JP2017183298A - Exposure apparatus, exposure method, and device manufacturing method - Google Patents

Abstract

The position of a mask pattern formed on a mask is suitably estimated.
An exposure apparatus (1) is an exposure apparatus that irradiates a mask (111) with an energy beam (EL) to transfer a mask pattern formed on a mask pattern surface (111PA) to an object (141). Then, a light irradiation unit (151, 152) that irradiates a plurality of measurement lights (LB2) having different incident angles with respect to the predetermined surface of the mask, and a plurality of measurement light reflected or scattered by the predetermined surface And a sensor unit (153) for detecting at least a part of.
[Selection] Figure 3

Description

  The present invention relates to a technical field of, for example, an exposure apparatus, an exposure method, and a device manufacturing method.

  The exposure apparatus is used, for example, in a lithography process for manufacturing an electronic device such as a semiconductor element or a liquid crystal display element. This type of exposure apparatus applies a mask pattern formed on a mask (in other words, a reticle) to each of a plurality of shot regions on a resist-coated wafer (or an arbitrary object such as a glass substrate). And transfer through the projection optical system. In this case, it is important to accurately transfer a reduced image of the mask pattern corresponding to the projection magnification of the projection optical system to each shot area on the wafer. In other words, the overlay accuracy between the mask and the wafer becomes important.

  In order to accurately transfer a reduced image of the mask pattern to each shot area, for example, Patent Document 1 discloses a reticle alignment mark formed on the mask so as to have a predetermined positional relationship with the mask pattern and each shot area. A technique using a wafer alignment mark formed on a wafer so as to have the following positional relationship is disclosed.

US Pat. No. 5,646,413

  In the technique using the reticle alignment mark and the wafer alignment mark, the position of the mask pattern is estimated based on the position of the reticle alignment mark, and the position of each shot area is estimated based on the position of the wafer alignment mark. Here, the estimation of the position of the mask pattern based on the position of the reticle alignment mark is established for the following reason. First, a reticle alignment mark and a mask pattern are simultaneously drawn on a glass substrate by an electron beam exposure apparatus. For this reason, the positional relationship between the reticle alignment mark and the mask pattern is guaranteed within the range of the drawing error of the electron beam exposure apparatus. Therefore, the exposure apparatus can estimate the position of the mask pattern in a predetermined positional relationship with the reticle alignment mark by detecting the position of the reticle alignment mark.

  However, the estimation of the position of the mask pattern based on the position of the reticle alignment mark is established on the assumption that the positional relationship between the reticle alignment mark and the mask pattern is unchanged. In other words, the estimation of the position of the mask pattern based on the position of the reticle alignment mark may not be established if the positional relationship between the reticle alignment mark and the mask pattern changes.

  For example, the mask pattern may be distorted due to thermal deformation of the mask caused by exposure light exposure. Here, normally, in the mask position control using the reticle alignment mark (so-called reticle alignment), the reticle alignment mark formed on the outer periphery of the mask pattern (for example, any four points around the mask pattern) is used. There are many. In this reticle alignment, in addition to position information within the mask pattern plane (for example, in the XY plane), the amount of linear distortion of the mask pattern (that is, a linear variation amount of a predetermined region on the mask pattern, for example, , Only changes in magnification in the X-axis direction and Y-axis direction, parameters such as orthogonality and rotation amount) are measured. Therefore, according to reticle alignment, although the linear distortion of the mask pattern is compensated, there is a possibility that the nonlinear distortion of the mask pattern is not compensated. Therefore, depending on the state of distortion generated in the mask pattern, it may be difficult to estimate the position of the mask pattern with high accuracy based on the position of the reticle alignment mark.

  On the other hand, it is assumed that by forming a large number of reticle alignment marks around the mask pattern, it is possible to measure the amount of nonlinear distortion of the mask pattern (that is, the amount of nonlinear fluctuation of a predetermined region on the mask pattern). Is done. However, as the number of reticle alignment marks increases, the time required to detect the position of the reticle alignment mark increases, so the throughput of the exposure apparatus may be significantly reduced.

  An object of the present invention is to provide an exposure apparatus, an exposure method, and a device manufacturing method capable of suitably estimating the position of a mask pattern formed on a mask.

  A first exposure apparatus is an exposure apparatus that irradiates a mask with an energy beam and transfers a mask pattern formed on a pattern surface of the mask to an object, with respect to the predetermined surface of the mask. A light irradiating unit configured to irradiate a plurality of measurement light beams having different incident angles; and a sensor unit configured to detect at least a part of the plurality of measurement light beams reflected or scattered by the predetermined surface.

