JP2009016412A - Measuring method, setting method and pattern forming method, and moving body drive system and pattern forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a measuring method, a setting method and a pattern forming method that can measure and set a reference posture of a moving body, and to provide a moving body drive system and a pattern forming device. <P>SOLUTION: A reflecting surface 54Y (54X) provided on a flank of a wafer table WBT is irradiated with a measurement beam WY (WX) and the distance to the reflecting surface is measured. At the same time, the position of the center of a reference mark FM1 from the detection center of an alignment system ALG is measured. Further, the wafer table WBT while held in its posture is moved by a distance DY (DX) in a Y(X)-axial direction and a reference mark FM2 (FM3) is detected to measure the distance to the reflecting surface 54Y (54X) and the position of the center of the reference mark FM2 (FM3). Based upon those measured values, a rotation angle θz and a tilt angle θx (θy) of the wafer table WBT, and further relation to the movement distance DY (DX), a desired angle, i.e. a reference posture of the wafer table WBT is measured and set without taking absolute measurements of the angles θz and θx (θy). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a measuring method, a setting method, a pattern forming method, a moving body drive system, and a pattern forming apparatus, and more specifically, a measuring method for obtaining a reference state of a moving body, and setting the moving body to a reference state. The present invention relates to a setting method, a pattern forming method using the measuring method or the setting method, a moving body driving system suitable for carrying out the measuring method or the setting method, and a pattern forming apparatus including the moving body driving system.

  Conventionally, in a lithography process for manufacturing an electronic device such as a semiconductor element (such as an integrated circuit) or a liquid crystal display element, a wafer or glass plate coated with a resist (photosensitive agent) is applied to a mask or reticle pattern through a projection optical system. Step-and-repeat type reduction projection exposure apparatus (so-called stepper) or step-and-scan type projection exposure apparatus (so-called “wafer”) or a step-and-repeat type projection exposure apparatus (so-called stepper). Scanning steppers (also called scanners)) are mainly used.

  In this type of projection exposure apparatus, a wafer table (or wafer stage) on which a wafer is placed is freely movable along a predetermined plane (moving surface) that intersects (for example, orthogonally) with the optical axis of the projection optical system. In addition, in order to align the surface of the wafer with the image plane (best imaging plane) of the projection optical system, the wafer can also be moved in the direction of the optical axis and in the tilt direction with respect to the predetermined plane.

  In particular, in recent projection exposure apparatuses, the position information of the wafer table in the direction of five degrees of freedom other than the optical axis direction is measured by an interferometer that irradiates the wafer table with a measurement beam parallel to a predetermined plane. . In this case, the position information of the wafer in the optical axis direction is measured by a surface position detection device (for example, a focus position detection system) that is different from the interferometer that measures the surface position information of the wafer surface.

  In the projection exposure apparatus, when the wafer table is tilted with respect to a predetermined plane, a lateral shift of the pattern image corresponding to the tilt angle occurs. Therefore, it is important to accurately measure and manage the tilt angle.

  In addition, in order to manage the position of the wafer table with high accuracy, a reference state (for example, an ideal state, that is, a state in which the beam from the interferometer is perpendicularly incident on the reflecting surface of the wafer table, or the ideal state). It is important to be able to reproduce the initial state set as close as possible.

  For this reason, conventionally, in order to reproduce the reference state of the wafer table, a tool prism is inserted on the optical path of the measurement beam of the interferometer system, and the reflection of the measurement beam from the reflecting surface of the wafer table through the prism. A method of measuring the tilt angle (for example, orthogonality) of the reflecting surface with respect to the measurement beam by taking out the light and observing the extracted reflected light with an image processing type autocollimator has been performed (for example, Patent Document 1). reference). In addition to exposure and alignment, an interferometer having a special structure that also serves as another application is provided, and the wavefront of the return light beam from the interferometer is divided into two in a predetermined direction and received. A method has also been proposed in which the absolute phase of the interference signal (interferometer reference beam and measurement beam interfering light signal) is obtained and the incident angle of the measurement beam with respect to the reflecting surface is obtained by taking the difference between the two. . (For example, refer to Patent Document 2).

  However, the methods disclosed in Patent Documents 1 and 2 require a tool prism other than the interferometer, an autocollimator, or the like, or prepare an interferometer having a special structure.

JP 2006-100817 A JP 2007-010529 A

  From a first aspect, the present invention is a measurement method for obtaining a reference state of a movable body that is movable within a predetermined plane including at least a first axis and a second axis that intersect each other, Based on the measurement values of a measurement system including a first interferometer that irradiates a plurality of measurement beams in a direction parallel to the first axis onto a reflecting surface provided on the movable body, the position and orientation of the movable body are managed. On the other hand, a plurality of reference marks including first and second reference marks having different positions with respect to a direction parallel to the first axis arranged on the moving body are marked by changing the position or posture of the moving body. A first step of detecting each using a detection system; and detection of each of the first and second reference marks and the mark detection system detected using the mark detection system in a plurality of different postures of the moving body. Positional relationship with the center and at each detection Based on the measurement value of the first interferometer, the first of the posture of the moving body and the physical quantity related to the distance in the direction parallel to the first axis between the first and second reference marks. A measurement method comprising: a second step for obtaining a relationship; and a third step for obtaining a posture of the movable body in a reference state where the first axis and the reflection surface intersect based on the first relationship. is there.

  According to this, based on the measurement value of the measurement system including the first interferometer that irradiates a plurality of measurement beams in the direction parallel to the first axis onto the reflection surface provided on the movable body, the position / posture of the movable body And managing a plurality of fiducial marks including first and second fiducial marks having different positions with respect to a direction parallel to the first axis arranged on the movable body by varying the position or posture of the moving body Each is detected using a detection system. Based on the detected positional relationship between each of the first and second reference marks and the detection center of the mark detection system, and the measured value of the first interferometer at each detection, A first relationship with a physical quantity related to a distance in a direction parallel to the first axis between the first and second reference marks is obtained. Thereby, based on this 1st relationship, it becomes possible to obtain | require the attitude | position of a moving body in the reference | standard state where a 1st axis | shaft and a reflective surface cross | intersect. That is, the posture of the moving body in the reference state can be obtained without using a tool or the like other than the mark detection system and the interferometer. As the interferometer, a general interferometer such as a Michelson interferometer can be used.

  According to a second aspect of the present invention, the step of executing the measurement method and setting the moving body to a reference state based on the measurement result; and the object on the moving body set to the reference state And a step of forming a pattern on an object placed on the moving body while managing the position and posture of the moving body using the measurement system. It is a forming method.

  According to this, the posture of the moving body in the reference state is measured by executing the measurement method, and the moving body is set to the reference state based on the measurement result. Thereby, a mobile body can be set or reset to a reference | standard state easily and reliably. Then, an object is placed on the moving body set to the reference state, and a pattern is formed on the object placed on the moving body while managing the position and posture of the moving body using the measurement system. . Accordingly, it is possible to accurately form a pattern on an object placed on the moving body while managing the position and orientation of the moving body with high accuracy.

  From a third aspect, the present invention is a setting method for setting a movable body that is movable in a predetermined plane including at least a first axis and a second axis that intersect each other to a reference state, the movement While managing the position / posture of the moving body based on the measurement values of a measurement system including a first interferometer that irradiates a reflecting surface provided on the body with a plurality of measurement beams in a direction parallel to the first axis The first and second reference marks having different positions with respect to the direction parallel to the first axis arranged on the moving body by using different positions or postures of the moving body, respectively, using a mark detection system A positional relationship between each of the first and second reference marks and the detection center of the mark detection system, detected using the mark detection system in a plurality of different postures of the moving body; Measurement of the first interferometer at each detection Based on the above, the first relationship between the posture of the moving body and the physical quantity related to the position of one of the first and second reference marks in the direction parallel to the first axis, Second to obtain first offset information for converting into a second relationship between the posture of the movable body and a physical quantity related to the distance in the direction parallel to the first axis between the first and second reference marks; And after obtaining the first offset information, the physical quantity related to the position of the one reference mark in the direction parallel to the first axis for each posture of the moving body, or the first quantity obtained from the physical quantity. And a third step of controlling the posture of the movable body based on the relationship between the first offset information and the first offset information.

  According to this, once the first offset information is acquired, one reference mark is detected using a mark detection system in a plurality of different postures of the moving body, and one reference mark and the detection center of the mark detection system are detected. And the physical quantity related to the position of the one reference mark in the direction parallel to the first axis for each posture of the moving body based on the positional relationship of Only by obtaining the first relationship obtained from the physical quantity, the moving body can be set to an arbitrary posture including the reference state. This is based on the physical quantity related to the position of the one reference mark in the direction parallel to the first axis for each posture of the moving body, or the first relation obtained from the physical quantity, and the first offset information. Thus, the second relationship between the posture of the moving body and the physical quantity related to the position of the one reference mark in the direction parallel to the first axis is the first relationship between the posture of the moving body and the first and second reference marks. It can be converted into a second relationship with a physical quantity related to the distance in the direction parallel to the axis, and by performing a predetermined calculation based on this conversion result, the moving body can be set to the reference state, and the reference This is because the posture of the moving body may be set to an arbitrary posture based on the state.

  From a fourth aspect, the present invention provides a step of setting the moving body to a reference state using the setting method; and a step of placing the object on the moving body set to the reference state; Forming a pattern on an object placed on the moving body while managing the position / posture of the moving body using the measurement system; and a second pattern forming method.

  According to this, the moving body is set to the reference state by the above setting method. Thereby, a mobile body can be set or reset to a reference | standard state easily and reliably. Then, an object is placed on the moving body set to the reference state, and a pattern is formed on the object placed on the moving body while managing the position and posture of the moving body using the measurement system. . Accordingly, it is possible to accurately form a pattern on an object placed on the moving body while managing the position and orientation of the moving body with high accuracy.

  From a fifth aspect, the present invention is a movable body that is movable in a predetermined plane including at least a first axis and a second axis that intersect each other, and is provided with at least one reflecting surface; A measurement system including a first interferometer that irradiates a plurality of measurement beams in a direction parallel to the first axis on a surface; a drive system that drives the movable body; and a mark that detects a mark present on the movable body A detection system; arranged on the moving body by managing the position / orientation of the moving body based on the measurement value of the measuring system, and changing the position or the posture of the moving body via the drive system A processing device for detecting a plurality of reference marks including first and second reference marks having different positions in a direction parallel to the first axis using the mark detection system; and a plurality of different moving bodies The mark detection system in posture Based on the positional relationship between each of the first and second reference marks and the detection center of the mark detection system detected by using and the measurement value of the first interferometer at the time of each detection, the moving body And a physical quantity related to a distance in a direction parallel to the first axis between the first and second reference marks, and based on the first relation, An arithmetic device that obtains the posture of the moving body in a reference state in which an axis and the reflecting surface intersect with each other.

