for measuring the position of the stage 1. It is composed of The drive means 10 is installed between the stage 1 and the base 2 to adjust the vertical displacement and the horizontal state of the stage 1. The measuring means 50 is installed above the stage 1 to measure the vertical position and the horizontal state of the stage 1.

The measuring means 50 is provided with three pairs so as to measure the positions of the three points of the stage 1, respectively, each of which has a light source 51 for emitting light and the light emitted from the light source 51. A collimating lens 52 for converting into parallel light, an objective lens 53 for condensing the light reflected by the stage 1 after passing through the collimating lens 52, and light for detecting the collected light Detector 54.

The driving means 10 are provided in three pairs to support three points of the stage 1.

2 is a side view schematically showing the driving means 10 described above. As shown, the driving means 10 includes a protrusion 3 protruding from the base 2, a lever 20 rotatably coupled to the protrusion 3 by a hinge 4, and the lever ( It consists of the drive part 30 and the encoder 37 which raise and lower the 20.

The lever 20 has a support portion 21 protruding to contact the stage 1 to support the stage 1. The drive unit 30 includes a motor 31 for providing a driving force, a worm 33 fixed to the rotating shaft 32 of the motor 31, a worm gear 34 geared to the worm 33, and It is composed of an eccentric cam 35 is fixed to the worm gear 34 and to be in contact with the lower side of the lever (20). The eccentric cam 35 raises and lowers the lever 20 in accordance with the rotation of the worm gear 34 in the upward direction of the outer portion 35a. The encoder 37 is installed on the rotation shaft of the motor 31 and outputs a pulse signal in accordance with the rotation of the motor 31.

The vertical displacement and horizontal adjustment device of the conventional stage described with reference to FIGS. 1 and 2 is driven when the motor 31 is driven in accordance with the position information of the stage 1 detected by the measuring means 50. The worm gear 34 is transmitted to the worm gear 34 through the worm 33, and the worm gear 34 and the eccentric cam 35 are rotated accordingly. Accordingly, the levers 20 in contact with the outer portion 35a of the eccentric cam 35 are lifted to adjust the height of the stage 1 supported by the support portion 21. Here, since the rotation of the motor 31 is output as a pulse signal of the encoder 37, it is possible to know the height adjustment amount of the stage (1). At this time, the pulse signal of the encoder 37 is counted at intervals of sampling time to calculate the vertical position change, and then compared with the vertical position and the horizontal state measured by the measuring means 50 of the stage 1. It will control the vertical displacement and the horizontal state.

However, as described above, since the vertical displacement and horizontal adjustment degree of the stage 1 are detected by the encoder 37 provided on the rotation shaft of the motor 31, the worm 33, the worm gear 34, the lever 20 and When mechanical friction, backlash, and the like occur between the stage 1, a difference is generated between the actual position change amount of the stage 1 in the vertical direction and the position detection amount due to the pulse signal of the encoder 37. There is a problem that precise control of the direction displacement and the horizontal state is difficult.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems described above, and an object thereof is to provide a vertical displacement and horizontal adjustment apparatus of a stage capable of precisely controlling the vertical displacement and the horizontal state of the stage by improving the structure.

1 is a perspective view schematically showing a vertical displacement and leveling device of a general stage,

Figure 2 is a side view schematically showing a vertical displacement and leveling device of the conventional stage,

3 is a perspective view schematically showing a vertical displacement and horizontal adjusting device of a stage according to an embodiment of the present invention;

4 is a perspective view schematically showing the detection unit of FIG.

5 is a circuit diagram schematically showing the position control means of FIG.

