WO2004051184A1

WO2004051184A1 - Shape measurement method, shape measurement device, tilt measurement method, stage device, exposure device, exposure method, and device manufacturing method

Info

Publication number: WO2004051184A1
Application number: PCT/JP2003/015491
Authority: WO
Inventors: Saburo Kamiya; Yutaka Kanakutsu
Original assignee: Nikon Corporation
Priority date: 2002-12-03
Filing date: 2003-12-03
Publication date: 2004-06-17
Also published as: AU2003289146A1; JPWO2004051184A1

Abstract

A shape measurement method for measuring the shape of reflection planes 7XS, 7YS of a stage (4) moving along a reference plane. While moving the stage (4) in the Y axis direction, the primary shape of the reflection plane 7XS associated with the Y axis direction is measured at two positions apart from each other in the Z axis direction, so as to obtain first data corresponding to a difference between one and the other primary shape data. The stage (4) is moved in the Y axis direction while adjusting the posture of the stage (4) so that the measurement result based on the measurement beam LWXP applied simultaneously to two positions apart from each other in the Z axis direction of the reflection plane 7XS is constant. During this movement, displacement of the stage (4) in the Z axis direction accompanying the posture adjustment is measured at a plurality of positions so as to obtain second data equivalent to a change of the rotation amount around the Y axis associated with the Y axis direction. Third data equivalent to a difference between the first data and the second data is subjected to linear approximation to obtain fourth data. According to the fourth data, the primary shape data is corrected.

Description

Description · Shape measurement method, shape measurement device, tilt measurement method, stage device,

Exposure apparatus, exposure method, and depiice manufacturing method

The present invention relates to a shape measuring method and a shape measuring device for a reflection surface provided on a moving body such as a stage, a tilt measuring method for measuring a posture of the moving body, a stage apparatus for moving the moving body, an exposure apparatus, The present invention also relates to an exposure method and a device manufacturing method using the exposure method. Background art

2. Description of the Related Art Conventionally, in a lithographic process for manufacturing a semiconductor element, a liquid crystal display element, or the like, a pattern formed on a mask or a reticle (hereinafter, collectively referred to as a “reticle”) is formed by a resist or the like via a projection optical system. There is used an exposure apparatus that transfers an image onto a substrate such as a wafer or a glass plate (hereinafter, referred to as “substrate” or “wafer” as appropriate). As such an exposure apparatus, a stationary exposure type projection exposure apparatus such as a so-called stepper and a scanning exposure type projection exposure apparatus such as a so-called scanning stepper are mainly used. In these types of projection exposure apparatuses, a wafer stage that can move two-dimensionally while holding the wafer is provided because it is necessary to sequentially transfer the pattern formed on the reticle to a plurality of shot areas on the wafer. . In the case of a scanning exposure type projection exposure apparatus, a reticle stage for holding a reticle is also movable in the scanning direction.

In such a projection exposure apparatus, since a circuit pattern having a very fine structure is transferred to a wafer, it is necessary to control the position of the wafer reticle with high accuracy. For this high-precision position control, the two-dimensional position of the wafer stage and reticle stage is adjusted by irradiating the measuring mirror from the laser interferometer to the reflecting mirror provided on the wafer stage and reticle stage, and the reflected light and reference light. It is detected with high accuracy based on the fringe pattern or phase difference of the interference light with In the measurement of the positions of the wafer stage and the reticle stage, if the mirror surface of the reflecting mirror provided on the stage has undulations or twists, errors will occur in the measurement values obtained by the laser interferometer, resulting in highly accurate exposure. May not be possible. Therefore, the surface shape (two-dimensional shape) of the mirror surface of the reflecting mirror is measured, and the measurement result of the laser interferometer is corrected based on the measurement result.

Techniques for measuring the surface shape of the mirror surface of the reflecting mirror include, for example, International Publication No. WO 00/223736 published by the applicant of the present invention and U.S. Pat. The technology described in No. 955 is known. According to this technology, the two-dimensional shape along the longitudinal direction of the reflecting mirror in each of two positions (hereinafter, also referred to as an upper stage and a lower stage) in the lateral direction (height direction) of the reflecting mirror is appropriately adjusted. In addition to the measurement based on the reference, the relative relationship between the measured value in the upper row and the measured value in the lower row (here, the offset in the direction perpendicular to the reflecting surface) is determined as follows, and the surface of the mirror surface of the reflecting mirror is obtained. The shape is specified.

That is, a measurement wafer on which a plurality of reference marks arranged in a predetermined relationship is formed is placed on a wafer stage such that the arrangement direction of the reference marks and the axial direction of the wafer stage exactly match. Before or after each of the upper one-dimensional shape measurement and the lower one-dimensional shape measurement, the position of the reference mark on the measurement wafer is measured with an off-axis alignment sensor. The above offset is determined from the positional deviation of.

However, in the above-described conventional technology, a measurement wafer having a predetermined reference mark formed thereon is prepared, and is placed on a wafer stage in a predetermined posture, and then the positions of the plurality of reference marks are aligned with an alignment sensor. However, there is a problem that the number of work steps is large and measurement cannot be performed easily and quickly.

In addition, the measurement results necessarily include errors in the formation of fiducial marks on the measurement wafer, errors due to surface undulations when the stage is placed on the measurement wafer, and measurement errors in the fiducial marks. Is also low. Disclosure of the invention

The present invention has been made in view of such circumstances, and its purpose is to: It is an object of the present invention to make it possible to measure the reflection surface provided on a moving body such as a stage easily, quickly and with high accuracy, and to control the position of the stage etc. with high accuracy. According to a first aspect of the present invention, the shape of a reflecting surface provided on a movable body that moves along a reference plane orthogonal to a first axis and extending along a second axis direction orthogonal to the first axis direction is defined as A shape measurement method for measuring, wherein the one-dimensional shape of the reflection surface in the second axis direction is separated in the first axis direction while moving the moving body along the second axis direction. Measurement for each of the two positions, obtaining first data corresponding to the difference between the one-dimensional shape data for one of the two positions and the one-dimensional shape data for the other, and in the first axial direction of the reflection surface. The moving body is moved in the second axial direction while the posture of the moving body is adjusted such that the measurement result based on the measurement beam radiated simultaneously to the two positions separated from the moving body becomes constant. The first due to the posture adjustment of the moving body Directional displacement is measured at a plurality of locations to obtain second data corresponding to a change in the amount of rotation of the moving body about the second axis in the second axis direction, and the first data and the second data are obtained. There is provided a shape measuring method for correcting the one-dimensional shape data based on fourth data obtained by linearly approximating third data corresponding to a difference between the two data.

According to a second aspect of the present invention, the shape of a reflecting surface provided on a moving body that moves along a reference plane orthogonal to the first axis and extending along a second axis direction orthogonal to the first axis direction is defined. A shape measuring device for measuring, wherein the one-dimensional shape measuring device for measuring a one-dimensional shape of the reflection surface in the second axis direction at each of two positions separated in the first axis direction; A posture adjusting device for adjusting a posture of the moving body with respect to the reference plane, and a displacement measurement for measuring the displacement of the moving body in the first axial direction at a plurality of different positions with the posture adjustment of the moving body by the posture adjusting device. A tilt measuring device for simultaneously irradiating a measurement beam to two positions of the reflecting surface separated in the first axis direction and measuring a rotation amount of the reflecting surface about the second axis; and For one-dimensional shape measurement equipment First data corresponding to the difference between the one-dimensional shape data for one of the two positions and the one-dimensional shape data for the other is obtained, and the posture is set so that the measurement result by the tilt measuring device is constant. The moving body is moved in the second axis direction while controlling the adjusting device, and the displacement is measured by the displacement measuring device during the movement. Based on the result, second data corresponding to a change in the amount of rotation about the second axis in the direction of the second axis of the moving body is obtained, and the second data corresponding to the difference between the first data and the second data is obtained. And a control device for correcting the one-dimensional shape data as a measurement result by the one-dimensional shape measurement device based on fourth data obtained by linearly approximating the third data to be obtained. Provided.

According to a third aspect of the present invention, there is provided a reflecting surface extending along a second axis direction orthogonal to the first axis, and the reference of the moving body moving along a reference plane orthogonal to the first axis. A tilt measurement method for measuring an attitude with respect to a flat surface by a measurement beam that is simultaneously applied to two positions of the reflection surface separated in the first axis direction, wherein the tilted surface is separated from the reflection surface in the first axis direction. First data corresponding to the difference between one and the other of the one-dimensional shape data of the reflection surface in the second axis direction measured at each of the two positions, and that the measurement result based on the measurement beam is constant. Moving the moving body in the second axial direction while adjusting the posture of the moving body so that the displacement of the moving body in the first axial direction accompanying the posture adjustment of the moving body is measured at a plurality of locations. The moving body in the second axial direction. Second data corresponding to a change in the amount of rotation about the two axes is obtained, and the fourth data obtained by linearly approximating the third data corresponding to the difference between the first data and the second data is obtained. There is provided a tilt measuring method for correcting a measurement result by the measurement beam based on fifth data obtained by adding the first data.

According to a fourth aspect of the present invention, there is provided a scanning device having a reflecting surface extending along a second axis direction orthogonal to the first axis, and having a moving body moving along a reference plane orthogonal to the first axis. A tilt device for simultaneously irradiating a measurement beam to two positions of the reflection surface separated in the first axis direction and measuring a rotation amount of the reflection surface around the second axis. A measuring device; a one-dimensional shape measuring device that measures a one-dimensional shape of the reflection surface in the second axis direction at each of two positions separated in the first axis direction; and a moving body with respect to the reference plane. A posture adjusting device for displacing the moving body in the first axial direction at a plurality of positions different from each other to adjust the posture; and Different displacements in one axis direction Displacement measuring device that measures at a number of positions, and the one-dimensional shape measurement First data corresponding to the difference between the one-dimensional shape data for one of the two positions and the one-dimensional shape data for the other of the two positions is obtained, and the measurement result by the tilt measuring device is made constant. The moving body is moved in the second axis direction while controlling the attitude adjusting device, and the second axis of the moving body in the second axis direction is measured based on a measurement result by the displacement measuring device at this time. Second data corresponding to the change in the amount of rotation about the center is obtained, and the fourth data obtained by linearly approximating the third data corresponding to the difference between the first data and the second data is obtained. A stage device comprising: a control device that corrects a measurement result by the tilt measuring device based on fifth data obtained by adding the first data.

According to a fifth aspect of the present invention, there is provided an exposure apparatus for projecting and exposing an image on a first surface onto a second surface, comprising: a mask stage for disposing a mask on the first surface; and a substrate on the second surface. There is provided an exposure apparatus including a stage device according to the fourth aspect of the present invention, which moves at least one of the substrate stages to be moved as the movable body.

The fourth data obtained by the measurement and the calculation in the inventions according to the first to fifth aspects described above is one-dimensional shape data on one of two positions of the reflecting surface separated in the first axis direction. In the present invention, the relative relationship between the one-dimensional shape data and the other is shown without using a measurement wafer on which a reference mark is formed in order to derive the relative relationship. You can ask. Therefore, the shape data of the reflecting surface can be obtained easily and quickly, and the accuracy associated with the measurement of the reference mark is not included, so that the accuracy can be improved.

According to a sixth aspect of the present invention, there is provided an exposure method for transferring a mask pattern onto a photosensitive object held by a movable body along a reference plane orthogonal to a first axis, the method comprising: The posture of the moving body is adjusted so that the measurement results obtained by the measurement beams applied to the two positions separated in the first axis direction on the reflecting surface of the moving body extending in the second orthogonal axis direction become constant. Moving the moving body in the second axis direction while measuring rotation data relating to a change in the amount of rotation of the moving body around the second axis;

Using the shape data of the reflection surface at each of a plurality of positions separated in the one-axis direction in the second-axis direction and the measured rotation data, the movement of the moving body is determined. An exposure method is provided for controlling.

In the exposure method according to a sixth aspect of the present invention, in the exposure method, information on a displacement amount of the moving body in the first axis direction due to the posture adjustment during the movement is detected, and the information is detected based on the detected information. The rotation data can be obtained.

In the exposure method according to a sixth aspect of the present invention, measurement beams are respectively obtained at a plurality of positions on the reflection surface separated in the second axis direction, which are obtained by moving the moving body in the second axis direction. The shape data can be obtained based on the measurement result of the interferometer system that irradiates the light.

In the exposure method according to a sixth aspect of the present invention, in the exposure method, at least one of the plurality of positions spaced apart in the second axis direction on the reflection surface from the interferometer system is located at a position separated in the first axis direction from at least one of the plurality of positions. When the rotation data is measured, the attitude of the moving body can be adjusted using the interferometer system.

According to a seventh aspect of the present invention, there is provided a device manufacturing method including an exposure step of transferring a pattern of a mask onto a photosensitive object using the exposure method according to the sixth aspect of the present invention.

According to an eighth aspect of the present invention, in an exposure apparatus for transferring a pattern of a mask onto a photosensitive object, the exposure apparatus holds the photosensitive object, is movable along a reference plane orthogonal to a first axis, and is movable with respect to the reference plane. A stage system having a movable body in which a posture is adjustable and a reflecting surface parallel to a second axis orthogonal to the first axis is formed, and two stages separated in the first axis direction of the reflecting surface. An interferometer system that irradiates a position with a measurement beam to at least measure rotation information about the second axis of the moving object; and a measurement beam at two positions of the reflection surface that are separated in the first axis direction. A displacement measuring device for measuring displacement information of the moving body in the first axis direction by the posture adjustment, and measuring the moving body with the rotation information of the interferometer system. So that Based on the measurement result of the displacement measurement device obtained by moving the moving body in the second axis direction while adjusting the posture of the moving body, obtaining rotation data on a change in the amount of rotation of the moving body around the second axis, An exposure device comprising: a control device configured to control movement of the moving body by using shape data and the rotation data of the reflection surface in the second axis direction at each of the plurality of positions separated in the first axis direction. Equipment provided It is.

In the exposure apparatus according to an eighth aspect of the present invention, the interferometer system is separated in the second axis direction from at least one of two positions separated in the first axis direction on the reflection surface. Irradiating a position with a measurement beam to measure rotation information about the first axis of the moving body, wherein the control device is configured to move the moving body in the second axis direction. The shape data can be obtained based on a measurement result regarding the rotation information about the first axis.

In the exposure apparatus according to an eighth aspect of the present invention, the stage system includes a plurality of actuators for adjusting a posture of the moving body, and the displacement measuring device includes a driving amount of the plurality of actuators as the displacement information. Can be measured. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic configuration diagram of an exposure apparatus of one embodiment,

Fig. 2 is a diagram for explaining the configuration of the substrate table and the arrangement of the laser interferometer for detecting the position of the substrate table.

Figure 3 is a schematic configuration diagram of a laser interferometer for detecting the two-dimensional position of the substrate table.

FIG. 4 is a diagram for explaining an optical path in the laser interferometer of FIG. 3,

FIG. 5 is a diagram for explaining an optical path in the laser interferometer of FIG. 3,

FIG. 6 is a diagram for explaining an optical path in the laser interferometer of FIG. 3,

FIG. 7 is a schematic configuration diagram of a laser interferometer for detecting tilt information of a reflection surface, FIG. 8 is a diagram illustrating an optical path in the laser interferometer of FIG. 7,

FIG. 9 is a diagram for explaining an optical path in the laser interferometer of FIG. 7,

FIG. 10 is a diagram for explaining an optical path in the laser interferometer of FIG. 7,

FIG. 11 is a diagram for explaining the configuration of the reticle fine movement stage and the arrangement of the laser interferometer for detecting the position of the reticle fine movement stage.

