JP4594841B2 - Stage device and control method thereof - Google Patents

Description

  The present invention relates to a stage apparatus and a control method thereof, and in particular, a process in which a first stage operates to transport a second stage outside a processing area, and a second stage that has arrived at a processing position is moved with respect to the first stage. The present invention relates to a stage apparatus configured to perform the control and a control method thereof.

  For example, as a stage device for holding and moving an optical processing mask or the like, a coarse movement stage driven by a pair of linear motors provided on a surface plate, a fine movement stage mounted on the coarse movement stage, and a sensor There is a stage apparatus configured to detect the position of the fine movement stage and move the fine movement stage by a voice coil motor (see, for example, Patent Document 1).

In this stage apparatus, a pair of linear motors provided on a surface plate moves the coarse movement stage in the Y direction, and a fine movement stage provided at the center of the coarse movement stage is mounted on the coarse movement stage. Is configured to move a minute distance.
JP 2001-102279 A

  In the above conventional stage device, the fine movement stage and the voice coil motor are mounted on the coarse movement stage, so the error and reaction force of the coarse movement stage affect the position control of the fine movement stage. It was difficult to control fine movement. Further, since the response characteristic of the coarse movement stage affects the fine movement stage, it takes time until the position of the fine movement stage is determined, and there is a problem that the responsiveness at the time of position control is poor. In addition, the fine movement stage is superposed on the coarse movement stage to raise the center of gravity of the stage, and accordingly, there is a problem that the stability of the fine movement stage is inferior when precisely controlling the position of the fine movement stage.

  Accordingly, an object of the present invention is to provide a stage apparatus and a control method therefor that solve the above problems.

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

The invention according to claim 1 includes a base,
A first stage movably provided on the base;
First measuring means for measuring the position of the first stage;
First driving means for driving the first stage;
A second stage provided to move on the base together with the first stage;
Second measuring means for measuring the position of the second stage;
Second driving means for driving the second stage in the other direction with respect to the first stage;
A movement restricting means for restricting movement of the second stage relative to the first stage in the X and Y directions when the first stage is moved by the first driving means;
When performing coarse movement control for moving the first stage, the second stage is held in contact with the movement restricting means by the suction force of the second driving means, and measured by the first measuring means. When fine movement control is performed to drive the first driving means and finely move the second stage based on the obtained position data, the holding by the second driving means is released and the position measured by the second measuring means Control means for driving the second drive means based on the data;
It is characterized by having.

  The invention according to claim 2 is characterized in that the first driving means is a linear motor for coarsely moving the first stage, and the second driving means is a voice coil motor for finely moving the second stage. It is what.

  According to a third aspect of the present invention, the second driving means includes a first voice coil motor that drives the second stage in one direction, a second voice coil motor that drives the second stage in the other direction, and And a third voice coil motor for driving the second stage in the rotation direction.

  The invention according to claim 4 is characterized in that the second stage is slidably supported by a hydrostatic pad that floats on the base via an air layer.

  The invention described in claim 5 is characterized in that the first measuring means is a linear scale and the second measuring means is a laser interferometer.

  According to a sixth aspect of the present invention, the movement restricting means is provided on the first stage or the second stage, and abuts so as to restrict a relative position between the first stage and the second stage in the proximity direction. It is a positioning member.

  The invention according to claim 7 is characterized in that the second stage is provided so as to be positioned in the same plane as the first stage.

  The invention according to claim 8 is characterized in that the movement restricting means is provided so as to be located in the same plane as the second driving means.

  According to a ninth aspect of the present invention, when the second stage moves out of the processing position along with the movement of the first stage, the control means holds the second stage in a state in which the movement is restricted by the movement restricting means. It is a feature.

  The invention according to claim 10 is characterized in that the control means causes the second driving means to generate a predetermined thrust in accordance with the acceleration of the first stage.

  The invention according to claim 11 is characterized in that the control means obtains an acceleration of the first stage based on a measurement result of the first measurement means.

  The invention according to claim 12 is characterized in that the control means performs switching between measurement start and measurement stop by the second measurement means at a reference position of the first measurement means.

The invention of claim 13 wherein, the control means, the first, the first based on the position data measured by the first measuring means when the second stage moves a position out of the processing position, The second driving means is driven, and when the first and second stages are stopped at the processing position, the second driving means is driven based on the position data measured by the second measuring means. Is.

  According to a fourteenth aspect of the present invention, when the second stage moves out of the processing position along with the movement of the first stage, the control means performs the second measurement in a state where the movement of the second stage is restricted by the movement restricting means. The means is reset.

The invention according to claim 15 is a base;
A first stage movably provided on the base;
First measuring means for measuring the position of the first stage;
First driving means for driving the first stage;
A second stage provided to move on the base together with the first stage;
Second measuring means for measuring the position of the second stage;
Second driving means for driving the second stage in the other direction with respect to the first stage;
A movement restricting means for restricting movement of the second stage relative to the first stage in the X and Y directions when the first stage is moved by the first driving means;
A method for controlling a stage apparatus comprising:
When the second stage deviates from the processing position, the second stage is brought into contact with the movement restricting means by the suction force of the second driving means to maintain the movement restricted state of the second stage, and the second stage When the stage is at the processing position, the second driving unit is controlled to switch the second stage to a state in which the limitation is released by moving the second stage away from the movement limiting unit.

