KR20200049538A - Stage apparatus, lithography apparatus, and article manufacturing method - Google Patents

Abstract

Provided is a favorable technology for controlling a posture of a stage with high precision. A stage apparatus for moving a substrate comprises: a first stage to support the substrate; a second stage including a support mechanism to support the first stage having a rotation angle of which is controlled when the first stage is rotatably mounted; a detecting unit to detect misalignment of the first stage with respect to the second stage; and a control unit to move the second stage before a support force of the support mechanism becomes a threshold value after the support mechanism starts to support the first stage. The control unit estimates a posture error of the second stage due to transformation of the second stage at the processing based on a detection result of the detecting unit, and controls a posture of the second stage for reducing the posture error based on the estimation.

Description

Stage apparatus, lithographic apparatus, and article manufacturing method {STAGE APPARATUS, LITHOGRAPHY APPARATUS, AND ARTICLE MANUFACTURING METHOD}

The present invention relates to a stage apparatus, a lithographic apparatus, and a method of manufacturing an article.

In a lithographic apparatus used for manufacturing semiconductor devices and the like, a stage apparatus for holding and moving a substrate or the like is used. Patent Document 1 discloses a substrate stage (stage apparatus) having a θ table for holding a substrate and an XY table in which the θ table is rotatably mounted. In the substrate stage described in Patent Document 1, the position and posture of the XY table are controlled by using an interferometer that measures the position of the XY table by irradiating light to a mirror provided on the XY table.

Japanese Patent Publication No. 62-200726

In a lithographic apparatus, improvement in tact time is desired. Therefore, as described in Patent Document 1, in the substrate stage having the θ table and the XY table, it is preferable to move the XY table before the holding force of the θ table by the XY table reaches a threshold. However, in such control, since the relative positions of the XY table and the θ table are displaced and their XY tables can be deformed, it may be difficult to accurately control the posture of the XY table. .

Therefore, it is an object of the present invention to provide an advantageous technique for controlling the posture of a stage with high precision.

In order to achieve the above object, a stage device as one aspect of the present invention is a stage device for moving a substrate, a first stage holding the substrate, and the first stage being rotatably mounted, and rotating angle A movable second stage having a holding mechanism for holding the adjusted first stage, a detection unit for detecting a positional deviation of the first stage with respect to the second stage, and the holding mechanism with the first And a control unit for controlling the process of moving the second stage before the holding force of the holding mechanism reaches a threshold value after starting the holding of the stage, wherein the control unit is configured to detect the detection result in the detecting unit. Based on the posture error of the second stage due to the deformation of the second stage during the processing, It is characterized by performing estimation and controlling the posture of the second stage to reduce the posture error based on the estimation.

Another object or other aspect of the present invention will be revealed by preferred embodiments described below with reference to the accompanying drawings.

According to the present invention, it is possible to provide an advantageous technique, for example, in order to accurately control the posture of the stage.

1 is a diagram showing a processing flow of this embodiment.
2 is a schematic view showing the configuration of an exposure apparatus.
3 is a schematic view showing the configuration of a substrate stage.
4 is a diagram showing a conventional processing flow.
5 is a schematic view of a substrate stage.
6 is a schematic view of a substrate stage.
7 is a view for explaining the deformation of the substrate stage (mirror).
8 is a view for explaining the exposure result.
9 is a view for explaining overlapping precision.
10 is a flowchart showing a method for obtaining a reference value.
11 is a flowchart showing a method for determining a correction value.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in each drawing, the same reference numerals are assigned to the same members or elements, and overlapping descriptions are omitted.

A stage device according to an embodiment of the present invention and a configuration of a lithographic apparatus including the stage device will be described. The lithographic apparatus employing the stage apparatus of the present embodiment is used, for example, in a lithography process when manufacturing a liquid crystal display device (liquid crystal panel) or a semiconductor device. Examples of the lithographic apparatus include an exposure apparatus that exposes a substrate, and a molding apparatus (imprint apparatus, flattening apparatus) that molds a composition on a substrate using a mold. Hereinafter, an example in which the stage device of the present embodiment is employed in an exposure device will be described.

