Positioning device, lithographic apparatus and article manufacturing method

Abstract

This invention relates to a positioning device, a photolithography apparatus, and a method for manufacturing an article. The invention provides a positioning device for positioning an object, comprising: a first actuator and a second actuator configured to be arranged parallel to each other along a first direction and to move a beam in the first direction; a third actuator configured to be built into the beam and to move the object relative to the beam in a second direction, the second direction intersecting the first direction; and a control unit configured to control the first actuator, the second actuator, and the third actuator.

Description

Technical Field

[0001] This invention relates to positioning devices, photolithography devices, and methods for manufacturing articles. Background Technology

[0002] In recent years, with the rapid development of high integration in semiconductor devices, higher positioning accuracy is required in lithography equipment (such as exposure equipment) used to manufacture semiconductor devices. In addition, high-precision positioning needs to be completed at a faster speed in lithography equipment to increase production volume.

[0003] Japanese Patent Publications H6-163359 and H8-314517 disclose technologies related to positioning devices applicable to this photolithography apparatus. Japanese Patent Publication H6-163359 discloses a positioning device called an H-shaped stage device, configured such that an X-beam including a built-in X-actuator is connected to two parallel Y-actuators (extending horizontally relative to the two Y-actuators). In this positioning device, yaw vibrations caused by movement in the X and Y directions are suppressed by performing feedback control, in which the distribution ratio between the two Y-actuators is calculated in real time by measuring the rotational displacement about the center of mass caused by the position in the X direction.

[0004] Furthermore, Japanese Patent Publication No. H8-314517 discloses a technique in which, in order to suppress inter-axis interference and disturbances that depend on the position and orientation of the worktable, switching between inter-axis decoupling commands to be applied based on position and speed. This technique suppresses vibrations of the XY worktable and the θz worktable (rotary worktable) on the XY worktable caused by torques generated by movement in the X or Y direction.

[0005] During the movement of an object, a torque is generated in a direction different from the direction of movement due to the displacement between the object's center of mass and the applied force. Therefore, in high-precision positioning devices, the torque generated by the object's movement is suppressed by aligning the object's center of mass and the applied force with each other. However, due to factors such as weight reduction, constraints on arrangement, and manufacturing tolerances, it is strictly impossible to make the object's center of mass and the applied force coincide. Therefore, vibration is transmitted not only to the main axis of movement but also to other axes not involved in the movement.

[0006] The techniques disclosed in Japanese Patent Publication Nos. H6-163359 and H8-314517 effectively suppress vibrations caused by interference with other axes. However, the technique disclosed in Japanese Patent Publication No. H6-163359 uses sensors to detect the yaw vibration of the X-beam and suppresses this vibration through feedback control; this results in a response delay. Furthermore, the technique disclosed in Japanese Patent Publication No. H8-314517 can suppress the vibration of the θz stage, but cannot suppress the yaw vibration of the X-beam connected between the two Y actuators. In particular, with the increase in precision and production volume in lithography equipment (such as exposure equipment) in recent years, the impact of X-beam yaw vibration on equipment performance has become significant. Summary of the Invention

[0007] This invention provides a positioning device that facilitates high-precision positioning.

[0008] According to a first aspect of the invention, a positioning device is provided for positioning an object, the positioning device comprising: a first actuator and a second actuator configured to be arranged parallel to each other along a first direction and to move a beam in the first direction; a third actuator configured to be built into the beam and to move the object relative to the beam in a second direction, the second direction intersecting the first direction; and a control unit configured to control the first actuator, the second actuator, and the third actuator, wherein the control unit obtains from a first operating amount to be applied to the third actuator to move the object to a first target position in the second direction, and respective first correction operating amounts to be applied to the first actuator and the second actuator to reduce rotation in the beam caused by the object moving to the first target position, applies the first operating amount to the third actuator, applies the respective first correction operating amounts to the first actuator and the second actuator, and performs feedforward control on the first actuator and the second actuator.

[0009] According to a second aspect of the invention, a positioning device is provided for positioning an object, the positioning device comprising: a first actuator configured to move a beam in a first direction; a second actuator configured to be integrated within the beam and configured to move the object relative to the beam in a second direction, the second direction intersecting the first direction; and a control unit configured to control the first actuator and the second actuator, wherein the control unit obtains from an operation amount to be applied to the second actuator to move the object to a first target position in the second direction a correction operation amount to be applied to the first actuator to reduce displacement in the beam in a direction other than the second direction caused by the object moving to the first target position, applies the operation amount to the second actuator, applies the correction operation amount to the first actuator, and performs feedforward control on the first actuator.

[0010] According to a third aspect of the present invention, a photolithography apparatus is provided for forming a pattern on a substrate, the photolithography apparatus including the aforementioned positioning device, the positioning device using the substrate as an object for positioning.

[0011] According to a fourth aspect of the present invention, a photolithography apparatus is provided for forming a pattern on a substrate using a master plate, the photolithography apparatus including the aforementioned positioning device, the positioning device using the master plate as an object for positioning.

[0012] According to a fifth aspect of the present invention, a method for manufacturing an article is provided, comprising: forming a pattern on a substrate using the aforementioned photolithography apparatus; processing the substrate on which a pattern has been formed in a pattern forming process; and manufacturing an article from the processed substrate.

[0013] Other aspects of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0014] Figure 1 This is a schematic diagram showing the configuration of a positioning device as one aspect of the present invention.

[0015] Figure 2 This is a schematic diagram showing the configuration of a positioning device as one aspect of the present invention.

[0016] Figure 3A and Figure 3B This is a diagram used to describe the reduction of X-beam yaw vibration (rotation) according to this embodiment.

