JP2007067162A - Xy stage - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an XY stage that can easily reduce a stage reaction force by a simple and inexpensive structure. <P>SOLUTION: This XY stage 10 is composed of a surface table 12 and a stage 16. The surface table 12 has a counter mass storage 32, and a counter mass 36 is provided at the lower surface 34 of the table in a way that it can slide freely. The counter mass 36 is provided with a counter mass platen 40 which is a planar material where protruding magnetic areas 58 and non-magnetic areas 60 are located in a grid. At the lower surface 34 of the table, there are counter mass forcers 42, 44 and 46 each of which faces the counter mass platen 40 and serves as a control electronic device with a pair of pole faces 56 where their phases can be shifted at particular phase angles. Because the counter mass 36 is driven by such a linear pulse motor, a reaction caused by stage driving can be reduced easily and inexpensively. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an XY stage that reduces the influence of the driving reaction force of the stage.

In an XY stage applied to a semiconductor, liquid crystal exposure apparatus, inspection apparatus, or the like, when the stage installed on the surface plate is driven, the surface plate vibrates by the reaction force. This vibration causes the positioning time and accuracy of the XY stage to decrease. As a method for reducing the influence of the reaction force when driving the stage, a counter mass method for driving a dummy mass called a counter mass to cancel the drive reaction force of the stage is effective. In order to dispose the actuator for driving the counter mass so as not to interfere with the stage, the design becomes difficult, and there are problems such as complication of the apparatus and increase in footprint. Further, when a reduction mechanism such as a ball screw is used for the counter mass drive mechanism, the reaction force generated by driving the counter mass becomes complicated. For this reason, in Patent Document 1, for example, when the stage is driven, a thrust having the same magnitude as that of the stage is generated by a linear motor to drive the counter mass, thereby canceling the driving reaction force of the stage.
JP 2004-193424 A

  However, since a general linear motor performs commutation control, a position measurement sensor is required. For this reason, a sensor for position measurement is also required for drive control of the counter mass, and there is a problem that the apparatus becomes complicated and expensive.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an XY stage that can reduce the driving reaction force of the stage with a simpler and less expensive configuration.

  The present invention includes a plate-shaped surface plate, a stage that slides on the upper surface of the surface plate, a counter mass that moves so as to cancel the reaction force of sliding of the surface plate, a linear pulse motor that drives the counter mass, The linear pulse motor includes a planar member in which a magnetic region and a nonmagnetic region are arranged in a lattice shape, and a pair of magnetic pole surfaces that face the planar member and can be shifted in phase by a specific phase angle. An XY stage including a control electronic element.

  According to this configuration, the linear pulse motor that drives the counter mass includes a planar member (platen) in which the magnetic area and the non-magnetic area are arranged in a lattice pattern, and faces the planar member by a specific phase angle. Since it has a control electronic element (forcer) including a pair of magnetic pole faces that can be displaced, a sensor for position measurement or the like becomes unnecessary, and the apparatus can be made simple and inexpensive.

  In this case, it is preferable that the counter mass slides on the lower surface of the surface plate. According to this configuration, since the counter mass is provided on the lower surface of the surface plate, it is easy to design so as to avoid interference with the stage, and the area occupied by the apparatus can be reduced.

  In this case, it is preferable that the planar member is provided on the counter mass and the control electronic element is provided on the surface plate. According to this configuration, since the counter mass provided with the planar member (platen) is a mover and the control electronic element (forcer) is provided on the surface plate side, it is not necessary to provide wiring or piping on the mover side, and the design It can be easy.

  In this case, the control system of the linear pulse motor calculates the sum of the target position of the counter mass, the product of the first derivative of the target position and the speed gain, and the product of the second derivative of the target position and the acceleration gain value. Preferably comprising an element consisting of

  According to this configuration, the control system of the linear pulse motor that drives the counter mass has the target position of the counter mass, the product of the first derivative of the target position and the speed gain, the second derivative of the target position, and the acceleration. Since the element including the sum of the gain value and the product is included, the linear pulse motor can be controlled to follow the target position without delay or vibration.