The exposure apparatus exposes the substrate M to each of a plurality of shot regions on the substrate W by exposing the substrate W (specifically, a resist (photosensitive agent) applied on the substrate W) with the original M and the light passing through the projection optical system. The process of transferring the pattern of the (exposure process) is performed. The exposure apparatus of this embodiment is a step-and-scan exposure apparatus (scanner) that transfers the pattern of the original plate M to the substrate W while relatively scanning the original plate M and the substrate W, but the exposure apparatus of the step-and-repeat method (Stepper) may be used. Here, as the original plate M, for example, a mask, a reticle, or the like is used, and as the substrate W, for example, a glass plate, a semiconductor wafer, or the like can be used.

[About the configuration of the exposure device]

2 is a schematic diagram showing the configuration of the exposure apparatus 10 of the present embodiment. The exposure apparatus 10 includes, for example, an illumination optical system 1, an alignment detection unit 2, a disc stage 3, a projection optical system 4, a substrate stage 5 (stage apparatus), and a control unit (9). The control unit 9 is configured by, for example, a computer having a CPU, memory, or the like, and is electrically connected to each unit in the device, and controls the overall operation of the device (i.e., exposure processing of the substrate W) Control).

The illumination optical system 1 receives light emitted from a light source (not shown), such as a high-pressure mercury lamp, for example, and illuminates a part of the original plate M with illumination light shaped in a slit shape (for example, arc shape). The disc stage 3 holds the disc M and is configured to be movable at least in the X and Y directions. The projection optical system 4 projects, among the patterns formed on the original plate M, a part of the image illuminated by the illumination optical system 1 onto the substrate W held by the substrate stage 5. The substrate stage 5 holds the substrate W, and on the platen 6 supported by the vibration isolator 8, for example, X, Y, Z, ωX (Roll), ωY (Pitch), ωZ It can be configured to be movable in the 6-axis direction of (Yaw). The original plate M held by the original stage 3 and the substrate W held by the substrate stage 5 are optically conjugated through the projection optical system 4 (the object surface of the projection optical system 4 and Each). The control unit 9 relatively synchronously scans the disk stage 3 and the substrate stage 5 at a speed ratio corresponding to the projection magnification of the projection optical system 4 (for example, in the X direction), so that the pattern of the disk M is placed on the substrate. Can be transferred.

Here, the exposure apparatus 10 may be provided with a measurement unit 7 for measuring the position and posture of the substrate stage 5. The measurement unit 7 irradiates, for example, a light beam (laser light) on the mirror 72 provided on the substrate stage 5, and the substrate stage 5 (mirror 72) by the reflected light from the mirror 72 It may include a laser interferometer 71 to measure the distance to. A plurality of such laser interferometers 71 are provided so as to measure the positions (distances to the plurality of locations) of a plurality of locations on the substrate stage 5 (mirror 72). Thereby, the measurement part 7 can measure (require) the position and posture of the board | substrate stage 5. The control unit 9 can control the movement of the substrate W by controlling the position and posture of the substrate stage 5 on the basis of the measurement result in the measurement unit 7.

Further, the alignment detection unit 2 (alignment scope) has, for example, an imaging element and an optical element, and the position of the mark provided on the substrate W is detected through the original plate M and the projection optical system 4. In the exposure apparatus 10, alignment processing (global alignment) is performed by using the alignment detection unit 2 to obtain arrangement information of a plurality of shot areas on the substrate W. Specifically, before starting the exposure process of the substrate W, the control unit 9 determines the positions of the marks provided in some representative shot regions (sample shot regions) of the substrate W, the substrate stage 5 (substrate W ) Is detected by the alignment detection unit 2 while stepping. Then, by performing statistical processing on the detection values obtained by the alignment detection unit 2, it is possible to obtain the array information of a plurality of shot areas.

[Composition of substrate stage]

Next, a specific configuration of the substrate stage 5 (stage device) will be described. 3 is a schematic diagram showing the configuration of the substrate stage 5. Fig. 3 (a) is a view of the substrate stage 5 seen from above (Z direction), and Fig. 3 (b) is a view of the substrate stage 5 seen from the side (Y direction). The board | substrate stage 5 is the XY stage 52 which can move in the 6-axis direction, with the jaw θ stage 51 (first stage) holding the substrate W and the jaw θ stage 51 rotatably mounted. ) (Second stage). Moreover, the board | substrate stage 5 has the detection part 53 which detects the position shift of the jaw θ stage 51 with respect to the XY stage 52 (relative position of the jaw θ stage 51 and the XY stage 52). It can contain.