Explanation of symbols for the main parts of the drawings

1 ... Stage 2 ... Base

3 ... 4 projections

20 Lever member 30 Drive unit

31.Motor 32.Rotating shaft

33 Worm 34 Worm Gear

35.Eccentric Cam 35a ... Outer side

50 Measuring means 51,510

54 Photodetector 100 Driving means

400 position control means 500 detector

520 Slit member 521 Transmitting area 530 Reflective member

531 Reflective area 540 Receiver 550 Collimating lens

560 focusing lens 600 circuit

Vertical displacement and horizontal adjustment device of the stage according to the present invention for achieving the above object comprises a measuring means for measuring the vertical position and the horizontal state of the stage installed on the base; A lever member installed between the stage and the base and hinged to a protrusion formed on the base to support the stage; A driving part for driving the lever member up and down; In the vertical displacement and horizontal adjustment device of the stage comprising a; position control means for detecting and controlling the vertical position change of the lever member, the position control means is installed on the base and generates light A light source; A slit member disposed on an optical path between the light source and the lever member and having a plurality of transmission regions adapted to pass incident light therethrough; A reflection member installed on the lever member and having a plurality of reflection areas and non-reflection areas alternately formed to selectively reflect light incident through the slit member; A light receiving unit which receives the light reflected from the reflective member; And a circuit unit configured to control the vertical displacement of the stage according to the detection signal of the light receiving unit and the detection signal of the measuring unit.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a perspective view schematically showing a vertical displacement and horizontal adjustment device of a stage according to an embodiment of the present invention, FIG. 4 is a perspective view schematically showing a detector of FIG. 3, and FIG. 5 is a position control means of FIG. 3. It is a schematic circuit diagram.

As shown, the vertical displacement and horizontal adjustment apparatus of the stage according to the present invention includes measuring means 50 for measuring the vertical position and the horizontal state of the stage 1 on which the substrate to be exposed is placed, and the stage 1 It comprises a driving means 100 for adjusting the vertical displacement and the horizontal state of the). Here, the measuring means 50 and the driving means 100 are provided in plural numbers so as to face at least three points of the stage 1 in order to adjust the vertical displacement and horizontality of the stage 1.

The measuring means 50 converts the light source 51, the collimating lens 52 that converts the light emitted from the light source 51 into parallel light, and the light reflected by the stage 1 into focused light. An objective lens 53 and a photodetector 54 for detecting the focused light are provided to measure the vertical position and the horizontal state at different positions of the stage 1.

The driving means 100 includes a lever member 20, a drive unit 30 for driving the lever member 20, and a vertical position change (A) of the lever member 20 according to the driving of the drive unit 30. It is configured to include a position control means 400 for detecting and controlling.

The lever member 20 is installed on the stage 1 between the stage 1 and the base 2 and is rotatably coupled to the protrusion 3 protruding from the base 2 by a hinge 4. . The lever member 20 has a support portion 21 which protrudes to contact the stage 1 and supports the stage 1. The drive unit 30 includes a motor 31, a worm 33 installed on the rotation shaft 32 of the motor 31, a worm gear 34 geared to the worm 33, and the worm gear 34. It is configured to include an eccentric cam 35 fixed to one side of the. The eccentric cam 35 raises and lowers the lever member 20 in accordance with the rotation of the worm gear 34 in the upward direction of the outer portion 35a.

The position control means 400 includes a detector 500 capable of detecting a vertical position change A of the lever member 20, and a circuit unit 600. The detection unit 500 is provided so as to detect the vertical position change (A), that is, the vertical displacement of each lever member 20 by selectively transmitting and reflecting light. As illustrated in FIG. 4, the detection unit 500 is installed on the base 2 and disposed on a light path 510 for generating and emitting light, and on an optical path between the light source 510 and the lever member 20. A slit member 520, a reflective member 530 installed on the lever member 20 so as to face the slit member 520, and provided to be movable relative to the slit member 520, and the reflective member 530. It is configured to include a light receiving unit 540 for receiving the light reflected from.

The slit member 520 includes a plurality of transmission regions 521 disposed in a direction substantially parallel to the A direction to selectively transmit the light incident from the light source 510. In addition, the reflective member 530 includes a plurality of reflective regions 531 and non-reflective regions 532 arranged in the A direction to selectively reflect the light incident through the transmission region 521. .

