JP4451374B2 - Stage equipment - Google Patents

Description

  The present invention relates to a stage apparatus, and more particularly to a stage apparatus configured to measure a moving state of a stage and control a yaw angle of either a stage or a horizontal portion.

  For example, in the process of surface treatment of a glass substrate used in a liquid crystal monitor, a gantry unit that is horizontally mounted on the stage while moving the stage in the Y direction at a constant speed while the glass substrate is adsorbed to an adsorption board on the stage Work is being carried out using a stage device configured to perform predetermined processing by a processing unit mounted on (horizontal member). In this type of stage apparatus, it is desired to cope with an increase in the size of the glass substrate. Therefore, the suction plate on which the glass substrate is placed is enlarged to a size corresponding to the size of the glass substrate, and the stage for moving the suction plate, the linear motor (driving means) for driving the stage, and the position of the stage are measured. The linear scale is also extended in the moving direction.

  On the other hand, when the stage is moved, the linear motor is controlled so as to suppress the swing around each of the X, Y, and Z axes as much as possible. As a detecting means for detecting the swing around each axis, the distance to the stage is measured by a pair of laser interferometers, and the tilt of the stage is detected from the difference between the two points. This laser interferometer is composed of a laser emitting section that is arranged on the fixed side and emits laser light, a mirror provided on the movable side, and a light receiving section that receives light reflected from the mirror, and is reflected from the mirror. Thus, the distance is accurately measured from the change in the wavelength of light.

Here, if the stage is enlarged in the X direction and the Y direction as the glass substrate becomes larger, the mirror of the laser interferometer is extended according to the moving distance. However, since the flatness of the mirror is required to be precise, there is a limit to extending the length of the mirror while maintaining the flatness. Therefore, a plurality of mirrors are alternately arranged on the side surface of the stage at positions shifted up and down, and a plurality of laser light emitting units are provided, and the laser is adjusted to the height position of the mirror that irradiates the laser light according to the stage moving position. What was comprised so that a light emission part might be switched is developed (for example, refer patent document 1).
Japanese Patent No. 3282233

  However, in the apparatus described in Patent Document 1, since the control is performed so as to switch to the laser light emitting unit corresponding to the height position of the mirror in accordance with the movement of the stage, not only the configuration becomes complicated, but also the laser interferometer There is a problem that switching control is difficult.

  In view of the above circumstances, an object of the present invention is to provide a stage apparatus configured to realize a measuring unit corresponding to an increase in the size of a stage with a simple configuration.

  In order to solve the above problems, the present invention has the following means.

  The invention according to claim 1 includes a stage, a horizontal part that is horizontally installed above the stage, a driving unit that moves either the stage or the horizontal part, the horizontal member, and the stage. In a stage apparatus having a measuring means for measuring a relative position and a control means for controlling the driving means based on a value measured by the measuring means, the measuring means is either the horizontal section or the stage. A laser emission means provided on one side and a laser beam received from the laser emission means provided on either the horizontal portion or the stage, and a detection signal corresponding to a change in intensity distribution of the received laser light And a light detection means for outputting.

  According to a second aspect of the present invention, the light detecting means includes a light receiving element having first to fourth light receiving portions in which a light receiving surface is divided into four, and a detection signal output from the first to fourth light receiving portions. And an optical axis position detecting means for detecting a position in the direction perpendicular to the optical axis from the light intensity distribution.

  According to a third aspect of the present invention, the driving means is configured so that the control means receives the laser light at the center of the light receiving element when the laser light from the laser light emitting means is shifted in a direction perpendicular to the optical axis. It is characterized by controlling.

  According to a fourth aspect of the present invention, the optical axis position detecting unit detects that the stage is at a reference position when the optical axis of the laser beam from the laser emitting unit coincides with the center of the light receiving element. Features.

  According to a fifth aspect of the present invention, a pair of the driving means is provided so as to drive either the stage or the horizontal portion in one direction from both sides, and the control means is detected by the optical axis position detecting means. The drive control of the pair of drive means is individually performed according to the deviation of the optical axis, and the yaw rate control of either the stage or the horizontal portion is performed.