Fig. 12 is a diagram for explaining the movement of the substrate table and the fiducial marks during one-dimensional shape measurement. Fig. 13 is a diagram for explaining the optical path in the laser interferometer when measuring the one-dimensional shape, Fig. 14 is a diagram for explaining the optical path in the laser interferometer when measuring the one-dimensional shape, and Fig. 15 is the fiducial mark. Diagram for explaining the shape measurement result of the reflective surface before correction by position measurement,

Figure 16 is a diagram for explaining the result of measuring the shape of the reflective surface after correction by measuring the reference mark position.

FIG. 17 is a flowchart for explaining a device manufacturing method using the exposure apparatus shown in FIG. 1,

FIG. 18 is a flowchart of the processing in the wafer process step (step 204) of FIG.

FIG. 19 is a perspective view showing a configuration of a peripheral portion relating to attitude control of the substrate stage, FIG. 20A is a diagram showing an example of a difference between upper and lower stage shape data and an encoder measurement result, and FIG. A diagram showing an example of the difference between the difference and the encoder measurement result and a linear approximation thereof,

FIG. 21 is a diagram for explaining a modification in which the stage shape is a triangle.

FIG. 22 is a view for explaining a modification in which the shape of the reflecting surface is measured on the reticle stage. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a schematic configuration of an optical device 100 according to one embodiment. The exposure apparatus 100 is a so-called step-and-scan type scanning exposure apparatus. The exposure apparatus 100 includes an illumination system (not shown) for uniformly illuminating a slit (rectangular or arc-shaped) illumination area on a reticle R as a mask, and a mask stage as a mask stage for holding the reticle. A wafer stage including a reticle stage RST, a reticle layer R, and a projection optical system PL for projecting the pattern of the reticle layer onto a wafer W having a photoresist coated on its surface, and a substrate table 4 for holding the wafer W. It has equipment and these control systems.

The illumination system includes a light source unit, an optical It consists of an optical system, a beam splitter, a condenser lens system, a reticle blind (field stop), and an imaging lens system (all not shown). The configuration and the like of this illumination system are disclosed in, for example, JP-A-6-349701 and US Patent No. 5,534,970 corresponding thereto. Here, as the light source unit, K r F excimer laser light source (oscillation wavelength 2 4 8 nm), A r F excimer laser light source (oscillation wavelength 1 9 3 nm), or F ₂ laser light source (oscillation wavelength 1 5 7 nm), Kr (Crypton dimer) Laser light source (Oscillation wavelength: 146 nm), Ar ₂ (Argon timer) Laser light source (Oscillation wavelength: 126 nm), Harmonic of copper vapor laser light source and YAG laser A wave generator or an ultra-high pressure mercury lamp (g-line, i-line, etc.) is used. Hereinafter, the illumination system excluding the light source unit is also referred to as an illumination optical system.

The reticle stage RST (moving body) moves in a predetermined scanning direction (here, FIG. 1) on the upper surface (reference plane) of a reticle support table (surface plate) 9 horizontally arranged below the illumination optical system. A reticle scanning stage 10 that can be moved with a predetermined stroke in the Y direction that is a direction perpendicular to the paper surface), and is mounted on the reticle scanning stage 10 in the X direction with respect to the reticle scanning stage 10. A reticle fine movement stage 11 that can be finely driven in each of the Y direction and the rotation direction (0 Z direction) around the Z axis is provided. Reticle R is fixed on reticle fine movement stage 11 by vacuum suction or electrostatic suction. The reticle R is held by the reticle stage RST such that the lower surface (pattern surface) of the reticle R at least substantially coincides with the first surface (object surface) of the projection optical system PL described later in the above-mentioned illumination area. The positions of the reticle fine movement stage 11 in the X, Y, and 0 Z directions are constantly controlled by a reticle laser interferometer (hereinafter referred to as a “reticle interferometer”) 14 disposed on the reticle support 9. Being monitored. On the reticle fine movement stage 11, as described later, an X-axis reflecting mirror 21 X and two Y-axis reflecting mirrors (corner cube, retro-reflector) 21 Y 1, 21 Y 2 is fixed, and the reticle interferometer 14 correspondingly has a force S composed of the laser interferometers 14 X 1, 14 X 2, 14 Y 1, 14 Y 2 (Fig. 11), these are shown as a reflector 21 and a reticle interferometer 14 as representatives in FIG. Reticle stage RST incorporates a fine movement mechanism (actuator such as voice coil motor) for the reticle table that holds reticle R. The movable body may be one-dimensionally driven in a scanning direction (Y direction) by, for example, a linear motor. Further, the end surface of reticle fine movement stage 11 (or reticle table) may be mirror-finished and used as a reflecting surface (corresponding to the reflecting surface of reflecting mirrors 21X, 21Y1, 21Y2 described above). Good.

The position information (or speed information) of the reticle fine movement stage 11 obtained by the reticle interferometer 14 is supplied to a main control system 22 that controls and controls the operation of the entire apparatus. The main control system 22 includes a reticle scanning stage 10 and a reticle via a reticle driving device 25 including a linear motor for driving the reticle scanning stage 10 and a voice coil motor for driving the reticle fine movement stage 11. The operation of the fine movement stage 1 1 is controlled.

Here, as the projection optical system PL, a dioptric optical system having a predetermined reduction magnification β (j3 is, for example, 4, 1 ノ 5, etc.) in both-side telecentricity is used. 6: Refer to Fig. 11) and project a reduced image of the reticle R pattern into the exposure area (34: See Fig. 2). The direction of the optical axis AX of the projection optical system PL is a Z direction orthogonal to the XY plane. Also, on the side surface of the projection optical system PL in the Y direction, an image processing method for observing alignment marks (wafer marks) attached to each shot area SA (see FIG. 2) on the wafer W is turned off. Axis sensors (hereinafter referred to as “alignment sensors”) 26 are arranged. The optical axis FX of the optical system of the alignment sensor 26 is parallel to the optical axis AX of the projection optical system. The detailed configuration of such an alignment sensor 26 is disclosed in, for example, Japanese Patent Application Laid-Open No. Heisei 9-219354 and U.S. Pat. No. 5,859,707 corresponding thereto. The alignment sensor 26 forms a mark detection system.

The wafer stage device is disposed below the projection optical system PL, and is capable of moving in a Y direction on the upper surface (reference plane) of a wafer support (stool) 1 in the Y direction. A wafer X-axis drive stage 3 that can move on the drive stage 2 in the X direction perpendicular to the Y direction (the horizontal direction in the drawing in FIG. 1), and is mounted on the wafer X-axis drive stage 3 and is placed in the Z direction. (Including rotation around the X axis and rotation around the Y axis) and a substrate table (moving body) 4 that can rotate around the Z axis. The wafer W is held on the substrate table 4 by vacuum suction, electrostatic suction or the like. Note that the surface of the wafer W (sensitive surface) substantially coincides with the second surface (imaging surface) of the projection optical system PL at least within the above-described exposure area (that is, the focal depth of the projection optical system PL). Is set by the wafer stage device. Further, the wafer stage device may be configured to two-dimensionally drive a movable body incorporating a fine movement mechanism (an actuator such as a voice coil motor) of the substrate table 4 by, for example, a linear motor. May be finely movable in the X direction and the Y direction, respectively.

As shown in Fig. 19, the substrate table 4 is mounted on the wafer X drive stage 3 via three actuators AC1 to AC3 (posture adjustment devices) that can be extended and contracted in the Z-axis direction. Have been. The displacement of each of the actuators AC1 to AC3 is measured by the encoder EN1 to EN3 (posture measuring device) attached to each actuator. Rectifiers AC 1 to AC 3 are configured using a method using a single tally motor and a cam, a laminated piezoelectric element (piezo element), or a voice coil motor (here, a voice coil motor). Is done. The encoders EN 1 to EN 3 f are arranged near the actuators AC 1 to AC 3. As the encoders EN 1 to EN 3, a linear encoder such as an optical encoder or a capacitance encoder can be used. The sensors EN1 to EN3 for measuring the displacements (driving amounts) of the actuators AC1 to AC3 are not limited to encoders and may be arbitrary.

The three actuators AC 1 to AC 3 are controlled by the main control system 22. By making the actuators AC 1 to AC 3 expand and contract evenly, the position (focal position) of the substrate stage 4 in the Z direction can be adjusted, and the amount of expansion and contraction of the three actuators AC 1 to AC 3 can be adjusted individually. By adjusting, the tilt angles of the substrate stage 4 around the X axis and the Y axis can be adjusted. The detected values (displacement) in the Z-axis direction obtained from the three encoders EN 1 to EN 3 are supplied to the main control system 22. The main control system 22 determines the position of the wafer W in the Z-axis direction based on the detected values of the encoders EN 1 to EN 3 and the arrangement of the encoders EN 1 to EN 3 (the positional relationship in the XY plane). Find the position, tilt angle around the X axis and tilt angle around the Y axis.

A reflector 7 is provided on the side of the substrate table 4 and is located outside. A laser interferometer (hereinafter referred to as a “wafer interferometer”) 13 monitors the position of the substrate table 4 (wafer W) in the X, Y, and rotation directions (Z direction) around the Z axis. The position information obtained by the wafer interferometer 13 is also supplied to the main control system 22. As will be described later, a reflecting mirror 7 X for the X axis and a reflecting mirror 7 Y for the Y axis are fixed to the side surface of the substrate table 4 (see FIG. 2) ', but in FIG. , 7 Y are representatively shown as reflector 7. Further, instead of providing the reflecting mirror 7, for example, the side surface of the substrate table 4 may be mirror-finished and used as a reflecting surface (corresponding to the reflecting surface of the reflecting mirror 7 described above). The wafer interferometer 13 is a laser interferometer as a two-dimensional position detection system that projects laser beams in two axes to the reflecting mirrors 7X and 7Y to detect the XY position of the substrate table 4. 1 3 X 1, 1 3 X 2, 1 3 Y 1, 1 3 Y 2, 1 3 FX, tilt of board table 4 with respect to X axis (rotation angle around Y axis), and Y axis of board table 4 Laser interferometer as a tilt detection system that projects two-axis laser beams to the reflecting mirrors 7X and 7Y to detect the tilt (rotation angle about the X axis) with respect to the laser. It consists of 3 YP, 13 FP (tilt measuring device) (see Fig. 2), but these laser interferometers are shown as a wafer interferometer 13 in Fig. 1 as a representative.

Note that a reticle reference mirror (not shown) that the reticle interferometer 14 irradiates a reference light beam and the wafer interferometer are provided on the mirror of the projection optical system PL (or a mount on which the projection optical system PL is mounted). The wafer reference mirror MRW 13 for irradiating the reference beam is fixed. The wafer reference mirror MRW is composed of an X-axis wafer reference mirror MRWX (see FIG. 3) in which the laser interferometers 13 X 1 and 13 X 2 irradiate a reference beam, and the laser interferometers 13 Y 1 and 13 Y 2 is composed of a Y-axis wafer reference mirror (not shown) that irradiates a reference light beam. In FIG. 1, the X-axis wafer reference mirror MR WX and the Y-axis wafer reference mirror are shown as wafer reference mirrors MRW. Have been. Similarly to the wafer reference mirror, the reticle reference mirror is an X-axis reticle reference mirror that irradiates the reference beam with the laser interferometers 14 X 1, 14 X 2 and the laser interferometers 14 Y 1, 14. Y2 is configured with a Y-axis reticle reference mirror (all not shown) that irradiates a reference beam.

In addition, the alignment sensor 26 (or a mount to which the alignment sensor 26 is fixed) has a laser interferometer 13 FX which is used to irradiate the reference beam. A mirror (not shown) is fixed.

Further, the apparatus 100 shown in FIG. 1 includes a light transmitting system 28 and a light receiving system 29, and the inside of an exposure area 34 on a wafer W conjugated with an illumination area on the reticle R with respect to the projection optical system PL. It is one of the oblique incident light type focus detection systems (focus detection systems) for detecting the position in the Z direction (optical axis AX direction) of the wafer surface at each of a plurality of detection points set in the vicinity thereof. A multipoint focus position detection system is provided as a leveling detection system. The detailed configuration and the like of this multi-point focus position detection system (28, 29) are described in, for example, Japanese Patent Application Laid-Open No. HEI 6-283043 and US Pat. , 332, etc. In the multi-point focus position detection system, a plurality of detection points may be set only in one of the inside and outside of the exposure area 34. In addition, the plurality of detection points are at least detection points apart from the scanning direction (Y direction) in which the wafer W is moved during the scanning exposure and the non-scanning direction (X direction) orthogonal thereto. It is preferable to include

The Z-direction position information from the multi-point focus position detection system (28, 29) is supplied to the main control system 22. Based on the position information supplied from the wafer interference system 1.3 and the multi-point focus position detection system (28, 29), the main control system 22 drives the wafer Y-axis drive stage 2 Via a wafer driving device 24 including a linear motor for driving the X-axis drive stage 3 for the wafer, an actuator for finely moving the substrate table 4 in the XY direction, and an actuator for adjusting the posture of the substrate table 4 AC:! By controlling the operations of the wafer Y-axis drive stage 2, the wafer X-axis drive stage 3, and the substrate table 4, the position of the wafer W is controlled in each of the XYZ axis directions and the XYZ axis directions.

Note that the wafer stage device may be configured by the wafer support table 1 and the substrate table 4, and the wafer driving device 24 may be configured to include a planar motor.

A reference mark plate 6 is fixed near the wafer W on the substrate table 4. The surface of the reference mark plate 6 is set at the same height as the surface of the wafer W, and various reference marks such as alignment reference marks to be described later are formed on the surface.

In addition, the upper part of reticle R in Fig. 1 shows a pair of reticle alignment systems. 9 and 20 are arranged. These reticle alignment systems 19 and 20 are not shown here, but each of them is an epi-illumination system for illuminating a mark to be detected with the exposure light EL or illumination light of the same wavelength, and its detection system. And an alignment microscope for capturing an image of the target mark. The alignment microscope includes an imaging optical system and an image sensor. In this case, deflection mirrors 15 and 16 for guiding the detection light from the reticle to the reticle alignment systems 19 and 20, respectively, are movably arranged. In response to a command from the control system 22, the deflection mirrors 15 and 16 are integrated with the reticle alignment systems 19 and 20, respectively, out of the optical path of the exposure light EL by the driving devices 17 and 18. Evacuated to

Further, the apparatus shown in FIG. 1 is an optical path for changing the optical path of the light beam irradiated to the reflecting mirrors 7 X and 7 Y of the laser interferometers 13 X 1, 13 X 2, 13 Y 1 and 13 Y 2. It has change device 40. This optical path changing device 40 will be described later.

The main control system 22 is composed of a microcomputer, a workstation, or the like, and controls the entire apparatus. For example, at the time of scanning exposure, the main control system 22 controls the reticle driving device 25 and the wafer driving device 24, respectively, and controls the irradiating region (the illuminating region 36 and the exposing region 34) of the exposure light EL. The reticle R is kept constant in one Y direction (or + Y direction) in synchronism with scanning the wafer W in the + Y direction (or one Y direction) perpendicular to the paper surface of Fig. 1 at a constant speed V. Control to scan at speed VZ j3. The main control system 22 is connected to an input device 23 for the operator to input various commands and the like. In the present embodiment, the main control system 22 includes the shape information of the reflecting mirrors 7 (actually, the reflecting mirrors 7X and 7Y: see FIG. 2) provided on the substrate table 4. A storage device 27 in which operation parameters including data 27a are stored is provided.