The jaw θ stage 51 may include, for example, a substrate chuck 51a that holds the substrate W by vacuum adsorption or the like, and a jaw θ guide 51b that rotatably guides the XY stage 52. have. In this embodiment, the jaw θ guide 51b can have a function as a driving mechanism for rotationally driving the jaw θ stage 51 (substrate chuck 51a) with respect to the XY stage 52. In addition, the reason for providing the crude θ stage 51 in this way is that the driving amount of the substrate W in the ωZ (Yaw) direction cannot be increased in the XY stage 52. That is, by providing the jaw θ stage 51, it becomes possible to sufficiently correct the rotation angle of the substrate W in the ωZ (Yaw) direction.

The XY stage 52 may include, for example, a ceiling plate 52a, an X stage 52b, a driving mechanism 52c, and a holding mechanism 52d. The ceiling plate 52a is mounted with a rotatable θ stage 51 rotatably, and a mirror 72 that reflects light from the measurement unit 7 (laser interferometer 71) is mounted. The X stage 52b is configured to support the ceiling plate 52a and to be movable in the X direction on the platen 6. That is, the substrate W can be moved in the X direction by the X stage 52b. Here, the X stage 52b may be mounted on a Y stage (not shown). The Y stage is configured to support the X stage 52b and to be movable on the platen 6 in the Y direction. That is, the substrate W can be moved in the XY direction by the X stage 52b and the Y stage.

The drive mechanism 52c includes a plurality of actuators disposed between the ceiling plate 52a and the X stage 52b, and drives the ceiling plate 52a in the Z direction by each actuator, so that the ceiling plate 52a and the X stage are driven. The interval of 52b is changed. Thereby, the position and attitude of the top plate 52a in the Z, ωX (Roll), and ωY (Pitch) directions can be adjusted to control the position and attitude of the substrate W. Further, the holding mechanism 52d is provided on the ceiling plate 52a, and is configured to be capable of holding the jaw stage 51 by a holding force such as, for example, a vacuum adsorption force. Specifically, when the rotation angle of the substrate W in the ωZ (Yaw) direction is adjusted (corrected) by the jaw θ stage 51, compressed air is blown out from the holding mechanism 52d (that is, at a constant pressure). ), The jaw θ stage 51 is floated with respect to the ceiling plate 52a. On the other hand, when the rotation angle of the jaw θ stage 51 is adjusted and the substrate W (XY stage 52) is moved, a holding force is generated in the holding mechanism 52d (that is, negative pressure), so that the jaw θ is adjusted. By holding the stage 51, the relative positions of the jaw θ stage 51 and the XY stage 52 are fixed.

Here, in the ceiling plate 52a, as shown in Fig. 3 (a), the mirror 72x for measuring the position of the substrate stage 5 in the X direction, and the position of the substrate stage 5 in the Y direction A mirror 72y for measuring the may be provided. The mirror 72x is irradiated with a plurality of light beams, for example, from the laser interferometer 71x of the measurement unit 7, and the mirror 72y is irradiated with a plurality of light beams, for example, from the laser interferometer 71y of the measurement unit 7 This is investigated. By using a plurality of luminous fluxes in this way, the measurement unit 7 can position the top plate 52a in the X and Y directions, and the top plate 52a in the ωX (Roll), ωY (Pitch), and ωZ (Yaw) directions. ) Can be measured. In addition, the measurement unit 7 may further include a laser interferometer 71z for measuring the position of the ceiling plate 52a in the Z direction.

[Conventional alignment processing]

In the manufacture of a semiconductor device, a liquid crystal panel, or the like, a process of transferring a plurality of patterns to each of the plurality of shot regions on the substrate W may be performed using a lithographic apparatus such as the exposure apparatus 10. At this time, if the position of each layer is shifted, since a desired function as a product cannot be obtained, it is important to superimpose a plurality of layers on the substrate W with high precision. Therefore, in the exposure apparatus 10, the relative position of the mark (alignment mark) of the mask M and the mark (alignment mark) of the substrate W is measured at the time of exposure of the substrate after the second layer and the mask M based on the measurement result. And the substrate W are aligned. The relative position of the mark of the mask M and the mark of the substrate W can be measured from the image obtained by observing the substrate W through the mask M and the projection optical system 4 by the alignment detection unit 2.