  According to a sixth aspect of the present invention, there is provided a moving direction measuring means for measuring a relative distance between the stage and the horizontal member, and the control means emits the laser light according to a measurement position by the moving direction measuring means. The driving means is controlled so that the laser beam from the means is received at the center of the light receiving element.

  According to the present invention, the measuring means receives laser light from the laser emitting means provided on either the horizontal part or the stage, and the laser light from the laser emitting means provided on either the horizontal part or the stage, And a light detection means for outputting a detection signal corresponding to a change in the intensity distribution of the received laser light, so that a mirror is unnecessary, so that even if the moving distance of the horizontal portion or the stage is extended, it can be easily handled. In addition, the configuration can be simplified.

  In addition, the light detection means compares the detection signal output from the first to fourth light receiving parts with the light receiving element having the first to fourth light receiving parts in which the light receiving surface is divided into four, and from the light intensity distribution. Since it has an optical axis position detecting means for detecting the position of the optical axis in the orthogonal direction, the position by swinging around each of the X, Y, and Z axes accompanying relative movement of the stage and the horizontal member It becomes possible to accurately measure the deviation.

  Further, the control means controls the driving means so as to receive the laser light at the center of the light receiving element when the laser light from the laser light emitting means is shifted in the direction perpendicular to the optical axis, thereby increasing the positioning of the stage. In addition to the accuracy, the stage can be prevented from swinging around each axis and the stage can be moved more stably.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a perspective view showing Embodiment 1 of the stage apparatus according to the present invention. FIG. 2 is a side view of the stage apparatus according to the first embodiment. As shown in FIGS. 1 and 2, the stage apparatus 10 is configured to move the Y stage 12 only in the Y direction, and a processing unit or an inspection unit ( Both are not shown). The Y stage 12 obtains thrust in the Y direction by a pair of Y-axis linear motors (drive means) 16 on both the left and right sides and moves at a constant speed. In addition, a stone surface plate 18 is supported below the Y stage 12 by a gantry 20, and the Y stage 12 has an air layer with respect to the stone surface plate 18 by a static pressure pad (not shown) provided on the lower surface. And can move with low friction.

  The Y stage 12 has a static pressure pad (not shown) facing the side surface of the guide rail 24 protruding on the stone surface plate 18 and measures the Y-direction moving distance between the Y stage 12 and the stone surface plate 18. A Y linear scale 28 is provided.

  An adsorption board 30 for adsorbing the substrate 29 is fixed to the upper surface of the Y stage 12, and a photodetector (light detection means) 32 is attached to the center of the front end of the Y stage 12 in the Y direction. A laser emitter (laser emitting means) 34 for irradiating the photodetector 32 with laser light is attached at an intermediate position of the gantry section 14. The light detector 32 and the laser emitter 34 constitute a measuring means for measuring a positional deviation with respect to the Y axis, are provided at the same height, and the laser emitter 34 when the Y stage 12 is at the reference position. The optical axis of the laser beam emitted from the Y stage 12 is provided so as to coincide with the moving direction (Y direction) of the Y stage 12.

  The control unit 36 drives and controls the pair of linear motors 16 based on the control side set in advance, and translates the pair of linear motors 16 so that the Y stage 12 moves at a constant speed in the Y direction. To control. In this embodiment, when the Y stage 12 is at point A (base point), the relative position between the center of the photodetector 32 and the optical axis in the Y direction of the laser emitter 34 is adjusted. . The control unit 36 then adjusts the Y position so that the relative position between the center of the photodetector 32 and the optical axis of the laser emitter 34 does not shift during the process of moving the Y stage 12 from point A (base point) to point B. The stage 12 is controlled to move.

  FIG. 3 is an enlarged view showing the photodetector 32. As shown in FIG. 3, the photodetector 32 includes a light receiving element 40 that receives laser light, and the light receiving element 40 detects an optical axis position of the received laser light. It is connected to the. The light receiving element 40 is composed of, for example, a planar element typified by a CCD image sensor having first to fourth light receiving portions 40a to 40d each having a light receiving surface divided into four. In this embodiment, when the relative position between the center of the photodetector 32 and the Y direction optical axis of the laser emitter 34 coincides, the light intensity distribution I of the light receiving element 40 is in any region of the light receiving portions 40a to 40d. It is set to be equal. Then, the optical axis position detection unit 42 compares the detection signals output from the first to fourth light receiving units 40a to 40d, and detects a positional deviation amount in the direction perpendicular to the optical axis from the light intensity distribution.