According to the present invention, when the first stage and the second stage are movably provided on the same base, and the coarse motion control for moving the first stage is performed, the second stage is moved by the suction force of the second driving means. When holding the state in contact with the restricting means and driving the first driving means based on the position data measured by the first measuring means to finely control the second stage, the second measuring means Since the second driving means is driven based on the position data measured by the above, the error of the first stage does not affect the second stage during the fine movement control , and the second stage is mounted on the first stage. In addition, the position control of the second stage can be performed with higher accuracy, and the responsiveness during the position control can be further improved. Further, since the first stage and the second stage are provided with the measurement system on the same base standard, no stacking error occurs compared to the case where the second stage is mounted on the first stage, so that the positional accuracy is improved. Is possible.

  Further, when the first stage is moved by the first driving means or when the second stage is moved together with the first stage, the first stage and the second stage come into contact with each other by making the position command trajectory generation the same. This can be prevented.

  Further, according to the present invention, the first drive means is a linear motor that coarsely moves the first stage, and the second drive means is a voice coil motor that finely moves the second stage, so that the first stage is the second stage. At the same time, the movement distance can be extended by coarse movement, and the second stage can be finely moved by the voice coil motor to enable precise position control.

  According to the present invention, since the second stage is slidably supported on the base by the hydrostatic pad that floats through the air layer, the second stage can be moved with a relatively small force. 2 It is possible to reduce the burden on the driving means and to prevent the vibration generated in the coarse movement stage from being transmitted to the fine movement stage.

  In addition, according to the present invention, the coarse movement position of the first stage is measured by the linear scale, and the fine movement position of the second stage is measured by the laser interferometer. Therefore, the measurement means has accuracy suitable for position control of each stage. It becomes possible to measure using.

  Further, according to the present invention, since the movement restricting means includes the positioning member that comes into contact so as to restrict the relative position of the first stage and the second stage in the proximity direction, the second stage is the first stage or the second stage. Contact with the driving means can be prevented.

  According to the present invention, since the second stage is located on the same plane as the first stage, the position of the center of gravity can be lowered, and the movement of the stage is stabilized accordingly.

  According to the present invention, when the second stage moves out of the processing position with the movement of the first stage, the second stage is measured by the laser interferometer in order to keep the second stage in a state where the movement is restricted by the movement restricting means. Therefore, it is possible to shorten the length of the mirror.

  Further, according to the present invention, since the second driving means generates a predetermined thrust in accordance with the acceleration of the first stage, the current flowing through the voice coil motor can be minimized, so that the motor heat generation amount is minimized. It becomes possible.

  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 plan view of the stage apparatus shown in FIG. FIG. 3 is a rear view of the stage apparatus shown in FIG.

  As shown in FIGS. 1 to 3, the stage apparatus 10 includes a base 12 formed in a flat plate shape, a coarse movement stage (first stage) 14 movably provided on the base 12, and a coarse movement stage. The Y-direction linear scale (first measuring means) 16 that measures the position of the 14, the Y-direction linear motor (first driving means) 18 that drives the coarse movement stage 14, and the coarse movement stage 14 move along the base 12. Fine movement stage (second stage) 20 provided in this manner, laser interferometers (second measurement means) 21 to 23 for measuring the position of fine movement stage 20, and fine movement stage 20 in the other direction with respect to coarse movement stage 14 Voice coil motors (second driving means) 24-26.

  Further, the stage device 10 moves the coarse movement stage 14 to a position other than the processing area (including the mask exchange area), and a movement restriction unit (movement) that restricts the movement of the fine movement stage 20 relative to the coarse movement stage 14 in the X and Y directions. Limiting means) 28, 29 and the Y direction linear motor 18 are driven based on the position data measured by the Y direction linear scale 16, and the voice coil motor 24 is based on the position data measured by the laser interferometers 21-23. Control device 30 for driving .about.26.

  On the upper surface of the base 12, a Y-direction linear scale 16, a yoke 32 of the Y-direction linear motor 18, and a pair of linear guides 34 that guide the movement of the coarse movement stage 14 in the Y direction are provided. As a driving means for the coarse movement stage 14, another driving means (for example, a ball screw mechanism) may be used instead of the Y-direction linear motor 18. Further, instead of the linear guide 34, another guide means (for example, a static pressure pad) for guiding the sliding motion of the coarse motion stage 14 with low friction may be used.

  The coarse movement stage 14 is sufficiently moved between a processing position (one of a plurality of processing positions) where optical processing is performed by being guided by a linear guide 34 on the base 12, and an alignment position and a workpiece replacement position. It is provided to move with a simple stroke. The coarse movement stage 14 is formed in an approximately L shape when viewed from above, and includes a Y-direction arm portion 14a extending in the Y direction and an X-direction arm portion 14b extending in the X direction. Sliding portions 36 for sliding the linear guide 34 are provided on the lower surface of the Y-direction arm portion 14a and the lower surface of the end portion of the X-direction arm portion 14b located at both ends of the coarse movement stage 14, respectively.

  Further, a support portion 44 that supports the linear encoder 40 of the Y-direction linear scale 16 and the coil 42 of the Y-direction linear motor 18 is provided at the center of the lower surface of the X-direction arm portion 14b. In the present embodiment, a configuration example in which the coil 42 is disposed on the movable side will be described as an example, but the coil 42 may be provided on the fixed side (base 12 side).