Next, the configuration and the like of the reticle interferometer 14 on the reticle stage RST side and the wafer interferometer 13 on the wafer stage apparatus side will be described with reference to FIGS. FIG. 2 is a plan view showing the periphery of the substrate table 4. As shown in FIG. 2, a reference mark plate 6 is fixed near the wafer W on the substrate table 4. On the fiducial mark plate 6, a set of fiducial marks 30 A, 30 B, 30 C, 30 D, 30 E, 30 F and a mark for measuring a pace line (not shown) are formed.

Further, an X-axis reflecting mirror 7X extending in the Y direction and a Y-axis reflecting mirror 7Y extending in the X direction are fixed to end side surfaces of the substrate table 4 in the X and + Y directions, respectively. In addition, an image of a part of the pattern of the reticle R is projected onto the slit-shaped exposure area 34 on the wafer w, and the reticle alignment system 1 shown in FIG. 9, 20 observation areas are set.

The reflecting mirror 7X is irradiated with laser beams LWX1 and LWX2 arranged in the Y-axis direction at a distance L11 and parallel to the X-axis. In addition, a pair of laser beams LWXP parallel to the X-axis are irradiated at a distance DX (see Fig. 8) along the Z-axis. The laser beams LWXl and LWX2 are distributed in the Y-axis direction with respect to an axis XWA parallel to the X-axis and passing through the optical axis AX of the projection optical system PL.

Further, the reflecting mirror 7X is irradiated with a laser beam LFX parallel to the X-axis, and is arranged at a distance DX along the Z-axis direction in the same manner as the laser beam LWXP, and is parallel to the X-axis. A pair of laser beams LFXP is irradiated. The laser beam LFX is applied to the reflecting mirror 7X along an axis XFA parallel to the X-axis and passing through the optical axis FX of the alignment sensor 26.

Each of the laser beams LWX l, L WX 2, L WX P, LFX, L FXP is from the laser interferometers 13 X 1, 13 2, 13 XP, 13 FX, 13 FP shown in Figure 2. Supplied. These laser interferometers 13X1, 13X2, 13XP, 13FX, and 13FP will be described with reference to FIGS.

As shown in FIG. 3, the laser interferometer 13 X 1 includes a light source 51 X 1, a light receiver 52 X 1, and a polarizing beam source. 5 3 X 1, 1 Z 2 wavelength plate 54 X 1, polarizing beam splitter 55 X 1, 1/4 wavelength plate 56 X 1, reflective prism (corner cube) 57 X 1, and It has 58 x 1 reflective prism, 59 x 1 polarizing beam splitter, 60 x 1/4 wavelength plate, and 61 x 1 reflective prism (corner cube). Here, the operation of the laser interferometer 13 X 1 will be described. As shown in FIG. 3, the laser interferometer 13 X 1 emits a light beam traveling in the + X direction from the light source 51 X 1. Is done. Here, as the light source 51 X1, for example, a two-frequency laser utilizing the Zeeman effect is used, and the first polarization component and the second polarization component whose frequencies (that is, wavelengths) are slightly different and whose polarization directions are orthogonal to each other are used. A laser beam composed of polarized light components is output, where the first polarized light component is a vertical polarized light component (V-polarized light) and the second polarized light component is a horizontal polarized light component (H-polarized light).

As shown in FIG. 4, the light beam emitted from the light source 51 X1 enters the polarization beam splitter 53XI, and is split into two light beams according to the polarization direction. That is, the light beam LWX 1 composed of the first polarization component emitted from the light source 51 X 1 passes through the polarization beam splitter 53 X 1 as it is and travels in the + X direction, and the second polarization component The light beam LWXR 1 is deflected by the polarization beam splitter 53 X 1 and travels in the + Z direction.

As shown in FIG. 5, the light beam LWX 1 that has passed through the polarizing beam splitter 5 3 X 1 as it is is rotated by 90 ° through the 波長 wavelength plate 54 X 1 and the polarization direction is rotated 90 °, so that the polarizing beam splitter The light enters the splitter 55 X 1 and passes directly through the polarizing beam splitter 55 X 1. The light beam L WX 1 that has passed through the polarizing beam splitter 55 X 1 as it is is converted into circularly polarized light by the quarter-wave plate 56 X 1, and then the Z position is ZW 1 and the Y position is near YW 1 Reflecting surface 7 A point on XS is incident and reflected. The light beam LWX 1 reflected by the reflecting surface 7 XS is rotated by 90 ° from the polarization beam splitter 55 X 1 by the 1/4 wavelength plate 56 X 1, and the polarization direction is rotated by 90 °. Return to One Musplitter 5 5 X 1. Then, the light beam LWX 1 is deflected by the polarization beam splitter 55 X 1 and travels in one Y direction.

In this way, the light beam LWX 1 traveling in the one Y direction is reflected by the reflecting prism 57 X 1 serving as a corner cup, and re-enters the polarizing beam splitter 55 X 1. The light beam LWX 1 re-entering the polarizing beam splitter 55 X 1 from the reflecting prism 57 X 1 is deflected by the polarizing beam splitter 55 X 1 and travels in the + X direction. After being converted into circularly polarized light by the wave plate 56X1, the light is incident on a point on the reflecting surface 7XS where the Z position is ZW1 and the Y position is near YW1, and is reflected again. The light beam LWX 1 reflected by the reflecting surface 7 XS again has a polarization direction of 9 from the polarization beam splitter 55 X 1 by the 1/4 wavelength plate 56 X 1. PC orchid painting 15491

After being rotated by 0 °, the beam returns to the polarizing beam splitter 55 X 1 again, and passes through the polarizing beam splitter 55 X 1 as it is.

The light beam LWX 1 transmitted through the polarizing beam splitter 55 X 1 in this way is rotated by 90 ° through the 1 × 2 wave plate 54 X 1 and the polarization beam splitter 55 After being incident on X1, it passes through the polarization beam splitter 55X1 and travels as a measurement light beam to the receiver 52X1.

On the other hand, the light beam LWXR 1 deflected by the polarization beam splitter 53 X 1 and travels in the + Z direction is reflected by the reflection prism 58 X 1 and travels in the + X direction, and is deflected by the deflection beam splitter 59 It is incident on X1. Thereafter, as shown in FIG. 6, in the same manner as in the case of FIG. 5 described above, X is passed through the deflecting beam splitter 59 X1, the quarter-wave plate 60X1, and the reflecting prism 61X1. After being reflected twice by the axis wafer reference mirror MRWX, it is emitted from the polarizing beam splitter 59 X 1 and enters the reflecting prism 58 X 1. The light beam LWXR 1 thus incident on the reflecting prism 58 X 1 is reflected by the reflecting prism 58 X 1, travels in the Z direction, is deflected by the polarization beam splitter 53 X 1, and is deflected by the polarizing beam splitter 53 X 1. The light beam travels in the direction, and travels on the same optical path as the above-mentioned light beam LWX 1 as a reference light beam to the light receiver 52 2 X 1.

That is, the light beam incident on the photodetector 52 X 1 is a combined light of the measurement light beam LWX 1 and the reference light beam LWXR 1. Then, in the receiver 5 2 X 1, the interference light reflecting the difference in the optical path length between the measurement light beam LWX 1 and the reference light beam LWXR 1 is caused by causing the measurement light beam LWX 1 and the reference light beam LWXR 1 to have the same polarization direction and causing interference. And the interference state is measured. By the way, the X-axis wafer reference mirror MRWX is fixed to the projection optics PL, and the optical path length of the reference beam from the light source 51 X1 to the light receiver 52 X1 via the X-axis wafer reference mirror MRWX is By measuring the interference state between the measured light beam and the reference light beam, it is possible to determine the position of the irradiation point of the measurement light beam on the reflecting surface 7 XS in the length measurement direction (X-axis direction), that is, the X position. To detect. Actually, the laser interferometer 13 X 1 is reset in a predetermined state (for example, the state at the time of reticle alignment), and the X-axis of the irradiation point of the measurement light beam on the reflecting surface 7 XS in the reset state is set. Position detection is performed using the direction position as the coordinate origin in the X-axis direction. The X position detected as described above is hereinafter referred to as “XW1”. Referring back to FIG. 3, the laser interferometer 13 X 2 is provided adjacent to the laser interferometer 13 X 1, and has the same configuration as the laser interferometer 13 X 1. More specifically, as shown in FIG. 3, the laser interferometer 13 × 2 has the components 5 of the laser interferometer 13 × 1 based on the surface adjacent to the laser interferometer 13 × 1. The constituent element 5 1 X 2 -61 X 2 corresponding to 1 X 1 -61 X 1 is arranged symmetrically with respect to the adjacent plane.

That is, in the laser interferometer 1 3 X 2, similarly to the laser interferometer 1 3 X 1, the light beam LWX 2 is irradiated on the opposite side 7 XS, and the measurement light beam is reflected and directed to the light receiver 5 2 X 2. (See Fig. 5) and the X-axis wafer reference mirror MRWX is irradiated with the light beam LWX R2, and the interference between the reflected light beam and the reference beam (see Fig. 6) directed to the receiver 52X2 is measured. , Detects the position of the irradiation point of the measurement light beam on the reflecting surface 7 XS in the measurement direction (X-axis direction). The X position detected as described above is hereinafter referred to as “XW2”. As shown in FIG. 7, the laser interferometer 13 XP includes a light source 51 XP, a light receiver 52 XP, a polarizing beam splitter 53 XP, a 1 X2 wavelength plate 54 XP, and a polarizing beam splitter 5. 5 XP, 1/4 wavelength plate 5 6 XP, reflective prism (corner cube) 57 XP, and reflective prism 58 XP, polarizing beam splitter 59 XP, 1/4 wavelength plate 60 XP, reflective prism Corner cube) has 6 1 XP. That is, the laser interferometer 13 XP has the same components as the laser interferometer 13 X 1 described above, but the arrangement positions of the components in the Z-axis direction are different.

Here, the operation of the laser interferometer 13 XP will be described. In the laser interferometer 13 XP, a light beam traveling in the + X direction is emitted from the light source 51 XP as shown in FIG. Here, the light source 51 XP uses, for example, a two-frequency laser utilizing the Zeeman effect, similar to the light source 51 X 1 in the laser interferometer 13 X 1, and has a frequency ( That is, it outputs a laser beam composed of a first polarization component and a second polarization component whose wavelengths are slightly different and whose polarization directions are orthogonal to each other. It is assumed that the first polarized light component is a vertical polarized light component (V polarized light) and the second polarized light component is a horizontal polarized light component (H polarized light).

The light beam emitted from the light source 51 XP enters the polarization beam splitter 53 XP as shown in FIG. 8, and is split into two light beams according to the polarization direction. That is, light The light beam LWXP 2 composed of the first polarization component of the light beam emitted from the source 51 XP passes through the polarization beam splitter 53 XP as it is and travels in the + X direction. The resulting light beam LWX P 1 is deflected by the polarizing beam splitter 53 XP and travels in the + Z direction.

As shown in FIG. 9, the light beam L WX P 2 transmitted through the polarizing beam splitter 53 XP as it is, as in the case of the laser interferometer 13 X 1, is a half-wave plate 54 XP, a polarizing beam splitter. After passing through the splitter 55 XP and the 1/4 wavelength plate 56 XP sequentially, it is incident on a point on the reflection surface 7 XS where the Z position is ZW2 (= ZW 1—DX) and the Y position is near YWP. Reflected. The light beam LWX P 2 reflected by the reflecting surface 7 XS passes through a 1Z4 wavelength plate 56 XP, a polarizing beam splitter 55 XP, a reflecting prism 57 XP, and a 1/4 wavelength plate 56 XP sequentially. Thereafter, the light is incident on a point on the reflecting surface 7XS where the Z position is ZW2 (= ZW1 -DX) and the Y position is near YWP, and is reflected again. The light beam LWXP 2 re-reflected by the reflecting surface 7 XS consists of a 1/4 wavelength plate 56 XP, a polarizing beam splitter 55 XP, a 1/2 wavelength plate 54 XP, and a beam splitter 53 XP. After passing through, the light travels toward the light receiver 52 XP as the first measurement light flux.

On the other hand, the light beam LWX P 1 deflected by the polarization beam splitter 53 XP and traveling in the + Z direction is reflected by the reflection prism 58 XP and travels in the + X direction, and is transmitted to the deflection beam splitter 59 XP. Incident. Thereafter, as shown in FIG. 10, in the same manner as in FIG. 9 described above, the light is reflected while passing through the polarizing beam splitter 59 XP, the quarter-wave plate 60 XP, and the reflecting prism 61 XP. After being reflected twice near the YZ coordinates (YWP, ZW1) of the surface 7 XS, it is emitted from the polarizing beam splitter 59 XP and enters the reflecting prism 58 XP. The light beam LWXP 1 thus incident on the reflecting prism 58 XP is reflected by the reflecting prism 58 XP, travels in the Z direction, is deflected by the polarizing beam splitter 52 XP, and is deflected in the X direction. Then, the light travels on the same optical path as the first measurement light flux as the second measurement light flux toward the light receiver 52 XP. That is, the light beam incident on the light receiver 52 XP is a combined light of the first measurement light beam and the second measurement light beam. Then, in the light receiver 52 XP, the first measurement light beam and the second measurement light beam are caused to interfere with the same polarization direction, thereby causing interference light reflecting the optical path length difference between the first measurement light beam and the second measurement light beam. Generate and measure the interference state. By measuring the interference state, the amount of rotation of the reflecting surface 7XS about the Y axis is detected. Note that, similarly to the case of the laser interferometer 13 X 1 described above, the laser interferometer 13 XP is reset in a predetermined state (for example, the state at the time of reticle alignment), and the reset state is set. The amount of rotation of the reflecting surface 7 XS around the Y axis (mouth-to-ring amount) is detected, with the amount of rotation of the reflecting surface 7 XS around the Y axis at zero. Hereinafter, the tilt information (the pitching amount, which is the amount of rotation around the Y axis) detected by the laser interferometer 13 XP is referred to as “ALWXP”.

The laser beam LWX1, laser beam LWX2, and laser beam LWXP1 are arranged in the Y-axis direction at the same Z position ZW1, and as shown in FIG. 2, the laser beam LWX1 and the laser beam LWXP The distance in the Y-axis direction from 1 is L12.