  According to this, based on the measurement value of the measurement system including the first interferometer that irradiates the plurality of measurement beams in the direction parallel to the first axis onto the reflection surface provided on the movable body by the processing device. The first and second references differing in the direction parallel to the first axis arranged on the moving body by controlling the position and posture of the moving body and changing the position or posture of the moving body via the drive system. A plurality of reference marks including a mark are detected using a mark detection system. Then, the positional relationship between each of the first and second reference marks and the detection center of the mark detection system detected by the arithmetic device using the mark detection system in a plurality of different postures of the moving body, and at the time of each detection Based on the measurement value of the first interferometer, the first relationship between the posture of the moving body and the physical quantity related to the distance in the direction parallel to the first axis between the first and second reference marks is obtained. Based on the first relationship, the posture of the moving body in the reference state where the first axis and the reflecting surface intersect is obtained. This makes it possible to obtain the attitude of the moving body in the reference state without using any tools other than the mark detection system and the interferometer. As the interferometer, a general interferometer such as a Michelson interferometer can be used.

  According to a sixth aspect of the present invention, there is provided a pattern forming apparatus for forming a pattern on an object, the moving body driving system in which the object is placed on the moving body; and the driving by the processing apparatus. And a pattern generation device that generates a pattern on an object on the moving body set in the reference state via a system.

  According to this, since the moving body drive system in which an object is placed on the moving body is provided, the posture of the moving body in the reference state of the moving body is obtained by the processing device and the arithmetic device, and the processing device The moving body is set to the reference state via the drive system. And a pattern is formed in the object on the moving body set to the reference | standard state by the pattern generation apparatus. Therefore, it becomes possible to form a pattern with high accuracy on the object placed on the moving body.

<< First Embodiment >>
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 shows a schematic configuration of an exposure apparatus 10 according to the first embodiment. The exposure apparatus 10 is a step-and-repeat batch exposure type projection exposure apparatus. As will be described later, in the present embodiment, a projection optical system PL is provided. In the following, a direction parallel to the optical axis AX of the projection optical system PL is set in the Z-axis direction, and in a plane perpendicular to the Z-axis direction. The direction perpendicular to the plane of the paper is the Y-axis direction, and the direction perpendicular to the Z-axis and the Y-axis (the direction parallel to the plane of the paper in FIG. 1) is the X-axis direction. ) Directions are θx, θy, and θz directions, respectively.

  The exposure apparatus 10 includes an illumination unit IOP, a reticle holder RH that holds the reticle R, a projection optical system PL, an alignment system ALG, a stage apparatus 50 that includes a wafer stage WST that holds the wafer W and moves in the XY plane, and these And a body BD for holding the projection optical system PL, the alignment system ALG, and the like.

  The illumination unit IOP includes a light source and an illumination optical system, and irradiates illumination light IL to a rectangular illumination area defined by a field stop (also called a mask king blade or reticle blind) disposed therein, thereby forming a circuit pattern. The illuminated reticle R is illuminated with uniform illuminance. Here, as the light source, an ultra-high pressure mercury lamp that emits a bright line in the ultraviolet region (for example, an i-line with a wavelength of 365 nm or a g-line with a wavelength of 436 nm) is used. Note that a pulsed laser light source such as an ArF excimer laser (output wavelength 193 nm) or a KrF excimer laser (output wavelength 248 nm) may be used instead of the ultrahigh pressure mercury lamp.

  Reticle holder RH is placed on the upper surface of projection optical system PL disposed below illumination unit IOP (however, for convenience, reticle holder RH and projection optical system PL are shown apart from each other). ) Then, on the base (not shown) fixed on the upper surface of the projection optical system PL, the actuator 12 (for example, a voice coil motor, etc., not shown in FIG. 1, see FIG. 4) is finely driven in the X axis, Y axis, and θz directions. Is possible.

  As the projection optical system PL, for example, a refractive optical system including a plurality of lenses (lens elements) arranged along an optical axis AX parallel to the Z-axis direction is used. The projection optical system PL is, for example, both-side telecentric and has a predetermined projection magnification (for example, 1/4 times, 1/5 times, etc.). Therefore, when the reticle R is illuminated by the illumination light IL from the illumination unit IOP, the circuit pattern formed on the reticle R is reduced and projected by the projection optical system PL, and the reduced image (inverted image) is formed on the wafer W. It is formed.

  The body BD includes a column 34 and a lens barrel surface plate 38 supported by the column 34. The column 34 has a top plate portion 32 and a plurality of (for example, three) leg portions 33 that support the top plate portion 32 horizontally (in parallel to the XY plane) from below (however, the legs on the back side of the paper surface in FIG. (Not shown). The lower end of each leg portion 33 is fixed to the floor surface F. An opening 32a serving as a passage for the illumination light IL is formed through the top plate portion 32 in the vertical direction (Z-axis direction).

  The lens barrel surface plate 38 is suspended by a plurality of, for example, three suspension support mechanisms 37 (one of which is not shown in FIG. 1). It is supported by lowering. The lens barrel surface plate 38 is formed with a circular opening penetrating in the vertical direction in plan view (viewed from above), and the projection optical system PL is inserted into the opening from above. The lens barrel of the projection optical system PL is integrally provided with a flange FLG at a substantially central position in the height direction, and the projection optical system PL is supported by the lens barrel surface plate 38 from below via the flange FLG. Has been. Here, each suspension support mechanism 37 includes a coil spring 36 and a wire 35 that are flexible connection members. Since the coil spring 36 vibrates like a pendulum in the direction perpendicular to the optical axis, the vibration isolation performance in the direction perpendicular to the optical axis of the projection optical system PL (vibration from the floor F is transmitted to the projection optical system PL). Performance). Also, it has high vibration isolation performance in the direction parallel to the optical axis.

  Further, a convex portion 33 a is formed in the vicinity of the center portion in the Z-axis direction of each of the three leg portions 33 of the column 34. Drive mechanisms 40 are provided between the three convex portions 33a and the lens barrel surface plate 38, respectively. Each drive mechanism 40 includes an actuator (for example, a voice coil motor) that drives the projection optical system PL in the radial direction of the lens barrel and in the Z-axis direction parallel to the optical axis AX. The three drive mechanisms 40 can finely drive the projection optical system PL in the direction of six degrees of freedom.

  The flange FLG is provided with a vibration sensor group, for example, an acceleration sensor group VS (not shown in FIG. 1, refer to FIG. 4) for detecting vibration in the direction of six degrees of freedom applied to the projection optical system PL. Based on the detection signal of the acceleration sensor group VS, the main controller 20 (not shown in FIG. 1, refer to FIG. 4) is arranged so that the projection optical system PL is kept stationary with respect to the column 34 and the floor surface F. The drive of the actuator of the drive mechanism 40 is controlled.

  From the lower surface of the lens barrel surface plate 38, a ring-shaped measurement mount 51 is suspended and supported via a plurality of, for example, three support members 53 (however, a support member on the back side of the paper surface is not shown). The measurement mount 51 holds an interferometer system 58, an alignment system ALG, a multipoint focal position detection system FS (not shown in FIG. 1, refer to FIG. 4), and the like. Here, as the alignment system ALG, for example, an FIA (Field Image Alignment) sensor of an image processing method is used. This FIA system irradiates a detection target mark (in this embodiment, an alignment mark on a wafer W or a reference mark on a reference mark plate described later) with a broadband detection light beam that does not sensitize the resist on the wafer. An image of a mark and an image of an index (not shown) formed on the light receiving surface by reflected light from the image is captured using an image sensor (CCD) or the like, and an image signal thereof is output. The imaging signal is sent to a signal processing device (not shown), and the signal processing device supplies the main controller 20 with a mark displacement amount (position information) with respect to the index center (detection center). As the multipoint focal position detection system FS, for example, a focus sensor disclosed in JP 2001-75294 A can be used. The interferometer system will be described later.

  Stage device 50 includes a wafer stage WST for holding wafer W, a wafer stage drive system 130 (see FIG. 4) for driving wafer stage WST, and the like. Wafer stage WST is supported in a non-contact manner above stage surface plate BS via a clearance of, for example, several μm via an air bearing or the like provided on the bottom surface thereof. Here, the upper surface of the stage surface plate BS is flattened and used as a movement reference surface (guide surface) of the wafer stage WST. Note that the stage surface plate BS is installed directly on the floor surface F.

  FIG. 2 shows a plan view of the stage device 50. As shown in FIG. 2, the wafer stage drive system 130 is moved in the X-axis direction by a pair of X-axis linear motors 136A and 136B composed of a moving magnet type or moving coil type linear motor, and the X-axis linear motors 136A and 136B. And a Y-axis linear motor including a driven Y-axis stator 134Y.

The X-axis linear motors 136A and 136B are respectively installed on one side and the other side of the floor surface F across the stage surface plate BS, and the X stators 134X ₁ and 134X ₂ having the X-axis direction as the longitudinal direction. And X movers 132X ₁ and 132X ₂ engaged with the X stators 134X ₁ and 134X ₂ in a non-contact manner, respectively. Wafer stage WST is driven in the X-axis direction by X-axis linear motors 136A and 136B, and the driving force generated by X-axis linear motors 136A and 136B is slightly changed to move wafer stage WST in the θz direction. It can also be rotated.

  Wafer stage WST includes stage 31 and wafer table WTB supported at three points on stage 31 via three self-weight cancellers 150 (which are provided at three positions not on a straight line). Each self-weight canceller 150 includes a drive mechanism (for example, a voice coil motor). With the driving mechanism of the three self-weight cancellers 150, the wafer table WTB can be finely driven in three degrees of freedom in the Z-axis direction, θx direction, and θy direction.

An X fine movement mechanism VX and a pair of Y fine movement mechanisms VY ₁ and VY ₂ are provided between the stage 31 and the wafer table WTB. Each of these X fine movement mechanism VX and Y fine movement mechanisms VY ₁ , VY ₂ is composed of an actuator such as a voice coil motor including a stator fixed to the upper surface of stage 31 and a movable element fixed to wafer table WTB. . Wafer table WTB is finely driven in the X-axis direction by X fine movement mechanism VX, and finely driven in the Y-axis direction and θz direction by a pair of Y fine movement mechanisms VY ₁ and VY ₂ .

As shown in FIG. 2, each of the X movers 132X ₁ and 132X ₂ is fixed to one end and the other end in the longitudinal direction of a Y-axis stator 134Y whose longitudinal direction is the Y-axis direction.

  The stage 31 includes a frame-shaped member having a rectangular XZ section in which a plurality of the air bearings described above are fixed to the bottom surface, and a Y mover (not shown) is provided in the internal space of the frame-shaped member. The Y mover constitutes a moving magnet type or moving coil type Y-axis linear motor that drives the stage 31 together with the wafer table WTB in the Y-axis direction together with the Y stator 134Y inserted in the internal space of the frame-shaped member. To do. Hereinafter, this Y-axis linear motor is also referred to as a Y-axis linear motor 134Y using the same reference numeral as that of the Y stator.

As can be understood from the above description, the wafer stage is obtained by the Y-axis linear motor 134Y, the pair of X-axis linear motors 136A and 136B, the three self-weight cancellers 150, the X fine movement mechanism VX, and the pair of Y fine movement mechanisms VY ₁ and VY _2. At least a part of the drive system 130 is configured. Each component of the wafer stage drive system 130 is controlled by the main controller 20 (see FIG. 4).

  On wafer table WTB, wafer W is held via wafer holder 25 by vacuum suction or the like. On the upper surface of wafer table WTB, as shown in FIG. 5A and the like, three reference mark plates on which reference marks FM1, FM2, and FM3 are respectively formed are provided. The three reference mark plates are set so that their respective surfaces are almost the same height as the wafer W.