As described above, such mark measurement is performed on some representative shot areas (sample shot areas) on the substrate W, and the arrangement information of the plurality of shot areas on the substrate W is obtained from the measurement results. . The processing for obtaining the arrangement information is also called "alignment processing". By comparing the arrangement information obtained in the alignment process with ideal arrangement information (for example, design information), it can be calculated that a plurality of shot regions on the substrate W are arranged with a magnification component or a rotation component compared to the above arrangement. . Based on the calculation results, the posture and rotation of the substrate stage 5 are controlled, or the projection magnification of the projection optical system 4 at the time of scanning exposure, the scanning speed of the original stage 3 and the substrate stage 5 are adjusted. By controlling it, the overlapping precision can be made within an allowable range.

Next, a conventional processing flow that can be performed in the above-described exposure apparatus 10 will be described. 4 is a diagram showing a conventional processing flow. Each process of the flowchart shown in FIG. 4 can be performed by the control unit 9. In addition, FIG. 5 is a diagram for explaining the flowchart process of FIG. 4, and is a schematic view when the substrate stage 5 is viewed from above (top view) and a schematic view when the substrate stage 5 is viewed from the side (bottom) Drawings).

In S201, the control unit 9 moves the XY stage 52 to arrange the first sample shot area at the detection position (alignment position) by the alignment detection unit 2. In S202, the control unit 9 causes the alignment detection unit 2 to perform mark measurement (pre-image measurement) of the first sample shot area (see Fig. 5 (a)). Thereby, a rough (approximately) rotating component of the substrate W can be obtained. In S203, the control unit 9 adjusts the rotation angle of the jaw θ stage 51 so that the rotational component of the substrate W obtained in the mark measurement of S202 is corrected (see Fig. 5B). In the steps of S201 to S203, the control unit 9 ejects compressed air from the holding mechanism 52d of the XY stage 52 (that is, at a constant pressure), and sets the jatheta stage 51 to the XY stage 52. ).

In S204, the control unit 9 generates a holding force to the holding mechanism 52d (that is, a negative pressure), and starts holding the jaw stage 51 by the holding mechanism 52d. In S205, the control unit 9 determines whether or not the holding force of the holding mechanism 52d has reached the first threshold. The 1st threshold value is the holding | maintenance force with which the jaw θ stage 51 in the state seated on the XY stage 52 (holding mechanism 52d) does not generate | occur | produce with respect to the XY stage 52. Is the value of That is, the first threshold value may be a value of the holding force when the jaw θ stage 51 is fixed to the XY stage 52 so that mark measurement by the alignment detection unit 2 can be performed with high precision. The holding force of the holding mechanism 52d can be detected using, for example, a pressure sensor or the like that detects a vacuum adsorption force. In S206, the control unit 9 causes the alignment detection unit 2 to perform mark measurement (fine image measurement) in the first sample shot area (see Fig. 5 (c)).

In S207, the control unit 9 determines whether or not the holding force of the holding mechanism 52d has reached the second threshold. The second threshold value is such that even if the XY stage 52 is moved, the positional shift of the jaw θ stage 51 relative to the XY stage 52 can fall within an allowable range (ie, the jaw for the XY stage 52). θ can be set to the value of the holding force (which can fix the position of the stage 51). In S208, the control unit 9 moves the XY stage 52 so as to arrange the second sample shot area at the alignment position (step movement). In S209, the control unit 9 causes the alignment detection unit 2 to perform mark measurement (fine image measurement) in the second sample shot area (see Fig. 5 (d)).

In S210, the control unit 9 determines whether mark measurement (fine image measurement) has been performed on all sample shot areas. When there is a sample shot area in which mark measurement has not been performed, steps S208 to S209 are performed on the sample shot area. On the other hand, when mark measurement (fine image measurement) is performed for all sample shot areas, the process proceeds to S211. In S211, the control unit 9 obtains a correction value for the magnification component and the rotational component of the substrate W by performing statistical processing on the measurement result in the mark measurement (fine image measurement) of the sample shot area (multiple shot area) You may obtain the array information of). In S212, the control unit 9 performs exposure processing of each shot area while reflecting the correction value obtained in S211.