Returning to FIG. 2, the laser interferometer 13F is configured in the same manner as the laser interferometer 13X1 described above. Then, in the laser interferometer 13 FX, similarly to the laser interferometer 13 X1, the measurement light flux irradiated on the reflecting surface 7XS and reflected toward the receiver is separated from the X-axis wafer reference mirror MRWX. By irradiating the above-mentioned alignment reference mirror (not shown) and measuring the state of interference with the reference light beam which is reflected and directed to the receiver, the irradiation point of the measurement light beam on the reflecting surface 7XS is determined. Detects the position in the measurement direction (X-axis direction). The X position detected as described above is hereinafter referred to as “XF”. The laser interferometer 13 FP has the same configuration as the laser interferometer 13 XP described above. In the laser interferometer 13 FP, similarly to the laser interferometer 13 XP, the state of interference between the first measurement light beam and the second measurement light beam that irradiate the reflecting surface 7 XS and is reflected and directed toward the light receiver is measured. By measuring the rotation amount, the rotation amount of the reflecting surface 7XS around the Y axis in the reset state is set to zero, and the rotation amount of the reflecting surface 7XS around the Y axis is detected. Hereinafter, the tilt information detected by the laser interferometer 13 FP is referred to as “ALFXP”. The laser interferometers 13 XP and 13 FP detect the above-mentioned tilt information by detecting the interference light of the first and second measurement light beams irradiated at different points on the reflecting surface 7 XS at different Z positions. However, for example, the measurement light beams from the two laser interferometers are applied to points at different Z positions on the reflecting surface 7 XS, and based on the X position of the reflecting surface 7 XS obtained by each laser interferometer. To obtain the tilt information described above. You may. At this time, the laser interferometer 13 XP may use one of the two interferometers as the laser interferometer 13 X 1 or 13 X 2, or the laser interferometer 13 FP 2 The rotation amount (jowing amount) of the reflecting surface 7 XS about the Z axis may be obtained based on the X positions obtained by one of the two laser interferometers and the laser interferometer 13 FX.

The reflecting mirror 7Y is irradiated with laser beams LWY1 and LWY2 which are separated from each other at an interval L21 along the X-axis direction and are parallel to the Y-axis. Further, a pair of laser beams LWYP parallel to the X axis are irradiated at intervals of D Y (not shown) along the Z axis direction. The laser beams LWY 1 and LWY 2 are distributed in the X direction with respect to an axis YWA which is parallel to the Y axis and passes through the optical axis AX of the projection optical system PL.

Each of the laser beams LWY 1, L WY 2, and LWYP is supplied from a laser interferometer 13 Yl, 13 Y 2, 13 YP shown in FIG. 2, and a laser interferometer 13 Y 1 , 13 Y 2, except that the measurement direction is the Y-axis direction, and the laser interferometer 13 X 1, described above, except that it is disposed to face the reflecting mirror 7 Y and the Y-axis wafer reference mirror. It has the same configuration as 1 3 X 2. The Y positions detected by the laser interferometers 13Yl and 13Y2 are hereinafter referred to as "YW1" and "YW2". The laser interferometer 13YP is configured in the same manner as the above-described laser interferometer 13XP, except that the measurement direction is the Y-axis direction and the laser interferometer 13YP is disposed so as to face the reflecting mirror 7Y. You. The tilt information detected by the laser interferometer 13 YP (the pitching amount, which is the amount of rotation around the X axis) is hereinafter referred to as ΓΔLWYP ”.

The laser beams LWX 1, LWX 2, LWX P, LWY 1, LWY 2, and L WYP do not come off when controlling the position of the reflecting mirrors 7 X and 7 Y such as scanning exposure or stepping of the wafer W. As described above, the laser beams LFX, LFXP, LWY1, LWY2, and LWYP are formed to be sufficiently long so as not to come off during alignment measurement of the wafer W by the alignment sensor 26. In the exposure apparatus of the present embodiment, the laser interferometer 13 Y 1, 13 Y 2, and 13 YP are used for both scanning exposure and alignment measurement. For example, the laser interferometer 13 FX, A set of laser interferometers having the same configuration as the 13 FP may be provided for detecting the Y position and the amount of rotation around the X axis (and the amount of rotation) during alignment measurement. In this configuration, without increasing the size of the wafer stage device (that is, without increasing the length of the reflecting surface 7), the projection optical system: the exposure position where the reticle pattern is transferred via the PL, and the alignment. The measurement position (alignment position) at which mark detection is performed by the sensor 26 can be set at a large distance, and the exposure operation and the alignment operation can be performed almost in parallel as a wafer stage device. As a result, a double wafer stage system having two independently movable wafer stages can be employed.

The XY position (XW, YW) of the substrate table 4 and thus the wafer at the time of position control such as scanning exposure or stepping are controlled by the above-mentioned laser interferometer 13 X 1, 13 X 2, 13 Y 1, 13 Y 2. The XY position of W is detected. That is, based on the X position measurement results XW 1 and XW 2 by the laser interferometers 13 X 1 and 13 X 2, the X position X W of the board table 4 is

XW = (XW 1 + XW 2) / 2… (3)

Is detected by Also, based on the Y position measurement results YW1 and YW2 using the laser interferometers 13Yl and 13Y2, the Y position YW of the substrate table 4 is

YW = (YW 1 + YW 2) / 2… (4)

Is detected by

Further, the laser interferometers 13 FX, 13 Y 1, 1, 3 Y 2 are used to adjust the position (XW (= XF), YW) of the substrate table 4 at the time of alignment measurement, and thus the XY of W The position is detected. That is, the X position measurement result XF by the laser interferometer 13 FX is detected as the X position XW of the substrate table 4. The Y position YW of the substrate table 4 is detected based on the Y position measurement results YW 1 and YW 2 by the laser interferometers 13 Y 1 and 13 Y 2.

In addition, based on the measured values XW1 and XW2 or the measured values YW1 and YW2, the amount of rotation (the amount of rotation about the Z axis) 0 ZW of the board table 4 is

Θ ZW = (XW1 -XW2) / L 1 1… (5)

Or

Θ ZW = (YW 1-YW 2) / L 2 1-(5 ')

Is detected by That is, irradiation of the measurement light beam LWX 1 on the reflecting surface 7 XS Local rotation angle of reflection surface 73 around two axes between point and irradiation point of measurement light beam LWX 2, or irradiation of measurement light beam LWY 1 and measurement light beam LWY 2 at reflection surface 7 YS The jogging amount 0 ZW of the substrate table 4 is detected from the local rotation angle of the reflecting surface 7YS around the Z-axis between the point and the point.

Further, based on the measured values XW 1, XW 2, YW 1, and YW 2, the orthogonality error variation Δ coW in the substrate table 4 from the reset state of the reflecting mirrors 7 X and 7 Y is expressed as ω W = (YW 1 -YW 2) / L 2 1-Detected by (XW 1-XW 2) / LI 1-(6). That is, the local rotation angle of the reflecting surface 7 XS around the Z axis between the irradiation point of the measuring light beam LWX 1 on the reflecting surface 7 XS and the irradiation point of the measuring light beam LWX, and the measuring light beam LWY 1 on the reflecting surface 7 YS. The substrate table from the reset state of the mirrors 7 X and 7 Y is determined by the difference between the reflection surface 7 YS and the local rotation angle of the YS around the Z-axis between the irradiation point of The orthogonality error fluctuation ΔcoW in 4 is detected.

The coordinate system consisting of the X coordinate XW and the Y coordinate YW detected as described above is called the coordinate system (XW, YW) of the wafer stage. This coordinate system (XW, YW) is a value from the reset state, and differs to some extent from the design orthogonal coordinate system consisting of the X-axis and the Y-axis. After the calibration, the movement of the wafer W is performed based on the new coordinate system (XW, YW) of the calibrated wafer stage.

FIG. 11 shows a plan view around reticle fine movement stage 11. As shown in FIG. 11, reticle R is held on reticle fine movement stage 11. At the end of the reticle fine movement stage 11 in the + X direction and at the end in the −Y direction, there are an X-axis reflecting mirror 2 1X extending in the Y direction, and two Y-axes including a corner and a cube. The reflecting mirrors 2 1 Y 1 and 2 1 Y 2 are fixed respectively. Reticle fine movement stage 11 is driven by actuators 38 L and 38 R using a voice coil motor as a drive source under the control of main control system 22. Note that an actuator that finely moves the reticle fine movement stage 11 in the X direction is also provided, but is not shown in FIG. 11.

The reflecting mirror 2 IX is irradiated with laser beams LRX 1 and LRX 2 which are spaced at a distance L 3 along the Y-axis direction and parallel to the X-axis. The laser beam LRX 1, The LRX 2 is distributed in the Y-axis direction with respect to an axis XRA which is parallel to the X-axis and passes through the optical axis AX of the projection optical system PL. Further, the reflecting mirrors 21Y1 and 21Y2 are irradiated with laser beams LRY1 and LRY2 that are separated from each other at intervals L3 along the X-axis direction and are parallel to the Y-axis. The laser beams LRY 1 and LRY 2 are distributed in the X-axis direction with respect to an axis YRA which is parallel to the Y-axis and passes through the optical axis AX of the projection optical system: PL.

Each of the laser beams L RX 1, L R X 2, LRY 1, and LRY 2 is supplied from a reticle interferometer 14 X 1, 14 X 2, 14 Y 1, 14 Y 2 force. Then, the X position of the reticle fine movement stage 11 is detected based on the measurement values obtained by the reticle interferometers 14 X 1 and 14 X 2, and the Y position of the reticle fine movement stage 11 is detected by the reticle interferometer 14 Y It is detected based on the measurement value of 1,14Y2.

The reticle interferometers 14 X 1, 14 X 2 are the same as the laser interferometers 13 X 1, It has the same configuration as 1 3 X 2. The X position detected by the reticle interferometers 14 X 1 and 14 X 2 is hereinafter referred to as “XR 1” and “XR 2”.

The reticle interferometers 14 Y 1 and 14 Y 2 are the same as the lasers described above except that they are disposed opposite the reflecting mirrors 21 Y 1, 21 Y 2 and the Y-axis reticle reference mirror. Interferometer

It has the same configuration as 13 Y 1 and 13 Y 2. The Y positions detected by the reticle interferometers 14 Y 1 and 14 Y 2 are hereinafter referred to as “YR 1” and “YR 2”.

The laser beams LRY 1 and LRY 2 reflected by the Y-direction reflecting mirror (corner cube) 2 1 Y 1 and 21 Y 2 are reflected by the reflecting mirrors 14 M 1 and 14 M 2, respectively, and returned. In addition, even if the reticle fine movement stage 11 rotates, the laser beam is not displaced. In addition, rectangular illumination area 3 on reticle R

Exposure light EL is applied to 6, and observation regions of reticle alignment systems 19 and 20 are set at both ends of an illumination region 36 in the X direction. The illumination area 36 is shown in the figure.

It is conjugate to the exposure area 34 on the second wafer W. In addition, as shown in FIG. 11, as an example, a cross-shaped alignment mark 3 is provided on both sides of the reticle R pattern area.

2 A to 32 F are formed. Reference mark 30 on reference mark plate 6 in Fig. 2

The positional relationship between each projected image when 30 F is projected on the reticle side is as follows: Approximately equals the mutual positional relationship of the criterion 32A to 32F.

The XY position (XR, YR) of reticle fine movement stage 11 and XY position of reticle R are detected by the above laser interferometers 14 X 1, 14 X 2, 14 Y 1, 14 Y 2 Is done. That is, based on the X position measurement results XR 1 and X R 2 by the laser interferometers 14 X I and 14 X 2, the X position XR of the fine movement stage 11 is

X R = (X R 1 + XR 2) / 2… (7)

Is detected by Also, based on Y position measurement results YR 1 and YR 2 using reticle interferometers 14Y 1 and 14 Y 2, the Y position YR of fine movement stage 11 is

Y R = (YR 1 + YR 2) / 2… (8)

Is detected by

Also, based on the measured values XR 1 and XR 2, the amount of reticle R joing 0 Z R is

Θ Z R = (XR 1 -XR 2) / L 3… (9)

Is detected by Further, based on the measured values XR 1, XR 2, YR 1, and YR 2, the orthogonality error variation Δ ω R between the reflecting mirror 21 X and the reflecting mirrors 21 Y 1 and 21 Y 2 becomes

ΔωR = (YR 1 -YR 2) / L 4 (XR 1—XR 2) / L 3... (10)

The coordinate system consisting of the X coordinate XR and the Υ coordinate YR detected as described above is called the reticle stage coordinate system (XR, YR). Although this coordinate system (XR, YR) may differ to some extent from the design ideal rectangular coordinate system consisting of the X-axis and the Υ-axis, reticle R is the reticle stage coordinate system (XR , YR).

Next, the reflecting mirrors 7, 7 provided on the side surfaces of the substrate table 4 are used for correcting the ΧΥ position (XW, YW) of the substrate table 4 and the Abbe error of the ΧΥ position of the wafer W. The measurement of the shape of the reflective surface of Υ will be described with reference to FIGS. 12 to 16, FIG. 19, FIG. 20 Α, and FIG. 20 Β. For such shape measurement, the main control system 22, the laser interferometer 13 X 1, 13 X 2, 13 Y 1, 13 3 2, and the wafer A driving device 24, an optical path changing device 40, and the like are used. That is, the main control system 22, the laser interferometers 13 X 1, 13 X 2, 13 Υ 1, 13 Υ 2, the wafer driving device 24, the optical path changing device 40, etc. of A reflection surface shape measurement device (one-dimensional shape measurement device) is configured.

Here, the optical path changing device 40 will be described. As shown representatively for the laser interferometer 13 X 1 in Figs. 12 and 14, the laser interferometers 13 X 1, 1

An optical path changing device 40 is disposed downstream of the quarter-wave plates 56 X 1 and 56 X 2 from which the 3 X 2 measurement light beams LWX 1 and LWX 2 are emitted. In the following description with reference to the figure, the components of the laser interferometer 13X1 will be denoted by reference numerals, and the positional relationship and the like will be described.

The optical path changing device 40 includes a movable mirror 410 and a fixed mirror 420. The movable mirror 4100 has a mirror surface with respect to the optical path of the measurement light beam LWX1 emitted from the 1/3 wavelength plate 56X1 of the laser interferometer 13X1 and directed to the reflection surface 7XS.

It is configured so that it can be selectively moved between a reflection position arranged at an angle of 45 ° and a retracted position arranged outside the optical path of the measurement light beam LWX1.

That is, the movable mirror 4 10 is supported by the movable mirror support member 4 11, and the movable mirror support member 4 11 is within a predetermined angular range (here, 45 °) about the support shaft 4 12. It is rotatably supported by a frame (not shown) (for example, a frame on which the projection optical system PL is mounted). The movable mirror support member 4 11 is driven by a driving device 4 13 such as an air cylinder, etc., and the driving device 4 13 is moved to the reflection position based on a control signal sent from the main control system 22. Or, it is controlled to be set at the retreat position. The position of the movable mirror 410 shown by the solid line in FIG. 12 and the position of the movable mirror 410 shown by the dotted line in FIG. 14 are the retracted positions, and the movable mirror 4 100 shown by the dotted line in FIG. The position of the movable mirror 410 shown by a solid line in FIG. 14 is the reflection position.

With the movable mirror 410 set to the retracted position (Fig. 12), the 1 Z4 wave plate

The measurement light beam LWX 1 emitted from 5 6 X 1 and traveling in the + X direction goes straight on, the Z direction position of the reflecting surface 7 XS is irradiated to the ZW 1 position, and the movable mirror 4 10 moves to the reflecting position. In the set state (Fig. 14), the measurement light beam LWX1 emitted from the 1Z4 wave plate 56X1 and traveling in the + X direction is moved in the 1Z direction at an angle of 90 ° by the movable mirror 410. It is totally reflected toward.

When the movable mirror 4100 is at the reflection position, the fixed mirror 4 (1) A frame (not shown) that is parallel to the movable mirror 4100 at the reflection position so that the light beam LWX1 reflected by 410 is reflected toward the reflection surface 7XS of the reflection mirror 7X. (For example, a mount on which the projection optical system PL is placed). The measurement light beam LWX 1 reflected by the movable mirror 4 10 and traveling in one Z direction is totally reflected in the + X direction by the fixed mirror 4 20, and the reflection surface 7 XS is positioned at ZW 1 in the Z direction. Irradiates the position ZW2 shifted by the distance DX from the distance (see Fig. 14).