  The fine movement stage 20 is provided so as to be movable on the base 12 without being yaw-guided, and can perform position control in each of the X, Y, and θ directions with high speed response and high accuracy as will be described later. Further, an X mirror 46 for measuring the position in the X direction is provided in the right end recess 20a of the fine movement stage 20. A pair of Y1 and Y2 mirrors 47 and 48 for measuring the position in the Y direction are provided in the rear end recesses 20b and 20c of the fine movement stage 20 in the Y direction. The X mirror 46 is formed to extend in the Y direction, and is used to detect the X direction position when the fine movement stage 20 arrives at the processing position and performs fine movement control, and is a length that covers the fine movement operation range. Have Therefore, since the X mirror 46 does not cover the operating range in which the coarse movement stage 14 moves coarsely, the entire length is shortened accordingly. In the present embodiment, since the coarse movement stage 14 and the fine movement stage 20 are provided with the X mirror 46 and the Y1, Y2 mirrors 47 and 48 as the measurement system on the same base, the fine movement stage is mounted on the coarse movement stage. Compared to the above, no stacking error occurs, so that the positional accuracy can be improved.

  An X-direction laser interferometer 21 that irradiates the X mirror 46 with laser light is provided on the rear side of the base 12. Further, Y direction laser interferometers 22 and 23 for irradiating Y1 and Y2 mirrors 47 and 48 with laser light are provided on the rear portion of the base 12. The X direction laser interferometer 21 and the Y direction laser interferometers 22 and 23 irradiate the X mirror 46 and the Y1 and Y2 mirrors 47 and 48 with laser light, detect the reflected light, and measure the distance from the fine movement stage 20. To do.

  As shown in FIG. 4 in an enlarged manner, the upper surface recess 14c of the Y direction arm portion 14a is provided with an X direction voice coil motor 24 for driving the fine movement stage 20 in the X direction, and the upper surface of the X direction arm portion 14b. In the recess 14d, voice coil motors 25, 26 for Y direction that drive the fine movement stage 20 in the Y direction are provided. Therefore, since the voice coil motors 24 to 26 are mounted at the same height so as to face the side surface of the fine movement stage 20, the side surface of the fine movement stage 20 can be directly driven and the coarse movement stage 14 can be driven. Since it does not protrude from the upper surface, it is configured to cope with thinning.

  The voice coil motors 24 to 26 have the same configuration, and are composed of yokes 24 a to 26 a fixed to the coarse movement stage 14 and coils 24 b to 26 b fixed to the side surface of the fine movement stage 20. In this embodiment, the movable side coils 24b to 26b are movably fitted to the fixed side yokes 24a to 26a. Of course, the yokes 24a to 26a may be provided on the movable side and the coils 24b to 26b may be provided on the fixed side.

  The voice coil motors 24 to 26 generate an attractive force or a repulsive force with respect to a permanent magnet (not shown) held by the yokes 24a to 26a by controlling the current supplied to the coils 24b to 26b. Let That is, since the yokes 24a to 26a and the coils 24b to 26b are not in contact with the voice coil motors 24 to 26, the vibration of the coarse movement stage 14 is not directly transmitted to the fine movement stage 20, and the fine movement stage 20 is driven. It is provided to generate a driving force when

  The pair of voice coil motors 25 and 26 are separated by a predetermined distance, drive means for generating forces in the same direction (Y direction), and force in the opposite directions to generate fine movement stage 20 by θ. It also functions as a driving means for rotating in the direction.

  The voice coil motors 24 to 26 enable high-speed response and high-accuracy positioning, but have a problem that the operation stroke is short. However, according to the present embodiment, since the coarse movement stage 14 and the fine movement stage 20 are positioned at the same target position (processing position), the positions of the yokes and coils of the voice coil motors 24 to 26 attached thereto, respectively. The deviation is the sum of the positioning error of the coarse movement stage 14 and the positioning error of the fine movement stage 20 at the maximum.

  Since the total value of the errors is sufficiently small with respect to the driving strokes of the voice coil motors 24 to 26, the positioning by the voice coil motors 24 to 26 can be sufficiently performed with a longer stroke than the errors. Further, by generating a command pattern that does not exceed the maximum acceleration of the coarse movement stage 14 and the fine movement stage 20 during stage movement, the fine movement stage 20 is always kept within the drive stroke range of the voice coil motors 24 to 26. be able to.

  The X-direction movement limiting unit 28 has an X-direction positioning pin (positioning member) 50 that limits the position of the fine movement stage 20 in the X direction, and the Y-direction movement limiting unit 29 is a position of the fine movement stage 20 in the Y direction. A pair of Y-direction positioning pins (positioning members) 51 and 52 for limiting the above. The X direction positioning pin 50 is provided in the upper surface recess 14e of the Y direction arm portion 14a, and the Y direction positioning pins 51 and 52 are provided in the upper surface recess 14f of the X direction arm portion 14b.

  As shown in FIG. 4, the Y-direction positioning pins 51 and 52 are provided at the same height as the side surface and the front surface of the fine movement stage 20, respectively, and protrude in the horizontal direction from the L-shaped bracket 54. It is attached so that the contact position (movement restriction position) with the side surface and the front surface of fine movement stage 20 can be adjusted by adjusting the protruding length. Similarly to the positioning pins 51 and 52, the X-direction positioning pin 50 is screwed so as to protrude from the L-shaped bracket 54 in the horizontal direction.