[Improvement of tact time]

In the exposure apparatus 10, it is desired to improve the tact time (throughput). In the above-described conventional alignment process, the waiting time (S207) until the holding force of the holding mechanism 52d reaches the second threshold value is one factor that decreases the tact time. Time can be improved. However, if the XY stage 52 is moved before the holding force of the holding mechanism 52d reaches the second threshold value, the jaw θ stage 51 is moved to the XY stage 52 by acceleration / deceleration of the XY stage 52. ) May cause positional displacement (see FIG. 6 (b)). Then, when the holding force of the holding mechanism 52d reaches the second threshold value in the state where such a position shift occurs, deformation (elastic deformation) may occur in the XY stage 52 (see FIG. 6 (c)). ). 6 is a diagram showing the state transition of the substrate stage 5, and FIG. 6 (a) is a state before starting the holding of the jaw θ stage 51 by the holding mechanism 52d. Is shown.

For example, in the sequence of the conventional alignment process, the XY stage 52 is moved while the holding force of the holding mechanism 52d reaches the second threshold. Therefore, even if the static frictional force between the jaw θ stage 51 and the holding mechanism 52d acts sufficiently and the XY stage 52 is accelerated or decelerated, the jaw θ stage 51 is displaced relative to the XY stage 52. It is difficult to cause. On the other hand, if the XY stage 52 is moved before the holding force of the holding mechanism 52d reaches the second threshold, the jaw stage 51 is fully supported by the static frictional force of the holding mechanism 52d. It cannot be done. As a result, some force is transmitted to the ceiling plate 52a of the XY stage 52 through the jaw θ guide 51b, and the ceiling plate 52a causes deformation (elastic deformation). In addition, since this force is generated only during acceleration / deceleration of the XY stage 52, if the jaw θ stage 51 floats when the acceleration / deceleration is finished, the deformation of the ceiling plate 52a is released.

However, in reality, the holding force of the holding mechanism 52d reaches the second threshold while the ceiling plate 52a of the XY stage 52 deforms, and the jaw θ stage 51 holds the holding mechanism ( Since it is held by 52d), the deformation of the ceiling plate 52a is not released but remains. Since the mirror 72 is fixed to the top plate 52a, the deformation of the top plate 52a causes the mirror 72 to be inclined as shown in Fig. 6 (c) or shown in the right figure of Fig. 7 As described above, the mirror 72 can be curved. Therefore, if the attitude of the XY stage 52 is controlled based on the measurement result of the measurement unit 7 (laser interferometer 71), the attitude error of the XY stage 52 due to the deformation of the XY stage 52 is reduced. Can occur.

For example, when the mirror 72 is inclined as shown in Fig. 6C, the inclination of the mirror 72 is corrected based on the measurement results of the measurement unit 7 (laser interferometer 71). The attitude of the XY stage 52 is controlled to do so. Therefore, as a posture error of the XY stage 52, as shown in Fig. 6D, the XY stage 52 (ceiling plate 52a) tilts, and as a result, defocus may occur. Moreover, as shown in the right figure of FIG. 7, when the mirror 72 is curved, between the sample shot areas performed based on the measurement result of the measurement unit 7 (laser interferometer 71) during alignment processing An error occurs in the control of the step movement. Therefore, even when the step is moved, a posture error of the XY stage occurs, and in the array information obtained in the alignment process, deformation that mimics the curvature of the mirror 72 may occur. That is, if exposure processing is performed using such arrangement information, as shown in the right figure of FIG. 8, even in the exposure result, deformation that mimics the curvature of the mirror 72 occurs, and the overlapping accuracy may be lowered. have. In addition, since such deformation and curvature of the mirror 72 occurs during the alignment process, the misalignment component is not detected, and the overlapping accuracy may be reduced to the shape shown in FIG. 9.

[Alignment processing of this embodiment]

In order to improve the tact time, the exposure apparatus 10 (control unit 9) of this embodiment starts holding of the jaw θ stage 51 to the holding mechanism 52d, and then holds the holding mechanism 52d ) Is performed to move the XY stage 52 before the holding force of the second reaches the second threshold value. In addition, in this embodiment, the posture error of the XY stage 52 due to the deformation of the XY stage 52 during the above processing is estimated, and based on the estimation, the posture error of the XY stage 52 The posture of the XY stage 52 is controlled to reduce. The processing flow of this embodiment will be described below.