Now, the shape measurement of the reflecting surfaces of the reflecting mirrors 7X and 7Y provided on the side surface of the substrate table 4 is performed by first controlling the substrate table 4 by the main control system 22 via the wafer driving device 24. Drive the substrate table 4 so that the surface of the substrate table 4 is substantially parallel to the XY plane. Then, the main control system 22 controls the driving device 4 13 of the optical path changing device 40, and as shown representatively for the wafer interference system 13 X 1 in FIG. 12, the movable mirror 4 10 The measurement is emitted from the laser interferometers 13 X 1 and 13 X 2. The light beams LWX 1 and LWX 2 are retracted from the optical path reaching the reflecting mirror 7 X. As a result, the measurement light beams L WX 1 and LWX 2 are irradiated to the Z position ZW 1 of the reflecting mirror 7X. Subsequently, the main control system 22 controls the wafer X-axis drive stage 2 and the wafer Y-axis drive stage 3 via the wafer drive device 24, and moves the substrate table 4 to the measurement start position indicated by a solid line in FIG. Move to When the substrate table 4 is at a predetermined position during the movement of the substrate table 4, the laser interferometers 13XI, 13X2, 13Y1, 13Y2 are reset. In the present embodiment, when the substrate table 4 reaches the measurement start position, the laser interferometers 13X1, 13X2, 13Y1, 13Y2 are reset. The reset positions of the laser interferometers 13 X 1, 13 X 2, 13 Y 1, 13 Y 2 at the time of shape measurement, and the laser interferometers 13 X 1, 1 at the time of position control described later It has a predetermined positional relationship with the reset positions of 3X2, 13Y1, and 13Y2.

Next, the main control system 22 controls the Y-axis wafer driving stage 2 via the wafer driving device 24 to move the substrate table 4 in one Y direction, and the laser interferometers 13 X 1, 13 X X position XW1 (t, ZW1), XW2 (t, ZW1) and Y position YW1 (t, ZW1), YW2 (t, ZW1) detected by 2, 1 3 Y1, 1 3 Y2 ) (t: time) is performed almost simultaneously. By the way, the local rotation amount 反射 ZX (t, ZW 1) of the reflecting surface 7 XS around the Z axis and the local rotation amount Θ ZY (t, ZW 1) of the reflecting surface 7 YS around the Z axis at each collection. )

Θ Z X (t, Z W 1) = (XW 1 (t, Z W 1)

-XW2 (t, ZW 1)) / L l l ■ (1 1)

Θ Z Y (t, Z W 1) = (YW 1 (t, Z W 1)

-YW 2 (t, ZW 1)) / L 2 1… (1 2)

Is required by

Here, since the substrate table 4 moves in one Y direction, the measurement light beams LWY 1 and LWY 2 emitted from the wafer interferometers 13 Y 1 and 13 Y 2 are substantially the same as the reflecting mirror 7 Y. The position continues to be irradiated. Therefore, the local rotation amount 0 ZY (t, ZW 1) of the reflecting mirror 7Y around the Z axis does not include the contribution of the one-dimensional shape change of the reflecting mirror 7Y in the Y axis direction. Therefore, the rotation amount Θ Ζ Υ (t, ZW 1) is the rotation amount of the tomb plate table 4 around the Z axis at the time t due to the movement of the substrate table 4, that is, the joing amount of the substrate table 4 itself. May be considered.

On the other hand, the local rotation amount 6 ZX (t, ZW 1) of the reflecting mirror 7 X around the Z axis is determined by the amount of jogging of the substrate table 4 at each collection and the reflecting surface 7 XS of the reflecting mirror 7 X. It is the sum of the one-dimensional shape change in the X-axis direction. Therefore, the local rotation amount 0 Z X (t, ZW 1) of the reflecting mirror 7 X about the Z axis due to the one-dimensional shape change of the reflecting surface 7 X S in the X-axis direction of the reflecting mirror 7 X is

Θ Z X (t, Z W 1) = θ Z X (t, Z W 1)

-Θ ZY (t, Z W 1)

Required by

By the way, the Y position YW (t, ZW1) of the substrate table 4 at each collection is

YW (t, Ζ W 1) = (YW 1 (t, ZW 1)

+ YW2 (t, Z W 1)) / 2… (1 4)

And is uniquely determined for time t.

In other words, the local rotation amount 0 ZX (t, ZW 1) of the reflecting mirror 7 X about the Z axis is represented as the local rotation amount 0 ZX (YW, ZW 1) of the reflecting mirror 7 X around the Z axis. With Wear. Therefore, the Y position (hereinafter referred to as “measurement reference Y position”) at the time of resetting the laser interferometers 13 X 1 and 13 X 2 is defined as YWS, and the Y axis of the reflecting mirror 7 X at the Z position ZW 1 is defined. The one-dimensional shape DXW (YW, ZW1) is obtained by the following equation. β face lia 1::,; 0 ft Tanazaki · 1 The main control system 2 2 collects the X position XW 1 (t, ZW 1), XW2 (t, ZW 1) and Y position YW1 (t , ZW 1), YW 2 (t, ZW 1), using the above equations (1 1) to (15), the reflection mirror 7 at the Z position ZW 1 with respect to the Y-axis direction Calculate the dimensional shape DXW (YW, ZW1).

Next, the main control system 22 controls the wafer X-axis drive stage 2 and the wafer Y-axis drive stage 3 via the wafer drive device 24, and moves the substrate table to the measurement start position shown by the solid line in FIG. . Subsequently, the main control system 22 controls the driving device 4 13 of the optical path changing device 40, and the laser interferometer 1 3 X 1, as typically shown in FIG. The movable mirror 410 is moved on the optical path (reflection position) to the reflecting mirror 7X of the measurement light beam LWX1 and LWX2 emitted from 1, 13X2. As a result, the measurement light beams LWX 1 and LWX 2 are applied to the Z position ZW 2 of the reflecting mirror 7X. After that, reset the laser interferometers 13 XI and 13 X 2.

Next, in the same manner as in the one-dimensional shape measurement at the Z position ZW1, the main control system 22 controls the Y-axis wafer stage 3 via the wafer driving device 24 to move the substrate table 4 in one Y direction. While the X position XW 1 (t, ZW 2), XW 2 (t, ZW2) and Y position YW 1 detected by the laser interferometers 13 XI, 13 X 2, 13 Y 1 and 13 Y 2 The task of collecting (t, ZW2) and YW2 (t, ZW2) almost simultaneously is performed sequentially. Then, the main control system 22 receives the collected X position XW 1 (t, ZW 2), XW 2 (t, ΖW 2) and ぴ position YW 1 (t, ZW 2), YW 2 (t, ZW Based on 2), the one-dimensional shape D XW (YW, YW, Y) of the reflecting mirror 7X at the Z position ZW2 in the Y-axis direction is obtained by using the same equations as the above equations (11) to (15). Z W2) is calculated. Thus, the shape information [DXW (YW, ZW1), DXW (YW, ZW2)] of the reflecting surface 7XS of the reflecting mirror 7X is obtained.

The shape information [DYW (XW, ZW1), DYW (XW, ZW2)] of the reflecting surface 7 YS of the reflecting mirror 7 Y is stored in the main control system 2 in the same manner as the shape measurement of the reflecting surface 7 XS. 2. Laser interferometers 13XI, 13X2, 13Y1, 13Y2, wafer driving device 24, optical path changing device 40, etc. are used. That is, the main control system 22, the laser interferometers 13 X 1,. 13 X 2, 13 Y 1, 13 Υ 2, the wafer driving device 24, the optical path changing device 40, etc. This is obtained by measuring the shape of the reflective surface 7YS.

The shape information of the reflecting surface 7 XS [DXW (Υ W, ZW 1), DXW (YW, ZW 2)] and the reflecting surface 7 YS of the reflecting mirror 7 られ obtained as described above Information [DYW (XW, ZW 1), DYW (XW, ZW 2)] 1 This is shown in FIG. Here, comparing the one-dimensional shape D XW (YW, Z W 1) with the one-dimensional shape D XW (YW, Z W 2), the measurement reference Υ position YWS

D XW (YWS, Z W 1) = D XW (YWS, Z W2)

It has become. This is because both the laser interferometers 13 X 1 and 13 X 2 are measured at the measurement reference Y position YWS for the one-dimensional shape DXW (YW, ZW1) and the one-dimensional shape DXW (YW, ZW2). This is because it is reset.

Therefore, based on the one-dimensional shape DXW (YW, ZW 1) and the one-dimensional shape D XW (YW, ZW 2), the rotation amount 0 Y (YW) about the Y axis at each Y position of the reflecting surface 7 XS is calculated as follows. ,

Θ Y (YW) = (DXW (YW, Z W 1)

-DXW (YW, ZW2)) / DX… (1 6)

If you ask for

Θ Y (YWS) = 0… (1 7)

It will be.

That is, according to the above equation (17), at the measurement reference Y position YWS. Of the reflection surface 7 XS, the rotation amount of the reflection surface 7 XS around the Y axis is always measured as “0”. However, actually, the one-dimensional shape measurement at the Z position ZW1 and the Z position ZW2 In the one-dimensional shape measurement in, the states of the laser interferometers 13 X 1 and 13 X 2 at the time of reset are not necessarily the same. Therefore, in general, the two-dimensional position detection values XW (ZW1) and YW (ZW1) at the Z position ZW1 and the two-dimensional position detection values XW (ZW2) and YW (ZW2) at the Z position ZW2 There will be an offset between them. Therefore, the amount of rotation 0 Y (YW) about the Y axis at each Y position of the reflecting surface 7 XS obtained by equation (16) is different from the actual amount of rotation of the reflecting surface 7 XS around the Y axis. I have. The same applies to the amount of rotation of the reflecting surface 7YS around the X axis.

In this embodiment, the one-dimensional shape data D XW (YW, ZW 1), D YW at the Z position ZW 1 (hereinafter sometimes to be referred to as the upper stage) of the reflecting surfaces 7 XS, 7 YS of the reflecting mirrors 7 X, 7 Y Relative relationship (offset) between (XW, ZW 1) and one-dimensional shape data D XW (YW, ZW 2), D YW (XW, ZW 2) at Z position ZW 2 (hereinafter sometimes referred to as the lower row) Is determined as follows.

The reflecting surface 7XS of the reflecting mirror 7X along the Y-axis direction is as follows. First, the main control system 22 sets the predetermined measurement start position (here, the measurement reference Y position) by controlling the substrate table 4 via the wafer driving device 24, as shown in FIG. The actuators AC1 to AC3 are controlled so that the surface of the substrate table 4 is set to be substantially parallel to a predetermined surface, for example, an XY surface. In this state, reset the laser interferometer 13 XP (zero reset).

Then, while appropriately controlling the displacement amounts of the actuators AC1 to AC3 so that the tilt information ΔLWXP as a measurement result of the laser interferometer 13XP keeps a constant (here, zero) state, Table 4 is moved at a constant speed along the Y-axis direction. At this time, the output (displacement in the Z-axis direction) of each of the encoders EN 1 to EN 3 is sequentially sampled in relation to the Y position (YW) of the board table 4. The substrate table 4 is moved while performing these steps until reaching a predetermined measurement end position.

The main control system 22 based on the output (displacement in the Z-axis direction) of each encoder EN 1 to EN 3 and the arrangement (positional relationship) of each encoder EN 1 to EN 3 Change of rotation angle around Y axis 0 Calculate YEN (YW). The change in the rotation angle about the Y axis in the direction along the Y axis of the substrate table 4 0 YEN (YW) is Equivalent to 2 data. This 0 Y _EN (YW) results, for example, as shown by the dotted line in FIG. 20A. In FIGS. 20A and 20B, the vertical axis is the rotation angle (0Y) about the Y axis, and the horizontal axis is the position (YW) in the Y axis direction.

Next, the difference between the upper shape data DXW (YW, ZW1) and the lower shape data DXW (YW, ZW2) (hereinafter sometimes referred to as the difference between the upper and lower bends) is calculated and converted into an angle (Z The difference between the upper and lower bends divided by the distance DX between the positions ZW1 and ZW2), that is, 0Y (YW) in the above equation (16) is obtained. The difference 0 Y (YW) between the upper and lower bends corresponds to the first data of the present invention. 0 Y (YW) is shown in Fig. 20A if the upper shape data DXW (YW, ZW1) and the lower shape data D XW (YW, ZW2) are as shown in Fig. 15. The result is as shown by the solid line. Then, find the difference between この Y (YW) and 0 Y _EN (YW). That is, this difference is defined as DIF Θ Y (YW),

D I F Θ Y (YW) = Θ YEN (YW)-Θ Y (YW)

Ask for. D IF 0 Y (YW) results, for example, as shown by the dotted line in FIG. 20B.

Here, DIF 0 Y (YW) is the upper shape data D XW (YWS, ZW 1) and the lower shape data DXW (Y WS, ZW 2) when the laser interferometers 13 X 1 and 13 X 2 are reset. (Here, the angle around the Y axis), so in the ideal state (assuming that there is no error in each part), the chopsticks have a slope of zero. However, since such an ideal state cannot exist in reality, D I F

Θ Y (YW) is not usually a straight line. The main error in this case is that the influence of the undulation or twist on the upper surface of the wafer support table 1 constituting the reference plane for the movement of the substrate table 4 is based on the outputs of the encoders EN 1 to EN 3. Probably due to being included in Y _EN (YW).

As described above, since DIF 0 Y (YW) is not usually a straight line, for example, a linear approximation is performed using the least squares method so that the sum of the squares of the error is minimized, and this is reflected along the Y-axis direction. Let RELθY (YW) be the relative relationship between the upper and lower shape data of mirror 7X. RE L 0 Y (YW) in this case is, for example, as shown by a solid line in FIG. 20B. By linearly approximating DIF 0 Y (YW) in this way, ゥ The influence of local undulation and twist on the upper surface of the wafer support 1 can be reduced to some extent. At this time, a straight line may be approximated with a straight line having a slope of zero, that is, the straight line may be approximated so that the sum of the squares of the error in the Y-axis direction is minimized. in this case,

RE L 0 Y (YW) is a straight line parallel to the YW axis in Fig. 20B, and the relative values of the upper and lower tier shape data DXW (YW, ZW1) and DXW (YW, ZW2) that do not depend on the YW value. It will reflect the relationship.

As described above, when the linear approximation is performed so as to minimize the error, RE L 0 Y (YW) usually has a certain slope. This inclination is considered to reflect the influence of the overall undulation and deflection of the upper surface of the wafer support 1. In the present embodiment, RELOY (YW) is obtained by including this as it is.

Next, the value obtained by adding RE L 0 Y (YW) to the difference between the upper and lower bends 0 Y (YW) is the correction value XO F Θ Y (YW) for the measurement result Δ LWX P obtained by the laser interferometer 13 XP. And stored in the storage device 27.

The reflecting surface 7 YS of the reflecting mirror 7 Y along the X-axis direction is as follows. First, the main control system 22 controls the substrate table 4 via the wafer driving device 24 to determine a predetermined measurement start position (here, the laser interferometers 13 Y 1 and 13 Y 2 in one-dimensional shape measurement). And the actuators AC1 to AC3 shown in FIG. 19 are controlled so that the surface of the substrate table 4 is substantially parallel to a predetermined surface, for example, the XY surface. In this state, reset the laser interferometer 13 YP (zero reset).