  The fine movement stage 20 is formed in a substantially rectangular frame when viewed from above, and an opening 20d for holding a mask for optical processing such as annealing is provided at the center thereof. . As shown in FIG. 3, a plurality of static pressure pads 56 that float on the top surface of the base 12 through an air layer are provided at the bottom of the fine movement stage 20 (3 to 4 in this embodiment). Is provided. The static pressure pad 56 is disposed so as not to contact the linear guides 34 and 35, the Y-direction linear scale 16, and the yoke 32 of the Y-direction linear motor 18, and the upper surface of the fine movement stage 20 is the upper surface of the coarse movement stage 14. The fine movement stage 20 is supported at a height position that is in the same plane.

  Thus, the fine movement stage 20 is not mounted on the coarse movement stage 14, but is supported at the same height position as the coarse movement stage 14 from the upper surface of the base 12, so that the position of the center of gravity is lowered. And stability during movement is further enhanced. Thereby, movement control when moving coarse movement stage 14 and fine movement stage 20 can be performed with higher accuracy.

  Further, since the error and reaction force due to the coarse movement of the coarse movement stage 14 do not affect the fine movement stage 20, the position control of the fine movement stage 20 can be controlled more precisely, and the responsiveness at the time of position control is improved. It has been.

  FIG. 5 is an enlarged plan view showing the state of the fine movement stage 20 that performs fine movement control at the processing position. As shown in FIG. 5, when the fine movement stage 20 is at the processing position and the coarse movement stage 14 is stopped, the fine movement stage 20 is in a movable state separated from the positioning pins 50 to 52. The fine movement stage 20 that has arrived at a predetermined processing position is driven by the voice coil motors 24 to 26 and finely controlled.

  FIG. 6 is an enlarged plan view showing a holding state of the fine movement stage 20 when the coarse movement operation is performed. As shown in FIG. 6, in order to move the fine movement stage 20 out of the processing position, the fine movement stage 20 when moving the coarse movement stage 14 is moved to the positioning pins 50 to 52 by the driving force of the voice coil motors 24 to 26. It is held in the contact movement restricted state.

  As described above, the coarse movement stage 14 is provided with the positioning pins 50 to 52 for restricting the operation of the fine movement stage 20 at a total of three positions. The positioning pins 50 to 52 can determine the relative positions of the fine movement stage 20 with respect to the coarse movement stage 14 in the X direction, the Y direction, and the θ direction by pressing the fine movement stage 20, and at least three positions are required. is there. Further, each positioning pin 50 to 52 has a tip having a spherical shape with a small curvature in order to reduce friction with respect to the fine movement stage 20. Further, the tip of the positioning pins 50 to 52 may be made of a low friction material having a small friction coefficient or provided with a rotating body such as a rollable roller.

  Here, the control system of the stage apparatus 10 will be described. FIG. 7 is a block diagram showing a control system when the fine movement stage 20 moves. FIG. 8 is a block diagram showing a control system when fine movement stage 20 is in the holding state.

  As shown in FIG. 7, the control device 30 includes a position command unit 60 that outputs the operation positions of the coarse movement stage 14 and the fine movement stage 20, a coarse movement stage controller 70, and a fine movement stage controller 80.

  The position command unit 60 generates orbit data based on the position command output unit 62 in which the operation positions of the coarse movement stage 14 and the fine movement stage 20 are set in advance and the position data output from the position command output unit 62. And a generation unit 64.

  The coarse motion stage controller 70 includes a low-pass filter (LPF) 72 that removes high-frequency components from the command signal output from the trajectory data generation unit 64, and a resolution correction unit 74 that corrects the resolution of the signal output from the low-pass filter 72. The coarse motion PID control unit 76 generates a control signal for the Y-direction linear motor 18 based on the signal whose resolution is corrected by the resolution correction unit 74 and the signal detected by the linear encoder 40.

  The fine movement stage controller 80 generates fine control PID control for generating control signals to the voice coil motors 24 to 26 based on the command signal output from the trajectory data generation unit 64 and the measurement signals obtained from the laser interferometers 21 to 23. Part 82.

  First, control when the coarse movement stage 14 and the fine movement stage 20 are controlled and moved will be described. As shown in FIG. 7, when the fine movement stage 20 moves, the position data from the position command output unit 62 is stored in the X, Y, θ direction trajectory data generation units 64a to 64c for each direction. , Y, θ trajectory data. Then, the Y trajectory data is input to the Y direction feedback control unit 76 a of the coarse motion PID control unit 76 via the low pass filter 72 and the resolution correction unit 74. Then, the current supplied from the Y direction current control unit 76b of the coarse motion PID control unit 76 to the Y direction linear motor 18 is output as a Y control signal.

  The X, Y, and θ trajectory data generated by the X, Y, and θ direction trajectory data generating units 64a to 64c are input to the X, Y, and θ direction feedback control units 82a to 82c of the fine motion PID control unit 82. The Then, currents supplied to the voice coil motors 24 to 26 from the X, Y, and θ direction current control units 82d to 82f of the fine motion PID control unit 82 are output as control signals.

  The X, Y, and θ direction feedback control units 82a to 82c are supplied with X, Y, and θ position data measured by the laser interferometers 21 to 23 as a feedback signal after coordinate conversion by the coordinate conversion unit 84. . The Y trajectory data is corrected by the origin offset amount corresponding to the position of the coarse movement stage 14, and this correction value is input to the Y direction feedback control unit 82b.