1 is a diagram showing a processing flow of the present embodiment. Each step of the flowchart shown in FIG. 1 can be performed by the control unit 9. In addition, since S101 to S105 are the same steps as S201 to S205 in the flowchart shown in FIG. 4, description thereof is omitted here.

In S106, the control unit 9 causes the alignment detection unit 2 to perform mark measurement (fine image measurement) in the first sample shot area. In S107, the control unit 9 detects the positional shift of the jaw θ stage 51 with respect to the XY stage 52 to the detection unit 53 (hereinafter sometimes referred to as "positional shift detection"). Since the steps of S106 to S107 are before moving the XY stage 52, the position shift of the jaw stage 51 relative to the XY stage 52 does not occur. Therefore, the result of mark measurement in S106 and the result of position misalignment detection in S107 can serve as a reference for the result of subsequent mark measurement and the result of position misalignment detection.

In S108, the control unit 9 moves the XY stage 52 so as to arrange the second sample shot area at the alignment position (step movement). In S109, the control unit 9 causes the alignment detection unit 2 to perform mark measurement (fine image measurement) in the second sample shot area. In S110, the control unit 9 detects the position shift of the jaw θ stage 51 with respect to the XY stage 52 to the detection unit 53. In S111, the control unit 9 determines whether mark measurement (fine image measurement) and position misalignment detection have been performed for all sample shot areas. When there is a sample shot area in which mark measurement and position misalignment detection are not performed, S108 to S110 are performed on the sample shot area. On the other hand, when mark measurement and position misalignment detection are performed for all sample shot areas, the process proceeds to S112.

In S112, the control unit 9 obtains a correction value for the magnification component and the rotation component of the substrate W by performing statistical processing on the measurement result in the mark measurement (fine image measurement) of the sample shot area (multiple shot area) You may obtain the array information of). In S113, the control unit 9 estimates (calculates) the posture error of the XY stage 52 (substrate stage 5) in each shot region based on the detection result by detecting the displacement of the sample shot region. . Then, based on the estimation, a correction value for reducing the posture error of the XY stage 52 is obtained. In S114, the control unit 9 reflects the correction values of the magnification component and the rotational component of the substrate W obtained in S112, and while controlling the posture of the XY stage 52 based on the correction values obtained in S113, each shot The area is exposed.

Here, the deformation of the XY stage 52 (ceiling plate 52a) is caused by a change in the stress state of the jaw θ guide 51b due to the misalignment of the jaw θ stage 51 with respect to the XY stage 52. Therefore, the amount of deformation of the XY stage 52 (ceiling plate 52a) and the amount of displacement of the jaw stage 51 relative to the XY stage 52 are correlated. Since the diameters and / or bends of the mirrors 72x, 72y are caused by deformation of the XY stage 52 (ceiling plate 52a), the inclinations and bends of the mirrors 72x, 72y are XY stages 52 ( It is correlated with the deformation of the ceiling plate 52a. Therefore, the amount of displacement of the jaw θ stage 51 with respect to the XY stage 52 is correlated with the amount of inclination and the amount of bending of the mirrors 72x and 72y. Accordingly, from the amount of displacement of the jaw θ stage 51 with respect to the XY stage 52, the amount of inclination and bending of the mirrors 72x and 72y, and the amount of deformation of the XY stage 52 (ceiling plate 52a) are estimated ( Calculation). Further, based on the estimated value, the posture of the XY stage 52 during scanning exposure can be corrected.

[Estimate of attitude error of XY stage]

Next, a method of estimating the attitude error of the XY stage 52, that is, a method of obtaining a correction value for reducing the attitude error of the XY stage 52 (S113 in FIG. 1) will be described. The attitude error of the XY stage 52 represents information indicating the error component of the attitude of the XY stage 52 when an arbitrary (predetermined) positional shift occurs in the jaw θ stage 51 with respect to the XY stage 52. It is estimated as a reference value and multiplied by a coefficient.

First, a method of obtaining a reference value will be described with reference to FIG. 10. 10 is a flowchart showing a method for obtaining a reference value. Each process of the flowchart shown in FIG. 10 can be performed by the control unit 9. Further, as a premise, the device is adjusted in a state in which no positional displacement occurs between the XY stage 52 (ceiling plate 52a) and the jaw θ stage 51, and the mirrors 72x and 72y in this state are It is assumed that the shape and the Z displacement (planar view) of the upper surface of the jaw θ stage 51 are known.