  The photodetector 32 has a configuration in which a mirror is provided instead of the light receiving element 40, and the laser beam reflected from the mirror is received at another location (for example, a support portion supported by the base 20). It may be guided to the element.

  The optical axis position detector 42 outputs the difference between the peak values obtained from the comparator 44 to the controller 36, and the relative position between the center of the photodetector 32 and the Y direction optical axis of the laser emitter 34. When the positions match, it is detected that the Y stage 12 is at the reference position. Then, the control unit 36 controls the drive voltage supplied to the pair of linear motors 16 so that the peak values of the light intensity distribution match. Therefore, when positioning the Y stage 12 using a laser interferometer, it is necessary to extend the total length of the mirror in accordance with the increase in the size of the substrate. However, as in the present invention, the photodetector 32 and the laser emitter are used. Since the positional deviation of the Y stage 12 can be accurately detected by the relative position to the position 34, a mirror requiring flatness is not required, and the configuration can be simplified.

  FIG. 4 is a block diagram showing a configuration of the optical axis position detection unit 42. As shown in FIG. 4, the optical axis position detection unit 42 includes a peak position detection unit 43 that detects a peak value of the light intensity distribution obtained from the light receiving units 40 a to 40 d of the light receiving element 40, and a peak position detection unit 43. The comparator 44 for comparing the peak values obtained from the above and a memory for storing the comparison result by the comparator 44 corresponding to the Y-direction position (movement distance from the base point) determined by the linear scale 28 (storage means) 46.

  As shown in FIG. 5, when the Y stage 12 swings in the θz direction around the Z axis when the Y stage 12 moves from the point A (base point) in the Y direction and reaches the point B (movement position). When the light intensity distribution II of the light receiving element 40 at the point B is biased to any one of the light receiving portions 40a to 40d, the light intensity distribution I of the light receiving element 40 at the point A shifts as shown by a broken line. It will be. The peak value difference δ between the light intensity distributions I and II is a deviation in the X direction, and the deviation amount in the X direction corresponds to the yaw angle θ of the Y stage 12. That is, if the peak value difference δ between the light intensity distributions I and II is zero, the yaw angle θ is also zero.

  Here, a detection pattern of the light intensity distribution in the light receiving units 40a to 40d will be described. FIG. 6A shows a light intensity distribution I when the optical axis of the laser light emitted from the laser emitter 34 coincides with the center of the light receiving element 40. In this detection pattern, the amount of light received by the light receiving units 40a to 40d is equal, so that the detection values of the respective light receiving units 40a to 40d are compared with each other between the Y stage 12 on the movable side and the gantry unit 14 on the fixed side. The relative displacement is zero.

  FIG. 6B shows a light intensity distribution II when the optical axis of the laser light emitted from the laser emitter 34 is shifted in the X direction from the center of the light receiving element 40. In this detection pattern, since the light intensity distribution II has no inclination, it can be seen that the circular pattern is translated in the X direction. In this case, the light receiving amounts of the light receiving portions 40a and 40b disposed on the left side of the light receiving element 40 are the same, and the light receiving amounts of the light receiving portions 40c and 40d disposed on the right side of the light receiving element 40 are both zero.

  FIG. 6C shows a light intensity distribution III when the optical axis of the laser light emitted from the laser emitter 34 is shifted in the Z direction from the center of the light receiving element 40. In this detection pattern, since the light intensity distribution III has no inclination, it can be seen that the circular pattern is translated in the Z direction. In this case, the light receiving amounts of the light receiving portions 40a and 40d arranged above the light receiving element 40 are the same, and the light receiving amounts of the light receiving portions 40b and 40c arranged below the light receiving element 40 are both zero.