[0017] Figure 4 This is a diagram used to describe the control of each actuator according to this embodiment.

[0018] Figure 5 This is a diagram used to describe the control of each actuator according to this embodiment.

[0019] Figure 6 This is a diagram used to describe the control of each actuator according to this embodiment.

[0020] Figure 7A , Figure 7B and Figure 7C This is a diagram illustrating an example of thrust correction.

[0021] Figure 8A , Figure 8B and Figure 8C This is a diagram illustrating an example of X-beam rotation information.

[0022] Figure 9 This is a schematic diagram showing the configuration of an exposure apparatus as one aspect of the present invention. Detailed Implementation

[0023] Embodiments will be described in detail below with reference to the accompanying drawings. It should be noted that the following embodiments are not intended to limit the scope of the invention. Multiple features are described in the embodiments, but the invention is not limited to all of them; multiple features can be appropriately combined. Furthermore, the same reference numerals in the drawings denote the same or similar configurations, and repeated descriptions are omitted.

[0024] Figure 1 and Figure 2 This is a schematic diagram showing the configuration of the positioning device 100, which is one aspect of the present invention. Figure 1 This is a diagram used to describe the first worktable SG1 that makes up the positioning device 100. Figure 2 This is a diagram illustrating the second worktable SG2 that makes up the positioning device 100. The positioning device 100 has the function of positioning objects and is specifically implemented as a worktable device with XY actuators arranged in an H-shape, or a so-called H-shaped worktable device, such as... Figure 1 As shown. The positioning device 100 is suitable as a positioning device, for example, for positioning a substrate S in an exposure apparatus for exposing the substrate S. In this embodiment, the direction parallel to the X-beam 1 is the X-direction (a second direction intersecting the first direction), and the direction perpendicular to the X-beam 1 is the Y-axis.

[0025] YL actuator 3-1 (first actuator) and YR actuator 3-2 (second actuator) are arranged parallel to each other along the Y direction (first direction). YL actuator 3-1 and YR actuator 3-2 are actuators for moving X beam 1 in the Y direction.

[0026] X-beam 1 includes a built-in X-actuator 1-1 (third actuator), which is connected to YL-actuator 3-1 and YR-actuator 3-2 while spanning between them (extending horizontally). In other words, the two actuators, YL-actuator 3-1 and YR-actuator 3-2, are arranged on both sides of X-beam 1, perpendicular to X-beam 1. Additionally, an X-slider air cushion guide 5 is provided, allowing X-slider 2 (the object) to move along X-beam 1 while avoiding contact with it. X-actuator 1-1 is an actuator for moving X-slider 2 relative to X-beam 1 in the X direction (a second direction intersecting the first direction).

[0027] like Figure 2 As shown, the second worktable SG2 (object) holding the substrate S is mounted on the first worktable SG1 in a non-contact manner. The second worktable SG2 is a worktable that can move on the first worktable SG1 within the gap of the radial air cushion guide 4 along the Z direction, the tilt direction, and the rotation direction. In this way, the positioning device 100 is configured to move along six axes in the X, Y, Z, θx, θy, and θz directions.

[0028] The second stage SG2 is equipped with an X-bar mirror 8-2 and a Y-bar mirror 9-2. Additionally, an X-laser interferometer 8-1 is positioned relative to the X-bar mirror 8-2, and a Y-laser interferometer 9-1 and a Y-yawing interferometer 10 are positioned relative to the Y-bar mirror 9-2. In this manner, the position of the second stage SG2 in the X direction, its position in the Y direction, and its rotation θz about the Z-axis can be measured. Furthermore, an X-pitch laser interferometer (not shown) arranged along the Z direction at a position different from that of the X-laser interferometer 8-1 measures the rotation θy of the second stage SG2 about the Y-axis. Similarly, a Y-pitch laser interferometer (not shown) arranged along the Z direction at a position different from that of the Y-laser interferometer 9-1 measures the rotation θy of the second stage SG2 about the X-axis. Furthermore, three Z encoders are provided, which measure the position and tilt of the first stage SG1 relative to the second stage SG2 in the Z direction.

[0029] In this embodiment, the second worktable SG2 is rotated relative to the first worktable SG1 about the Z-axis by means of the θz motor 6 (fourth actuator) (performing θz drive). The θz motor 6 is an actuator for rotating the second worktable SG2, which is mounted on the X slider 2, in a plane defined by two axes (Y-axis and X-axis) extending along the Y and X directions respectively (in the XY plane). Therefore, the second worktable SG2 serves as a worktable that can rotate in the XY plane. In addition, three Z motors (not shown) are provided, which are capable of movement in the Z direction and rotation about the X and Y axes (performing θx drive and θy drive).

[0030] The control unit CU consists of an information processing device (computer) including a CPU and memory, and controls the entire positioning device 100 according to the program stored in the storage unit. In this embodiment, the control unit CU controls YL actuator 3-1, YR actuator 3-2, X actuator 1-1, etc. The following is a detailed description of the control performed by the control unit CU on YL actuator 3-1, YR actuator 3-2, and X actuator 1-1.

[0031] Assume that the X slider 2 moves along the X direction on the positioning device 100, specifically in the positive direction of the X-axis as shown by arrow AR1. Furthermore, assume that a centroid displacement 103 has occurred between the centroid 101 of the XY moving part including the second worktable SG2 and the reaction force 102 caused by the force of the X actuator 1-1.