  The X, Y, θ direction feedback control units 82 a to 82 c generate X, Y, θ control signals based on the X, Y, θ trajectory data and the feedback signal output from the coordinate conversion unit 84. A current corresponding to the Y and θ control signals is supplied from the current controller 82g to the voice coil motors 24 to 26. As a result, fine movement stage 20 moves to the position specified by position command output unit 62.

  Next, the control when the fine movement stage 20 is restricted in movement and moves together with the coarse movement stage 14 will be described. When fine movement stage 20 stops, the control system is switched to the control system shown in FIG. As shown in FIG. 8, the Y trajectory data generated by the trajectory data generation unit 64 is input to the fine movement stage holding thrust calculation unit 86. The fine movement stage holding thrust calculation unit 86 outputs a control signal to hold the fine movement stage 20 on the coarse movement stage 14 with respect to the Y-direction current control units 82d to 82f. As a result, the voice coil motors 24 to 26 generate a suction force so that the fine movement stage 20 is held by the Y-direction arm portion 14 a and the X-direction arm portion 14 b of the coarse movement stage 14. Therefore, fine movement stage 20 is brought into contact with positioning pins 50 to 52 by the force generated from voice coil motors 24 to 26, and is held in a state where movement in the X and Y directions is restricted.

  FIGS. 9A to 9G are timing charts showing an example of changes in each signal related to stage control, and FIG. 9A is an operation pattern of the coarse movement stage 14 and the fine movement stage 20 integrated with movement limitation. (B) is a waveform diagram showing changes in the speed of the coarse movement stage 14 and the fine movement stage 20, (c) is a waveform diagram showing acceleration changes in the coarse movement stage 14 and the fine movement stage 20, and (d) is a coarse drawing. (E) is a waveform diagram showing a thrust pattern of the voice coil motor 25, (f) is a waveform diagram showing a thrust pattern of the voice coil motor 26, and (g) is a voice coil motor. It is a wave form diagram which shows 24 thrust patterns.

  For example, when the coarse movement stage 14 is moved in the Y direction with the operation pattern shown in FIG. 9A, the coarse movement stage 14 and the fine movement stage 20 are accelerated between T1 and T2 and constant between T2 and T3. It moves at a speed and decelerates between T3 and T4 (see FIG. 9B). Then, a + acceleration signal G1 and a -acceleration signal G2 are generated from the speed changes of the coarse movement stage 14 and the fine movement stage 20, and are accelerated and decelerated (see FIG. 9C). Based on this, the Y-direction linear motor 18 generates a thrust + S1 for acceleration between T1 and T2, and generates a thrust -S2 for deceleration between T3 and T4 (see FIG. 9D). ).

  On the other hand, the voice coil motors 24 to 26 that drive the fine movement stage 20 generate a holding force that can maintain the state in which the fine movement stage 20 is pressed against the coarse movement stage 14. That is, when the coarse motion stage 14 accelerates, the thrust of the voice coil motors 25 and 26 in the Y direction is determined from the acceleration generated in the coarse motion stage 14, and a constant thrust for disturbance compensation is added to this thrust. By adding 24 to 26 and reinforcing the holding force, the fine movement stage 20 can follow the acceleration operation of the coarse movement stage 14 (see FIGS. 9E and 9F).

  In this embodiment, since the coarse movement stage 14 moves only in the Y direction, the thrust of the X direction voice coil motor 24 is kept constant only for disturbance compensation (see FIG. 9G). . As described above, since the current flowing through the voice coil motors 24 to 26 can be minimized, the amount of heat generated by the motor can be minimized.

  Here, a control procedure executed by the control device 30 configured as described above will be described with reference to a flowchart of FIG.

  As shown in FIG. 10, when the power switch is turned on in S11, the control device 30 proceeds to S12 and performs an initialization process. In this initialization process, the voice coil motors 24 to 26 are driven with a small drive current by the control method 2 shown in FIG. 8 to press the fine movement stage 20 against the positioning pins 50 to 52 at a slow speed. Thereafter, by gradually increasing the thrust of the voice coil motors 24 to 26, the impact caused by the contact between the fine movement stage 20 and the positioning pins 50 to 52 can be reduced.

  Next, magnetic pole detection of the Y direction linear motor 18 is performed. At this time, the coarse movement stage 14 may operate, but the magnitude of the thrust generated by the voice coil motors 24 to 26 is adjusted so that the fine movement stage 20 does not move away from the positioning pins 50 to 52.

  Next, the origin of the coarse movement stage 14 is reset. Thereby, the coordinate data of the origin position of the coarse movement stage 14 is updated.

The Y-direction linear motor 18 is driven by the control method 2 shown in FIG. The coarse movement stage 14 is positioned in the Y direction by feedback control by measuring the position by the Y direction linear scale 16 while being driven by the Y direction linear motor 18. At this time, the fine movement stage 20 is restricted in movement by the thrust of the voice coil motors 24 to 26 and the positioning pins 50 to 52, and moves together with the coarse movement stage 14. That is, fine movement stage 20 is driven by voice coil motors 24 to 26 and is held in a state of being pressed against positioning pins 50 to 52.