  In this case, the speed gain is a value that cancels out the deviation between the target position and the current position when the counter mass is moving at constant speed, and the acceleration gain is when the counter mass is moving at non-constant speed. It is preferable that the value cancels out the deviation between the target position and the current position.

  According to this configuration, it is possible to cancel the deviation between the target position and the current position when the counter mass is moved at a constant speed and during acceleration / deceleration.

  In this case, it is preferable that the control system of the linear pulse motor includes a proportional element including a mass ratio between the stage and the counter mass. According to this configuration, it is possible to make the reaction force accompanying the driving of the stage and the reaction force accompanying the driving of the counter mass the same.

  In this case, the control system of the linear pulse motor includes a differential element and an element for performing low-pass filter processing, which is obtained by multiplying the current position of the stage by the mass ratio of the stage and the counter mass as a target position of the counter mass. Is preferred.

  According to this configuration, since the current position of the stage is used for the control system, it is not affected by the delay from the target trajectory. In addition, since the differential element and the element that performs low-pass filter processing are included, it is possible to remove noise components included in the measured current position information and obtain good characteristics.

  In this case, the control system of the linear pulse motor includes an integral element and an element for performing high-pass filter processing by controlling the target position of the counter mass so that the force for moving the stage is equal to the output of the linear pulse motor. Is preferred.

  According to this configuration, the reaction force is canceled according to the thrust generated by the linear pulse motor, so that it is not affected by the stage characteristics or the target trajectory. In addition, since it includes an integration element and an element that performs high-pass filter processing, drift due to integration can be reduced.

  According to the XY stage of the present invention, reaction force due to driving of the stage can be reduced with a simpler and less expensive configuration.

  Hereinafter, an XY stage according to an embodiment of the present invention will be described with reference to the accompanying drawings. In addition, the same component is shown with the same code | symbol and the overlapping description is abbreviate | omitted.

  FIG. 1 is a perspective view showing the configuration of an XY stage according to the first embodiment of the present invention, and FIG. 2 is a perspective sectional view showing the internal configuration of the XY stage according to the first embodiment of the present invention. FIG. 2 is a side sectional view showing an internal configuration of an XY stage according to the first embodiment of the present invention.

  As shown in FIGS. 1 and 2, the XY stage 10 of the present embodiment is composed of a substantially plate-shaped surface plate 12 and a stage 16 that is slidable in the XY directions on the upper surface of the surface plate 12. Yes. A stage platen 14 is provided on the upper surface of the surface plate 12. The stage platen 14 is a planar member in which protruding magnetic areas 52 and nonmagnetic areas 54 surrounding the protruding magnetic areas 52 are arranged in a lattice pattern.

  Three forcers, a stage forcer (X) 18, a stage forcer (Y 1) 20, and a stage forcer (Y 2) 22, are attached to the lower surface of the stage 16. Each of the stage forcers 18, 20, and 22 is a control electronic element that has a plurality of pairs of magnetic pole faces 50 that face the stage platen 14 and can be shifted in phase by a specific phase angle. By shifting the phase of the magnetic force lines of the three stage forcers 18, 20, and 22, the balance of the magnetic force with the stage platen 14 fluctuates to generate driving thrust as a linear pulse motor, and the stage 16 is moved in the XY direction. It can be moved by a minute distance and rotated by a minute angle around the Z axis. The operation signals of the stage forcers 18, 20 and 22 are supplied by the control unit 48.

  An air ejection hole (not shown) is provided on the lower surface of the stage 16, and an air bearing is formed by the air ejected from the ejection port toward the stage platen 14, and the stage 16 slightly floats from the stage platen 14. To do.