[0032] In this case, due to the movement of slider 2 in the positive X-axis direction, a clockwise torque 104 is generated relative to beam 1, such as... Figure 1 As shown. Furthermore, due to the torque 104 already generated relative to X-beam 1, X-beam 1 rotates clockwise, as... Figure 3A As shown, since X-beam 1 is constrained by the Y-slider air cushion guide 12 in a manner supported externally between the movable elements of YL actuator 3-1 and YR actuator 3-2, the aforementioned rotational or so-called yaw vibration of X-beam 1 recovers to the neutral point of the guide over time. However, under the constraint of the Y-slider air cushion guide 12, the attenuation rate is low and a long time is required before the yaw vibration subsides; therefore, the yaw vibration becomes a disturbance to X, Y, and θz, thereby affecting the stability of X-beam 1.

[0033] In the positioning device 100, to achieve high-precision positioning, the torque 104 generated by the movement is suppressed as much as possible by aligning the center of mass 101 of the XY moving part and the force (reaction force 102) of the X actuator 1-1 with each other. However, considering factors such as weight reduction, constraints on arrangement, and manufacturing tolerances, it is strictly impossible to make the center of mass 101 of the XY moving part and the force (reaction force 102) of the X actuator 1-1 coincide with each other. Therefore, the movement in the X direction causes a certain degree of yaw vibration in the X beam 1.

[0034] For this reason, in this embodiment, in order to reduce the yaw vibration of X-beam 1, such as... Figure 3B As shown, a correction operation amount 105 is applied to the YL actuator 3-1 and the YR actuator 3-2 to counteract the torque 104 generated by the movement in the X direction. Specifically, different correction operation amounts 105 are applied to the YL actuator 3-1 and the YR actuator 3-2 respectively, so that a torque is generated in the opposite direction to the rotation direction of the torque 104. This can suppress the rotation (yaw vibration) of the X beam 1 caused by the torque 104 generated by the movement in the X direction.

[0035] Torque 104 is generated by the reaction force of actuator X 1-1. Figure 1 Since a centroid displacement 103 has already occurred in the positive direction along the Y-axis, the torque 104 applied to the X-beam 1 acts in a clockwise direction when the X-slider 2 moves in the positive direction along the X-axis. Therefore, the torque 104 applied to the X-beam 1 can be counteracted by generating a counterclockwise force in the YL actuator 3-1 and the YR actuator 3-2. Specifically, relative to the Y-coordinate, the torque 104 is counteracted by applying a force in the negative direction to the YL actuator 3-1 and a force in the positive direction to the YR actuator 3-2.

[0036] On the other hand, when the X slider 2 moves in the negative direction along the X-axis, the torque applied to the X beam 1 acts in the counterclockwise direction. Therefore, the counterclockwise torque applied to the X beam 1 can be counteracted by generating a clockwise force in the YL actuator 3-1 and the YR actuator 3-2. Specifically, relative to the Y coordinate, the torque 104 is counteracted by applying a force in the positive direction to the YL actuator 3-1 and a force in the negative direction to the YR actuator 3-2.

[0037] The moment 104 of X-beam 1 is proportional to the force in the X direction. Therefore, the yaw vibration of X-beam 1 can be reduced by applying a correction operation amount 105 with a proportional constant to the YL actuator 3-1 and YR actuator 3-2 respectively with the aforementioned positive and negative signs for the force in the X direction.

[0038] Figure 4 This is a diagram illustrating the control performed by the control unit CU on actuators YL 3-1, YR 3-2, and X 1-1. Figure 4 In the diagram, the upper box represents the control box related to the X-axis (X-actuator 1-1), and the lower box represents the control box related to the Y-axis (YL-actuator 3-1 and YR-actuator 3-2). Figure 4 In this embodiment, the control that is characteristic of this embodiment, specifically the control that suppresses the yaw vibration of beam X1 by using the X operation amount, is the control path from X to beam YL (XtoBeamYL) and from X to beam YR (XtoBeamYR).

[0039] The X-operation quantity is used as the input to X-to-beam YL and X-to-beam YR. The X-operation quantity is obtained as the sum of the following: the sum of the feedforward control set (acceleration feedforward (AccFF), jerk feedforward (JerkFF), and snap feedforward (SnapFF)) obtained by multiple time differentiations of the target value (target position in the X direction); and the output of the PID controller. The input to the control paths X-to-beam YL and X-to-beam YR is extracted in the early stage of the decoupling matrix so that only the force required for movement in the X direction (drive along the X axis) is extracted. For example, if the operation quantity is extracted from the later stage of the decoupling matrix, the X-operation quantity includes not only the force associated with movement from X to X (XtoX), but also the damping force interfering with other axes (such as Y to X (YtoX), Z to X (ZtoX), Qx to X (QxtoX), Qy to X (QytoX), and Qz to X (QztoX)).

[0040] In this embodiment, the result of multiplying the X operation amount by the gain and distribution rate of X to beam YL and X to beam YR is obtained. The sign of the result is reversed, and the result with the reversed sign is used as the correction operation amount to be applied to YL actuator 3-1 and YR actuator 3-2 (addition or subtraction), respectively. These correction operation amounts (outputs) are added to a later stage in which thrust distribution is performed on each of YL actuator 3-1 and YR actuator 3-2 according to the X position. When the force relative to X actuator 1-1 has already caused a centroid displacement 103 in the positive direction along the Y-axis, the movement of X slider 2 in the positive direction along the X-axis causes the torque 104 applied to X beam 1 to act in a clockwise direction, as mentioned above. Therefore, to suppress the rotation of X-beam 1, it is sufficient to generate a force in the counterclockwise direction, and thus the correction operation amount to be applied to YL actuator 3-1 is given a negative sign, and the correction operation amount to be applied to YR actuator 3-2 is given a positive sign. On the other hand, when the force relative to X actuator 1-1 has already caused a centroid displacement 103 in the negative direction along the Y-axis, although it is necessary to reverse the sign of the correction operation amount to be input, optimal control can be performed by making the gains of X-to-beam YL and X-to-beam YR negative and executing the input. The gains of X-to-beam YL and X-to-beam YR represent the proportionality constant of the centroid displacement 103. By appropriately setting the value of this proportionality constant, a force (correction operation amount) can be output to YL actuator 3-1 and YR actuator 3-2 to counteract the torque 104 generated in X-beam 1 relative to the force generated during movement in the X direction.