Then, while appropriately controlling the displacement amounts of the actuators AC1 to AC3 so that the tilt information ΔLWYP as the measurement result of the laser interferometer 13YP remains constant (here, zero), Table 4 is moved at a constant speed along the X-axis direction. At this time, the outputs (displacements in the Z-axis direction) of the encoders EN 1 to EN 3 are sequentially sampled in relation to the X position (XW) of the board table 4. The substrate table 4 is moved while performing these steps until reaching a predetermined measurement end position.

The main control system 22 is based on the output (displacement in the Z-axis direction) of each encoder EN 1 to EN 3 and the arrangement (positional relationship) of each encoder EN 1 to EN 3, in the direction along the X axis of the board table 4. Change of rotation angle around X axis 0 Calculate X _EN (XW). PCB tape The change of the rotation angle about the X axis in the direction along the X axis of the rule 4 0 X _EN (XW) corresponds to the second data of the present invention.

Next, the difference between the upper shape data D YW (XW, ZW 1) and the lower shape data D YW (XW, ZW 2) (hereinafter, also referred to as the difference between the upper and lower bends) is calculated and converted into an angle. (Division by the distance DX between the Z positions ZW1 and ZW2) Obtain the difference 0X (XW) between the upper and lower bends. That is,

Θ Calculate X (XW) = (D YW (XW, ZW 1)-D YW (XW, ZW 2)) / D X. The difference 0X (XW) between the upper and lower bends corresponds to the first data of the present invention.

Then, find the difference between (XW) and 0 X _EN (XW). That is, this difference is defined as DIF Θ X (XW),

D I F Θ X (XW) = Θ XEN (XW)-Θ X (XW)

Ask for.

Here, DIF 0 X (XW) is the upper shape data D YW (XWS, ZW 1) and the lower shape data D YW (XWS, ZW 2) when the laser interferometers 13 Y 1 and 13 Y 2 are reset. (In this case, the angle around the X-axis), so in an ideal state (assuming that there is no error in each part), the answer is a straight line with a slope of zero. However, DIF Θ X (XW) is not usually a straight line since such an ideal state cannot exist in reality. The main error in this case is that the influence of the undulation or twisting of the upper surface of the wafer support 1 constituting the reference plane for the movement of the substrate table 4 is based on the outputs of the encoders EN 1 to EN 3 0 X _EN (XW).

In this way, since DIF 0 X (XW) is not usually a straight line, it is approximated by a straight line using the least squares method so that the sum of the squares of the error is minimized, and this is reflected along the X-axis. Let REL 形状 X (XW) be the relative relationship between the upper and lower shape data of mirror 7Y. By linearly approximating DIF 0 X (XW) in this way, the effects of local undulation and twist on the upper surface of the wafer support 1 can be reduced to some extent. Note that, at this time, the linear approximation may be performed with a straight line having a slope of zero as in the case of the above-described reflecting mirror 7Y along the X-axis direction. Thus, REL 0 X (XW) usually has a certain slope when a straight line is approximated so that the error is minimized. This inclination is considered to reflect the influence of the overall undulation and deflection of the upper surface of the wafer support 1. In the present embodiment, REL 0 X (XW) is obtained by including this as it is.

Next, the value obtained by adding REL 0 X (XW) to the difference between the upper and lower bends 0 X (XW) as a correction value YOF Θ X (XW) for the measurement result ΔLWYP by the laser interferometer 13 YP is given as Store in storage device 27.

Either of the one-dimensional shape measurement and the measurement using the encoders EN1 to EN3 may be performed first.

Based on the correction values XOF 0 Y (YW) and YO F 0 X (XW) obtained as described above, the measurement results Δ LWX P and A LWY P of the laser interferometers 13 XP and 13 YP are corrected. By doing so, the iu rotation amount 0 YW of the substrate table 4 around the Y axis and the rotation amount 0 XW around the X axis can be accurately obtained. .

That is, the detected values ΔLWX P and ΔLWY P of the laser interferometers 13 XP and 13 YP include the Y axis of the substrate table 4 based on the reset state of the laser interferometers 13 XP and 13 YP. The optical path difference Δ LWX P 1, Δ LWY P 1 caused by the amount of rotation around the X-axis and the waviness and torsion in the Y-axis and X-axis directions of the reflective surfaces 7 XS and 7 YS The optical path differences Δ LWXP 2 and Δ LWX P 2 generated due to the above factors are included. The reset position of the laser interferometers 13 X 1, 13 X 2, 13 Y 1, 13 Y 2 and the position detection of the substrate table 4 when measuring the shape of the reflective surfaces 7 XS and 7 YS described above The positional relationship between the laser interferometers 13 X 1, 13 X 2, 13 Y 1, and 13 Y 2 at the time of resetting is predetermined and known.

The Y position YWP, X position XWP of the irradiation point of the measurement light beam LWX P, LWY P emitted from the laser interferometer 13 XP, 13 Y P

YWP = YW- (L 1 1/2)-L 1 2

XWP = XW- (L 2 1/2)-L 2 2… (1 8)

Required by Further, the Y position YWP 0 and the X position XWO of the irradiation point of the measurement light beams LWX P and LWY P at the time of resetting the laser interferometers 13 XP and 13 YP are known as described above. Therefore, the optical path differences A LWX P 2 and A LWY P 2 are Δ LWX P 2 =

{XO F Θ Y (YWP) -XO F Θ Y (YWP 0)}

LWY P 2 =

{YO F Θ X (XWP)-YO F Θ X (XWP 0)}-D X… (1 9)

Therefore, the optical path difference Δ LWX P 1, A LWY P l is

Δ LWX P 1 = A LWX P-A LWX P 2

LWY P 1 = Δ L WY P— Δ LWY P 2… (20)

Can be determined by: As a result, the rotation amount of the substrate table 4 around the Y axis 0 YW, the rotation amount around the X axis Θ XW is

Θ YW = Δ LWX P 1 / DX

Θ XW = Δ LWY P 1 / D X… (2 1)

Can be determined by:

To correct the Abpe error based on the rotation amount of the substrate table 4 around the X axis or Y axis, the difference L between the Z position ZW1 of the XY position detection of the substrate table 4 and the Z position of the wafer W surface (See Fig. 4), the Abbe error in the X-axis direction XA due to the rotation amount 0 YW of the substrate table 4 and the rotation amount around the X-axis θ XW in the Y-axis direction The error ΔYA is

, Δ X A = L. Θ YW

MM Y A = L · Θ XW… (2 2)

Required by The calculations of the above equations (18) to (22) are performed by the main control system 22.

Note that the tilt information ΔLFXP detected by the laser interferometer 13FP is processed in the same manner as in the case of the laser interferometer 13XP described above, and a description thereof will be omitted.

By the way, REL 0 Y (YW) and EL REL 0 X (XW) indicating the relative relationship between the upper and lower shape data described above have a certain inclination due to the undulation and undulation of the upper surface of the wafer support 1. XO F 0 Y (YW) and YO F Θ X (XW) were obtained as correction values in a form including this. Therefore, the laser interferometer 1 3 XP, If the measurement result of 13 YP is corrected with these correction values, an error corresponding to the inclination will be included.

When the wafer is actually exposed, the error due to the inclination is expressed as the orthogonality error of the arrangement of the circuit patterns formed on the wafer. Therefore, the effect can be eliminated by further executing the correction method which is usually performed to correct the orthogonality error of the pattern.

As a method of correcting the orthogonality error, a wafer for orthogonality measurement in which a plurality of reference marks are formed in a grid pattern is mounted on the substrate table 4 in a predetermined state, and the main control system 22 drives the wafer. The wafer X-axis drive stage 2 and the wafer Υ-axis drive stage 3 are controlled via the device 24, and the reference marks on the measurement wafer are sequentially measured by the alignment sensor 26 to determine the positions thereof. The correction value is obtained from the relationship between the measurement result and the reference position where the reference mark should be, and the drive of the stage is controlled based on the correction value. After measuring the reference mark of the orthogonality measurement wafer, the wafer is further placed on the substrate stage 4 with the orthogonality measurement rotated 90 degrees, and the reference mark is further measured. By calculating the orthogonality between the reflective surface 7X and the reflective surface 7mm by statistically processing these measurement results, etc., the undulation of the surface of the orthogonality measurement wafer on which the fiducial mark is formed can be measured. The effect of errors due to torsion and the like can be reduced. In the method of rotating the wafer by 90 degrees to obtain the above-described correction value, it is possible to use a device manufacturing wafer having alignment marks formed integrally with a reticle pattern without using a wafer dedicated to measurement. Good.

Note that such correction of the orthogonality error is a process that is usually performed, and that XOF 0 Y (YW) and YOF Θ X (XW) are used as correction values for the laser interferometers 13 XP and 13 Υ Ρ. ) Is not specifically performed to eliminate errors due to the effects of the undulations and torsion of the wafer support table 1 included in), so that the man-hour is not particularly increased.

As described above, since the relative relationship between the upper shape data and the lower shape data can be obtained without using a measurement wafer having a fiducial mark as in the conventional technology, the man-hour for collecting the correction data is reduced. It is possible to improve the measurement accuracy because it can be reduced and errors due to measurement of the fiducial mark are not included. Can be.

In addition, the shape information D XW (YW, ZW 1) and D XW (YW, ZW 2) of the reflecting surface 7 XS, and the shape information D YW (XW, ZW1) and D YW (XW, ZW2) of the reflecting surface 7 YS. The relative relationship between the upper and lower shape data RE L 0 Y (YW) and RE L 0 X (XW) can be corrected to obtain more accurate two-dimensional shape data of the reflecting surface 7 XS, 7 YS. Can be. That is, the corrected two-dimensional shape data of the reflecting surface 7 XS is dXW (YW, ZW1) and dXW (YW, ZW2), and the corrected two-dimensional shape data of the reflecting surface 7 YS is dYW (XW, XW, ZW 1), d YW (XW, ZW2), X position of substrate table 4 when measuring 1D shape of reflector 7 X, XWP, Y position of substrate table 4 when measuring 1D shape of reflector 7 Y As YWP,

d XW (YW, Z W 1) = DXW (YW, Z W 1)

d XW (YW, ZW2) = D XW (YW, ZW 2) + REL 0 Y (YW) d YW (XW, ZW 1) = D YW (XW, ZW 1)

d YW (XW, ZW 2) = D YW (XW, ZW 2) + RELΘX (XW). When REL 0 Y (YW) and RE L 0 X (XW) are constant values AXOF, AYOF (when the inclination is zero), the corrected shape data d XW (YW, ZW 1), d XW ( YW, ZW2), dYW (XW, ZW1), dYW (XW, ZW2) are shown in FIG.

Next, an exposure operation for transferring the pattern formed on the reticle R to the wafer W by the exposure apparatus 100 of the present embodiment will be described.

First, a reticle is loaded on fine movement stage 11 of reticle stage R ST by a reticle loader (not shown). Then, reticle alignment is performed using the reference mark plate 6.

The operation of the reticle alignment is briefly described as follows. First, by controlling the main control system 22, the wafer Y-axis drive stage 2 and the wafer X-axis drive stage 3 are driven to form the reference mark plate 6. The reference marks 30 A and 30 B are moved in the exposure area (projection area of the pattern image) 34 conjugate with the illumination area 36 on the reticle R with respect to the projection optical system PL and stopped, and the reticle scanning stage 1 Drive 0 to move the alignment marks 3 2A and 3 2B on the reticle 1 2 in Fig. 11 into the illumination area 36. Moving.

Next, the reticle alignment system 19, 20 detects the amount of displacement between the reference marks 30A, 30B and the corresponding alignment marks 32A, 32B. Then, the main control system 22 drives the reticle scanning stage 10 and the reticle fine movement stage 11 on the basis of the detected positional deviation amount, and forms the images of the reference marks 30A and 30B. On the other hand, the alignment marks 32A and 32B are aligned so that the amount of displacement is symmetrical. As a result, the position and the rotation angle of the reticle R are aligned with the reference mark plate 6. In this state, for example, the measured values of the 4-axis reticle interferometers 14 X 1, 14 X 2, 14 Y 1, 14 Y 2 on the RST side of the reticle stage, and the 4-axis laser on the wafer stage side By resetting the interferometer 1 3 X 1, 1 3 X 2, 1 3 Y 1, 1 3 Y 2 measurement values, the coordinate system of the reticle stage (XR, YR) and the coordinate system of the wafer stage The offset of the origin with (XW, YW) is corrected. At this time, the offset may be stored without resetting the measured value of each laser interferometer, or the reticle stage may be moved (rotated, etc.) without correcting or storing the offset without moving the reticle stage. The offset may be corrected or stored using the detection results of the alignment systems 19 and 20.

Next, the scanning direction of the substrate table 4 at the time of the scanning exposure performed later is set to be parallel to the arrangement direction of the reference marks 30 A, 30 C, and 30 E of the reference mark plate 6. For this purpose, for example, the arrangement direction of the reference marks 30 A, 30 C, 30 E is mechanically set parallel to the reflection surface 7 XS of the reflection mirror 7 X. However, when a mechanical adjustment error remains, each time the Y coordinate YW of the wafer stage changes by a predetermined step, the X coordinate XW is changed by a corresponding amount, and the substrate test is performed in software. The scanning direction of one bull 4 may be corrected. In the following, the coordinate system in which the scanning direction corrected in this way is the Y axis is referred to as the wafer stage coordinate system (XW, YW).

Next, without irradiating the exposure light EL, the stage on the wafer stage side and the stage on the reticle stage side are moved in opposite directions to each other as in the case of scanning exposure, and the reference mark 30 C on the reference mark plate 6 is moved. The relative displacement between .about.30 F and the corresponding alignment marks 32C to 32F on the reticle R is sequentially detected by the reticle alignment system 19,20. From the average of these relative displacements, The tilt angle between the scanning direction of the reticle R and the scanning direction of the wafer W, that is, the rotation angle of the axis in the scanning direction between the coordinate system (XR, YR) of the reticle stage and the coordinate system (XW, YW) of the wafer stage. Ask. Thereafter, when scanning the reticle R, the reticle scanning stage 10 and the reticle fine movement stage 11 are used to shift the X coordinate XR by a corresponding amount while the Y coordinate YR changes by a predetermined interval. Then, the scanning direction of the reticle R is adjusted to the arrangement direction of the reference marks on the reference mark plate 6 in a soft-to-air manner. Hereinafter, the coordinate system in which the scanning direction corrected in this way is the Y axis is referred to as the coordinate system (XR, YR) of the reticle stage.