When the lever member 20 moves up and down (A direction), the light emitted from the light source 510 and passing through one transmission region 521 of the slit member 520 is selectively reflected by the reflection member 530. To face the light receiving unit 540. The amount of light received by the light receiving unit 540 is changed because the reflective region 531 and the non-reflective region 532 are alternately formed.

The light receiver 540 includes four light sensors A, B, C, and D for photoelectric conversion of incident light independently to detect a change in the interference fringe. The photosensors A, B, C, and D are disposed adjacent to each other to form a lattice shape, and are provided to have a phase difference of 90 degrees between the photosensors A, B, C, and D adjacent to each other.

On the other hand, the detector 500 is disposed on the optical path between the light source 510 and the slit member 520 collimating lens 550 for converting the light emitted from the light source 510 into parallel light, and It is preferable to further include a focusing lens 560 to reflect the light reflected from the reflecting member 530 and passed through the slit member 520 into the focused light.

As shown in FIG. 6, the circuit unit 600 performs differential noise amplification and signal amplification by differentially amplifying detection signals of the optical sensors A, B, C, and D, and then converting them into square waves. A converter 605, a counter 610 for sampling and counting an input signal at predetermined intervals, and a central computing unit (CPU) for transmitting a position control command using the position signal counted by the counter 610 as a feedback signal. 620. The position of the stage 1 is adjusted by feeding back the signal output from the CPU 620 to the motor 31.

Hereinafter, the operation of the vertical displacement and the horizontal adjustment device of the stage according to the embodiment of the present invention.

When the initial vertical position and the horizontal state of the stage 1 are detected by the measuring means 50, the driving means 100 is operated to adjust the height of the stage 1. That is, the position control means 400 is operated to count the number of waveforms according to the position change of the stage 1. Here, the value initially counted by the counter 610 is zero since the stage 1 is displaced.

Thereafter, the motor 31 is driven and the worm 33 and the worm gear 34 are rotated to raise or lower the lever member 20 to displace the height of the stage 1. The value counted by the counter 610 changes according to the displacement of the stage 1, from which the CPU 620 can know the error value between the displacement amount of the stage 1 and the desired displacement amount. Meanwhile, the control signal output from the CPU 620 is fed back to the motor 31 so that the displacement error of the stage 1 is corrected.

The vertical displacement and horizontal adjustment device of the stage according to the present invention as described above counts the change in the interference fringes caused by the slit member and the reflection member installed in the lever member according to the vertical movement of the lever member to increase the vertical movement of the lever member By detecting, the actual position change amount of the stage can be known irrespective of mechanical friction, backlash, or the like, thereby enabling precise control of the vertical displacement and horizontal state of the stage.

Claims (4)

Measuring means for measuring a vertical position and a horizontal state of the stage installed on the base; A lever member installed between the stage and the base and hinged to a protrusion formed on the base to support the stage; A driving part for driving the lever member up and down; In the vertical displacement and horizontal adjustment device of the stage comprising; position control means for detecting and controlling the vertical position change of the lever member; The position control means includes a light source installed in the base for generating and emitting light; A slit member disposed on an optical path between the light source and the lever member and having a plurality of transmission regions adapted to pass incident light therethrough; A reflection member installed on the lever member and having a plurality of reflection areas and non-reflection areas alternately formed to selectively reflect light incident through the slit member; A light receiving unit which receives the light reflected from the reflective member; And a circuit unit for controlling the vertical displacement of the stage in accordance with the detection signal of the light receiving unit and the detection signal of the measuring means. The apparatus of claim 1, wherein the light receiving unit comprises four light sensors each independently photoelectrically converting incident light. The vertical displacement and horizontal adjustment device of claim 2, wherein the optical sensors are disposed adjacent to each other to form a lattice, and have a phase difference of about 90 degrees between the adjacent optical sensors. 2. The apparatus of claim 1, wherein the position control means comprises: a collimating lens disposed on an optical path between the light source and the stage to convert light emitted from the light source into parallel light; And a focusing lens disposed on an optical path between the slit member and the light receiving part to focus the light reflected by the stage.