  The XY stage includes an X-axis laser interferometer 28 and a Y-axis laser interferometer 30. In addition, the stage 16 includes an X-axis mirror 24 and a Y-axis mirror 26 that receive and reflect laser beams from the X-axis laser interferometer 28 and the Y-axis laser interferometer 30, respectively. The X-axis laser interferometer 28 and the Y-axis laser interferometer 30 can measure the position and rotation angle of the stage by measuring the laser beams reflected from the X-axis mirror 24 and the Y-axis mirror 26, respectively. It is like that. As shown in FIG. 3, the measurement results of the X-axis laser interferometer 28 and the Y-axis laser interferometer 30 are transmitted to the control unit 48.

  As shown in FIGS. 2 and 3, the surface plate 12 is provided with a counter mass accommodating portion 32, and the surface plate lower surface 34 is slidably provided with a counter mass 36. A counter mass platen 40 is provided on the upper surface of the counter mass 36. As shown in FIG. 4, the counter mass platen 40 is a planar member in which protruding magnetic areas 58 and nonmagnetic areas 60 surrounding the counter magnetic area 58 are arranged in a lattice pattern.

  As shown in FIG. 5, the surface plate lower surface 34 is provided with three forcers, a counter mass forcer (X) 42, a counter mass forcer (Y 1) 44, and a counter mass forcer (Y 2) 46. Each counter mass forcer 42, 44, 46 is a control electronic element that has a plurality of pairs of magnetic pole surfaces 56 that face the counter mass platen 40 and can be shifted in phase by a specific phase angle. By shifting the phase of the magnetic lines of force of the three counter mass forcers 42, 44, 46, the balance of the magnetic force with the counter mass platen 40 fluctuates to generate driving thrust as a linear pulse motor, It can be moved by a minute distance in the XY directions and rotated by a minute angle around the Z axis. The arrangement of the counter mass forcers 42, 44, 46 is preferably the same as that of the stage forcers 18, 20, 22. The operation signals of the counter mass forcers 42, 44, 46 are supplied from the control unit 48.

  An air jet hole (not shown) is provided in the lower surface 34 of the platen, and an air bearing is formed by the air jetted from the jet port toward the counter mass platen 40. The counter mass 36 is suspended in the counter mass housing portion 32 by the balance between the attractive force generated by the magnetic force of the counter mass forcers 42, 44 and 46 and the repulsive force of the air bearing.

  The capacity of the counter mass forcers 42, 44, 46 and the mass of the counter mass 36 are appropriately determined by the mass of the stage 16 and the driving thrust of the linear pulse motor that drives the stage 16. The driving thrust required for the counter mass forcers 42, 44, 46 may be the same as the driving thrust of the stage forcers 18, 20, 22. On the other hand, since the counter mass 36 is suspended by the adsorption force of the counter mass forcers 42, 44, 46, the mass of the counter mass 36 must be within an adsorbable range. Generally, the attracting force of the forcer is 5 to 10 times the driving thrust. If the mass of the counter mass 36 is large, the operation stroke required for the reaction force processing may be small. If the mass of the counter mass is n times the mass of the stage 16, the operation stroke of the counter mass 36 may be 1 / n of the operation stroke of the stage 16.

  Contrary to the configuration shown in FIG. 3, the counter mass plater 40 may be provided with the counter mass forcers 42, 44, 46, and the counter mass platen 40 may be provided on the surface plate lower surface 34. By attaching to the counter mass 36, it is not necessary to attach wiring and piping for operating the forcer and the air bearing to the moving counter mass 36, and the configuration of the apparatus can be simplified.

  Hereinafter, the control system in the XY stage of this embodiment will be described. In the linear pulse motor, in order to move from a certain stable state to a stable point separated by a distance x, the tooth pitch τ of the counter mass platen 40 (the length between the pair of magnetic sections 58 and the nonmagnetic section 60) is used. Sometimes, the phase of the excitation current supplied to the magnetic poles of the counter mass forcers 42, 44, 46 may be advanced by 2π · x / τ.