As a result, in the coordinate system (XW, YW) of the wafer stage and the coordinate system (XR, YR) of the reticle stage, the axes in the scanning direction are parallel to each other with respect to the reference mark plate 6, and the reticle R during the scanning exposure. And the wafer W are scanned in parallel. In this case, since the movement of each stage is based on the guide surface of each stage, when adjusting the assembly of the exposure apparatus 100, for example, the guide surface of the reticle scanning stage 10 and the wafer Y-axis drive stage Mechanically adjust the parallelism with the guide surface of No. 2 to less than about 100 rad

Further, by fixing the reflecting mirror and the reference mark plate 6 to the guide surfaces, the amount of software correction by driving each stage in the non-scanning direction during scanning exposure is reduced. And control accuracy has been improved. Note that the reticle stage and the wafer stage may both be guides. In this case, a virtual guide surface may be defined, and a mirror or the like may be fixed to the virtual surface. When the reticle R is actually placed on the reticle fine movement stage 11 adjusted in this way, if the reticle R is provided on the basis of the outer shape or the like, each of the reflecting mirrors 21 X, 21 Y 1, 21 Y There is a possibility that only the alignment marks 32 A to 32 F of the reticle R are largely rotated with respect to the reference mark plate 6. This is because the displacement between the outer shape of the reticle R and the transfer pattern is about 0.5 mm when the displacement is large.

If the amount of misalignment between the outer shape of the reticle R in FIG. 11 and the transfer pattern is large, the alignment marks 32 A to 32 F of the reticle R and the reference marks 30 A to 30 F of the reference mark plate 6 are obtained. Relative to the reticle R and the reference mark plate 6 and a large rotation are recognized as having a large offset. In such a case, since the reference mark plate 6 is fixed to the reflecting mirrors 7X and 7Y, the correction is performed by rotating or shifting the reticle fine movement stage 11.

When the reticle fine movement stage 11 is rotated, the reflecting mirror 21 X also rotates in the same manner, so that the reflecting mirror 21 X is inclined with respect to the running direction of the reticle R. The alignment marks 32A to 32F are parallel to the reference marks 30A to 30F on the reference mark plate 6, and the scanning direction of the reticle R and the scanning direction of the wafer W are parallel during scanning exposure. Is controlled so that

At the time of the reticle alignment described above, the interval (baseline amount) between the detection center of the alignment sensor 26 and the reference point in the exposure area 34 is obtained by a so-called baseline etching using the reference mark plate 6. Stored in 27. Next, the wafer W is loaded on the substrate table 4 by a wafer loader (not shown), and is held by the substrate table 4. Then, a wafer alignment for obtaining an arrangement of each shot area on the wafer W on the coordinate system (XW, YW) of the wafer stage is performed. In such a wafer alignment, for example, Japanese Patent Application Laid-Open No. 61-44429 and corresponding US Pat. Nos. 4,780,617 using the alignment sensor 26 shown in FIG. As disclosed, an EGA (Electro Gas Gauge) that detects the coordinate position of a wafer mark (not shown) of a predetermined number of shot areas (sample shots) selected from the wafer W and processes this measurement result with a gun gauge The array coordinates of the entire shot area on the wafer W are calculated by the method of “Enhanced-global alignment”. Note that the wafer mark coordinate position is the measurement result (XW (= XF), YW) using the laser interferometers 13 FX, 13 Y 1, and 13 Y 2 described above, and the measurement result using the laser interferometer 13. FP. Measured by ΔLFXP and laser interferometer 13 YP Detected based on ΔLWYP.

Then, the arrangement coordinates of each shot area on the wafer W, the pace line amount of the alignment sensor 26, and the coordinate system of the wafer stage (XW, YW) and the coordinate system of the reticle stage (XR, YR) Based on the relationship, the shot area to be exposed on wafer W is positioned at the scanning start position, and reticle R is also positioned at the corresponding position. It is decided.

Next, while irradiating the exposure light EL, the reticle R and the wafer W are synchronized according to the coordinate system (XW, YW) of the wafer stage and the coordinate system (XR, YR) of the reticle stage determined at the time of the previous reticle alignment. By moving, a scanning exposure operation is performed. In this case, the coordinate system (XW, YW) and the coordinate system (XR, YR) are soft to air based on the reflecting surface of the reflecting mirror 7X, 7Y, 21X, 21Y1, 21Y2. If the position of each reflecting mirror is relatively shifted with respect to the reticle R or the wafer W, it will affect the shape of the shot area and the shot arrangement. In the present embodiment, even in such a case, scanning exposure and stepping are performed by the following methods so that an accurate rectangular shot area and an orthogonal lattice shot arrangement are formed.

That is, the coordinates of the reticle stage coordinate system (XR, YR) when the shot area to be exposed and the reticle are aligned by the wafer alignment are (XR0, YR0), and the coordinate system of the wafer stage. If the coordinates of (XW, YW) are (XW 0, YW0), the projection magnification of the projection optical system PL is j8, so the reticle micro-drive stage 11 (reticle R) and the substrate table 4 (wafer) W) and the synchronization error ΔX, ΔΥ in the scanning direction and the non-scanning direction are

X = (XW-XWO) / / 3-(XR -X R 0)… (2 3)

Δ Υ = (YW- YWO) / β-(YR— YR O)… (24)

It becomes. However, these synchronization errors are errors converted on reticle 12. The projection optical system PL in FIG. 1 is a reverse projection system, but as shown in FIG. 2, the reticle interferometer 14 and the wafer interferometer 13 have the X-axis direction and the Y-axis direction Since it is reversed, the synchronization error can be obtained simply by taking the difference between the magnification correction values of the movement amount. Further, in the present embodiment, the difference between the jowing angle 0 ZW of the substrate table 4 expressed by the equation (5) and the joing angle 0 ZR of the reticle fine movement stage 11 expressed by the equation (9) is expressed by the following equation. As described above, it is assumed that the synchronization error in the rotation direction is Δ 方向.

0 = 0 ZW— 6 Z R = (XW 1-XW 2) / L 1 1

(X R 1-X R 2) / L 3 (25)

At the time of scanning exposure, the reticle scanning stage 10 of FIG. The moving stage 2 starts accelerating, and after each of them reaches a predetermined scanning speed, the reticle fine moving stage is adjusted so that the above-mentioned synchronization errors ΔΧ, ΔΥ, ΔΘ are each zero or less than a predetermined allowable value. 1 Synchronous control is performed by driving 1. In this state, after a predetermined settling time has elapsed, irradiation of the exposure area EL on the reticle R with the exposure light EL is started, and exposure is performed. In the present embodiment, the reticle fine movement stage 11 is driven to set the synchronization errors ΔΧ, ΔΥ, ΔΘ to zero or less than the allowable value, respectively. However, instead of the reticle fine movement stage 11 or in combination therewith. The synchronization error may be corrected by driving a wafer stage device (for example, the substrate table 4). During scanning exposure, the Z position, rotation angle around the X-axis, and rotation angle around the Y-axis of the wafer W (the shot area where the reticle pattern is transferred) are determined by the multipoint focus detection system (28). , 29). Then, based on the detection result, the main control system 22 drives the substrate table 4 via the wafer driving device 22 to bring the surface of the wafer W into the image plane of the projection optical system PL in the exposure area 34 described above. Match within the depth of focus.

Further, at the time of wafer alignment, the tilt amounts of the reflecting surfaces 7 XS and 7 YS are detected by the laser interferometers 13 FP and 13 YP, and at the time of scanning exposure, the laser interferometers 13 XP and 13 XP are used. The tilt amount of the reflecting surfaces 7 XS and 7 YS is detected by 13 YP. Then, based on this detection result, the Abbe errors ΔXA, ΔYA are obtained as described above, and the XY position of the substrate table 4 (the wafer W) is corrected by the Abbe error ΔXA, ΔYA. .

In the above embodiment, the optical path changing device 40 including the movable mirror 410 and the fixed mirror 420 is used. On the surface thereof, for example, a dielectric multilayer film in which a plurality of dielectric films are stacked, Alternatively, it is preferable to deposit a metal film or the like, and to provide the two mirrors with good reflection polarization characteristics for reflecting the measurement light beam as faithfully as possible without disturbing the polarization state. In the above embodiment, the movable mirror 4 10 of the optical path changing device 40 is rotated to change the Z position of the measurement light beam on the reflection surface. For example, only the movable mirror 4 10 The mirror may be integrally held so that its surfaces are parallel to each other, and may be configured to slide in the Z direction. Alternatively, other optical members such as a prism other than the mirror may be used. Further, in the above embodiment, the positions of the measurement light beams of the interferometers 13 X 1, 13 X 2, 13 Y 1, and 13 Υ 2 on the reflection surface are denoted by ZW1 and ZW2 by the optical path changing device 40. And the shape information of the reflection surface is measured, but the optical path changing device 40 is not necessarily provided. For example, the interferometers 13 X 1, 13 X 2, 1 3 Υ 1 and 13 Y 2 are separated from each other in the Ζ direction by a pair of measurement beams (one is LWX 1, L WX 2, LWY 1, LWY 2) May be applied to the reflecting surface to independently measure the position information of the substrate table 4 at different positions ZW 1 and ZW 2. In this configuration, the Ζ positions of the pair of measurement beams on the reflection surface are respectively set to the pair of measurement beams (LWXΡ1, LWXΡ2), (LWYΡ1,) of the interferometers 13ΧΡ and 13 3. It is preferable that LWY Ρ 2) be made to substantially match. Further, in this configuration, since the tilt measurement of the substrate table 4 can be performed by the pair of measurement light beams, it is not necessary to separately provide the interferometers 13 X 1 and 13 Υ 、, and the encoder の Ν 1 In the measurement using ~ 3, instead of the interferometer 13 XP, 13 3, one of the interferometers 13 X 1 and 13 X 2 for the reflective surface 7 XS, and the interferometer 13 Y for the reflective surface 7 YS One of 1, 13 32 may be used.

In the above-described embodiment, the wafer stage is moved in one direction, for example, only one direction (one X direction) when measuring the shape information of the reflection surface described above. The wafer stage is reciprocated, that is, moved in the earth direction (± Χ direction), the shape information obtained on the outward path (movement in one X direction and the X direction) and the return path (+ Υ direction Ζ + χ direction) It is preferable to determine the final shape information by averaging the shape information obtained in (2) and (3).

Further, in the above-described embodiment, the wafer stage may be continuously moved in one direction or may be step-moved at the time of measuring the shape information of the reflection surface described above. When the wafer stage is moved continuously, it is preferable to obtain the shape information using the interferometer measurement values obtained during the constant velocity period substantially excluding the acceleration / deceleration period. For this reason, continuous measurement can shorten the measurement time compared to step movement, but the measurement range of the reflective surface can be narrowed. Also, the wafer stage may be moved continuously or stepwise during measurement using the encoders 1 to 3 described above. In the above embodiment, the measurement of the shape information of the reflection surface is performed periodically, for example, at a predetermined time or every time one lot is completed, and the shape information may be sequentially updated. Alternatively, the shape information may be accumulated and the average value may be used. At this time, in the measurement of the shape information from the second time onwards, for example, ① shape measurement of two reflective surfaces 7 XS, 7 YS, ② shape measurement at different Z positions ZW 1, ZW 2, ③ outgoing at the same Z position At least one of the return path shape measurement, the shape measurement of the reflection surface, and the measurement using the encoder described above may be performed at different timings. In this case, it is possible to improve the throughput by shortening the stop time of the exposure apparatus by these measurements.

Further, in the above-described embodiment, both the reticle interferometer and the wafer interferometer have the reference mirror provided on the mirror の of the projection optical system PL or its mount, but the arrangement of the reference mirror is not limited to this. For example, a reference mirror may be provided inside the interferometer. In addition, the reference mirror of the interferometers 13 FX and 13 FP used when the mark is detected by the alignment sensor 26 may be provided inside the interferometer instead of the barrel of the alignment sensor 26 or its mount. Good ..

Further, in the above embodiment, the measurement value of the interferometer is reset before the measurement of the shape information of the reflection surface or the measurement using the encoder described above. However, it is also possible to reset the measurement value of the interferometer to a predetermined value other than zero. Yes, it is not always necessary to reset (or reset).

Note that the exposure apparatus 100 of the present embodiment includes the illumination system having a large number of mechanical components and optical components, the projection optical system PL having a plurality of lenses and the like, and the large number of mechanical components described in the above embodiment. Reticle stage with RST and wafer stage device, and laser interferometer 13 X 1, 13 X 2, 13 XP, 13 Y 1, 13 Y 2, 13 YP, 13 FX, 1 3 FP, 14 X 1, 14 X 2, 14 X 2, 14 M 1, 14 M 2, optical path changing device 40 are assembled and connected mechanically and optically, and furthermore, main control system 22, and It can be manufactured by combining the storage device 27 and the like mechanically and electrically, and then performing overall adjustment (electrical adjustment, operation confirmation, etc.).

It is desirable that the exposure apparatus 100 be manufactured in a clean room where the temperature, cleanliness, etc. are controlled. Next, the manufacture of a device using the exposure apparatus of the present embodiment will be described. FIG. 17 shows a flowchart of the production of devices (semiconductor chips such as ICs and LSIs, liquid crystal panels, CCDs, thin-film magnetic heads, micromachines, etc.) according to the present embodiment. As shown in Fig. 17, first, in step 201 (design step), functional design of a device (for example, circuit design of a semiconductor device, etc.) is performed, and pattern design for realizing the function is performed. . Subsequently, in step 202 (mask manufacturing step), a mask on which the designed circuit pattern is formed is manufactured. On the other hand, in step 203 (wafer manufacturing step), a wafer is manufactured using a material such as silicon.

Next, in step 204 (wafer process step), using the mask and wafer prepared in steps 201 to 203, as described later, an actual circuit is formed on the wafer by lithography technology. Etc. are formed. Next, in step 205 (assembly step), chips are formed by using the wafer processed in step 204. This step 205 includes processes such as an assembly process (dicing and bonding) and a packaging process (chip encapsulation).

Finally, in step 206 (inspection step), an operation check test, a durability test, and the like of the device manufactured in step 205 are performed. After these steps, the device is completed and shipped.

FIG. 18 shows a detailed example of the step 204 in the case of a semiconductor device. In FIG. 18, in step 2 11 (oxidation step), the surface of the wafer is oxidized. In step 2 12 (CVD step), an insulating film is formed on the wafer surface. In step 2 13 (electrode formation step), electrodes are formed on the wafer by vapor deposition. In step 2 14 (ion implantation step), ions are implanted into the wafer. Each of the above steps 211 to 214 constitutes a pre-process of each stage of the wafer process, and is selected and executed according to a necessary process in each stage.

At each stage of the wafer process, when the pre-process is completed, the post-process is executed as follows. In the subsequent process, first, in step 215 (resist processing step), a photosensitive agent is applied to the wafer, and then in step 216 (exposure step). In step (2), the circuit pattern of the mask is printed and exposed on the wafer by the scanning exposure apparatus described above. Next, in Step 217 (development step), the exposed wafer is developed, and then in Step 218 (etching step), the exposed members other than the portion where the resist remains are etched. Remove more. Then, in step 2 19 (register removing step), unnecessary resists after etching are removed.

By repeating these pre-process and post-process, multiple circuit patterns are formed on the wafer.

As described above, a device on which a fine pattern is accurately formed is manufactured with high mass productivity.

In the above embodiment, the shape of the wafer mounting surface of the substrate table is rectangular, but may be other shapes. For example, in the case of a triangular shape, as shown in FIG. 21, each of the reflecting surfaces 4 ′ a, 4 ′ b, and 4 ′ c formed on the three side surfaces of the substrate table 4 ′, Laser interferometer for 2D position detection 13 X 11, 13 X 12, 13 X 21, 13 X 22, 13 Y 1, 13 Y 2 and laser for tilt detection Interferometers 13 PI, 13 P 2, and 13 YP may be provided.