  At this time, the current to the voice coil motors 24 to 26 is controlled so as to generate a thrust force required for the voice coil motors 24 to 26 to press the fine movement stage 20 against the positioning pins 50 to 52. As this control method, for example, there is a method of continuously generating a value obtained by adding disturbance compensation to a thrust required to realize the maximum acceleration of the coarse movement stage 14 by the fine movement stage 20. Further, by suppressing the thrust by the voice coil motors 24 to 26 to the minimum necessary, heat generation due to the current applied to the voice coil motors 24 to 26 is reduced, and accuracy deterioration can be suppressed.

As a method of determining the thrust required for the operation from the stage command pattern, the following method is performed.
(1) The operation pattern of the stage is determined (see FIG. 9A).
(2) The thrust required for each of the voice coil motors 24 to 26 is calculated from the acceleration of the stage (see FIG. 9D).
(3) In the direction in which fine movement stage 20 is pushed by positioning pins 50 to 52 by acceleration, the necessary thrust is set to O (see FIGS. 9E and 9F).
(4) Add disturbance compensation components (see FIGS. 9E and 9F).

  In the holding state in which the fine movement stage 20 is pressed against the positioning pins 50 to 52, there is no fear that the fine movement stage 20 may become uncontrollable due to disturbance or the like, so that the coarse movement stage 14 can be operated at a higher speed and acceleration. become. In this embodiment, a dedicated structure such as a holding brake for locking the fine movement stage 20 is not necessary. Moreover, you may implement the measurement by the laser interferometers 21-23 as needed.

  In next S14, the laser interferometers 21 to 23 are reset. In S14, since the fine movement stage 20 may rotate and exceed the measurement allowable range of the laser interferometers 21 to 23, the measured value of the fine movement stage 20 is reset by resetting the laser interferometers 21 to 23 before being operated. To reset.

  As a method of improving the reproducibility of the measurement value of the fine movement stage 20, the driving force of the voice coil motors 24-26 is made constant while the coarse movement stage 14 is positioned at a predetermined reset position. If the reset is performed in a state where the pressing force of the positioning pins 50 to 52 is constant, the accuracy of the origin position can be further improved. Further, by performing alignment before processing, the reproducibility of the measurement value of fine movement stage 20 by resetting laser interferometers 21 to 23 can be prevented from affecting processing accuracy.

  In the next S15, by switching from the control method 2 shown in FIG. 8 to the control method 1 shown in FIG. 7, the fine movement stage 20 uses the laser interferometers 21 to 23 while being driven by the voice coil motors 24 to 26. Positioning in the XYθ direction is performed by feedback control by performing the measured position.

  Next, by the control method 1 shown in FIG. 7, the voice coil motors 24 to 26 are driven to start position control for finely moving the fine movement stage 20 conveyed to the processing area by the coarse movement stage 14 to a predetermined position. In this processing area, high-speed response and high-accuracy positioning by driving the voice coil motors 24 to 26 are required.

  That is, in the coarse motion control in which the coarse motion stage 14 is moved at a high speed, the coarse motion stage 14 is driven by the linear motor 18, and positioning in the Y direction is performed by feedback control based on position measurement data from the linear scale 16. Thereafter, in fine movement control, fine movement stage 20 is driven by voice coil motors 24 to 26, and positioning of XYθ is performed by feedback control based on position measurement data measured by laser interferometers 21 to 23.

  At this time, position commands for the X and θ axes are input only to the fine movement stage controller 80, and command values for the Y axis are input to the coarse movement stage controller 70 and the fine movement stage controller 80. The coarse movement stage controller 70 and the fine movement stage controller 80 perform positioning by feedback control with respect to each position command.

  Then, in S16, the fine movement stage 20 stops at a predetermined processing position, and in S17, it is confirmed whether or not the optical processing is finished. When the optical processing is completed, it is confirmed whether all the processing positions set in advance in S18 are completed. If all the preset processing positions have not been completed in S18, the process proceeds to S19, the coordinate data of the next processing position is read, and the processes of S14 to S18 are repeated.

  In S18, when all the preset processing positions are completed, the process proceeds to S20 to check whether there is a request for optical processing mask replacement. In S20, when there is no request for mask exchange, the process proceeds to S21, and it is confirmed whether or not the work exchange is completed. If the workpiece replacement is completed in S21, the process returns to S14 and the processes after S14 are executed.

  Thus, when moving to a mask exchange position, it switches from the control system 1 shown in FIG. 7 to the control system 2 shown in FIG.

  In the next S22, the coarse movement stage 14 is moved to the mask replacement position by the driving force of the Y-direction linear motor 18 as in S13. At this time, the fine movement stage 20 is restricted in movement by the thrust of the voice coil motors 24 to 26 and the positioning pins 50 to 52, and moves together with the coarse movement stage 14.

  In next S23, it is confirmed whether or not the mask exchange is completed. If the mask replacement is completed in S23, the process proceeds to S24 to check whether the power switch is turned off. In S24, when the power switch is on, the process returns to S13, and the processes after S13 are executed.

  Proceed to check whether the work exchange has been completed. If the workpiece replacement is completed in S21, the process returns to S14 and the processes after S14 are executed.

  If the power switch is turned off in S24, the current process is terminated.

  FIG. 11 is a perspective view showing the configuration of the second embodiment. FIG. 12 is a front view showing the configuration of the second embodiment. 11 and 12, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  11 and 12, the stage device 90 includes a base 12, a pair of Y-direction linear scales 16 provided on the base 12, and a pair of Y-direction linear motors 18 provided on the base 12. A pair of linear guides 34 and a Y-direction coarse movement stage 92 driven by the Y-direction linear motor 18.