[0041] As described above, in this embodiment, the control unit CU obtains different first correction operation amounts to be applied to the YL actuator 3-1 and the YR actuator 3-2 respectively, from the first operation amount, which is the X operation amount, in order to reduce the rotation occurring in the X beam 1. It should be noted that the first operation amount is the first operation amount applied to the X actuator 1-1 to move the X slider 2 to a first target position in the X direction. Then, the control unit CU applies the different first correction operation amounts to the YR actuator 3-2 and the YL actuator 3-1 respectively. At this time, since the control unit CU applies the first operation amount to the X actuator 1-1, feedforward control is performed on the YR actuator 3-2 and the YL actuator 3-1.

[0042] In this embodiment, the positioning device 100 does not require a measurement unit for measuring the rotation (yaw vibration) of the X-beam 1. However, a measurement unit for measuring the rotation of the X-beam 1 can be provided along with the control paths from X to beam YL and from X to beam YR, and feedback control can be performed on the YL actuator 3-1 and YR actuator 3-2 based on the measurement results from this measurement unit. For example, based on the rotation of the X-beam 1 measured by the measurement unit after a first operation amount (X operation amount) is applied to the X actuator 1-1, different second correction operation amounts are obtained to be applied to the YR actuator 3-2 and YL actuator 3-1 respectively to reduce the aforementioned rotation. Then, feedback control is performed on the YL actuator 3-1 and YR actuator 3-2 by applying the different second correction operation amounts to the YL actuator 3-1 and YR actuator 3-2 respectively. This can accelerate the response to suppressing the yaw vibration of the X-beam 1, thereby achieving an enhanced effect compared to simple feedback control.

[0043] Furthermore, although this embodiment has been described for the case where the correction operation amounts to be applied to YL actuator 3-1 and YR actuator 3-2 are obtained from the X operation amount, interaxial interference occurs not only relative to X, but also relative to Y and θz. For example, when a displacement of the center of mass has already occurred in the X direction, the rotation (yaw vibration) of X beam 1 can be suppressed by obtaining the correction operation amounts to be applied to YL actuator 3-1 and YR actuator 3-2 respectively from the Y operation amount. In addition, when the second stage SG2 rotates about the Z-axis (θz), the center of mass of the XY moving part and the force of X actuator 1-1 are always different from each other, so X beam 1 is subjected to a reaction force. In this case, the rotation (yaw vibration) of X beam 1 can be suppressed by obtaining the correction operation amounts to be applied to YL actuator 3-1 and YR actuator 3-2 respectively from the θz operation amount.

[0044] In addition, refer to Figure 4 The decoupling matrix is ​​the inter-axis decoupling control disclosed in Patent Document 2. When the control paths X to beam YL and X to beam YR are applied, decoupling control of the Z, tilt, and rotation of the second worktable SG2 (not shown) together with the X and Y of the first worktable SG1 leads to overcorrection. Therefore, a more enhanced effect is achieved by readjusting the individual parameters of the decoupling matrix (X to X, Y to X, Z to X, Qx to X, Qy to X, and Qz to X). It should be noted that in Figure 4 In the diagram, the input of each parameter of the decoupling matrix is ​​omitted.

[0045] In addition, such as Figure 5As shown, filters can be added to the control paths from X to beam YL and from X to beam YR. This filter is a bandpass filter that extracts and outputs only the specific frequency corresponding to the principal component of the rotation (yaw vibration) of beam X1, which is currently moving in the X direction. However, depending on the positioning device, a high-pass filter that blocks only the DC component or a low-pass filter that blocks only the AC component can be added to the control paths from X to beam YL and from X to beam YR. These filters can reduce the influence of noise and increase gain, thereby improving the vibration suppression effect relative to a specific frequency.

[0046] In addition, such as Figure 6 As shown, YL ripple, YR ripple, and X ripple can be added. Figure 5 The control unit CU shown in the diagram (control block) serves as a thrust correction table for correcting thrust unevenness in each actuator. In this embodiment, as mentioned earlier, feedback control of the YL actuator 3-1 and YR actuator 3-2 is not required by measuring the rotation of the X-beam 1; open-loop control without measuring the rotation of the X-beam 1 can be performed. However, when the rotation of the X-beam 1 is not measured, it is preferable that the forces of the YL actuator 3-1 and YR actuator 3-2 are balanced.

[0047] In linear motors, typically used as a typical example of actuators, thrust non-uniformity (thrust fluctuation) occurs periodically due to changes in the magnetic flux of the magnet and coil, corresponding to the distance between the magnet and coil, depending on the position of the movable element relative to the stationary element. Given this situation, as... Figure 6 As shown, X-ripple is used to correct thrust non-uniformity depending on the position in the X direction. Additionally, YL and YR ripples are used to correct thrust non-uniformity depending on the position in the Y direction. These types of ripples are table parameters of thrust non-uniformity relative to position, and the correction values ​​change depending on the position. Therefore, the actual actuator force corresponding to the operating amount can be applied consistently at any position along the X direction, thus controlling the YL actuator 3-1 and YR actuator 3-2 to have completely equal thrust. Therefore, even in open-loop control without measuring the rotation of X-beam 1, the suppression of yaw vibration of X-beam 1 corresponding to the X-direction movement operating amount can be stably achieved.