  The second exposure apparatus is an exposure apparatus that irradiates an energy beam onto a mask and transfers a mask pattern formed on the pattern surface of the mask onto an object, and irradiates a predetermined surface of the mask with measurement light. A light irradiation unit; a sensor unit that detects at least a part of the measurement light reflected or scattered by the predetermined surface; and a moving unit that moves at least one of the light irradiation unit and the sensor unit.

  The third exposure apparatus is an exposure apparatus that irradiates the mask with an energy beam and transfers the mask pattern formed on the pattern surface of the mask to the object, wherein the mask pattern is transferred to the object. A light irradiating unit that irradiates the predetermined surface of the mask with the measurement light at a second timing different from the timing of the above, and reflection or scattering on the predetermined surface at a third timing different from the first timing. And a sensor unit for detecting at least a part of the measured light.

  A first exposure method is an exposure method in which a mask pattern formed on a pattern surface of a mask is transferred to an object by irradiating the mask with an energy beam, and the mask is formed with respect to the predetermined surface of the mask. A plurality of measurement lights having different incident angles are irradiated, and at least a part of the plurality of measurement lights reflected or scattered by the predetermined surface is detected.

  A second exposure method is an exposure method in which an energy beam is irradiated onto a mask to transfer a mask pattern formed on the pattern surface of the mask onto an object, and a predetermined surface of the mask is applied using a light irradiation unit. On the other hand, measurement light is irradiated, and at least a part of the measurement light reflected or scattered by the predetermined surface is detected using a sensor unit, and at least one of the light irradiation unit and the sensor unit is moved.

  A third exposure method is an exposure method in which an energy beam is irradiated onto a mask to transfer a mask pattern formed on the pattern surface of the mask onto an object, and the mask pattern is transferred onto the object. The measurement light is irradiated to the predetermined surface of the mask at a second timing different from the timing of the measurement, and reflected or scattered by the predetermined surface at a third timing different from the first timing. Detect at least part of the light.

  In the device manufacturing method, the mask pattern is transferred to a sensitive substrate by the first exposure method, the second exposure method, or the third exposure method described above, and the sensitive substrate to which the mask pattern is transferred is developed.

  The effect | action and other gain of this invention are clarified from the form for implementing demonstrated below.

It is a side view which shows an example of a structure of the exposure apparatus of 1st Embodiment. 3A is a top view showing a configuration around a reticle stage included in the exposure apparatus of the first embodiment, and FIG. 2A shows a II-II ′ cross section of the configuration around the reticle stage shown in FIG. It is a block diagram showing an example of composition of a speckle measuring device, a sectional view showing an optical member with which a speckle measuring device is provided, and a top view showing an optical member with which a speckle measuring device is provided. The top view which shows the measurement object area | region of a speckle measuring device corresponding with the reticle 111, the top view which shows the light-receiving surface of the light receiving element with which a speckle measuring device is provided, and the speckle acquired from the measurement result of a speckle measuring device It is a graph which shows information. It is a side view which shows an example of the state of the exposure apparatus when 2nd speckle acquisition operation is performed. It is a graph which shows the speckle information acquired from the measurement result of a speckle measurement apparatus, and each variation amount of the X-axis direction of a measurement object area | region measured from the said speckle information, and a Y-axis direction. The amount of variation in the measurement target area from which the measurement error due to the output drift of the speckle measurement device has been removed, together with the amount of change in the measurement target region from which the measurement error due to the output drift of the speckle measurement device has not been removed It is a graph to show. It is a graph which shows each variation | change_quantity of the X-axis direction of a measurement object area | region measured from speckle information, and a Y-axis direction. It is a block diagram which shows an example of a structure of each speckle measuring device with which the exposure apparatus of a 1st modification is provided. It is a block diagram which shows an example of a structure of each speckle measuring device with which the exposure apparatus of a 2nd modification is provided. It is a block diagram which shows an example of a structure of each speckle measuring device with which the exposure apparatus of a 3rd modification is provided. It is a block diagram which shows an example of a structure of each speckle measuring device with which the exposure apparatus of a 4th modification is provided. It is a top view which shows the structure of the periphery of the reticle stage with which the exposure apparatus of 2nd Embodiment is provided. It is a top view which shows an example of the movement aspect of a speckle measuring device. It is a flowchart which shows the manufacturing method of microdevices, such as a semiconductor device.