The laser interferometers 13 X 11, 13 X 12 and the laser interferometers 13 X 21, 13 X 22 are the same as the laser interferometers 13 X 1, 13 X 2, and the laser interferometers 13 XP 1 and 13 XP 2 may be configured in the same manner as the laser interferometer 13 XP of the above embodiment. In this case, the optical path changing device has a configuration similar to that of the optical path changing device 40 described above, and the laser interferometers 13 X 11 and 13 X 12 and the laser interferometers 13 X 21 and 13 X 22 and the laser interferometers 13Y1 and 13Y2, respectively, ie, three sets are provided.

In such a case, for example, in measuring the shape of the reflection surface 4′a, for example, while moving the substrate table 4 ′ in the Y-axis direction, the Z-axis of the substrate table 4 ′ is moved by the laser interferometers 13Yl and 13Y2. At about the same time as measuring the amount of rotation around, the laser interferometers 13 X 11 and 13 X 12 measure the local rotation of the reflection surface 4 ′ a around the Z axis. Thus, the shape of the reflecting surface 4'a is measured in the same manner as in the above embodiment. In the case of the triangular substrate stage 4 ′ shown in FIG. Instead of disposing the laser interferometers facing each other, it is also possible to dispose the laser interferometers on two surfaces that intersect each other.

In the above embodiment, the shape of the reflecting surfaces 7 XS and 7 YS provided on the substrate table 4 was measured, and the position of the substrate table 4 was controlled using the shape information. It is also possible to measure the shape of the reflecting surface 21 XS provided on 11 and control the position of the reticle fine movement stage 11 using the shape information. In such a case, as shown in FIG. 22, the laser interferometers 14 X 1, 14 X 2, 14 M 1, and 14 M 2 shown in FIG. In addition, as shown in FIG. 22, a laser interferometer 14 XP for tilt detection is newly arranged. In this case, as the optical path changing device, one set having the same configuration as the optical path changing device 40 described above is provided for the laser interferometers 14X1 and 14X2. Then, similarly to the case of the substrate table 4, the shape of the reflecting surface 21 XS may be measured, and the position of the reticle fine movement stage 11 may be controlled using the shape information.

Further, in the above embodiment, the detection result of the laser interferometer for tilt detection is used exclusively for correcting the Abpe error, but is used for correcting the rotation of the stage around the X axis or the Y axis. It is also possible to use.

Further, the configurations of the reticle stage and the wafer stage are not limited to the above-described embodiment, and may have any configuration. That is, the reticle stage does not have to have a coarse / fine movement structure, and the wafer stage does not have to have a stacked stage structure or a flat motor as in the above embodiment.

In the above embodiment, the laser interferometer uses the Zeeman effect, but may be an interferometer having another configuration. Instead of the double-pass method, a simple-pass method may be used. Further, the above-mentioned reticle interferometer and wafer interferometer are not limited to the configuration of the above-described embodiment, but may be configured as long as they have a plurality of length measuring axes (interferometers) necessary for the shape measurement described above. Is optional. For example, an interferometer for measuring the relative positional relationship (interval) between the projection optical system PL or its mount and the substrate table 4 in the Z direction may be further provided.

Further, the exposure apparatus of the above-described embodiment may employ, for example, a double wafer stage system including two independently movable wafer stages. The shape measurement of each reflection surface is performed on each of the two wafer stages. At this time, each wafer stage may be arranged at the exposure position where the pattern of the reticle R is transferred via the projection optical system PL, and the shape of each reflection surface may be measured by the same operation as in the above embodiment. In parallel with the exposure operation of the wafer at the exposure position, the shape of the reflection surface of each wafer stage is measured at the measurement position where the alignment sensor 26 measures the alignment mark of the wafer and the reference mark of the wafer stage. May be measured. Alternatively, the shape information of the reflection surface on each wafer stage may be measured at the exposure position and the measurement position, and different shape information may be used at the two positions. It is preferable that the measurement interferometer system has the same configuration as the exposure interferometer system or has a plurality of length measurement axes (interferometers) necessary for the shape measurement described above. The double wafer stage type exposure apparatus is disclosed, for example, in Japanese Patent Application Laid-Open No. 10-214,833 and corresponding US Pat. No. 6,341,077, or in International Publication WO988. No. 4,079,91 and corresponding U.S. Patent Nos. 6,262,796.

In the above embodiment, the scanning exposure apparatus of the step and scan type has been described. However, in controlling the position of the stage (and, consequently, the sample mounted on the stage), the shape of the reflecting surface provided on the stage is controlled. It can be applied to various types of exposure equipment that measures position and performs position control using the shape information. As the exposure light (exposure beam), not only the above-described exposure apparatus using ultraviolet light, far ultraviolet light, or vacuum ultraviolet light, but also, for example, an exposure apparatus using soft X-ray (EUV light) having a wavelength of about 10 nm, It can also be applied to exposure equipment that uses X-rays with a wavelength of about 1 nm, and exposure equipment that uses charged particle beams such as EB (electron beam) and ion beams. Also, for example, a compact projection exposure apparatus using ultraviolet light as a light source, a reduced projection exposure apparatus using soft X-rays having a wavelength of about 10 nm as a light source, an X-ray exposure apparatus using a light source with a wavelength of about 1 nm, EB (Electronics) It can be applied to all kinds of wafer exposure equipment such as an exposure equipment using a beam or an ion beam, and a liquid crystal exposure equipment. In addition, the present invention can be applied to step and 'repeat machines, step and' scan 'machines, and step and stitching machines.

Further, the present invention is applied to, for example, an immersion type exposure apparatus disclosed in International Publication No. WO 99/49504, a mirror projection aligner, or the like. be able to. The projection optical system of the above embodiment is not limited to a refraction system, but may be a catadioptric system or a reflection system. The projection optical system is not limited to a reduction system and may be an equal magnification system or an enlargement system. Also, the projection optical system projects an inverted image of the reticle pattern, but the projected image may be an erect image. Further, the present invention can be applied to, for example, a proximity type exposure apparatus having no projection optical system.

In the above embodiments, the exposure apparatus used for manufacturing a semiconductor element has been described. However, a micro device (electronic device) other than the semiconductor element, for example, a display device such as a liquid crystal display element, a plasma display, and an organic EL, an image pickup element The present invention is also applied to an exposure apparatus used for manufacturing a thin film magnetic head, a micromachine, a DNA chip, and the like, and further to an exposure apparatus used for manufacturing a mask (reticle) used in the exposure apparatus. can do.

In addition, it is not limited to the stage apparatus of the exposure apparatus, and in controlling the position of the stage, it measures the shape of the reflecting surface provided on the stage and controls the position using the shape information. Can also be applied. For example, by configuring a stage device with components corresponding to the shape measuring device and the wafer stage device in the above embodiment, position control of a sample table corresponding to a substrate table can be performed in the above embodiment. This can be performed in the same manner as the position control of the substrate table.

It is needless to say that the present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention. In addition, to the extent permitted by the national laws of the designated country or selected elected country specified in this international application, the disclosures of all the aforementioned gazettes and US patents shall be incorporated herein by reference.

According to the present invention, the shape of the reflecting surface provided on a moving body such as a stage can be measured easily and quickly, so that the number of work steps involved in the measurement can be reduced and the measurement can be performed with high accuracy. As a result, the position of the stage or the like can be controlled with high accuracy, and as a result, a high-quality and high-precision device can be manufactured.

This disclosure relates to the subject matter included in Japanese Patent Application No. 200-350 3650 filed on Feb. 3, 2002, the entire disclosure of which is hereby incorporated by reference. As a reference Explicitly incorporated.

Claims

The scope of the claims

1. A shape measuring method provided on a moving body that moves along a reference plane orthogonal to a first axis and that measures a shape of a reflecting surface extending along a second axis direction orthogonal to the first axis direction. hand,

While moving the moving body along the second axis direction, the one-dimensional shape of the reflection surface in the second axis direction is measured at each of the two positions separated in the first axis direction. ,

First data corresponding to the difference between the one-dimensional shape data for one of the two positions and the one-dimensional shape data for the other is obtained;

The moving body is moved in the second axis direction while the posture of the moving body is adjusted so that the measurement result based on the measurement beam simultaneously irradiated on the two positions of the reflecting surface separated in the first axis direction becomes constant. While moving, the displacement in the first axis direction accompanying the posture adjustment of the moving body during this movement is measured at a plurality of locations, and the movement of the moving body is centered on the second axis in the second axis direction. Find the second data corresponding to the change in the rotation amount

A shape measurement method wherein the one-dimensional shape data is corrected based on fourth data obtained by linearly approximating third data corresponding to a difference between the first data and the second data.

2. A shape measuring device provided on a moving body that moves along a reference plane orthogonal to the first axis and that measures a shape of a reflecting surface extending along a second axis direction orthogonal to the first axis direction. hand,

A one-dimensional shape measurement device that measures a one-dimensional shape of the reflection surface in the second axis direction at each of two positions separated in the first axis direction;

An attitude adjustment device that adjusts the attitude of the moving body with respect to the reference plane,

A displacement measuring device that measures displacement of the moving body in the first axis direction at a plurality of different positions, with the posture of the moving body being adjusted by the posture adjusting device,

A tilt measuring device that simultaneously irradiates a measurement beam to two positions of the reflection surface separated in the first axis direction and measures a rotation amount of the reflection surface about the second axis; and the one-dimensional shape measurement. One-dimensional shape data of one of the two positions by the device The first data corresponding to the difference between the data and the one-dimensional shape data of the other is obtained, and while controlling the attitude adjustment device so that the measurement result by the tilt measurement device becomes constant, Moves in the second axis direction, and generates second data corresponding to a change in the amount of rotation of the moving body about the second axis in the second axis direction based on the measurement result by the displacement measuring device during the movement. Asked,

Based on the fourth data obtained by linearly approximating the third data corresponding to the difference between the first data and the second data, the one-dimensional shape data as a measurement result by the one-dimensional shape measurement device is obtained. And a control device that corrects the shape.

3. It has a reflecting surface extending along a second axis direction orthogonal to the first axis, and the posture of the moving body moving along the reference plane orthogonal to the first axis with respect to the reference plane is expressed by A tilt measurement method for measuring by a measurement beam simultaneously irradiating two positions separated in the first axis direction,

First data corresponding to the difference between one and the other of the one-dimensional shape data of the reflection surface in the second axis direction measured at each of the two positions of the reflection surface separated in the first axis direction. ,

While adjusting the posture of the moving body so that the measurement result based on the measurement beam is constant, and measuring the displacement in the first axial direction accompanying the posture adjustment of the moving body at a plurality of positions, Moving in the second axis direction to obtain second data corresponding to a change in the amount of rotation of the moving body about the second axis in the second axis direction;

Based on fifth data obtained by adding the first data to fourth data obtained by linearly approximating third data corresponding to the difference between the first data and the second data, A tilt measurement method that corrects the measurement results.

4. A stage device having a reflecting surface extending along a second axis direction orthogonal to the first axis, and having a moving body moving along a reference plane orthogonal to the first axis,

A tilt measuring device that simultaneously irradiates a measurement beam to two positions of the reflection surface separated in the first axis direction and measures a rotation amount of the reflection surface around the second axis; A one-dimensional shape measuring device that measures a one-dimensional shape of the reflecting surface with respect to each of two positions separated in the first axis direction; A posture adjusting device that displaces the moving body in the first axial direction at a plurality of different positions from each other to adjust a posture of the moving body with respect to the reference plane; and a posture adjustment of the moving body by the posture adjusting device. A displacement measurement device that measures displacement of the moving body in the first axis direction at a plurality of different positions.

First data corresponding to the difference between the one-dimensional shape data for one of the two positions and the one-dimensional shape data for the other is obtained by the one-dimensional shape measurement device, and the measurement result by the tilt measurement device is constant. The movable body is moved in the second axis direction while controlling the posture adjusting device so that the position of the movable body is related to the second axis direction based on the measurement result by the displacement measuring device at this time. Second data corresponding to a change in the amount of rotation about the second axis is obtained,

The tilt measuring device based on fifth data obtained by adding the first data to fourth data obtained by linearly approximating third data corresponding to a difference between the first data and the second data; Device with a control device for correcting the measurement result by

5. An exposure apparatus for transferring an image on a first surface onto a second surface,

5. The exposure apparatus according to claim 4, wherein at least one of a mask stage for disposing a mask on the first surface and a substrate stage for disposing a substrate on the second surface moves as the movable body.

6. An exposure method for transferring a pattern of a mask onto a light-sensitive object held by a movable body along a reference plane orthogonal to the first axis,

The movement is performed so that the measurement result by the measurement beam irradiated to the two positions separated in the first axis direction on the reflecting surface of the moving body extending in the second axis direction orthogonal to the first axis direction is constant. Moving the moving body in the second axis direction while adjusting the posture of the body, measuring rotation data on a change in the amount of rotation of the moving body about the second axis, and moving the moving body in the first axis direction An exposure method wherein the movement of the movable body is controlled using shape data of the reflection surface in the second axis direction at each of a plurality of positions and the measured rotation data.

7. During the movement, information on a displacement amount of the moving body in the first axis direction due to the posture adjustment is detected, and the rotation data is obtained based on the detected information. 7. The exposure method according to claim 6, wherein the exposure method comprises:

8. Based on measurement results of an interferometer system that irradiates a measurement beam to a plurality of positions on the reflection surface that are separated in the second axis direction and that is obtained by moving the moving body in the second axis direction. 8. The exposure method according to claim 6, wherein the shape data is obtained.

9. At least one of the plurality of positions spaced apart in the second axis direction on the reflection surface is irradiated with a measurement beam from the interferometer system at a position spaced apart in the first axis direction. 9. The exposure method according to claim 8, wherein, when measuring the rotation data, the attitude of the moving body is adjusted using the interferometer system.

10. A device manufacturing method including an exposure step of transferring a mask pattern onto a photosensitive object using the exposure method according to any one of claims 6 to 9.

1 1. An exposure apparatus for transferring a mask pattern onto a photosensitive object, wherein the exposure apparatus holds the photosensitive object, is movable along a reference plane orthogonal to a first axis, and has an adjustable posture with respect to the reference plane. And a stage system having a moving body on which a reflection surface parallel to a second axis orthogonal to the first axis is formed;

An interferometer system that irradiates a measurement beam to two positions of the reflection surface that are separated in the first axis direction, and at least can measure rotation information about the second axis of the moving body,

A displacement measuring device that measures displacement information of the moving body in the first axis direction due to the posture adjustment;

Based on the measurement result of the displacement measurement device obtained by moving the moving body in the second axis direction while adjusting its posture so that the measurement result related to the rotation information of the interferometer system becomes constant. And obtaining rotation data relating to a change in the amount of rotation of the moving body about the second axis, and the shape of the reflecting surface in the second axis direction at each of the plurality of positions separated in the first axis direction. An exposure apparatus, comprising: a control device that controls movement of the moving body using data and the rotation data.

12. The interferometer system irradiates a measurement beam to at least one of the two positions separated in the first axis direction on the reflection surface at a position separated in the second axis direction. Measuring rotation information about the first axis of the moving body, and 11. The apparatus according to claim 11, wherein the shape data is obtained based on a measurement result regarding rotation information about the first axis of the interferometer system obtained by moving the moving body in the second axis direction. 12. Exposure apparatus according to 1.

13. The stage system includes a plurality of actuators for adjusting a posture of the moving body, and the displacement measuring device measures information on drive amounts of the plurality of actuators as the displacement information. The exposure apparatus according to 11 or 12.