In S301, the control unit 9 drives the XY stage 52 so that an arbitrary position shift occurs in the jaw θ stage 51 with respect to the XY stage 52, and in this state, tightens the holding mechanism 52d. The θ stage is held. In S302, the control unit 9 detects the position shift of the jaw θ stage 51 with respect to the XY stage 52 to the detection unit 53. In S303, the control unit 9 measures the shape of the mirrors 72x and 72y. The shape measurement of the mirror 72 can be performed, for example, using the function of bar mirror vent measurement. Bar mirror vent measurement is a method of measuring the position of the mirror using two interferometers while moving the XY stage 52 along the mirror stretching direction of the measurement target. Thereby, the curvature and curvature of a mirror can be measured.

In S304, the control unit 9 moves the XY stage 52 to a plurality of positions on the platen 6, and measures the Z displacement (plan view) of the upper surface of the jaw θ stage 51 at each position. . The Z displacement can be measured, for example, by providing a wavefront sensor in the device and using the wavefront sensor. In S305, the control unit 9 stores the values obtained in S302 to S304 as a reference position shift amount, a reference mirror deformation amount, and a reference Z displacement amount, respectively. Thereby, the control unit 9 can obtain information indicating an error component (reference mirror deformation amount, reference Z displacement amount) of the posture of the XY stage 52 with respect to the amount of reference position shift.

Next, a method of estimating the attitude error of the XY stage 52 and determining the correction value will be described with reference to FIG. 11. 11 is a flowchart showing a method of determining a correction value for reducing the posture error of the XY stage 52. Each process of the flowchart shown in FIG. 11 can be performed by the control unit 9.

In S401, the control unit 9 acquires the position shift (position shift direction / amount) of the jaw θ stage 51 with respect to the XY stage 52 detected by the detection unit 53 in the flowchart shown in FIG. 1. . For example, the control unit may calculate the difference between the result of the position shift detection in S107 and the result of the position shift detection in S110 as the direction / amount of the position shift of the jatheta stage 51 with respect to the XY stage 52. do. In S402, the control unit 9 calculates the ratio of the amount of positional deviation acquired in S401 and the amount of reference positional deviation (arbitrary positional deviation) obtained in the flowchart shown in FIG. 10.

In S403, the control unit 9 estimates the position shift direction / amount obtained in S401 as the posture error of the XY stage 52, and obtains the correction value a. For example, between the XY stage 52 (ceiling plate 52a) and the jaw θ stage 51, a displacement meter is provided at three locations as the detection unit 53. As an example of the measurement direction of the displacement meter, the X direction: two places, and the Y direction: one place may be used, but the number of the X direction and the Y direction may be changed. Assuming that the rough θ stage 51 is a rigid body in the XYθ direction, it is possible to logically calculate the positional deviation at any point in the XY stage 52 from the measurement results of the three displacement meters. Specifically, since the coordinates of the position of the displacement meter are known in advance, the positional shift can be calculated under the condition that the cross product is the same in the vector before and after the movement.

In S404, the control unit 9 estimates the posture error (overlay change) of the XY stage due to mirror bending by multiplying the reference mirror deformation amount obtained in the flowchart shown in FIG. 10 by the ratio calculated in S402 as a coefficient, The correction value b is obtained. For example, the result of measurement of the bar mirror vent when the position shift is A is previously acquired and stored in the device, and the amount of bending of the bar mirror when the position shift is B is set as "the bar when the position shift is A. It can be calculated by multiplying "B / A" by the mirror vent measurement result ".

In S405, the control unit 9 estimates the attitude error (Z displacement) of the XY stage due to the mirror inclination by multiplying the reference Z displacement amount obtained in the flowchart shown in FIG. 10 by the ratio calculated in S402 as a coefficient, The correction value c is obtained. In S406, the control unit 9 calculates the sum (a + b + c) of the correction values obtained in S403 to S405, and calculates the sum of the correction values to correct the posture error of the XY stage 52 during exposure. Set as the correction value.