  Hereinafter, embodiments of an exposure apparatus, an exposure method, and a device manufacturing method of the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiments described below.

  In the following description, the positional relationship between various components constituting the exposure apparatus will be described using an XYZ orthogonal coordinate system defined by mutually orthogonal X, Y, and Z axes. In the following description, for convenience of explanation, each of the X-axis direction and the Y-axis direction is a horizontal direction (that is, a predetermined direction in the horizontal plane), and the Z-axis direction is a vertical direction (that is, a direction orthogonal to the horizontal plane). Yes, in the vertical direction). Further, the rotation directions around the X axis, the Y axis, and the Z axis (in other words, the tilt direction) are referred to as a θX direction, a θY direction, and a θZ direction, respectively.

(1) Exposure apparatus 1 of the first embodiment
The exposure apparatus 1 of the first embodiment will be described with reference to FIGS.

(1-1) Configuration of Exposure Apparatus 100 First, the configuration of the exposure apparatus 1 according to the first embodiment will be described with reference to FIG. 1, FIG. 2 (a), and FIG. 2 (b). FIG. 1 is a side view showing an example of the configuration of the exposure apparatus 1 of the first embodiment. FIG. 2A is a top view showing a configuration around the reticle stage 11 provided in the exposure apparatus 1 of the first embodiment. FIG. 2B shows a II-II ′ cross section of the configuration around the reticle stage 11 shown in FIG.

  As shown in FIG. 1, the exposure apparatus 1 includes a reticle stage 11, an illumination system 12, a projection optical system 13, a wafer stage 14, a speckle measurement device 15, a main control device 16, and a memory 17. I have.

  The reticle stage 11 can hold a reticle 111. The reticle stage 11 can release the held reticle 111.

  Reticle stage 11 moves along a plane (for example, an XY plane) including an area irradiated with exposure light EL emitted from illumination system 12 (that is, an illumination area IR described later) while holding reticle 111. Is possible. The reticle stage 11 is movable along the Y-axis direction. For example, the reticle stage 11 may move along the Y-axis direction by the operation of the reticle stage drive system 112 including a planar motor. In addition to or instead of being movable along the Y-axis direction, reticle stage 11 is movable along at least one of the X-axis direction, Z-axis direction, θX direction, θY direction, and θZ direction. It may be. An example of reticle stage drive system 112 including a planar motor is disclosed in, for example, US Pat. No. 6,452,292. However, reticle stage drive system 112 may include another motor (for example, a linear motor) in addition to or instead of the planar motor.

  The reticle stage 11 is movable on the reticle stage surface plate 113. The reticle stage surface 113 is formed with an opening 113a having a predetermined shape that penetrates the reticle stage surface 113 along the Z-axis direction. The opening 113a serves as a passage for the exposure light EL.

  As shown in FIG. 2A, the reticle 111 is composed of a rectangular (square in the example shown in FIG. 2A) glass plate. A rectangular pattern region 111PA whose longitudinal direction coincides with the Y-axis direction is formed at the center of the surface on the −Z side of the reticle 111. In the pattern area 111PA, an exposure pattern to be projected (in other words, transferred) onto the wafer 141 held by the wafer stage 14 is formed. Hereinafter, the −Z side surface of the reticle 111 on which the pattern region 111PA is formed is referred to as a “pattern surface”.

  A pair of reticle alignment marks 111RA sandwiching the pattern area 111PA along the Y-axis direction is formed on the pattern surface so as to be adjacent to the + X side end and the −X side end of the pattern area 111PA. Yes. That is, four reticle marks are formed on the pattern surface. The four reticle alignment marks 111RA are formed simultaneously with the exposure pattern formed in the pattern region 111PA by the electron beam exposure apparatus. For simplification of explanation, it is assumed that the formation error of the exposure pattern formed in the pattern region 111PA and the electron beam exposure apparatus for forming the reticle alignment mark 111RA is zero (or small enough to be regarded as zero).

  The reticle stage 11 is composed of a rectangular plate member whose longitudinal direction coincides with the Y-axis direction. On the upper surface of the plate member constituting the reticle stage 11, a rectangular shape in which the size in the Y-axis direction is larger than the size in the Y-axis direction of the reticle 111 and the size in the X-axis direction is larger than the size in the X-axis direction of the reticle 111. A recess 114 is formed. An opening 114 a that penetrates the reticle stage 11 along the Z-axis direction is formed in the center of the recess 114 in the X-axis direction over the entire Y-axis direction of the recess 114.