  The Y direction coarse movement stage 92 is provided with an X direction linear motor 94, an X direction linear guide 96, an X direction linear scale 98, and an X direction coarse movement stage 100 driven by the X direction linear motor 94. Yes. Accordingly, the coarse movement stage 14 is configured by combining the Y direction coarse movement stage 92 and the X direction coarse movement stage 100.

  The X direction coarse movement stage 100 is formed in an L shape when viewed from above, and voice coil motors 24 to 26 for driving the fine movement stage 20 are provided. An X-direction mirror 46 that reflects the laser light from the laser interferometer 21 and a Y-direction mirror 102 that reflects the laser light from the laser interferometers 22 and 23 are provided on the fine movement stage 20.

  Further, on the lower surfaces of the fine movement stage 20 and the X-direction coarse movement stage 100, a static pressure pad 56 that moves through the air layer is provided on the upper surface of the base 12. The fine movement stage 20 can move at a high speed in the Y direction integrally with the Y direction coarse movement stage 92 via the X direction coarse movement stage 100, or can move at a high speed in the X direction integrally with the X direction coarse movement stage 100. It is supported.

  Further, the position of the fine movement stage 20 is measured by the laser interferometers 21 to 23 as in the case of the first embodiment, and is finely controlled by being driven by the voice coil motors 24 to 26.

  Here, the control system of the stage apparatus 90 will be described. FIG. 13 is a block diagram illustrating a configuration example of a control system of the stage apparatus 90. In FIG. 13, similarly to the control system shown in FIG. 7 described above, the control device 30 includes a position command unit 60, a coarse movement stage controller 70, and a fine movement stage controller 80.

  The position command unit 60 includes a position command output unit 62 and a trajectory data generation unit 64. The coarse motion stage controller 70 includes a low-pass filter 72, a resolution correction unit 74, and a coarse motion PID control unit 76. The fine movement stage controller 80 has a fine movement PID controller 82.

  In the stage device 90, when the fine movement stage 20 is driven, the reaction force of the voice coil motors 24 to 26 is transmitted from the fine movement stage 20 to the coarse movement stage 14 (the X direction coarse movement stage 100 and the Y direction coarse movement stage 92). However, no reaction force is transmitted from the coarse movement stage 14 to the fine movement stage 20 when the coarse movement stage 14 is driven. The reaction force of the voice coil motors 24 to 26 generated in the fine movement stage 20 is transmitted to the coarse movement stage 14, but the influence is small. In particular, since the Y-direction linear motor 18 is used as means for driving the coarse movement stage 14, reaction force is hardly transmitted when the coarse movement stage 14 is driven.

  Further, although the motor reaction force generated by the coarse movement stage 14 and the disturbance force from the linear guide 34 are transmitted to the base 12, it is much smaller than the reaction force generated from the fine movement stage 20. That is, in the stage apparatus 90, since the guide of the fine movement stage 20 is performed by the static pressure pad 56 and the position measurement is performed by the laser interferometers 21 to 23, both the guide and the measurement system are performed based on the base 12, There is almost no influence by the coarse movement stage 14.

  Further, since the high-frequency component is removed by the low-pass filter 72 in the command for driving the coarse movement stage 14, the operation of the coarse movement stage 14 can be smoothed. It becomes possible to make the reaction force of F smaller.

  Further, when the cut-off frequency of the low-pass filter 72 is low, the reaction force becomes small, but the relative position between the coarse movement stage 14 and the fine movement stage 20 becomes large, so that the stroke of the voice coil motors 24 to 26 is increased. Need to be long.

  However, when the base 12 vibrates, a position error occurs not only in the coarse movement stage 14 but also in the fine movement stage 20, but the transmission of the disturbance force to the base 12 is small as described above. For this reason, the vibration of the base 12 is configured to be extremely small. Moreover, since both the guide and measurement of the fine movement stage 20 are performed in a non-contact manner with respect to the base 12, even if the base 12 vibrates, the transmission of disturbance force to the fine movement stage 20 is small.

  FIG. 14 is a waveform diagram of a position command signal output from the position command unit 60. FIG. 15 is a waveform diagram showing changes in the movement position of fine movement stage 20. FIG. 16 is a waveform diagram showing the position error of fine movement stage 20.

  Comparing the graph I of the position command signal shown in FIG. 14 with the graph II of the movement position change shown in FIG. 15, it can be seen that the graphs I and II substantially coincide with the passage of time. Also, from the graph III of FIG. 16, the difference between the graphs I and II is a very small difference, and it can be seen that the responsiveness of the position control when moving the fine movement stage 20 is high.

  In the above-described embodiments, the optical processing mask is described as being attached to the fine movement stage 20, but the present invention is not limited to this. For example, optical components such as lenses and filters, and semiconductor chips on which precision processing is performed. Etc.) can be attached.