  When the moving distance of the counter mass 36 is sufficiently smaller than the tooth pitch τ of the counter mass platen 40, the phase may be advanced instantaneously. However, when the moving distance is large, the phase of the excitation current is gradually advanced to finally It is necessary to set a desired phase. This has a relationship represented by C · I · sin (θ) between the torque F generated by the linear pulse motor and the phase advance angle θ (C and I are constants), and the torque F is the phase advance angle θ. This is because the linearity deteriorates when the value exceeds π / 4, the torque decreases when the value exceeds π / 2, and the torque reverses when the value exceeds π.

Here, consider driving of the counter mass 36 in the X-axis direction. The case where the counter mass 36 which is stably stopped at the position x _s by the excitation movement θ _s is moved to the target position x _e is taken as an example. First, appropriate speed and acceleration are set, and a trajectory as shown in FIG. 8 is generated. From the relationship between the position of the linear pulse motor and the excitation phase, the excitation phase θ _c for each time after the start of operation can be obtained from the instantaneous target position x _{com as} shown in the following equation (1). An excitation phase pattern for operating can be obtained.

However, since the linear pulse motor has a relationship in which the torque F is generated only after the phase advance angle θ is _output , there is a problem that the position x of the moving counter mass 36 is delayed compared to the instantaneous target position _xcom . Further, the relationship in which the torque F depends on the position x of the counter mass is equivalent to the fact that the mechanical spring is coupled, and there is a problem that vibration occurs due to acceleration / deceleration. Considering the application of the linear pulse motor to reaction force processing, the difference between the current position and the target position means that thrust is not generated as planned. It becomes a problem that is not fully countered. In particular, differences due to vibration and delay may not only counteract the reaction force associated with the stage drive, but may increase it.

Therefore, in the present embodiment, the following control law is used. The following equation is an equation showing the control law in this embodiment, and FIG. 6 is a block diagram showing the control system of the XY stage according to the first embodiment of the present invention.

However, in FIG. 6 and the above _{equation, x Sref:} stage target _{position, k aF:} acceleration _{gain, k vF:} speed gain, M: counter mass mass, _{m x:} Stage mass is. Moreover, s is a Laplace transformer and represents differentiation. Further, K _STG : stage control law, P _STG : stage characteristic, and P (s): counter mass characteristic. x _Sref includes an acceleration section, a constant speed section, and a deceleration section, but there may be no constant speed section depending on conditions. Another expression of the control law of this embodiment can be expressed by the following expression.

  FIG. 7 is a block diagram showing a linear pulse motor system for driving the counter mass according to the first embodiment of the present invention. In FIG. 7, D represents an attenuation coefficient. The CI in FIG. 7 is a linearization of the above-described CIsin (θ). If the phase advance angle θ is in the range of ± π / 4, this linearization error is small.

In the system of FIG. 7, the relationship between the position x of the counter mass 36 and the instantaneous target position _xcom is expressed by the following equation.

The vibration generated by the linear pulse motor is due to the denominator polynomial Ms ² + Ds + 2πCI / τ. Wherein the system described above _{^{(2): x com = (}} k aF s 2 + k vF s + 1) when performing controlled by _{x ref,} the deviation between the _{x ref} and x is expressed by the following equation.

The steady-state deviation while moving at a constant speed v ₀ is expressed by the following equation according to the final value theorem.

Therefore, when the servo gain is adjusted so as to reduce the deviation between the target position x _ref and the current position x in the constant speed section with respect to the speed gain k _vF , the following adjustment is made.

In a state where the adjustment for the speed gain k _vF is completed, a deviation that occurs during acceleration / deceleration at a constant acceleration a ₀ is expressed by the following equation.

Therefore, when the servo adjustment is performed so that the deviation between the target position x _ref and the current position x is reduced in the constant velocity section with respect to the acceleration gain _kaF , the following adjustment is performed.