  Returning to FIG. 1, the position information of wafer stage WST is constantly detected by interferometer system 58 that irradiates a measurement beam onto the reflection surface formed on the end surface of wafer table WTB. The end surfaces on the + Y side and −X side of wafer table WTB are each mirror-finished to form reflective surfaces 54Y and 54X with high flatness, as shown in FIGS. Here, in the reference state in which the reflecting surfaces 54Y and 54X of the wafer table WTB are perpendicular to the Y axis and the X axis, respectively, the reference marks FM1 and FM2 are parallel to the same Y axis. The positional relationship between the reference marks is determined by design so that the reference marks FM1 and FM3 are located on a straight line and are located on a straight line parallel to the same X axis.

The interferometer system 58 includes three double-pass interferometer units 58Y, 58X ₁ and 58X _{2 shown} in FIG. Each of the interferometer units 58Y, 58X ₁ , 58X ₂ branches in the position information of the reflecting surface 54Y or 54X of the wafer table WTB with reference to the reflecting surface of the fixed mirror provided therein, that is, in each interferometer unit. The positional information of the wafer table WTB (wafer W) is measured using information on the difference in optical path length from the branch point between the measured beam and the reference beam.

Here, a pair of measurement beams passes from the interferometer unit 58X ₁ along the measurement axes that pass through the detection center of the alignment system ALG, are parallel to the X axis, and are separated by a predetermined distance (ΔZ) in the Z axis direction. WXF ₁ and WXF ₂ are applied to the reflecting surface 54X. Also, from the interferometer unit 58X _2, passes through the optical axis AX of the projection optical system PL, respectively along a measurement axis a predetermined distance ([Delta] Z) parallel to and Z-axis direction in the X-axis, a pair of measurement beams WX ₁ and WX ₂ are applied to the reflecting surface 54X. In this case, the measurement beam WXF ₁ and the measurement beam WX ₁ pass on the same XY plane, and the measurement beam WXF ₂ and the measurement beam WX ₂ pass on the same XY plane.

Further, from the interferometer unit 58Y, a pair of measurement beams WY ₁ , WY passes along the optical path parallel to the Y axis that passes through the same XY plane as the measurement beams WXF ₁ , WX ₁ and is spaced a predetermined distance in the X axis direction. ₂ is applied to the reflecting surface 54Y. In this case, the measurement beams WY ₁ and WY ₂ pass through optical paths that are symmetrical with respect to an axis parallel to the Y axis passing through the optical axis AX of the projection optical system PL and the detection center of the alignment system ALG. From the interferometer unit 58Y, the measurement beam WY _{3 further} passes along the measurement axis parallel to the Y axis passing through the same XY plane as the measurement beams WXF ₂ and WX ₂ and passing through the optical axis of the projection optical system PL. The reflecting surface 54Y is irradiated.

The measurement values of the three interferometer units 58Y, 58X ₁ and 58X ₂ of the interferometer system 58 are supplied to a calculation unit (not shown). The calculation unit calculates the position (Y position) of wafer table WTB in the Y-axis direction based on the average value of the measurement values of measurement beams WY ₁ and WY ₂ . That is, the actual measurement axes of the measurement beams WY ₁ and WY ₂ are axes parallel to the Y axis passing through the optical axis AX of the projection optical system PL and the detection center of the alignment system ALG. Further, the calculation unit calculates the rotation angle in the θz direction of wafer table WTB based on the difference between the measurement values of measurement beams WY ₁ and WY ₂ and the distance between both beams (assumed as ΔX). Further, the arithmetic unit obtains the rotation angle (tilt angle) of wafer table WTB in the θx direction based on the difference between the Y position and the measurement value of measurement beam WY ₃ and interval ΔZ.

Further, at the time of alignment for detecting an alignment mark on the wafer W using the alignment system ALG, the arithmetic unit, based on the measurement value of the measurement beam WXF ₁ , in response to an instruction from the main controller 20, the wafer table WTB. And the rotation angle (tilt angle) in the θy direction is calculated based on the difference between the measurement beam WXF ₁ and the measurement beam WXF ₂ and ΔZ.

On the other hand, at the time of exposure for transferring the pattern of the reticle R onto the shot area on the wafer W, the arithmetic unit, on the basis of the measurement value of the measurement beam WX ₁ , in response to an instruction from the main controller 20 The X position is calculated, and the rotation angle (tilt angle) in the θy direction is calculated based on the difference between the measurement beam WX ₁ and the measurement beam WX ₂ and ΔZ.

  The calculation result of the calculation unit is supplied to the main controller 20. Therefore, main controller 20 can obtain wafer table WTB in the Y-axis direction without so-called Abbe error. Further, main controller 20 can determine the position of wafer table WTB without so-called Abbe error both in the X-axis direction and at the time of alignment and exposure. The measurement resolution of the position in the X-axis and Y-axis directions by the laser interferometer system 58 is about 0.5 to 1 nm, and the measurement resolution in the rotation direction is about 1 μrad.

  FIG. 4 is a block diagram showing the configuration of the control system of the exposure apparatus 10. This control system is configured around a main controller 20 including a microcomputer or a workstation.

Here, a method for measuring the reference posture of wafer table WTB, which is performed by main controller 20, will be described with reference to FIGS. In this measurement method, the interferometer unit 58X ₁ and the interferometer unit 58Y, the reference mark FM1～FM3, is used and the alignment system ALG. The interval between the reference marks FM1 and FM2 is DY, and the interval between the FM1 and FM3 is DX.

In FIG. 5 (A) ~ FIG 12 (B), 3 pieces of the measurement beam of the foregoing from the interferometer unit 58Y are representatively shown as measurement beam WY, 2 pieces of the measurement beam from the interferometer unit 58X ₁ Is typically shown as measurement beam WX.

5A to 5C show the wafer table WTB in the posture in the reference state, that is, in the reference postures (θx ₀ , θy ₀ , θz ₀ ). Here, θx = θy = θz = 0 is defined in the reference state. In the reference posture, the measurement beams WX and WY are perpendicular to the reflecting surfaces 54X and 54Y of the wafer table WTB, respectively. That is, the upper surface of wafer table WTB is parallel to the XY plane. In the following, it is assumed that the reflecting surfaces 54X and 54Y are both ideal planes.

Prior to the description of the actual measurement method, the principle of the measurement method will be described. Assume that the wafer table WTB is in the reference posture (θx ₀ , θy ₀ ) and the reference rotation angle θz ₀ is measured. Here, interferometer unit 58Y (measurement beam WY) and reference marks FM1, FM2 are used. Instead of the interferometer unit 58X ₁ , similarly to the interferometer unit 58 Y described above, three measurement beams are irradiated onto the reflecting surface 54 X, and the position of the wafer table WTB in the X-axis direction, the tilt angle in the θy direction, and When using an interferometer unit capable of measuring the rotation in the θz direction (hereinafter referred to as interferometer unit 58X for convenience), interferometer unit 58X (measurement beam WX) and reference marks FM1 and FM3 may be used. it can.

  In the reference posture of wafer table WTB shown in FIG. 5A, it is assumed that the center of reference mark FM1 coincides with the detection center (index center) of alignment system ALG. At this time, (Δx1, Δy1) = (0, 0) is output from the alignment system ALG as the reference mark position information. At this time, if the distance from the interferometer unit 58Y to the irradiation point of the measurement beam WY on the reflecting surface 54Y is LY, the optical path length of the measurement beam WY is 2LY.

  Next, as shown in FIG. 6, the wafer table WTB is moved by a distance DY in the + Y direction while maintaining its posture (θx, θy, θz), and the center of the reference mark FM2 is detected by the alignment system ALG. Position in the center. Also in this case, (Δx2, Δy2) = (0, 0) is output from the alignment system ALG as the reference mark position information. At this time, the distance between the interferometer unit 58Y and the reflecting surface 54Y is (LY-DY), and the optical path length of the measurement beam WY is 2 (LY-DY). Therefore, the difference in optical path length before and after the movement of wafer table WTB is 2DY.

  Next, as shown in FIG. 7, a situation is considered in which wafer table WTB is rotated by angle θz from the state of FIG. Also in this case, the detection center of the alignment system ALG is assumed to coincide with the center of the reference mark FM1. The distance from the interferometer unit 58Y to the irradiation point of the measurement beam WY on the reflection surface 54Y is defined as LY ′. Since the measurement beam WY is incident on the reflecting surface at an incident angle θz, the incident beam and the reflected beam form an angle 2θz. Accordingly, the optical path length of the measurement beam WY is LY ′ [1 + sec (2θz)].

  Then, as shown in FIG. 8, while maintaining the posture, wafer table WTB is linearly moved in a predetermined direction so that fiducial mark FM2 coincides with the detection center of alignment system ALG. In this case, the movement distance of wafer table WTB is DY, as before. However, since the straight line connecting fiducial mark FM1 and fiducial mark FM2 forms an angle θz with the Y axis, the movement distance in the Y axis direction of wafer table WTB is DYcos (θz). Accordingly, the optical path length of the measurement beam WY at this time is [LY′−DYcos (θz)] · [1 + sec (2θz)]. As described above, the difference ΔLY (θz) in the optical path length of the measurement beam WY before and after the movement of the wafer table WTB is expressed by the following equation (1).

ΔLY (θz) = DYcos (θz) [1 + sec (2θz)] (1)
If the right side of equation (1) is Taylor-expanded, the following equation (1 ′) is obtained.

ΔLY (θz) = 2DY (1 + θz 2/2) + O (θz 3) ... (1 ')
In the formula (1 ′), O (θz ³ ) is a high-order term. As can be seen from the above equation (1 ′), the optical path length difference ΔLY (θz) is the shortest at 2DY when the rotation angle θz is the reference rotation angle θz ₀ (= 0). Accordingly, if the difference ΔLY (θz) in the optical path length is measured and θz is calculated so as to minimize it, the reference rotation angle (rotation angle in the reference state) θz ₀ can be obtained without absolute measurement of the rotation angle θz. Can be sought.

Note that the difference in optical path length also depends on the inclination angle θx in the same manner as in equation (1). Accordingly, the reference inclination angle θx ₀ can be obtained by calculating θx that minimizes the measured value of the optical path length difference ΔLY (θx) according to the same procedure as described above. On the other hand, the reference tilt angle θy ₀ can be obtained by measuring the difference in the optical path length of the measurement beam WX using the measurement beam WX and the reference marks FM1 and FM3 according to the same procedure.

  Next, an actual measurement method that is equivalent to the measurement method described above will be described.

First, consider the case where the reference rotation angle θz ₀ of the wafer table WTB is measured using the interferometer unit 58Y (measurement beam WY) and the reference marks FM1 and FM2 in the same manner as described above. As will be described later, the interferometer unit 58X (measurement beam WX) and the reference marks FM1 and FM3 can be used instead.

a. First, main controller 20 moves wafer table WTB so that fiducial mark FM1 is positioned within the detection area of alignment system ALG. This movement is performed by the main controller 20 driving each motor of the wafer stage drive system 130 based on the measurement values of the interferometer units 58X ₁ and 58Y.

FIG. 9A shows a state after wafer table WTB is moved. Further, in FIG. 9A, wafer table WTB is in a state rotated by angle θz from the reference posture. In general, for example, θx ≠ θx ₀ in a state after mechanical reset of wafer table WTB, for example, but in order to simplify the description, inclination angles θx and θy are set to reference states θx ₀ and θy ₀ , respectively. It shall be.