As described above, in the exposure apparatus 10 of the present embodiment, after the holding of the jaw stage 51 by the holding mechanism 52d is started, the holding force of the holding mechanism 52d is the second threshold. A process of moving the XY stage 52 is performed before reaching the value. Then, the attitude error of the XY stage 52 due to the deformation of the XY stage 52 at the time of processing is estimated, and based on the estimation, the XY stage 52 reduces the attitude error of the XY stage 52. ) To control the posture. By such control, the tact time can be improved, and the degradation of the exposure performance (for example, overlapping precision) due to deformation of the XY stage 52 is compensated, and the sequence degrees of freedom of alignment processing and exposure processing are compensated. Can be improved.

Here, as a modification of the present embodiment, for example, the first mode in which the XY stage is moved after the holding force of the holding mechanism 52d reaches the second threshold, and the holding force of the holding mechanism 52d The second mode in which the XY stage is moved before the second threshold value is reached may be configured to be selectable. The first mode is a mode for executing the processing flow shown in Fig. 4, and is a mode that gives priority to the overlapping precision (alignment precision). On the other hand, the second mode is a mode for executing the processing flow shown in Fig. 1, and is a mode giving priority to improvement of the tact time. Such mode selection can be performed through the user interface provided in the exposure apparatus 10.

<Embodiment of the manufacturing method of the article>

The method for manufacturing an article according to the embodiment of the present invention is suitable for manufacturing an article such as a micro device such as a semiconductor device or an element having a fine structure. The manufacturing method of the article of this embodiment is a process of forming a latent image pattern using the above exposure apparatus on a photosensitive agent applied to a substrate (step of exposing a substrate), and developing (processing) a substrate on which a latent image pattern is formed in this process It includes the process to do. In addition, such a manufacturing method includes other well-known processes (oxidation, film formation, vapor deposition, doping, planarization, etching, resist peeling, dicing, bonding, packaging, etc.). The article manufacturing method of the present embodiment is advantageous in at least one of performance, quality, productivity, and production cost of the article, compared to the conventional method.

The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist.

1: illumination optical system
2: Alignment detection unit
3: Disc stage
4: the optical system
5: substrate stage
51: Joe θ stage
52: XY stage
52a: Ceiling panel
52d: holding mechanism
53: detection unit

Claims (9)

It is a stage device for moving a substrate,
A first stage for holding the substrate,
A movable second stage having a holding mechanism for holding the first stage in which the rotation angle is adjusted while the first stage is rotatably mounted;
A detection unit for detecting a positional deviation of the first stage with respect to the second stage;
After starting the holding of the first stage to the holding mechanism, a control unit controlling processing to move the second stage before the holding force of the holding mechanism reaches a threshold value
Including,
The control unit estimates the attitude error of the second stage due to the deformation of the second stage during the processing based on the detection result by the detection unit, and reduces the attitude error based on the estimation. The stage device, characterized in that to control the posture of the second stage. The posture error according to claim 1, wherein the control unit determines the posture error based on information indicating an error component of the posture of the second stage when an arbitrary position shift occurs in the first stage with respect to the second stage. A stage device characterized by estimating. The stage according to claim 2, wherein the control unit estimates the posture error based on the information by multiplying the ratio of the position shift detected by the detection unit and the arbitrary position shift by the error component. Device. The method according to claim 1, wherein the threshold value is set to a value of a holding force capable of causing the positional displacement of the first stage relative to the second stage to fall within an allowable range even when the second stage is moved. Stage device to do. The method of claim 1, wherein the stage device comprises: a first mode in which the second stage is moved after the holding force of the holding mechanism reaches the threshold, and the holding force of the holding mechanism is set to the threshold value. And a second mode of moving the second stage before reaching. The method according to claim 1, further comprising a measurement unit for measuring the positions of a plurality of locations in the second stage,
The control unit controls the posture of the second stage based on a measurement result from the measurement unit. The stage device according to claim 1, wherein the detection unit is disposed between the first stage and the second stage. A lithographic apparatus that forms a pattern on a substrate,
A lithographic apparatus comprising the stage apparatus according to any one of claims 1 to 7. A forming process for forming a pattern on a substrate using the lithographic apparatus according to claim 8,
And a processing step of processing the substrate on which the pattern is formed in the formation step.
An article manufacturing method characterized by manufacturing an article with the substrate processed in the processing step.

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