[0048] On the other hand, when the aforementioned corrections using individual ripples are not performed, thrust variations occur in each actuator depending on its position. For example, in actuator X 1-1, the torque (force) generated relative to the X operation varies. Furthermore, in actuators YL 3-1 and YR 3-2, the balance between the thrust of actuator YL 3-1 and the thrust of actuator YR 3-2 varies depending on their position. Therefore, correcting the thrust non-uniformity of each actuator contributes to the stability of the effect of suppressing the yaw vibration of beam X1.

[0049] The method for obtaining such a thrust correction table as YL ripple, YR ripple, and X ripple is now described. The thrust of a linear motor is proportional to the back electromotive force (EMF). Therefore, when obtaining a thrust correction table, it is typically the back EMF or thrust correction table generated during constant acceleration movement is obtained. However, when the back EMF cannot be measured, the control quantity of feedback control can be used instead. For example, the operating quantity during the constant acceleration period (or constant deceleration period) during any constant acceleration movement can be extracted. Figure 6 In this context, the operand is equivalent to the sum of the following: the sum of the feedforward (FF) gains, and the output of the PID controller. This extraction of the operand is achieved by performing this extraction while simultaneously making a small change in position. Figures 7A to 7C The operation curves are shown, and a thrust correction table corresponding to each position can be generated. Figures 7A to 7C In the diagram, the horizontal axis represents the position to be controlled on each axis, and the vertical axis represents the operational quantity corresponding to any acceleration. Specifically, it is the average of the absolute values ​​of the operational quantities for the same acceleration and deceleration at the same position. By using the average of acceleration and deceleration, the effects of directional differences, such as the reaction force associated with the action, can be reduced. (Reference) Figures 7A to 7C The thin line represents the operating amount before correction ("before"), and the thick line represents the operating amount after correction. Using the values ​​shown by the thin line as a table, a gain corresponding to the ratio of the table values ​​is applied to the operating amount through multiplication, based on the amplitude (strength) of the table. When the ratio is precise, or when thrust non-uniformity is accurately reproduced, the corrected operating amount is represented by the constant value shown by the thick line. By adjusting the table to reduce the amplitude of the corrected operating amount, the actual actuator thrust is output accurately relative to the operating amount.

[0050] Figure 7A The thrust correction table for the X-axis (X-actuator 1-1) is shown. For the X-axis, since it is controlled by one actuator, X-actuator 1-1, it is sufficient to simply obtain the operating amount used to control the X-axis. On the other hand, for the Y-axis, it is controlled by two actuators, YL actuator 3-1 and YR actuator 3-2. Therefore, simply obtaining the operating amount used to control the Y-axis would involve generating the same thrust correction table relative to YL actuator 3-1 and YR actuator 3-2, thus deriving the sum. Since YL actuator 3-1 and YR actuator 3-2 are different actuators, it is necessary to generate different tables as thrust correction tables.

[0051] Therefore, in this embodiment, different types of thrust nonuniformity are obtained for the YL actuator 3-1 and the YR actuator 3-2. Specifically, equivalent to [the desired effect] is obtained by controlling the Y-axis using only the YL actuator 3-1 and extracting the operation amount during the iso-acceleration period of any acceleration movement. Figure 7BThe amount of operation before correction is shown for the thin line. Similarly, an equivalent is obtained by controlling the Y-axis using only the YR actuator 3-2 and extracting the amount of operation during the iso-acceleration period of arbitrary acceleration movement. Figure 7C The thin line shows the operating amount before correction. Therefore, different thrust correction tables can be generated for YL actuator 3-1 and YR actuator 3-2 respectively. For Y-axis control, since it is necessary to balance the thrust of YL actuator 3-1 and YR actuator 3-2, the thrust correction table is adjusted to produce the same operating amount as the corrected operating amount shown by the thick line. In this way, for Y-axis control, the balance between the thrust of YL actuator 3-1 and YR actuator 3-2 is ensured.

[0052] As mentioned above, even when the back electromotive force cannot be measured, a thrust correction table can be generated based on the amount of operation along each axis.

[0053] By adjusting the correction value according to the position based on this thrust correction table, for example, the balance between the thrust of YL actuator 3-1 and the thrust of YR actuator 3-2 is maintained. Therefore, even in open-loop control without measuring the rotation of X-beam 1, the suppression of the yaw vibration of X-beam 1 becomes stable and can be enhanced. Thus, the measurement unit for measuring the rotation of X-beam 1 becomes unnecessary, and the suppression of the yaw vibration of X-beam 1 can be achieved at low cost.

[0054] Next, the method for obtaining the parameters (control parameters) of X to beam YL and X to beam YR will be described. When the rotation of X beam 1 can be measured, it is sufficient to determine the parameters of X to beam YL and X to beam YR by reducing the rotation of X beam 1 while measuring the movement in the X direction. However, when the rotation of X beam 1 cannot be measured, the above method cannot be used to determine the parameters of X to beam YL and X to beam YR.