  After movement of wafer table WTB, main controller 20 detects reference mark FM1 using alignment system ALG, and measures the amount of positional deviation (Δx1, Δy1) of the reference mark center with respect to the detection center of alignment system ALG. . At the same time, main controller 20 captures the measurement value of interferometer unit 58Y (distance LY1 from interferometer unit 58Y to the irradiation point of measurement beam WY on reflection surface 54Y).

b. Next, main controller 20 moves wafer table WTB by a distance DY in the + Y direction while maintaining its posture. FIG. 10 shows a state after wafer table WTB is moved. Then, main controller 20 detects reference mark FM2 using alignment system ALG in the state of FIG. 10, and measures the positional deviation amount (Δx2, Δy2) of the reference mark center with respect to the detection center of alignment system ALG. At the same time, main controller 20 takes in the measurement value of interferometer unit 58Y (distance LY2 from interferometer unit 58Y to the irradiation point of measurement beam WY on reflection surface 54Y).

  From the measured values obtained in the above measurements a. And b., The apparent expansion / contraction rate (Y scaling) of the distance in the Y-axis direction between the reference marks FM1, FM2 expressed by the following equation (2): Sy can be determined.

Sy = | LY1 + Δy1-LY2-Δy2 | / DY (2)
Alternatively, since LY1−LY2 = DY, Y scaling Sy may be obtained using the following equation (2 ′).

Sy = | 1+ (Δy1−Δy2) / DY |, (2 ′)
Y scaling Sy follows the following theoretical formula (3).

Sy (θz) = 2−cos (θz) (3)
If the right side of equation (3) is Taylor-expanded, the following theoretical equation (3 ′) is obtained.

Sy (θz) = 1 + θz 2/2 + O (θz 3) ... (3 ')
In the formula (3 ′), O (θz ³ ) is a high-order term. As can be seen from the above equation (3 ′), the Y scaling Sy is the smallest when the rotation angle θz is the reference rotation angle θz ₀ (= 0). Therefore, if θz is calculated such that the measured value of Y scaling Sy is minimized, the reference rotation angle θz ₀ can be obtained without absolute measurement of the rotation angle θz.

In order to obtain the reference rotation angle θz ₀ from the measured value of the Y scaling Sy described above, a fitting method can be employed. For example, a quadratic fitting formula represented by the following equation (4) is adopted corresponding to the form of the theoretical equation (3 ′).

Sy ⁽²⁾ (θz) = c ₀ + c ₁ θz + c ₂ θz ² (4)
In this case, in order to determine the three coefficients c ₀ , c ₁ , c ₂ , measured values of Y scaling Sy at at least three different rotation angles θz are required. Three coefficients are determined by least square fitting using formula (4) for three or more measured values. Then, θz at which Sy ⁽²⁾ (θz) is minimized, specifically, dSy ⁽²⁾ (θz) / dθz = c ₁ + 2c ₂ θz = 0, and θz = −c ₁ / (2c ₂ ) is obtained. In addition, it is also possible to employ | adopt the fitting formula represented by following Formula (5) corresponding to a higher-order polynomial or the form of theoretical formula (3) as a fitting formula.

Sy ^(c) (θz) = c ₀ + c ₁ · cos (c ₂ θz) (5)
In addition, if there are many measured values of Y scaling Sy, the accuracy of determining the reference rotation angle by the fitting method is further improved.

  Therefore, main controller 20 repeatedly performs the position measurement of fiducial marks FM1, FM2 similar to the above-described a. And b. While changing the attitude (rotation angle θz) of wafer table WTB at least twice. In this case, the order of measurement of the reference marks is preferably FM1 → FM2 → FM2 → FM1 → FM1 → FM2... From the viewpoint of shortening the measurement time.

  Next, main controller 20 uses each of reference marks FM1 and FM2 detected by using alignment system ALG in different (at least three) postures of wafer table WTB obtained as described above and alignment system. Based on the positional relationship with the detection center of the ALG and the measurement value of the interferometer system 58Y at the time of each detection, the aforementioned Y scaling is calculated for each rotation angle θz.

  Then, main controller 20 uses the Y scaling for each calculated rotation angle θz to perform the least square fitting described above to determine the coefficient of equation (4), thereby determining Y scaling Sy and wafer table WTB. Equation (4) showing the relationship with the posture (rotation angle θz) of

  Next, main controller 20 obtains a rotation angle θz corresponding to the minimum value (minimum value) of the quadratic function of equation (4) by the above-described procedure.

The fitting method described above, it is assumed to determine the [theta] z of fitting formula Sy ^{(2) (θz)} is minimum, This has the great advantage as follows.

That is, according to the theoretical formula (3), the minimum value of the scaling Sy (θz) is 1. Therefore, obtaining θz for Sy ⁽²⁾ (θz) = 1 is equivalent to obtaining θz for which Sy ⁽²⁾ (θz) is minimized. However, the distance DY between the reference marks FM1 and FM2 and the movement distance DY of the wafer table WTB may vary due to changes over time of the wafer table WTB and / or measuring instrument (interferometer system, alignment system ALG, etc.) due to long-term use. It may not be guaranteed exactly. In addition, the minimum value of Y scaling Sy can be deviated from 1 by adopting the fitting method. However, even in such a situation, Y scaling Sy always takes a minimum value in the reference state. Therefore, by obtaining θz at which the above-described fitting formula Sy ⁽²⁾ (θz) is minimized, the wafer table WTB that minimizes the Y scaling Sy without being affected by the change over time of the wafer table WTB or the like. it is possible to obtain the reference rotation angle [theta] z ₀ of accurate and reliably.

So far, the description has been given of the case where the relationship between the rotation angle θ _Z and the Y scaling Sy is obtained under the assumption that the wafer table WTB is at the reference tilt angle (θx ₀ , θy ₀ ). As shown in FIG. 9B, the optical path length of the measurement beam WY, and hence the Y scaling, also changes as the tilt angle θx of the wafer table WTB changes. The principle is the same as that for the rotation angle θz. Accordingly, the dependency of the optical path length difference ΔLY on the inclination angle θx is expressed in the same form as in the equation (1). Similarly, the dependency of the Y scaling Sy on the inclination angle θx is expressed in the same form as in the equation (3).

  Therefore, in practice, the fitting method can be applied to obtain the inclination angle θx at which the Y scaling Sy is minimized. In fitting, for example, the formula of the following formula (6) having the same form as the formula (4) is adopted for Sy (θx).

Sy ⁽²⁾ (θx) = a ₀ + a ₁ θx + a ₂ θx ² (6)
Accordingly, the main controller 20, the procedure of measuring the same reference rotation angle [theta] z _0, while changing the tilt angle θx of wafer table WTB, performs measurement of the reference mark FM1, FM2, performs the same operation as described above Thus, the reference inclination angle θx ₀ that minimizes the measured value of Y scaling Sy is obtained.

The optical path length difference ΔLY does not depend on the tilt angle θy. Similarly, the Y scaling Sy does not depend on the tilt angle θy. Accordingly, the reference rotation angle θz ₀ and the reference tilt angle θx ₀ are obtained from the measurement of the Y scaling Sy.

In order to obtain the reference attitude of wafer table WTB, reference inclination angle θy ₀ must be obtained in addition to reference rotation angle θz ₀ and reference inclination angle θx ₀ obtained previously. Therefore, the apparent expansion / contraction ratio of the distance between the reference marks FM1 and FM3 in the X-axis direction, that is, the X scaling Sx is measured.

c. First, main controller 20 maintains reference mark FM1 in the detection region of alignment system ALG in a state where wafer table WTB is maintained in the previously obtained reference posture (θz ₀ , θx ₀ ). Move. This movement is performed by driving each motor of the wafer stage drive system 130 based on the measurement values of the interferometer units 58X ₁ and 58Y.

FIGS. 11A and 11B show a state after the wafer table WTB is moved in this manner. In FIG. 11 (B), wafer table WTB has an angle [theta] y tilted from the reference inclination angle [theta] y _0.

Next, main controller 20 detects reference mark FM1 using alignment system ALG, and measures the amount of positional deviation (Δx1, Δy1) of the reference mark center with respect to the detection center of alignment system ALG. At the same time, main controller 20 takes in the measurement values of the interferometer unit 58X ₁ (Distance LX1 from the interferometer unit 58X ₁ to the irradiation point of measurement beams WX on the reflection surface 54X).

d. Next, main controller 20 moves wafer table WTB by a distance DX in the −X direction while maintaining its posture. 12A and 12B show a state after the wafer table WTB is moved. Then, main controller 20 detects reference mark FM3 using alignment system ALG in the state of FIGS. 12A and 12B, and the amount of positional deviation of the reference mark center relative to the detection center of alignment system ALG ( Δx2, Δy2) are measured. Main controller 20 takes in the measurement values of the interferometer unit 58X ₁ (Distance LX2 from the interferometer unit 58X ₁ to the irradiation point of measurement beams WX on the reflection surface 54X).

  From the measurement values obtained by the above c. And d. Measurement, the X scaling Sx represented by the following equation (7) can be obtained.

Sx = | LX1 + Δx1-LX2-Δx2 | / DX (7)
Alternatively, since LX1−LX2 = DX, the X scaling Sx may be obtained using the following equation (7 ′).

Sx = | 1+ (Δx1−Δx2) / DX | (7 ′)
Here, the dependency of X scaling Sx on the inclination angle θy is the same as the dependency of Y scaling Sy on the inclination angle θx. That, X scaling Sx when the reference tilt angle [theta] y _0, the smallest to the inclined angle [theta] y. Therefore, by obtaining the inclination angle [theta] y of wafer table WTB the measurement value of X scaling Sx becomes minimum, without absolute measuring an inclination angle [theta] y, it is possible to determine the reference tilt angle [theta] y _0.

In order to obtain the reference inclination angle θy ₀ from the measurement of the X scaling Sx, the fitting method is applied in the same manner as described above to obtain the inclination angle θy at which the X scaling Sx is minimized. In fitting, for example, it can be adopted as a fitting formula represented by the following equation (8).

Sx ⁽²⁾ (θy) = b ₀ + b ₁ θy + b ₂ θy ² (8)
Therefore, main controller 20 repeatedly performs the position measurement of fiducial marks FM1 and FM3 similar to the above-described c. And d. While changing the attitude (tilt angle θy) of wafer table WTB at least twice. In this case, the order of measurement of the reference marks is preferably FM1 → FM3 → FM3 → FM1 → FM1 → FM3... In order to shorten the measurement time.

Next, main controller 20 detects alignment marks FM1 and FM3 detected by using alignment system ALG in a plurality of (at least three) different postures of wafer table WTB obtained as described above. the positional relation between the detection center of the ALG, based on the measurement values of the interferometer system 58X ₁ during each detection, the X scaling described above, is calculated for each of the tilt angle [theta] y.

  Then, main controller 20 performs the above-mentioned least square fitting using the X scaling for each calculated tilt angle θy, and determines the coefficient of equation (8), whereby X scaling Sx and wafer table WTB are determined. Equation (8) showing the relationship with the posture (tilt angle θy) is obtained.