  FIG. 6D shows a light intensity distribution IV when the optical axis of the laser light emitted from the laser emitter 34 is shifted around the θz axis on the XY plane from the center of the light receiving element 40. Since this detection pattern is an elliptical pattern in the X direction, it can be seen that the light intensity distribution IV has an inclination and the Y stage 12 is shifted around the θz axis (yawing). In this case, the light receiving amounts of the light receiving portions 40a and 40b of the light receiving element 40 and the light receiving amounts of the light receiving portions 40c and 40d are the same, but the light receiving portions 40a and 40c disposed in the diagonal direction of the light receiving element 40 are received. The slope of the light intensity distribution IV can be obtained from the difference in amount and the difference in the amount of light received by the light receiving portions 40b and 40d.

  FIG. 6E shows a light intensity distribution V when the optical axis of the laser light emitted from the laser emitter 34 is shifted around the θX axis on the ZY plane from the center of the light receiving element 40. Since this detection pattern is an elliptical pattern in the X direction, it can be seen that the light intensity distribution V has an inclination and the Y stage 12 is displaced around the θX axis (pitching). In this case, the light receiving amounts of the light receiving portions 40a and 40d of the light receiving element 40 and the light receiving amounts of the light receiving portions 40b and 40c are the same, but the light receiving portions 40a and 40c arranged in the diagonal direction of the light receiving element 40 are received. The slope of the light intensity distribution V can be obtained from the difference in amount and the difference in the amount of light received by the light receiving portions 40b and 40d.

  In this way, by comparing the amounts of light received by the light receiving units 40a to 40d, it is possible to accurately detect in which direction the Y stage 12 is displaced, and the Y stage 12 can be positioned with high accuracy. Furthermore, by supplying the comparison result of the received light amounts of the four light receiving units 40a to 40d to the control unit 36, the control unit 36 controls the received light amounts of the light receiving units 40a to 40d to be equal. The yawing operation of the Y stage 12 can be suppressed, and the Y stage 12 can be moved more stably.

  Further, when the Y stage 12 performs a pitching operation, for example, driving of a Z-axis actuator (not shown) provided in the gantry unit 14 is controlled to suppress the swing of the Y stage 12 due to the pitching operation. it can.

  FIG. 7 is a perspective view showing a stage apparatus according to the second embodiment. FIG. 8 is a plan view of the stage apparatus according to the second embodiment. 7 and 8 show a simplified stage device of the second embodiment. In FIGS. 7 and 8, the same parts as those of the first embodiment are denoted by the same reference numerals, and the description thereof will be given. Omitted.

  As shown in FIGS. 7 and 8, in the stage apparatus 60 according to the second embodiment, an X stage 62 is provided on the upper surface of the Y stage 12 so as to be movable in the X direction. The photodetector 32 is fixed at the center of the front end of the X stage 62. The laser emitter 34 is attached to the front surface of the processing unit attachment portion 64 fixed to the center of the gantry portion 14.

  In the stage device 60, the Y linear scale 66 for measuring the Y direction movement amount of the Y stage 12, the X axis linear motor 68 for moving the X stage 62 in the X direction, and the X direction movement amount of the X stage 62 are measured. An X linear scale 70 for measuring and a pair of Y axis laser interferometers 72 for measuring the moving distance of the Y stage 12. The Y-axis laser interferometer 72 includes a laser light emitting unit 74 that irradiates laser light, a mirror 76 provided at the peripheral edge of the Y stage 12, and a light receiving unit (not shown) that receives reflected light from the mirror 76. The position of the Y stage 12 in the Y direction is detected from the wavelength of the reflected light. Then, a yaw angle (θz direction angle) about the Z axis is determined from the distance difference detected by the pair of Y axis laser interferometers 72.

  In the stage device 60, the laser beam emitted from the laser emitter 34 is received by the photodetector 32, whereby the reference position of the substrate 29 adsorbed on the adsorption plate 30 on the X stage 62 can be set. That is, in the light detector 32, as shown in FIG. 6A, the optical axis of the laser light emitted from the laser light emitter 34 coincides with the center of the light receiving element 40, and the amount of light received by the light receiving portions 40a to 40d. Can be recognized as a reference position.

  Further, in the photodetector 32, as shown in FIG. 6B, it was detected that the optical axis of the laser beam emitted from the laser emitter 34 was shifted from the center of the light receiving element 40 in the X direction. In this case, the X-axis linear motor 68 is driven and controlled, and the X stage 62 is moved in the X direction to perform positioning control in the X direction so that the optical axis of the laser beam coincides with the center of the light receiving element 40.