[0055] In view of this situation, in this embodiment, firstly, the drive of the radial air cushion guide 4 is stopped, causing the second worktable SG2 to sit on the first worktable SG1, and then the servo control of the second worktable SG2 relative to Z, θx, θy, and θz is stopped (disabled). This puts the second worktable SG2 in a state constrained by the first worktable SG1; thus, the information about the rotation θz of the second worktable SG2 (rotation information) will be consistent with the information about the rotation of the X-beam 1 (rotation information). Rotation information about the rotation θz of the second worktable SG2 is obtained by generating movement in the X direction in the aforementioned state and obtaining rotation information about the rotation θz of the second worktable SG2 with a constant period. Figure 8A The rotation information is shown. Figure 8A The diagram shows the rotation information of beam X1 during movement in the X direction, with the horizontal axis representing time and the vertical axis representing rotation information. Figure 8AIn the diagram, the thin line represents the rotational information ("before") before the yaw vibration of X-beam 1 is reduced according to this embodiment, and the thick line represents the rotational information ("after") after the yaw vibration of X-beam 1 is reduced according to this embodiment. This is an example of applying Fourier transform to... Figure 8A The result of the rotation information shown yielded Figure 8B The horizontal axis represents frequency. Figure 8B In the diagram, the thin line represents the rotational information ("before") before the yaw vibration of X-beam 1 is reduced, according to this embodiment; the thick line represents the rotational information ("after") after the yaw vibration of X-beam 1 is reduced, according to this embodiment. (See reference) Figure 8B It can be seen that before the yaw vibration of X-beam 1 is reduced, there is a low-dampening yaw vibration around a frequency of 100Hz. At this time, the X-operation is... Figure 8C As shown in the image. Figure 8C The operating parameters shown include the effect of the yaw vibration of X beam 1. The yaw vibration during the stabilization period of X beam 1 can be suppressed by adding this X operating parameter to the operating parameters of YL actuator 3-1 and YR actuator 3-2 via a bandpass filter centered at 100Hz corresponding to low attenuation. Then, the optimal gain is obtained by checking X beam 1 while changing the gain and ratio to achieve the maximum attenuation effect of X to beam YL and X to beam YR (trial and error). As a result of setting the optimal bandpass filter and parameters in the aforementioned manner, the amplitude of the yaw vibration of X beam 1 can be reduced, and the attenuation of the yaw vibration of X beam 1 can be accelerated.

[0056] It should be noted that, according to the aforementioned method, since the second worktable SG2, which is actually to be in a non-contact state, comes into contact with the first worktable SG1, high-acceleration movement is impossible. Therefore, it is sufficient to use the aforementioned method for specifying the frequency of the yaw vibration of the X-beam 1 and making a coarse adjustment, and then perform a precise adjustment.

[0057] Specifically, with all axes under servo control, the control deviation in the Y direction after movement in the X direction is minimized by using the same distribution curve as in actual operation (e.g., during exposure), thus adjusting X to beam YL and Y to beam YR. Through this adjustment, the yaw vibration of X beam 1 generates maximum disturbance to the Y axis when the distance between the X coordinate of the Y-bar mirror 9-2 illuminated by light (optical axis) from the Y laser interferometer 9-1 and the X coordinate of the rotation center (θz) of X beam 1 is at its maximum. Therefore, it is effective to perform the aforementioned adjustment at an outer position relative to the X axis.

[0058] Furthermore, when performing actual operations, such as those identical to those during exposure, the deviation during exposure can be adjusted to an evaluation value. The control deviation in the Y direction has two metrics: absolute value and the variation in deviation at different positions in the X direction. The absolute value can be reduced by adjusting the gain while using the average control deviation at all exposure coordinates in the Y direction as the evaluation metric. On the other hand, variation can be suppressed by adjusting the gain while using the standard deviation of the control deviation at all exposure coordinates in the Y direction as the evaluation metric. To reduce the absolute value, it is effective to lower the frequency of the bandpass filter. On the other hand, to suppress the standard deviation, it is necessary to increase the frequency of the bandpass filter and increase the gain. As mentioned above, there is a trade-off between the average value and the standard deviation. When considering the balance, it is sufficient to perform adjustments by using the sum of the average value and the standard deviation as the evaluation value. The optimal adjustment state depends on the required performance of the positioning device, and adjustments need to be performed by selecting an evaluation value in light of this factor.

[0059] Although this embodiment has been described by way of example using an H-shaped worktable device as a positioning device 100, it is not limiting. For example, a method similar to that of this embodiment can also be applied to a worktable device having a structure in which, similar to the X-beam 1 and the second worktable SG2 according to the positioning device 100, a plurality of structural elements having degrees of freedom in the θ direction are configured.

[0060] For example, suppose the second stage SG2 rotates to reach a target rotational position in the XY plane. In this case, to reduce the rotation occurring in the X-beam 1, different correction operation amounts are obtained based on the operation amount applied to the θz motor 6, respectively, to be applied to the YL actuator 3-1 and the YR actuator 3-2. Then, feedforward control is performed on the YL actuator 3-1 and the YR actuator 3-2 by applying this operation amount to the θz motor 6 and applying the obtained different correction operation amounts to the YL actuator 3-1 and the YR actuator 3-2, respectively.

[0061] Alternatively, this method can also be applied to the case where the X slider 2 moves to a second target position in the Y direction. In this case, to reduce the rotation occurring in the X beam 1, different correction operation amounts are obtained for the YL actuator 3-1 and YR actuator 3-2, respectively, based on the operation amounts applied to the YL actuator 3-1 and YR actuator 3-2. Then, feedforward control is performed on the YL actuator 3-1 and YR actuator 3-2 by applying the obtained different correction operation amounts, together with the operation amount used to move to the second target position, to the YL actuator 3-1 and YR actuator 3-2.

[0062] Furthermore, this embodiment can also be applied to a positioning device comprising: a first actuator that moves a beam in a first direction; and a second actuator built into the beam and that moves an object relative to the beam in a second direction intersecting the first direction. In this case, to reduce displacement occurring in the beam in directions other than the second direction, a correction operation amount to be applied to the first actuator is obtained based on the operation amount applied to the second actuator to move the object to a first target position in the second direction. The feature is that feedforward control is performed on the first actuator by applying the operation amount for moving to the first target position to the second actuator and also by applying the obtained correction operation amount to the first actuator.