  Next, main controller 20 obtains the inclination angle θy corresponding to the minimum value (minimum value) of the quadratic function of equation (8) in the same procedure as described above.

As described above, the reference postures (θx ₀ , θy ₀ , θz ₀ ) are determined by combining the measurements of Y scaling Sy and X scaling Sx. Here, since the scalings Sx and Sy both depend independently on the rotation angle θz and the inclination angles θx and θy, measurement of the three reference angles can be performed independently in any order.

  In exposure apparatus 10 of the present embodiment, main controller 20 measures the above-described reference attitude of wafer table WTB when wafer stage WST is set or reset (when the origin of interferometer system 58 is reset). Based on the measurement result, wafer table WTB is set to the reference state via each fine movement mechanism of wafer stage drive system 130.

  In the exposure apparatus 10, when the device is manufactured, the wafer W having a surface coated with a sensitive material (photoresist) is placed on the wafer holder 25 on the wafer table WTB, and reticle alignment (θz rotation of the reticle holder RH) is performed. And fine adjustment of the XY position), the bayline measurement of the alignment system ALG, and the wafer alignment (EGA method, etc.), the pattern of the reticle R is projected onto the wafer W via the projection optical system PL under the illumination light IL. The operation of projecting onto one shot area and the operation of moving the wafer W stepwise in the X-axis direction and Y-axis direction via the wafer stage WST are repeated in a step-and-repeat manner.

As described above, according to the exposure apparatus 10 of the present embodiment, the main controller 20 measures the position of the reference marks FM1, FM2, and FM3 on the wafer table WTB on the alignment coordinate system. After the determination of the undetermined coefficient indicating the relationship between the aforementioned Y scaling and the attitude of the wafer table WTB (rotation angle θz, inclination angle θx) based on the measurement result while changing the attitude of the WTB. Based on Equations (4) and (6), the attitude of the wafer table WTB (reference rotation angle θz ₀ , reference inclination angle) in the reference state in which the Y axis and the reflection surface 54Y intersect (orthogonal in this embodiment). θx ₀ ). Similarly, the attitude (reference tilt angle θy ₀ ) of wafer table WTB in the reference state in which the X axis and reflection surface 54X intersect (in the present embodiment, orthogonal) can be obtained. Therefore, it is possible to obtain the attitude of wafer table WTB in the reference state without using any tools other than alignment system ALG and interferometer system 58. As each interferometer unit of the interferometer system 58, a general interferometer, for example, a Michelson interferometer or the like can be used.

  Further, according to the exposure apparatus 10 of the present embodiment, the main controller 20 determines the attitude of the wafer table WTB in the reference state as described above, and the wafer table via each fine movement mechanism of the wafer stage drive system 130. WTB is set to the reference state. That is, wafer stage WST is set or reset. In manufacturing the device, the wafer W is placed on the wafer table WTB set in the reference state, and the wafer alignment of the wafer W is managed using the interferometer system 58 while controlling the position of the wafer table WTB. The pattern of the reticle R is transferred to each shot area on the wafer W using the illumination system IOP and the projection optical system PL. Therefore, it becomes possible to form a pattern with high accuracy on the wafer W placed on the wafer table WTB.

In the above embodiment, the case where the common reference mark FM1 and the different reference mark FM2 or FM3 are detected when measuring the X scaling Sx and the Y scaling Sy has been described. However, the present invention is limited to this. Not. For example, in the measurement of Y scaling Sy and the measurement of X scaling Sx, two different reference marks, a total of four reference marks, may be detected, or in the measurement of Y scaling Sy and measurement of X scaling Sx, Two identical reference marks may be detected. In the latter case, the two reference marks need to be determined so that the X position and the Y position are different in the reference state of the wafer table, but the measurement of the (X, Y) coordinates of the two reference marks is necessary. Are performed in the same procedure as described above, and all three reference angles θx ₀ , θy ₀ , and θz ₀ can be measured.

  In the measurement of the scalings Sx and Sy, the movement of the wafer table WTB and the change of the posture can be performed in any order. In the above procedure, each time the posture of the wafer table WTB is changed, the wafer table WTB is moved to detect a pair of reference marks, and the position of the reference mark center is measured. In this case, the scaling Sx or Sy is calculated for every posture change. Not limited to this, first, main controller 20 measures the position of one reference mark center in the same manner as described above each time the posture changes while changing the posture of wafer table WTB a predetermined number of times. Thereafter, the wafer table WTB is moved, and the position of another reference mark center may be measured in the same manner as described above each time the posture changes while changing the posture of the wafer table WTB a predetermined number of times. In this case, the scaling Sx or Sy is calculated after all measurements are completed.

In the above embodiment, the relationship between the scaling Sx or Sy and the posture of the wafer table WTB is obtained, and the reference posture (θx ₀ , θy ₀ , θz ₀ ) is obtained by the fitting method based on this relationship. Not limited to this, for example, instead of the scaling Sx or Sy, an actual measurement value of a distance between the pair of reference marks in the Y-axis direction or the X-axis direction, or a multiple of the actual measurement value may be used.

In the above embodiment, instead of the interferometer unit 58X _1, when the interferometer unit 58X is used, using the measurement results of the X scaling may be calculated rotational angle [theta] z. In this case, for example, a fitting formula represented by the following formula (9) can be used.

Sx ⁽²⁾ (θz) = c ₀ + c ₁ θz + c ₂ θz ² (9)

  In the first embodiment described above, in principle, three reference marks are detected in order to measure the reference posture of the wafer table WTB. However, a simplified method is also desired in order to shorten the measurement time. The second embodiment has been made from this viewpoint.

<< Second Embodiment >>
Next, a second embodiment of the present invention will be described based on FIGS. 13 (A) to 13 (C) and FIG. The exposure apparatus according to the second embodiment is different from the first embodiment only in the method for measuring and setting the reference posture of the wafer table WTB. Below, it demonstrates centering on this difference.

  In the second embodiment, the reference posture of wafer table WTB is measured and set by detecting one reference mark FMn by introducing an offset function.

In order to introduce the offset function, the amount calculated from the measurement amount obtained when measuring the reference mark FMn corresponds to, for example, the X scaling Sx in the above equation (7) and the Y scaling Sy in the equation (2), respectively. Then, sx and sy represented by the following expressions (10a) and (10b) are respectively introduced.
sx = | LXn + Δxn | / DX (10a)
sy = | LYn + Δyn | / DY (10b)
Here, (Δxn, Δyn) is the amount of misalignment of the center of the reference mark FMn with respect to the detection center of the alignment system ALG, and LXn, LYn are the distances to the irradiation points on the reflecting surfaces 54Y, 54X of the measurement beams WX, WY, respectively. is there. The quantities sx and sy can be obtained when measuring the scalings Sx and Sy, respectively. Therefore, an offset function represented by the following expressions (11a) and (11b) is determined.
δSx = Sx−sx (11a)
δSy = Sy−sy (11b)
By using these offset functions δSx and δSy, it is possible to measure sx and sy only for one reference mark FMn and convert the measured values to scaling Sx and Sy. Similarly to the first embodiment, if θx, θy, and θz that minimize the converted scalings Sx and Sy are obtained, the reference postures (θx ₀ , θy ₀ , θz ₀ ) of the wafer table WTB are obtained. Can be obtained.

Next, a method for setting the offset functions δSx and δSy will be described. Scaling Sx, Sy depends only on the three rotation coordinates (θx, θy, θz) of wafer table WTB. However, since the amounts sx, sy depend on all six coordinates of the position (x, y, z) and rotation (θx, θy, θz) of the wafer table WTB, the offset functions δSx, δSy also depend on all six coordinates. Therefore, measurement points of the position coordinates (xn, yn, zn) and rotation coordinates (φx _i , φy _j , φz _k ) of the wafer table WTB at the time of detecting each reference mark FMn are determined. However, when the above-described three reference marks are used, the measurement position is determined so as to satisfy x1 = x2, | y1-y2 | = DY, | x1-x3 | = DX, y1 = y3, z1 = z2 = z3. Then, the observation points of I, J, and K are determined for the three inclinations and rotation angles, respectively. However, I = J = K ≧ 3. Furthermore, the index i, j, k is a run and i = 0~I-1, j = 0~J-1, k = 0~K-1, φx 0, φy 0, the reference measurement point .phi.z ₀ . These measurement points of inclination and rotation angle are common in the detection of all the reference marks.

  In order to determine the offset function, the three reference marks FM1, FM2, and FM3 described above are used.

(1) First, an offset function δSy (θz) relating to the rotation angle θz is determined using the reference marks FM1 and FM2. Specifically, main controller 20 moves wafer table WTB to a predetermined position (x1, y1, z1) in order to detect fiducial mark FM1. Next, main controller 20, the tilt angle of wafer table WTB θx = φx _0, while fixing the [theta] y = [phi] y _0, a predetermined rotation angle [theta] z (= .phi.z _k, provided that k = 0~K-1) for by performing position measurement of the foregoing and similar reference marks FM1, for each of the rotational angle _{θz = φz k Δx1, Δy1,} LY1 ( and LX1) were measured for each rotation angle [theta] z = .phi.z _k according to equation (10b) sy is calculated.

Next, main controller 20 moves wafer stage WTB to a predetermined position (x2, y2, z2) in order to detect fiducial mark FM2 while maintaining inclination angles θx and θy. Next, main controller 20 measures Δx2, Δy2, LY2 (and LX2) for each of predetermined rotation angles θz (= φz _k , where k = 0 to K−1) in the same manner as described above. Then, using the measured value obtained by the above measurement, Y scaling Sy is _{obtained for} each rotation angle θz = φzk, and an offset function δSy is calculated according to the equation (11b).

Then, main controller 20 applies the fitting method to the measured value (calculated value) of offset function δSy and stores it as a continuous function δSy (φx ₀ , φy ₀ ; θz) of θz.

(2) Similarly, an offset function δSy (θx) relating to the inclination angle θx is determined using the reference marks FM1 and FM2. Specifically, main controller 20 moves wafer table WTB to a predetermined position (x1, y1, z1) in order to detect fiducial mark FM1. Next, main controller 20, the tilt angle [theta] y = [phi] y ₀ of wafer table WTB, while fixing the rotation angle [theta] z = .phi.z _0, predetermined tilt angle θx (= φx _i, provided that i = 0~I-1) respect, by performing position measurement of the reference mark FM1 similar to that described above, the inclination angle [theta] x = .phi.x _i for each .DELTA.x1, .DELTA.y1, measured LY1 (and LX1), the inclination angle [theta] x = .phi.x according to equation (10b) sy is calculated for each _i .

Next, main controller 20 moves wafer stage WTB to a predetermined position (x2, y2, z2) in order to detect reference mark FM2 while maintaining tilt angle θy and rotation angle θz. Next, main controller 20 measures Δx2, Δy2, LY2 (and LX2) for each of predetermined inclination angles θx (= φx _i , where i = 0 to I-1), in the same manner as described above. Then, using the measurement values obtained in the above measurement, together with obtaining the Y scaling Sy every inclination angle [theta] x = .phi.x _i, calculates the offset function δSy according to equation (11b).

Then, main controller 20 applies the fitting method to the measured value (calculated value) of offset function δSy and stores it as a continuous function δSy (φy ₀ , φz ₀ ; θx) of θx.