  Further, in the stage device 60, the yaw angle of the Y stage 12 is detected by the pair of Y-axis laser interferometers 72, and the yaw angle of the X stage 62 is detected by the laser emitter 34 and the light receiving element 40. In addition, by aligning the optical axis of the laser beam emitted from the laser emitter 34 with the center of the light receiving element 40, the X stage 62 can be accurately positioned at the reference position, and stage alignment can be performed in a short time. Can do. Therefore, when the X stage 62 is moved in the X direction, the position where the center of the light receiving element 40 is irradiated with the laser beam is stored as a reference position, and the moving distance from the reference position is measured by the X linear scale 70. Thus, since the reference position can be positioned by the measuring means including the laser emitter 34 and the light receiving element 40, alignment after substrate replacement can be performed efficiently.

  In the above embodiment, the configuration in which the laser emitter 34 is provided on the fixed side and the light receiving element 40 is provided on the movable side is given as an example. However, the configuration is not limited thereto, and the laser emitter 34 is provided on the movable side. Of course, the light receiving element 40 may be provided.

  In the above-described embodiment, the configuration in which the X and Y stages are moved is given as an example. However, the present invention is not limited to this. For example, the present invention is also applicable to a configuration in which the Y stage is fixed and the gantry is moved in the Y direction. Of course, the invention can be applied.

It is a perspective view which shows Example 1 of the stage apparatus by this invention. It is a side view of the stage apparatus of Example 1. It is a figure which expands and shows the photodetector 32. FIG. 3 is a block diagram showing a configuration of an optical axis position detection unit 42. FIG. It is a graph which shows the shift | offset | difference of the light intensity distribution according to the movement position of Y stage. It is a figure which shows typically the detection pattern of the light intensity distribution in the light-receiving parts 40a-40d. It is a perspective view which shows the stage apparatus of Example 2. FIG. It is a top view of the stage apparatus of Example 2.

Explanation of symbols

10, 60 Stage device 14 Gantry unit 16 Y-axis linear motor 32 Photo detector 34 Laser light emitter 36 Control units 40a to 40d Light receiving unit 40 Light receiving element 42 Optical axis position detecting unit 43 Peak position detecting unit 44 Comparator 62 X stage 64 Machining unit mounting part 68 X-axis linear motor 70 X linear scale

Claims (6)

A stage, a horizontal part horizontally placed above the stage, a driving means for moving either the stage or the horizontal part, and a measuring means for measuring a relative position between the horizontal member and the stage; In a stage apparatus having a control means for controlling the drive means based on the value measured by the measurement means,
The measuring means includes
Laser light emitting means provided on either the horizontal part or the stage;
A light detection means that is provided on either the horizontal section or the stage and receives laser light from the laser light emission means, and outputs a detection signal according to a change in intensity distribution of the received laser light;
A stage apparatus comprising: The light detection means includes
A light receiving element having first to fourth light receiving portions in which the light receiving surface is divided into four;
The optical axis position detecting means for comparing the detection signals output from the first to fourth light receiving sections and detecting the position in the direction perpendicular to the optical axis from the light intensity distribution. The stage apparatus according to 1.   The control means controls the driving means to receive the laser light at the center of the light receiving element when the laser light from the laser light emitting means is shifted in a direction perpendicular to the optical axis. The stage apparatus according to claim 1.   3. The optical axis position detection unit detects that the stage is at a reference position when the optical axis of the laser beam from the laser emission unit coincides with the center of the light receiving element. Stage equipment. A pair of the driving means is provided so as to drive either the stage or the horizontal part in one direction from both sides,
The control means individually performs drive control of the pair of drive means according to the deviation of the optical axis detected by the optical axis position detection means, and performs yaw angle control of either the stage or the horizontal portion. The stage apparatus according to claim 4, wherein: A moving direction measuring means for measuring a relative distance between the stage and the horizontal member;
The control means controls the driving means so that laser light from the laser light emitting means is received at the center of the light receiving element according to a measurement position by the moving direction measuring means. The stage apparatus described in 1.

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