It is a perspective view which shows Example 1 of the stage apparatus by this invention. It is a top view of the stage apparatus shown in FIG. It is a rear view of the stage apparatus shown in FIG. 3 is an enlarged perspective view showing a mounting structure of fine movement stage 20. FIG. It is a top view which expands and shows the state of the fine movement stage 20 which performs fine movement control in a processing position. It is a top view which expands and shows the holding | maintenance state of the fine movement stage 20 at the time of carrying out coarse movement operation | movement. It is a block diagram which shows a control system when the fine movement stage 20 moves. It is a block diagram which shows a control system when the fine movement stage 20 has stopped. It is a timing chart which shows an example of change of each signal concerning stage control. 4 is a flowchart for illustrating a control procedure executed by control device 30. FIG. 6 is a perspective view showing a configuration of Example 2. 6 is a front view showing a configuration of Example 2. FIG. It is a block diagram which shows the structural example of the control system of the stage apparatus 90 of Example 2. FIG. It is a wave form diagram of the position command signal output from the position command part 60 of Example 2. FIG. It is a wave form diagram which shows the change of the movement position of the fine movement stage 20 of Example 2. FIG. It is a wave form diagram which shows the position error of the fine movement stage 20 of Example 2. FIG.

Explanation of symbols

10, 90 Stage device 12 Base 14 Coarse movement stage 16 Y direction linear scale 18 Y direction linear motor 20 Fine movement stages 21 to 23 Laser interferometers 24 to 26 Voice coil motors 28 and 29 Movement limiter 30 Controller 34 Linear guide 46 X Mirror 47, 48 Y1, Y2 mirror 50 X direction positioning pin 51, 52 Y direction positioning pin 56 Static pressure pad 60 Position command unit 62 Position command output unit 64, 64a-64c Orbit data generation unit 70 Coarse movement stage controller 72 Low pass filter 74 Resolution correction unit 76 Coarse motion PID control unit 80 Fine motion stage controller 82 Fine motion PID control units 82a to 82c Feedback control units 82d to 82f Current control unit 92 Y direction coarse motion stage 94 X direction linear motor 96 X direction linear guide 98 X Direction Linear scale 100 X direction coarse movement stage 102 Y direction mirror

Claims (15)

Base and
A first stage movably provided on the base;
First measuring means for measuring the position of the first stage;
First driving means for driving the first stage;
A second stage provided to move on the base together with the first stage;
Second measuring means for measuring the position of the second stage;
Second driving means for driving the second stage in the other direction with respect to the first stage;
A movement restricting means for restricting movement of the second stage relative to the first stage in the X and Y directions when the first stage is moved by the first driving means;
When performing coarse movement control for moving the first stage, the second stage is held in contact with the movement restricting means by the suction force of the second driving means, and measured by the first measuring means. When fine movement control is performed to drive the first driving means and finely move the second stage based on the obtained position data, the holding by the second driving means is released and the position measured by the second measuring means Control means for driving the second drive means based on the data;
A stage apparatus characterized by comprising: The first driving means is a linear motor that coarsely moves the first stage,
The stage device according to claim 1, wherein the second driving unit is a voice coil motor that finely moves the second stage.   The second driving means includes a first voice coil motor that drives the second stage in one direction, a second voice coil motor that drives the second stage in the other direction, and the second stage in the rotation direction. The stage device according to claim 2, further comprising a third voice coil motor to be driven.   The stage apparatus according to claim 1, wherein the second stage is slidably supported by a static pressure pad that floats on the base via an air layer. The first measuring means is a linear scale,
The stage apparatus according to claim 1, wherein the second measuring unit is a laser interferometer.   The movement restricting means is a positioning member that is provided on the first stage or the second stage and abuts so as to restrict a relative position between the first stage and the second stage in the proximity direction. The stage apparatus according to claim 1.   The stage apparatus according to claim 1, wherein the second stage is provided so as to be positioned on the same plane as the first stage.   The stage apparatus according to claim 1, wherein the movement restricting unit is provided so as to be located in the same plane as the second driving unit.   2. The control unit according to claim 1, wherein the control unit holds the second stage in a state where movement of the second stage is restricted by the movement restriction unit when the second stage moves out of the processing position along with the movement of the first stage. Stage equipment.   The stage device according to claim 9, wherein the control unit causes the second driving unit to generate a predetermined thrust in accordance with an acceleration of the first stage.   The stage device according to claim 9, wherein the control unit obtains an acceleration of the first stage based on a measurement result of the first measurement unit.   The stage device according to claim 9, wherein the control unit performs switching between measurement start and measurement stop by the second measurement unit at a reference position of the first measurement unit. The control means, the first, drives the first, second driving means on the basis of the position data measured by the first measuring means when moving the position where the second stage is out of the processing position, 13. The stage apparatus according to claim 12, wherein when the first and second stages are stopped at the processing position, the second driving unit is driven based on position data measured by the second measuring unit. .   The control means resets the second measuring means in a state where the movement of the second stage is restricted by the movement restricting means when the second stage moves out of the processing position along with the movement of the first stage. The stage apparatus according to claim 9. Base and
A first stage movably provided on the base;
First measuring means for measuring the position of the first stage;
First driving means for driving the first stage;
A second stage provided to move on the base together with the first stage;
Second measuring means for measuring the position of the second stage;
Second driving means for driving the second stage in the other direction with respect to the first stage;
A movement restricting means for restricting movement of the second stage relative to the first stage in the X and Y directions when the first stage is moved by the first driving means;
A method for controlling a stage apparatus comprising:
When the second stage deviates from the processing position, the second stage is brought into contact with the movement restricting means by the suction force of the second driving means to maintain the movement restricted state of the second stage, and the second stage When the stage is at the processing position, the second driving unit is controlled to switch the second stage to a state in which the second stage is separated from the movement limiting unit and the limitation is released.

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