(3) Next, an offset function δSx (θy) relating to the inclination angle θy is determined using the fiducial marks FM1, FM3. Specifically, main controller 20 moves wafer table WTB to a predetermined position (x1, y1, z1) in order to detect fiducial mark FM1. Next, main controller 20 maintains a predetermined inclination angle θy (= φy _j , where j = 0 to J−1) while fixing the inclination angle θx = φx ₀ and rotation angle θz = φz _{0 of} wafer table WTB. respect, by performing position measurement of the reference mark FM1 similar to that described above, the inclination angle [theta] y = [phi] y _j for each .DELTA.x1, .DELTA.y1, measured LX1 (and LY1), the inclination angle [theta] y = [phi] y according to equation (10a) sx is calculated for each _j .

Next, main controller 20 moves wafer table WTB to a predetermined position (x3, y3, z3) in order to detect fiducial mark FM3 while maintaining tilt angle θx and rotation angle θz. Next, main controller 20 measures Δx3, Δy3, LX3 (and LY3) for each of predetermined inclination angles θy (= φy _j , where j = 0 to J−1) in the same manner as described above. Then, using the measurement value obtained by the above measurement, the X scaling Sx is obtained for each inclination angle θy = φy _j, and the offset function δSx is calculated according to the equation (11a).

Then, main controller 20 applies the fitting method to the measured value of offset function δSx and stores it as a continuous function δSx (φx ₀ , φz ₀ ; θy) of θy.

  Although detailed description is omitted, when the interferometer unit 58X is used, the offset function δSx related to the rotation angle θz is used using the reference marks FM1 and FM3 according to the same procedure as the procedure for setting the offset function δSy (θz). (Θz) can also be determined.

  Next, a method for obtaining the reference state of the wafer table WTB by detecting the reference mark FM1 will be described based on FIGS. 13 (A) to 13 (C) and FIG. 14 (A). In FIG. 14A, the horizontal axis θ represents θx, θy, or θz, and the vertical axes S, s represent Sx, sx, or Sy, sy.

(4) First, the reference rotation angle θz ₀ is obtained. Here, since reference mark FM1 is selected as a detection target, main controller 20 moves wafer table WTB to the measurement position (x1, y1, z1) of reference mark FM1.

Next, main controller 20, [theta] x = .phi.x the inclination of wafer table WTB _0, while fixing the [theta] y = [phi] y _0, the rotation angle _{θz (= φz 0, φz 1} , φz 2) ( FIG. 14 (A) (Φ ₀ , φ ₁ , φ ₂ ) in the middle is measured for the position of the reference mark FM1 as described above (see FIG. 13A), and sy ( Or sx) is calculated. Then, the calculated values (s ₀ , s ₁ , s _{2 in} FIG. 14A) are converted into the offset function δSy (θz) [or δSx (θz)] defined above according to the equation (11b). Convert to scaling Sy (or scaling Sx according to equation (11a)).

Next, main controller 20 applies a fitting method to the converted values (S ₀ , S ₁ , S _{2 in} FIG. 14A) to obtain a fitting curve (S _{fit in the} figure), and the fitting A reference rotation angle θz ₀ (θ ₀ in FIG. 14A) is obtained by obtaining the rotation angle θz at which the curve S _fit takes a minimum value.

(5) Next, a reference inclination angle θx ₀ is obtained. The main controller 20, the tilt angle [theta] y = [phi] y of wafer table WTB _0, while fixing the [theta] z = .phi.z _0, the inclination angle _{θx (= φx 0, φx 1} , φx 2) (φ in FIG. 14 (A) ₀ , Φ ₁ , φ ₂ ), the position of the fiducial mark FM1 is measured as described above (see FIG. 13B), and sy is calculated for each inclination angle in the same manner as (2) described above. Then, the calculated values (s ₀ , s ₁ , s _{2 in} FIG. 14A) are converted into scaling Sy according to the equation (11b) using the offset function δSy (θx) determined in advance.

Next, main controller 20 applies the fitting method to the converted values (S ₀ , S ₁ , S _{2 in} FIG. 14 (A)) to obtain the inclination angle θx that takes the minimum value, thereby obtaining the reference A rotation angle θx ₀ (θ ₀ in FIG. 14A) is obtained.

(6) Next, a reference inclination angle θy ₀ is obtained. The main controller 20, the inclination angle [theta] x = .phi.x of wafer table WTB _0, while fixing the [theta] z = .phi.z _0, the tilt angle _{θy (= φy 0, φy 1} , φy 2) (φ in FIG. 14 (A) ₀ , Φ ₁ , φ ₂ ), the position of the fiducial mark FM1 is measured as described above (see FIG. 13C), and sx is calculated for each inclination angle in the same manner as (3) described above. Then, the calculated values (s ₀ , s ₁ , s _{2 in} FIG. 14A) are converted into scaling Sx according to the equation (11a) using the offset function δSx (θy) determined in advance.

Next, main controller 20 applies the fitting method to the converted values (S ₀ , S ₁ , S _{2 in} FIG. 14 (A)), and obtains the inclination angle θy that takes the minimum value, thereby obtaining the reference The rotation angle θy ₀ (θ ₀ in FIG. 14A) can be obtained.
The reference postures (θx ₀ , θy ₀ , θz ₀ ) of wafer table WTB are obtained by the above (4) to (6).

According to the second embodiment described above, an effect equivalent to that of the first embodiment described above can be obtained. In addition, according to the second embodiment, the offset functions δSx (θy), δSy () are preliminarily performed in accordance with the procedures (1) to (3) described above, for example, when the exposure apparatus is started (assembled). If [theta] x), [delta] Sy ([theta] z) [, [delta] Sx ([theta] z)] are determined, the above-described (4) to (4) are used at the time of exposure apparatus maintenance or when the wafer stage is reset such as when a failure occurs. By detecting one reference mark FMn (any one of FM1 to FM3), for example, FM1, the reference posture (θx ₀ , θy ₀ , θz ₀ ) of the wafer table WTB can be obtained by the procedure of (6). . Therefore, compared with the first embodiment, it is possible to shorten the measurement time of the reference posture of the wafer table WTB at the time of resetting the wafer stage, and hence the set time.

In the second embodiment, in the setting of the offset functions δSx (θy), δSy (θx), δSy (θz) [, δSx (θz)], the movement of the wafer table WTB and the change of the posture are not in any order. Can be done. Even in the measurement of the reference posture using the offset function, the three reference angles θx ₀ , θy ₀ , and θz ₀ can be measured in any order.

In the second embodiment, the offset function is used to convert the measured value of sx or sy into the scaling Sx or Sy. However, as shown in FIG. 14B, as shown in FIG. A fitting method is applied to the measured value of sy (s ₀ , s ₁ , s _{2 in} FIG. 14B) to obtain a fitting curve (s _fit in FIG. 14B), and sx or sy is The attitude (θ ′ ₀ in FIG. 14B) taking the extreme value is obtained. From the attitude, it is possible to calculate an attitude (θ ₀ in FIG. 14B) at which the scaling takes an extreme value using the offset function δSx or δSy.
In the method using the “offset function” as described above, the member in which the FM is configured is preferably in a stable state over a long period of time. However, it is not necessarily limited thereto.

<Modification>
In addition, the following method for measuring and setting the reference posture of the wafer table WTB, which is a combination of the first embodiment and the second embodiment, may be adopted.

That is, for example, from the measurement value of the position of the reference mark FM1 obtained in the measurement for obtaining the scalings Sy and Sx in the first embodiment, the position (X, Y), the rotation angle θz, and the inclination angle Fitting curves Y = f (θz), Y = g (θx), and X = h (θy) indicating the relationship with θy and θz are obtained by the same method as the fitting curve s _fit . Then, the difference between θz values corresponding to the minimum values of the fitting curves Sy (θz) and Y = f (θz), and the difference between θx corresponding to the minimum values of the fitting curves Sy (θx) and Y = f (θx). Differences in values, and differences in values of θy corresponding to the respective minimum values of the fitting curves Sx (θy) and X = f (θy) are previously calculated as offsets.

After that, the position of the reference mark FM1 is measured while changing θz, θx, and θz of the wafer table WTB, and the fitting curve Y = f (θz), Y = g (θx), and X = h. (Θy) is calculated, and the reference postures (θx ₀ , θy ₀ , θz ₀ ) of wafer table WTB are obtained based on the fitting curves and the corresponding offsets.

  Also by this, an effect equivalent to that of the second embodiment can be obtained.

  In this modification, for example, when the measurement accuracy is required for a complete reset, such as when the exposure apparatus is activated, the same scaling measurement as in the first embodiment is performed, and at this time, the above-described offset is obtained. It is good to keep.

  Of course, the measurement method of the first embodiment described above and the measurement method of the second embodiment may be combined. In this case as well, for example, when measurement accuracy is required for complete reset, such as when the exposure apparatus is started, the same scaling measurement as in the first embodiment is performed, and at this time, the offset function is determined. It is desirable to keep it.

  In each of the above embodiments and modifications, the case where an FIA sensor is used as the alignment system ALG has been described. However, the present invention is not limited to this, and the alignment coordinates are based on the measurement value of the interferometer system 58 and the detection result thereof. Any detection type alignment sensor may be used as long as the position of the reference mark on the system can be obtained. Of course, the reference mark is not limited to the reference mark plate, but may be formed on a reference wafer or the like that is sucked and held on the wafer table WTB.

  Further, in each of the above-described embodiments and modifications, the case where the position information of the wafer table WTB in the five-degree-of-freedom direction excluding the Z-axis direction is measured by the interferometer system 58 has been described. (Or X-axis direction) and θz direction (and θx direction or θy direction) wafer table WTB position information is measured by an interferometer, and wafer table WTB position information in other directions is measured by another measuring device such as an encoder. The present invention can also be suitably applied to a moving body drive system equipped with a measurement system for measuring by the above.

In each of the above embodiments, the ultraviolet light from the ultra-high pressure mercury lamp (g-line, i-line, etc.), KrF excimer laser light, ArF excimer laser light, etc. is used as the illumination light IL. However, vacuum ultraviolet light such as F ₂ laser light (wavelength 157 nm) or Ar ₂ laser light (wavelength 126 nm) may be used. Further, for example, as the vacuum ultraviolet light, a single wavelength laser beam oscillated from a DFB semiconductor laser or a fiber laser is a single wavelength laser light, for example, erbium (Er) (or both erbium and ytterbium (Yb)). It is also possible to use a harmonic that is amplified by a doped fiber amplifier and wavelength-converted to ultraviolet light using a nonlinear optical crystal.

  Further, an exposure apparatus that uses EUV light, X-rays, or charged particle beams such as an electron beam or an ion beam as illumination light IL, a projection system that does not use a projection optical system, such as a proximity type exposure apparatus, a mirror projection aligner, and The present invention may also be applied to an immersion type exposure apparatus disclosed in International Publication WO99 / 49504 and the like in which a liquid is filled between the projection optical system PL and the wafer.

  In addition, the present invention includes, for example, JP-A-10-163099, JP-A-10-214783 and the corresponding US Pat. No. 6,400,441, JP 2000-505958A, and the like. The present invention may be applied to a twin stage type exposure apparatus described in the corresponding US Pat. No. 5,969,441 and US Pat. No. 6,262,796.