As a result, the control law of this embodiment is adjusted as follows: This control law has a linear pulse motor denominator polynomial in the numerator and cancels it. Therefore, as a result, the linear pulse motor can be operated so as not to generate vibration.

The control system preferably has a feedback-free configuration that does not require a measurement system, but parameter adjustment is preferably performed while measuring. Or you may employ | adopt the value of following Formula directly as a theoretical value, without implementing adjustment according to the said procedure. As a result, the number of adjustment steps can be reduced, but an error between the design value and the actual machine may deteriorate the characteristics.

According to the control law according to the present embodiment, the position x of the counter mass 36 follows the instantaneous target position x _ref = − (m _x / M) × _Sref without delay or vibration. If the stage position x _STG follows the stage target position x _Sref with high accuracy, a relationship of the following equation is always established between the stage position x _STG and the position x of the counter mass 36.

Stage position _{x STG,} the reaction force _{f s} due to the stage driving stage mass _{m x} is approximately expressed by the following equation.

On the other hand, position x, the reaction force f _p with the driving of the counter mass 36 of mass M is roughly expressed by the following equation.

Accordingly, the opposite is always the same order of magnitude as the f _s and f _p, the force acting on the surface plate 12 is offset. The vibration of the surface plate 12 is suppressed, and the positioning accuracy of the stage 16 is improved. Further, the moment around the Y axis of gravity acting on the counter mass 36 and the stage 16 is expressed by the following equation. In the following formula, g is gravitational acceleration. According to the control law according to the present embodiment, the value of the following equation becomes substantially constant, and the inclination and vibration of the surface plate 12 due to the change in the balance of gravity acting on the surface plate 12 can be suppressed.

The above description is for the X axis, but the same is true for the Y axis. Furthermore, it also applies to the angle theta _Z around the Z-axis, the above-described method may be applied to convert the rotation system from translational system. If you want to increase the moment of inertia of the counter mass 36 because the θ _Z moment generated in the stage 16 is large, but you want to reduce the mass of the counter mass 36 due to the attraction force of the counter mass forcers 42, 44, 46, This can be dealt with by thinning only the center of 36.

Hereinafter, a second embodiment of the present invention will be described. FIG. 9 is a block diagram showing a control system of a linear pulse sawer motor for driving a counter mass according to the second embodiment of the present invention, and FIG. 10 shows an XY stage control system according to the second embodiment of the present invention. The following equation is an equation showing the control law. 9 and 10 and the following equation, K (s) represents a feedback control law, and PID control or the like is applied.

This embodiment is different from the first embodiment in that high accuracy is achieved by measuring the current position x of the counter mass 36 and performing feedback control. Although FIG. 14 is a block diagram showing a control system of a conventional Soyamota, in the control system of the embodiment as shown in FIG. 9, it is provided with a path for applying the instantaneous target position x _ref. For this reason, the driving accuracy of the counter mass 36 can be further improved.

In embodiments performing such feedback control, when adjusting the speed gain k _vF and acceleration gain k _aF is in a disabled state feedback control (K (s) = 0) , making these adjustments. After the adjustment of the speed gain _{k vF} and acceleration gain _{k aF} is completed, adjust the K (s).

  In the first and second embodiments described above, when the target trajectory of the stage 16 is stepped, or when an infinite acceleration that does not have an acceleration / deceleration section is requested, the input is abnormal and operates normally. There is a possibility not to. In the above embodiment, an appropriate acceleration / deceleration section is required for the trajectory generation pattern, and the magnitude of acceleration in that section must be smaller than the acceleration limit of the counter mass 36. Further, when the current position of the stage 16 has an error such as a delay with respect to the stage target trajectory, the reaction force may not be sufficiently canceled.