[0063] Figure 9 This is a schematic diagram illustrating the configuration of an exposure apparatus EX, which is one aspect of the present invention. The exposure apparatus EX is, for example, a photolithography apparatus used in a photolithography process (a manufacturing process for devices such as semiconductor elements and liquid crystal display elements) that forms patterns on a substrate using a master mask. The exposure apparatus EX performs an exposure process in which the pattern of the mask M is transferred to the substrate S by exposing the substrate S via the mask M (photomask) which serves as the master mask. In this embodiment, the exposure apparatus EX uses a step-scan method. However, the exposure apparatus EX may also use a step-repeat method or other exposure methods. It should be noted that... Figure 9 The orientation is represented by the XYZ coordinate system, where the plane parallel to the surface S of the substrate is the XY plane.

[0064] like Figure 9 As shown, the exposure apparatus EX includes a stage surface plate SP, a positioning device 100, a lens barrel surface plate LP, a damper DP, a projection optics system PS, an illumination optics system IS, a mask surface plate MP, and a mask stage MS.

[0065] The stage surface plate SP is supported by the base FL via a bracket (not shown). A positioning device 100 is mounted on the stage surface plate SP. The lens barrel surface plate LP is supported by the base FL via a damper DP. The lens barrel surface plate LP houses the projection optics system PS and the mask surface plate MP. The mask stage MS is movably (slidably) mounted on the mask surface plate MP. The illumination optics system IS is mounted above the mask stage MS.

[0066] During exposure, light emitted from a light source (not shown) illuminates the mask M via an illumination optics system IS. The pattern of the mask M is projected (formed) onto the substrate S via a projection optics system PS. At this time, the mask stage MS and the positioning device 100 scan the mask M and the substrate S respectively in the scanning direction relative to each other. As mentioned earlier, the positioning device 100 used in the exposure apparatus EX can achieve high-precision positioning. Therefore, the exposure apparatus EX can provide high-quality devices (such as semiconductor devices, magnetic storage media, and liquid crystal display elements) with high production volume and high economic efficiency.

[0067] The article manufacturing method according to embodiments of the present invention is applicable to, for example, the manufacture of articles such as devices (e.g., semiconductor elements, magnetic storage media, and liquid crystal display elements). This manufacturing method includes a step of forming a pattern on a substrate using an exposure apparatus EX, a step of processing the patterned substrate, and a step of manufacturing an article from the processed substrate. Additionally, this manufacturing method may include other known steps (oxidation, film formation, vapor deposition, doping, planarization, etching, photoresist stripping, slicing, wire bonding, encapsulation, etc.). Compared to conventional methods, the article manufacturing method according to this embodiment is advantageous in at least one aspect of article performance, quality, productivity, and production cost.

[0068] It should be noted that in this invention, the photolithography apparatus is not limited to an exposure apparatus, but is also applicable to, for example, an imprinting apparatus. The imprinting apparatus brings imprinting material supplied (arranged) on a substrate and a mold (original) into contact with each other, and applies energy for curing to the imprinting material, thereby transferring the pattern of the mold and forming a patterned, cured material.

[0069] In addition, in this embodiment, the positioning device 100 is used as a positioning device for the substrate S in the exposure apparatus EX; however, as long as it is an H-shaped stage device, it can also be used as any positioning device, such as a positioning device for the mask M, i.e., a mask stage MS.

[0070] Although the invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims should be given the broadest interpretation in order to cover all variations and equivalent structures and functions.

Claims

1. A positioning device for positioning an object, the positioning device comprising: first and second actuators arranged parallel to each other along a first direction and moving a beam in the first direction; a third actuator provided in the beam and configured to move the object in a second direction with respect to the beam, the second direction intersecting the first direction; and a control unit configured to control the first, second, and third actuators; wherein the control unit: obtains respective different first correction operation amounts to be applied to the first and second actuators, respectively, from a first operation amount to be applied to the third actuator in order to move the object to a first target position in the second direction, so as to reduce a rotation occurring in the beam due to the movement of the object to the first target position; applies the first operation amount to the third actuator; applies the respective different first correction operation amounts to the first and second actuators, respectively; performs feedforward control on the first and second actuators; includes a band-pass filter that extracts a specific frequency corresponding to a principal component of the rotation from the first operation amount and outputs the specific frequency; and obtains the respective different first correction operation amounts from the output of the band-pass filter.

2. The positioning device according to claim 1, wherein the respective different first correction operation amounts are operation amounts to move the object in the first direction toward an opposite direction.

3. The positioning device according to claim 1, further comprising: a measurement unit configured to measure a rotation of the beam, wherein the control unit performs feedback control on the first and second actuators by applying second correction operation amounts different from each other to the first and second actuators, respectively, from the rotation measured by the measurement unit after the first operation amount has been applied to the third actuator, so as to reduce the rotation.

4. The positioning device according to claim 1, wherein the control unit performs feedforward control on the first and second actuators by applying third correction operation amounts different from each other to the first and second actuators, respectively, from second operation amounts to be applied to each of the first and second actuators in order to move the object in the first direction, so as to reduce a rotation occurring in the beam due to the movement of the object in the first direction.

5. The positioning device according to claim 1, wherein the control unit determines a gain and a ratio for obtaining the respective different first correction operation amounts based on a measurement result of a rotation occurring in the beam due to the movement of the object in the second direction.

6. The positioning device according to claim 5, further comprising: a stage configured to hold the object and rotatable on a plane defined by two axes extending along the first and second directions, respectively; and a measurement unit configured to measure a rotation of the stage, wherein the control unit determines the gain and the ratio based on a measurement result obtained by the measurement unit in a state where the stage is constrained by the beam.