  In addition, as disclosed in JP-A-11-135400, the present invention includes an exposure stage that can move while holding a substrate to be processed such as a wafer, and a measurement stage having various measurement members and sensors. The present invention can also be applied to other exposure apparatuses.

  In each of the above-described embodiments, a light-transmitting mask in which a predetermined light-shielding pattern (or phase pattern / dimming pattern) is formed on a light-transmitting substrate, or a predetermined reflecting pattern on a light-reflecting substrate. However, the present invention is not limited to these. For example, instead of such a mask, an electronic mask (which is a kind of optical system) that forms a transmission pattern, a reflection pattern, or a light emission pattern based on electronic data of a pattern to be exposed may be used. Such an electronic mask is disclosed, for example, in US Pat. No. 6,778,257. Note that the above-described electronic mask is a concept including both a non-light-emitting image display element and a self-light-emitting image display element.

  Further, for example, the present invention can also be applied to an exposure apparatus that exposes a substrate with interference fringes caused by interference of a plurality of light beams, which is called two-beam interference exposure. Such an exposure method and exposure apparatus are disclosed in, for example, WO 01/35168.

  In each of the above-described embodiments, the case where the present invention is applied to the step-and-repeat reduction projection exposure apparatus has been described, but it is needless to say that the scope of the present invention is not limited to this. That is, the present invention can be suitably applied to a scanning exposure apparatus such as a step-and-scan method.

  The present invention is not limited to an exposure apparatus for manufacturing a semiconductor, but is used for manufacturing a display including a liquid crystal display element. An exposure apparatus for transferring a device pattern onto a glass plate and a device used for manufacturing a thin film magnetic head. The present invention can also be applied to an exposure apparatus that transfers a pattern onto a ceramic wafer, and an exposure apparatus that is used for manufacturing an imaging device (CCD or the like), micromachine, organic EL, DNA chip, and the like. Further, in order to manufacture reticles or masks used in not only microdevices such as semiconductor elements but also light exposure apparatuses, EUV exposure apparatuses, X-ray exposure apparatuses, electron beam exposure apparatuses, etc., glass substrates or silicon wafers, etc. The present invention can also be applied to an exposure apparatus that transfers a circuit pattern.

  Heretofore, the exposure apparatus for forming a pattern on a substrate has been described. However, the method for forming a pattern on a substrate by a scanning operation is not limited to the exposure apparatus, and for example, Japanese Patent Application Laid-Open No. 2004-13031. It can also be realized by using an element manufacturing apparatus provided with an ink jet functional liquid application device similar to the ink jet head group disclosed in the above.

  The ink jet head group disclosed in the above publication is applied to a substrate (for example, PET, glass, silicon, paper, etc.) by discharging a predetermined functional liquid (metal-containing liquid, photosensitive material, etc.) from a nozzle (discharge port). A plurality of inkjet heads. What is necessary is just to prepare a functional liquid provision apparatus like this inkjet head group, and to use it for the production | generation of a pattern. In the element manufacturing apparatus provided with this functional liquid application apparatus, the substrate may be fixed and the functional liquid application apparatus may be scanned in the scanning direction, or the substrate and the functional liquid application apparatus may be reversed. You may scan.

  A semiconductor device includes a step of performing functional / performance design of a device, a step of manufacturing a reticle based on the design step, a step of manufacturing a wafer from a silicon material, and a reticle by the above-described method using the exposure apparatus of the above-described embodiment. This is manufactured through a step of transferring the pattern to a wafer, a device assembly step (including a dicing process, a bonding process, and a packaging process), an inspection step, and the like.

  As described above, the measurement method and the setting method and the moving body drive system of the present invention are suitable for measuring the reference state of the moving body and setting the moving body to the reference state. The pattern forming method and pattern forming apparatus of the present invention are suitable for accurately forming a pattern on an object placed on a moving body.

It is a figure which shows schematically the structure of the exposure apparatus which concerns on 1st Embodiment. It is a top view which shows the stage apparatus which concerns on 1st Embodiment. It is a figure for demonstrating the structure of the interferometer which concerns on 1st Embodiment. It is a block diagram which shows the structure of the control system of the exposure apparatus of 1st Embodiment. FIG. 5A to FIG. 5C are views showing the wafer table in the reference posture. In particular, FIG. 5A shows a state where the center of the reference mark FM1 is positioned at the detection center of the alignment system. FIG. 6 is a diagram showing a state in which the wafer table is moved by a distance DY in the + Y direction from the position of FIG. 5A while maintaining the reference posture, and the center of the reference mark FM2 is positioned at the detection center of the alignment system. FIG. 6 is a diagram illustrating a state in which the wafer table is rotated by an angle θz around the center of the reference mark FM1 from the state of FIG. FIG. 8 is a diagram showing a state where wafer table WTB is linearly moved in a predetermined direction so that reference mark FM2 coincides with the detection center of the alignment system while maintaining the posture of FIG. FIG. 9A shows a state where the wafer table is moved so that the reference mark FM1 is positioned within the detection region of the alignment system in a state where the wafer table is rotated by an angle θz from the reference posture, and FIG. It is a figure which shows the state in which the wafer table incline angle (theta) x from the reference attitude. FIG. 10 is a diagram illustrating a state in which the wafer table has moved the distance DY in the + Y direction from the state of FIG. 9A while maintaining the posture. In FIGS. 11A and 11B, the reference mark FM1 is positioned within the detection region of the alignment system ALG in a state where the wafer table is maintained in the previously obtained reference posture (θz ₀ , θx ₀ ). It is a figure which shows the state which moved as follows. FIGS. 12A and 12B are views showing a state in which wafer table WTB has moved a distance DX in the −X direction from the state of FIG. 11A while maintaining its posture. FIG. 13A to FIG. 13C are diagrams for explaining the procedure for measuring the reference posture of the wafer table in the second embodiment. FIG. 14A and FIG. 14B are diagrams for explaining the procedure for calculating the reference orientation of the wafer table in the second embodiment.

Explanation of symbols

10 ... exposure apparatus, 20 ... main controller, 50 ... stage device, 54X, 54Y ... reflecting surface, 58 ... interferometer system, 58X _1, 58Y ... interferometer unit, 130 ... wafer stage drive system, ALG ... alignment system, FM1, FM2, FM3 ... reference mark, W ... wafer, WX, WY ... measurement beam, WTB ... wafer table.

Claims (39)