Hereinafter, a third embodiment of the present invention will be described. FIG. 11 is a block diagram showing a control system of the XY stage according to the third embodiment of the present invention, and the following equation is an equation showing the control law. However, in FIG. 11 and the following equation, ω is a cut-off angular frequency of the low-pass filter. The reaction force cannot be canceled at a frequency higher than ω, but the noise component can be removed. ζ is an attenuation coefficient, and is usually about 0.8.

In this embodiment, the current position x _STG of the stage multiplied by the mass ratio-(m _x / M) between the stage 16 and the counter mass 36 is used as the instantaneous target position x _ref of the counter mass, and a low-pass filter is used as a differential element. The point which utilized the element which performs the pseudo differentiation which performs a process differs from the above-mentioned 1st and 2nd embodiment. In this embodiment, since the current position x _STG of the stage 16 is used, it is not affected by the delay from the target trajectory. Since the current position x _STG of the stage 16 uses values measured by the X-axis laser interferometer 28 and the Y-axis laser interferometer 30, noise components increase when first-order differentiation and second-order differentiation are performed. Therefore, good characteristics can be obtained by using pseudo-differentiation applied with a low-pass filter.

However, in the present embodiment, when the stage 16 is subjected to friction, internal vibration, or the like, the position x _{STG of the} stage 16 is affected by other than the thrust generated from the linear pulse motor. When such a disturbance factor is large, reaction force cancellation by driving the stage 16 may be insufficient.

The fourth embodiment of the present invention will be described below. FIG. 12 is a block diagram showing the control system of the XY stage according to the fourth embodiment of the present invention, and the following equation is an equation showing the control law. In FIG. 12 and the following equation, f _Sref is a thrust generated by the linear pulse motor that drives the stage 16 and can be obtained from a torque command to the stage 16 and an applied current of the linear pulse motor that drives the stage 16. Further, ω is a cut-off angular frequency of the high-pass filter. For example, if it is 1 Hz, it is 2π. If ω is small, the reaction force can be canceled to a lower frequency, but the offset accompanying the drift becomes large. On the other hand, if ω is large, the drift is small but only the high frequency reaction force is canceled. ζ is an attenuation coefficient, and is usually about 0.8.

  In the present embodiment, the target position of the counter mass 36 is controlled so that the force that moves the stage 16 and the output of the linear pulse motor that drives the counter mass 36 are equal, and an element that performs high-pass filter processing is used as an integral element. This is different from the first to third embodiments described above. In the present embodiment, the reaction force is canceled according to the thrust generated by the linear pulse motor that drives the stage 16, so that it is not affected by the characteristics of the stage 16 or the conditions of the target trajectory.

The trajectory of the counter mass 36 that generates the thrust f _Sref is expressed by the following equation.

In order to prevent drift due to integration, it is preferable to use the following equation together with a high-pass filter.

Although it is difficult to obtain a general damping coefficient _{D, k vF → D / (} 2πCI / τ), since it is adjusted as _{k aF → M / (2πCI /} τ), the _{(k vF / k aF) M} → D It is good to use. Therefore, a desirable control law is as follows.

  In the present embodiment, the stationary position of the counter mass 36 becomes indefinite, and the gravity balance may be lost. In addition, the stroke of movement of the counter mass 36 may be increased.

The fifth embodiment of the present invention will be described below. FIG. 13 is a block diagram showing a control system of an XY stage according to the fourth embodiment of the present invention, and the following equation is an equation showing the control law. This embodiment is different from the first to fourth embodiments in that the position of the stage 16 is used by combining the control law of the third embodiment with the control law of the fourth embodiment described above. . Thereby, the gravity balance in 4th Embodiment collapses or the fault that the stroke of a counter mass becomes large can be reduced.

That is, the control law of the entire system is as follows.

  Note that the XY stage of the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the scope of the present invention.