  The reticle 111 is arranged in the vicinity of the end portion on the −Y side in the recess 114 so that the pattern region 111PA is positioned in the opening 114a. The reticle 111 is vacuum-adsorbed to the reticle stage 11 via a suction portion formed on the upper surface of a step portion at both ends of the concave portion 114 along the X-axis direction (hereinafter, the step portion is referred to as “slider 114SL”). Has been.

  A reticle fiducial plate 115 extending along the X-axis direction is disposed in the vicinity of the + Y side end in the recess 114. The reticle fiducial plate 115 is disposed at a predetermined interval from the reticle 111 along the Y-axis direction. The reticle fiducial plate 115 is vacuum-sucked to the reticle stage 11 via suction portions formed on the upper surface of the slider 114SL at both ends of the recess 114 along the X-axis direction. The reticle fiducial plate 115 is made of a glass having a low coefficient of thermal expansion (for example, Zero Dua of Schott). A pair of fiducial marks 115FA arranged along the X-axis direction are formed on the lower surface (that is, the surface on the −Z side) of the reticle fiducial plate 115. The distance between the pair of fiducial marks 115FA in the X-axis direction is the same as the distance between reticle alignment marks 111RA in the X-axis direction. Fiducial mark 115FA is the same mark as reticle alignment mark 111RA. In a state where reticle 111 is held on reticle stage 11, the position of fiducial mark 115FA in the X-axis direction is the same as the position of reticle alignment mark 111RA in the X-axis direction. A mark region 115MA sandwiched between a pair of fiducial marks 115FA is further formed on the lower surface of the reticle fiducial plate 115 along the X-axis direction. Various marks (for example, a plurality of AIS (Aerial Imaging Sensor) marks each including various measurement marks used for aerial image measurement) are formed in the mark area 115MA.

  In FIG. 1 again, the position of the reticle stage 11 in the XY plane (however, the rotation angle along the θZ direction may be included) is transferred via the movable mirror 116 a disposed on the reticle stage 11. For example, the laser interferometer 116 constantly measures with a resolution of about 0.25 nm. The measurement result of reticle laser interferometer 116 is output to main controller 16. Main controller 16 may control the movement mode of reticle stage 11 based on the measurement result of reticle laser interferometer 116.

  Further, the amount of change over time of the pattern area 111PA formed on the reticle 111 is measured by a plurality of speckle measuring devices 15 arranged in the reticle stage surface plate 113. In the example shown in FIG. 2A, five speckle measuring devices 15 are arranged so as to be aligned along the X-axis direction. In the following, in order to distinguish the five speckle measuring devices 15 from each other, the five speckle measuring devices 15 are arranged in order from the −X side, a speckle measuring device 15L2, a speckle measuring device 15L1, a speckle measuring device 15C, They are referred to as speckle measuring device 15R1 and speckle measuring device 15R2. However, the five speckle measuring devices 15 have the same configuration except that their arrangement positions are different from each other. The characteristics of the speckle measuring device 15 will be described later in detail (see FIG. 3).

  The illumination system 12 emits exposure light EL. The exposure light EL emitted from the illumination system 12 is applied to a slit-shaped illumination region IR extending elongated along the X-axis direction. The exposure light EL from the illumination system 11 is irradiated to a part of the reticle 111 arranged in the illumination area IR. The exposure light EL is ArF excimer laser light (wavelength 193 nm).

  The projection optical system 13 projects the exposure light EL from the reticle 111 (that is, the image of the exposure pattern formed on the pattern area 111PA of the reticle 111) onto the wafer 141. Specifically, the projection optical system 13 projects the exposure light EL onto the slit-shaped projection region PR. The projection optical system 13 projects an image of the exposure pattern onto a part of the wafer 141 (for example, at least a part of the shot area) arranged in the projection area PR.

  The projection optical system 13 is a reduction system. For example, the projection magnification of the projection optical system may be 1/4, 1/5, 1/8, or any other value. .