A measurement method for determining a reference state of a movable body that is movable within a predetermined plane including at least a first axis and a second axis that intersect each other,
Managing the position and orientation of the moving body based on the measurement values of a measurement system including a first interferometer that irradiates a plurality of measurement beams in a direction parallel to the first axis onto a reflecting surface provided on the moving body However, a plurality of fiducial marks including first and second fiducial marks that are different in position with respect to a direction parallel to the first axis arranged on the movable body by changing the position or posture of the movable body. A first step of detecting each using a mark detection system;
The positional relationship between each of the first and second reference marks and the detection center of the mark detection system, detected using the mark detection system in a plurality of different postures of the moving body, and the first at the time of each detection Based on a measurement value of one interferometer, a first relationship between the posture of the moving body and a physical quantity related to a distance in a direction parallel to the first axis between the first and second reference marks is obtained. A second step to be sought;
And a third step of determining a posture of the moving body in a reference state where the first axis and the reflecting surface intersect based on the first relationship. The first relationship includes a physical quantity related to a distance in a direction parallel to the first axis between the first and second reference marks, and an axis parallel to a third axis intersecting the plane of the movable body. Including the relationship with the rotation angle around
The measurement method according to claim 1, wherein in the third step, a rotation angle around an axis parallel to the third axis of the movable body in the reference state is obtained. The first relationship includes a physical quantity related to a distance in a direction parallel to the first axis between the first and second reference marks, a rotation angle of the movable body around the third axis, and the second Including the relationship with the rotation angle around the axis parallel to the axis,
The measurement method according to claim 1, wherein in the third step, a rotation angle around an axis parallel to the third axis of the movable body and a rotation angle around an axis parallel to the second axis in the reference state are obtained. The moving body is further provided with another reflecting surface that intersects the reflecting surface,
The measurement system further includes a second interferometer that irradiates the other reflective surface with a plurality of measurement beams in a direction parallel to the second axis,
In the first step, the position or posture of the moving body is managed based on the measurement value of the second interferometer, and the position or posture of the moving body is changed, and the moving body is arranged on the moving body. Two reference marks having different positions in a direction parallel to the second axis are detected using the mark detection system,
The positional relationship between each of the two reference marks and the detection center of the mark detection system detected using the mark detection system in a plurality of different postures of the moving body, and the second interferometer at the time of each detection A fourth step of obtaining a second relationship between the posture of the movable body and a physical quantity related to a distance in a direction parallel to the second axis between the two reference marks based on a measurement value;
5. A fifth step of obtaining a posture of the movable body in a reference state where the second axis and the another reflecting surface intersect based on the second relationship. 5. The measurement method according to one item. The second relationship includes a relationship between a physical quantity related to a distance in a direction parallel to the second axis between two reference marks, and a rotation angle about an axis parallel to the first axis of the moving body. ,
The measurement method according to claim 4, wherein in the fifth step, a rotation angle around an axis parallel to the first axis of the movable body in the reference state is obtained.   In the fifth step, a rotation angle about an axis parallel to the first axis of the movable body in the reference state is obtained based on an extreme value of a quadratic approximate curve corresponding to the second relationship. 5. The measuring method according to 5.   The at least one of the two reference marks used for determining the second relationship is the same as one of the first and second reference marks used for determining the first relationship. The measuring method as described in any one of 4-6.   In the first step, after the movable body is driven, a predetermined reference mark is positioned in a detection region of the mark detection system, and the predetermined reference mark is detected using the mark detection system, The operation of driving the moving body to place another reference mark in the detection region of the mark detection system and detecting the other reference mark using the mark detection system is performed by changing the posture of the moving body. The measurement method according to claim 1, wherein the measurement method is repeatedly performed by sequentially changing.   In the first step, a reference mark is positioned in a detection region of the mark detection system, and the posture of the moving body is sequentially changed at that position, and the reference mark is moved to the mark detection system each time the posture is changed. The measurement method according to any one of claims 1 to 7, wherein the operation of detecting using the is repeated for a plurality of reference marks.   The said 3rd process WHEREIN: Based on the extreme value of the quadratic approximate curve corresponding to the said 1st relationship, the attitude | position of the said mobile body in the said reference state is calculated | required. Measurement method.   11. The measurement method according to claim 1, wherein each of the plurality of reference marks is formed on either the moving body or a reference member placed on the moving body.   The measurement method according to claim 11, wherein the reference member is a substrate placed on the movable body and having a plurality of reference marks formed on the surface thereof in a predetermined positional relationship. Executing the measurement method according to any one of claims 1 to 12, and setting the movable body to a reference state based on the measurement result;
Placing the object on the moving body set to the reference state;
Forming a pattern on an object placed on the moving body while managing the position and orientation of the moving body using the measurement system. A setting method for setting a movable body movable in a predetermined plane including at least a first axis and a second axis intersecting each other to a reference state,
Managing the position and orientation of the moving body based on the measurement values of a measurement system including a first interferometer that irradiates a plurality of measurement beams in a direction parallel to the first axis onto a reflecting surface provided on the moving body However, the position or posture of the moving body is changed, and the first and second reference marks whose positions are different with respect to the direction parallel to the first axis arranged on the moving body are used using a mark detection system. A first step of detecting each of the;
The positional relationship between each of the first and second reference marks and the detection center of the mark detection system, detected using the mark detection system in a plurality of different postures of the moving body, and the first at the time of each detection Based on the measurement value of one interferometer, the attitude of the moving body and the physical quantity related to the position of one of the first and second reference marks in the direction parallel to the first axis. A first relationship for converting the first relationship into a second relationship between the posture of the moving body and a physical quantity related to a distance in a direction parallel to the first axis between the first and second reference marks. A second step for obtaining offset information;
After obtaining the first offset information, the physical quantity related to the position of the one reference mark in the direction parallel to the first axis for each posture of the moving body, or the first relation obtained from the physical quantity. And a third step of controlling the posture of the moving body based on the first offset information.   In the third step, the physical quantity related to the position of the one reference mark in the direction parallel to the first axis for each posture of the moving body is calculated for each posture of the moving body using the first offset information. Converting to a physical quantity related to a distance in a direction parallel to the first axis between the first and second reference marks, and obtaining a reference posture of the moving body based on the converted physical quantity; The setting method according to claim 14, comprising: In the second step, the first posture of the moving body corresponding to the extreme value of the quadratic approximate curve corresponding to the first relationship is changed to the pole of the secondary approximate curve corresponding to the second relationship. Information for converting to the second posture of the moving body corresponding to the value is obtained as the first offset information,
In the third step, the posture of the moving body is controlled based on the posture of the moving body corresponding to the extreme value of the quadratic approximate curve corresponding to the first relationship and the first offset information. The setting method according to claim 14.   The posture is a rotation angle around an axis parallel to the third axis among a rotation angle around an axis parallel to a third axis intersecting the plane of the movable body and a rotation angle around an axis parallel to the second axis. The setting method as described in any one of Claims 14-16 containing at least a rotation angle. The moving body is further provided with another reflecting surface that intersects the reflecting surface,
The measurement system further includes a second interferometer that irradiates the other reflective surface with a plurality of measurement beams in a direction parallel to the second axis,
Based on the measurement value of the measurement system, while managing the position and orientation of the moving body, the position of the moving body in the direction parallel to the second axis or the rotation angle around the axis parallel to the first axis A fourth step of differently detecting, using a mark detection system, two reference marks having different positions with respect to a direction parallel to the second axis disposed on the moving body;
The positional relationship between each of the two reference marks and the detection center of the mark detection system, detected using the mark detection system in different postures of the moving body, and the measurement value of the second interferometer at each detection Based on the rotation angle about the axis parallel to the first axis of the moving body and the physical quantity related to the position of one of the two reference marks in the direction parallel to the second axis; The fourth relationship between the rotation angle about the axis parallel to the first axis of the movable body and the physical quantity related to the distance in the direction parallel to the second axis between the two reference marks is A fifth step for obtaining second offset information for conversion into a relationship;
After obtaining the second offset information, the physical quantity related to the position of the one reference mark in the direction parallel to the second axis for each rotation angle around the axis parallel to the first axis of the movable body, or And a sixth step of controlling a rotation angle of the movable body around an axis parallel to the first axis based on the third relationship obtained from the physical quantity and the second offset information. Item 18. The setting method according to any one of Items 14 to 17.   In the sixth step, a physical quantity related to a position of the one reference mark in a direction parallel to the first axis for each rotation angle around an axis parallel to the first axis of the movable body is set to the second offset. Using information, it is converted into a physical quantity related to the distance in the direction parallel to the first axis between the first and second reference marks for each rotation angle around the axis parallel to the first axis of the moving body. The setting method according to claim 18, further comprising: a step of calculating a rotation angle about an axis parallel to the first axis in the reference state of the moving body based on the converted physical quantity. In the fifth step, a first rotation angle around an axis parallel to the first axis of the moving body corresponding to the extreme value of a quadratic approximate curve corresponding to the third relation is set to the fourth relation. Information for converting to a second rotation angle around an axis parallel to the first axis of the moving body corresponding to the extreme value of the quadratic approximate curve corresponding to is obtained as the second offset information,
In the sixth step, the rotation angle around the axis parallel to the first axis of the moving body corresponding to the extreme value of the quadratic approximate curve corresponding to the third relationship, and the first offset information The setting method according to claim 18, wherein the rotation angle of the movable body around an axis parallel to the first axis is controlled based on the rotation angle.   The at least one of the two reference marks used to determine the fourth relationship is the same as one of the first and second reference marks used to determine the second relationship. The setting method as described in any one of 18-20. Using the setting method according to any one of claims 14 to 21 to set the movable body to a reference state;
Placing the object on the moving body set to the reference state;
Forming a pattern on an object placed on the moving body while managing the position and orientation of the moving body using the measurement system.   23. The pattern forming method according to claim 13, wherein the pattern is formed by exposing the object with an energy beam. A moving body that is movable in a predetermined plane including at least a first axis and a second axis that intersect each other, and is provided with at least one reflecting surface;
A measurement system including a first interferometer that irradiates the reflective surface with a plurality of measurement beams in a direction parallel to the first axis;
A drive system for driving the movable body;
A mark detection system for detecting a mark present on the moving body;
Based on the measurement value of the measurement system, the position or posture of the moving body is managed, and the position or posture of the moving body is made different via the drive system, and the first moving body is arranged on the moving body. A processing device for detecting a plurality of reference marks including first and second reference marks having different positions with respect to a direction parallel to one axis using the mark detection system;
The positional relationship between each of the first and second reference marks and the detection center of the mark detection system, detected using the mark detection system in a plurality of different postures of the moving body, and the first at the time of each detection Based on a measurement value of one interferometer, a first relationship between the posture of the moving body and a physical quantity related to a distance in a direction parallel to the first axis between the first and second reference marks is obtained. And a computing device that obtains an attitude of the movable body in a reference state where the first axis and the reflecting surface intersect based on the first relationship.   The arithmetic unit includes a physical quantity related to a distance in a direction parallel to the first axis between the first and second reference marks, and a third axis and a second axis that intersect the plane of the movable body. Of the rotation angles around the axis parallel to each axis, the relationship between at least the rotation angle around the axis parallel to the third axis is obtained as the first relationship, and the reference is based on the first relationship. 25. The moving body drive system according to claim 24, wherein a rotation angle around an axis parallel to at least the third axis of the moving body in a state is obtained. The moving body is further provided with another reflecting surface that intersects the reflecting surface,
The measurement system further includes a second interferometer that irradiates the other reflective surface with a plurality of measurement beams in a direction parallel to the second axis,
The processing device manages the position / orientation of the moving body based on the measurement value of the measurement system, and changes the position or orientation of the moving body to arrange the second device arranged on the moving body. Two reference marks having different positions in a direction parallel to the axis are detected using the mark detection system,
The arithmetic device detects the positional relationship between each of the two reference marks and the detection center of the mark detection system detected using the mark detection system in a plurality of different postures of the moving body, and the detection time at each detection time. Based on the measurement value of the second interferometer, a second relationship between the posture of the moving body and a physical quantity related to the distance in the direction parallel to the second axis between the two reference marks is obtained, 26. The moving body drive system according to claim 24 or 25, wherein an attitude of the moving body is obtained based on a second relationship in a reference state in which the second axis and the another reflecting surface intersect.   The at least one of the two reference marks used for determining the second relationship is the same as one of the first and second reference marks used for determining the first relationship. 27. A moving body drive system according to 26. The second relationship includes a relationship between a physical quantity related to a distance in a direction parallel to the second axis between two reference marks and a rotation angle around an axis parallel to the first axis of the moving body,
28. The moving body drive system according to claim 26 or 27, wherein the arithmetic device obtains a rotation angle around an axis parallel to the first axis of the moving body in the reference state.   The arithmetic unit obtains a rotation angle about an axis parallel to the first axis of the moving body in the reference state based on an extreme value of a quadratic approximate curve corresponding to the second relationship. The moving body drive system described in 1.   30. The control device according to claim 24, further comprising a control device that controls the posture of the moving body through the drive system based on the posture of the moving body in the reference state obtained by the arithmetic device. Mobile drive system.   The arithmetic device detects the positional relationship between each of the two reference marks and the detection center of the mark detection system detected using the mark detection system in a plurality of different postures of the moving body, and the detection time at each detection time. Based on the measurement value of the second interferometer, the rotation angle around the axis parallel to the first axis of the moving body and the direction parallel to the second axis of one of the two reference marks A third relationship with a physical quantity related to the position of the moving body, relating to a rotation angle about an axis parallel to the first axis of the movable body and a distance in a direction parallel to the second axis between the two reference marks. 30. The moving body drive system according to claim 29, wherein first offset information for conversion to a second relationship with a physical quantity to be obtained is obtained.   The arithmetic unit calculates a first rotation angle around an axis parallel to the first axis of the moving body corresponding to an extreme value of a quadratic approximate curve corresponding to the third relationship, as the second relationship. The information for converting to the second rotation angle around the axis parallel to the first axis of the moving body corresponding to the extreme value of the quadratic approximate curve corresponding to is obtained as the first offset information. 31. A moving body drive system according to 31.   After the first offset information is acquired by the arithmetic unit, the one reference mark is positioned in a direction parallel to the second axis for each rotation angle around an axis parallel to the first axis of the moving body. And a controller that controls a rotation angle of the movable body around an axis parallel to the first axis based on the related physical quantity or the second relationship obtained from the physical quantity and the first offset information. 33. A moving body drive system according to claim 31 or 32.   The said arithmetic unit calculates | requires the attitude | position of the said mobile body in the said reference state based on the extreme value of the quadratic approximated curve corresponding to the said 1st relationship. Body drive system.   The arithmetic unit is configured to detect a positional relationship between each of the first and second reference marks and the detection center of the mark detection system, detected using the mark detection system in a plurality of different postures of the moving body, Based on the measurement value of the first interferometer at the time of detection, the position of the moving body and the position of one of the first and second reference marks in a direction parallel to the first axis The fourth relation with the related physical quantity is converted into the first relation between the posture of the moving body and the physical quantity related to the distance in the direction parallel to the first axis between the first and second reference marks. 35. The moving body drive system according to claim 34, wherein second offset information for obtaining the second offset information is obtained.   The computing device has the moving body posture corresponding to the extreme value of the quadratic approximate curve corresponding to the fourth relationship and the extremum of the quadratic approximate curve corresponding to the first relationship. 36. The moving body drive system according to claim 35, wherein information for converting to a posture of the moving body is obtained as the second offset information.   After the second offset information is acquired by the arithmetic unit, the physical quantity related to the position of the one reference mark in the direction parallel to the first axis for each posture of the moving body, or obtained from the physical quantity 37. The moving body drive system according to claim 35 or 36, further comprising a control device that controls an attitude of the moving body based on the fourth relationship and the second offset information. A pattern forming apparatus for forming a pattern on an object,
38. The moving body drive system according to any one of claims 24 to 37, wherein the object is placed on the moving body.
A pattern generating device that generates a pattern on an object on the moving body set in the reference state by the control device.   39. The pattern forming apparatus according to claim 38, wherein the pattern generating apparatus generates a pattern on the object by irradiating the object with an energy beam.

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