7. The positioning device according to claim 1, wherein the control unit determines a gain and a ratio for obtaining the respective different first correction operation amounts based on a positional control deviation of the object in the first direction due to the movement of the object in the second direction. ​ ​ 8. The positioning device according to claim 1, wherein the first direction and the second direction are perpendicular to each other.

9. A positioning device for positioning an object, the positioning device comprising: first and second actuators arranged parallel to each other along a first direction and configured to move a beam in the first direction; a third actuator provided in the beam and configured to move the object in a second direction with respect to the beam, the second direction intersecting the first direction; and a fourth actuator configured to rotate a table with respect to the beam on a plane defined by two axes extending along the first and second directions, respectively, the table being provided on a slide arranged on the beam; and a control unit configured to control the first, second, third, and fourth actuators; wherein the control unit: obtains respective different first correction operation amounts to be applied to the first and second actuators so as to reduce a rotation occurring in the beam due to the object moving to a first target position from a first operation amount to be applied to the third actuator so as to move the object to the first target position in the second direction; applies the first operation amount to the third actuator; applies the respective different first correction operation amounts to the first and second actuators, respectively; performs feedforward control on the first and second actuators; obtains respective different second correction operation amounts to be applied to the first and second actuators so as to reduce a rotation occurring in the beam due to the table moving to a target rotational position from a second operation amount to be applied to the fourth actuator so as to rotate the table to the target rotational position on the plane; applies the second operation amount to the fourth actuator; applies the respective different second correction operation amounts to the first and second actuators, respectively; and performs feedforward control on the first and second actuators.

10. A positioning device for positioning an object, the positioning device comprising: first and second actuators arranged parallel to each other along a first direction and configured to move a beam in the first direction; a third actuator provided in the beam and configured to move the object in a second direction with respect to the beam, the second direction intersecting the first direction; and a control unit configured to control the first, second, and third actuators; wherein the control unit: obtains respective different first correction operation amounts to be applied to the first and second actuators so as to reduce a rotation occurring in the beam due to the object moving to a first target position from a first operation amount to be applied to the third actuator so as to move the object to the first target position in the second direction; applies the first operation amount to the third actuator; applies the respective different first correction operation amounts to the first and second actuators, respectively; performs feedforward control on the first and second actuators; includes a thrust correction table for correcting thrust fluctuations of the first, second, and third actuators, respectively, and corrects thrust fluctuations of the first, second, and third actuators, respectively, based on the thrust correction table during movement of the object.

11. The positioning device according to claim 10, wherein the first direction and the second direction are perpendicular to each other. ​ ​ The thrust correction table is generated from operation amounts respectively applied to the first actuator, the second actuator, and the third actuator.

12. The positioning device according to claim 11, wherein The operation amounts respectively applied to the first actuator, the second actuator, and the third actuator include operation amounts during an equal acceleration period and operation amounts during an equal deceleration period when moving the object with constant acceleration.

13. The positioning device according to claim 12, wherein The thrust correction table is adjusted in a manner that reduces the amplitude of the operation amounts respectively applied to the first actuator, the second actuator, and the third actuator.

14. The positioning device according to claim 11, wherein The thrust correction table corresponding to the first actuator is generated from operation amounts applied to the first actuator when moving the object in the first direction using only the first actuator.

15. The positioning device according to claim 11, wherein The thrust correction table corresponding to the second actuator is generated from operation amounts applied to the second actuator when moving the object in the first direction using only the second actuator.

16. A positioning device for positioning an object, the positioning device comprising: a first actuator configured to move the object in a first direction; a second actuator provided in a beam and configured to move the object in a second direction with respect to the beam, the second direction intersecting the first direction; and a control unit configured to control the first actuator and the second actuator, wherein the control unit: obtains a correction operation amount to be applied to the first actuator so as to reduce displacement occurring in the beam in a direction other than the second direction due to movement of the object to a first target position from an operation amount to be applied to the second actuator so as to move the object in the second direction to the first target position; applies the operation amount to the second actuator; applies the correction operation amount to the first actuator; performs feedforward control on the first actuator; includes a band-pass filter that extracts a specific frequency corresponding to a principal component of rotation from the operation amount and outputs the specific frequency; and obtains the correction operation amount from the output of the band-pass filter.

17. A lithography apparatus for forming a pattern on a substrate, the lithography apparatus comprising: the positioning device according to claim 1, the positioning device positioning the substrate as the object.

18. A lithography apparatus for forming a pattern on a substrate, the lithography apparatus comprising: the positioning device according to claim 16, the positioning device positioning the substrate as the object.

19. A lithography apparatus for forming a pattern on a substrate by means of a master, the lithography apparatus comprising: the positioning device according to claim 1, the positioning device positioning the master as the object.

20. A lithography apparatus for forming a pattern on a substrate by means of a master, the lithography apparatus comprising: the positioning device according to claim 16, the positioning device positioning the master as the object.

21. An article manufacturing method comprising: forming a pattern on a substrate using the lithography apparatus according to claim 17; processing the substrate on which the pattern has been formed in the pattern forming process; and manufacturing an article from the processed substrate. ​ ​ 22. An article manufacturing method, comprising: forming a pattern on a substrate using the lithographic apparatus according to claim 18; processing the substrate on which the pattern has been formed in the pattern forming step; and manufacturing an article from the processed substrate.

23. An article manufacturing method, comprising: forming a pattern on a substrate using the lithographic apparatus according to claim 19; processing the substrate on which the pattern has been formed in the pattern forming step; and manufacturing an article from the processed substrate.

24. An article manufacturing method, comprising: forming a pattern on a substrate using the lithographic apparatus according to claim 20; processing the substrate on which the pattern has been formed in the pattern forming step; and manufacturing an article from the processed substrate. ​ ​ ​

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