It is a perspective view which shows the structure of the XY stage which concerns on 1st Embodiment of this invention. It is a perspective sectional view showing the internal configuration of the XY stage according to the first embodiment of the present invention. It is a sectional side view which shows the internal structure of the XY stage which concerns on 1st Embodiment of this invention. It is a perspective view which shows the platen provided in the counter mass upper surface which concerns on 1st Embodiment of this invention. It is a figure which shows arrangement | positioning of the forcer which drives the counter mass provided in the surface plate lower surface which concerns on 1st Embodiment of this invention. It is a block diagram which shows the control system of the XY stage which concerns on 1st Embodiment of this invention. It is a block which shows the system of the linear pulse motor which drives the counter mass which concerns on 1st Embodiment of this invention. It is a graph which shows the relationship between the target position of the counter mass which concerns on 1st Embodiment of this invention, speed and acceleration, and time. It is a block diagram which shows the control system of the linear pulse sawer motor which drives the counter mass which concerns on 2nd Embodiment of this invention. It is a block diagram which shows the control system of the XY stage which concerns on 2nd Embodiment of this invention. It is a block diagram which shows the control system of the XY stage which concerns on 3rd Embodiment of this invention. It is a block diagram which shows the control system of the XY stage which concerns on 4th Embodiment of this invention. It is a block diagram which shows the control system of the XY stage which concerns on 5th Embodiment of this invention. It is a block diagram which shows the control system of the conventional Soya motor.

Explanation of symbols

10 ... XY stage, 12 ... surface plate, 14 ... stage platen, 16 ... stage, 18 ... stage forcer (X), 20 ... stage forcer (Y1), 22 ... stage forcer (Y2), 24 ... X axis Mirror, 26 ... Y-axis mirror, 28 ... X-axis laser interferometer, 30 ... Y-axis laser interferometer, 32 ... Counter mass storage section, 34 ... Lower surface plate, 36 ... Counter mass, 40 ... Counter mass platen, 42 ... Counter mass forcer (X) 44 ... Counter mass forcer (Y1) 46 ... Counter mass forcer (Y2) 48 ... Control unit 50 ... Pole surface 52 ... Magnetic area 54 ... Non-magnetic area 56 ... magnetic pole, 58 ... magnetic area, 60 ... non-magnetic area.

Claims (8)

A surface plate,
A stage sliding on the upper surface of the platen;
A counter mass that moves so as to cancel the reaction force of sliding of the surface plate;
A linear pulse motor for driving the counter mass;
With
The linear pulse motor is
A planar member in which magnetic and non-magnetic areas are arranged in a grid pattern;
A control electronic element including a pair of magnetic pole faces facing the planar member and capable of shifting phases by a specific phase angle from each other;
Having
XY stage.   The XY stage according to claim 1, wherein the counter mass slides on the lower surface of the surface plate.   The XY stage according to claim 1, wherein the planar member is provided on the counter mass, and the control electronic element is provided on the surface plate. The control system of the linear pulse motor includes a target position of the counter mass, a product of a first derivative of the target position and a speed gain, and a product of a second derivative of the target position and an acceleration gain value. Including elements consisting of sums,
The XY stage according to any one of claims 1 to 3. The speed gain is a value that cancels a deviation between the target position and the current position when the counter mass is moving at a constant speed,
The acceleration gain is a value that cancels the deviation between the target position and the current position when the counter mass is moving at non-constant speed,
The XY stage according to claim 4. The control system of the linear pulse motor includes a proportional element composed of a mass ratio between the stage and the counter mass.
The XY stage according to any one of claims 1 to 5. The control system of the linear pulse motor includes a differential element and an element that performs a low-pass filter process using a current position of the stage multiplied by a mass ratio of the stage and the counter mass as a target position of the counter mass. ,
The XY stage according to any one of claims 1 to 6. The control system of the linear pulse motor includes an integral element and an element that performs high-pass filter processing by controlling the target position of the counter mass so that the force that moves the stage is equal to the output of the linear pulse motor.
The XY stage according to any one of claims 1 to 7.

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