  The projection optical system 13 includes a plurality of refractive optical elements (in other words, lens elements) arranged along an optical axis AX parallel to the Z-axis direction, but does not include a reflective optical element (for example, a mirror). It is. A part of the refractive optical elements located on the object plane side (that is, the reticle 111 side) among the plurality of refractive optical elements constituting the projection optical element 13 can be driven by a driving element (not shown) (for example, a piezoelectric element). There may be. In this case, some refractive optical elements may be driven so as to move along the Z-axis direction, or may be driven so as to move along the θX direction and the θY direction. A drive element (not shown) operates under the control of the imaging characteristic correction controller 131 that operates according to an instruction from the main controller 16. The imaging characteristic correction controller 131 individually controls the driving mode of some of the refractive optical elements, so that the imaging characteristics of the projection optical system 13 (for example, magnification, distortion, astigmatism, coma aberration, etc.) And curvature of field etc. can be adjusted. However, the imaging characteristic correction controller 131 may adjust the imaging characteristic of the projection optical system 13 by other methods in addition to or instead of driving some refractive optical elements.

  The wafer stage 14 can hold the wafer 141. The wafer stage 14 can release the held wafer 141.

  The wafer stage 14 is movable along a plane (for example, an XY plane) including the projection region PR while holding the wafer 141. The wafer stage 14 is movable on the wafer stage surface plate 143. The wafer stage 14 is movable along at least one of the X-axis direction, the Y-axis direction, the Z-axis direction, the θX direction, the θY direction, and the θZ direction. For example, the wafer stage 14 may be moved by the operation of the wafer stage drive system 142 including a planar motor. An example of the wafer stage drive system 142 including a planar motor is disclosed in, for example, US Pat. No. 6,452,292. However, the wafer stage drive system 142 may include another motor (for example, a linear motor) in addition to or instead of the planar motor.

  The position of the wafer stage 14 in the XY plane (however, it may include a rotation angle along at least one of the θX direction, the θY direction, and the θZ direction) is a movable mirror disposed on the wafer stage 14. Measurement is always performed by the wafer laser interferometer 146 through the 146a with a resolution of, for example, about 0.25 nm. The measurement result of wafer laser interferometer 146 is output to main controller 16. Main controller 16 may control the movement mode of wafer stage 14 based on the measurement result of wafer laser interferometer 146. However, the position of the wafer stage 14 in the XY plane may be measured by an encoder in addition to or instead of the wafer laser interferometer 146.

  The position of the wafer cottage 14 in the Z-axis direction is measured by a focus sensor (not shown) constituted by an oblique incidence type multipoint focal position detection system disclosed in, for example, US Pat. No. 5,448,332. The measurement result of the focus sensor is also output to the main controller 16.

  On the wafer stage 14, a reference plate 144 whose surface is the same height as the surface of the wafer 141 is fixed. On the surface of the reference plate 144, a first reference mark used for baseline measurement of a wafer alignment detection system 149 described later, a pair of second reference marks detected by a reticle alignment detection system 119 described later, and the like are formed. Yes.

  A wafer alignment detection system 149 that detects a first reference mark (or a wafer alignment mark formed on the wafer 141) formed on the reference plate 144 on the wafer stage 14 is disposed on the side surface of the projection optical system 13. Has been. As the wafer alignment detection system 149, an FIA (Field Image) that measures the position of the first reference mark by image processing the image of the first reference mark obtained by irradiating the first reference mark with broadband light such as a halogen lamp. Alignment) system is exemplified.

  A pair of reticle alignment detection systems 119 that can simultaneously detect a pair of reticle alignment marks 111RA arranged along the X-axis direction (in other words, the positions in the Y-axis direction are the same) are arranged above the reticle stage 11. ing. Each reticle alignment detection system 119 is a VRA (Visual Reticle Alignment) system that measures the position of the reticle alignment mark 111RA by performing image processing on an image of the reticle alignment mark 111RA captured by an image sensor such as a CCD. Each reticle alignment detection system 119 includes an epi-illumination system that irradiates the reticle alignment mark 111RA with illumination light having the same wavelength as the exposure light EL, and a detection system that images the reticle alignment mark 111RA. The imaging result by the detection system is output to the main controller 16.

  Each reticle alignment detection system 119 includes a mirror that can be inserted and removed on the optical path of the exposure light EL. When the mirror is inserted in the optical path of the exposure light EL, the illumination light emitted from the epi-illumination system is guided to the reticle 111, and from the reticle 111 to the projection optical system 13 and the wafer stage 14 (for example, the reference plate 144). Then, the detection light passing through the path of the projection optical system 13 and the reticle 111 is guided to the detection system. This mirror is retracted out of the optical path of the exposure light EL before the exposure light EL irradiation is started to transfer the exposure pattern image onto the wafer 141.

(1-2) Configuration of Speckle Measuring Device 15 Subsequently, the speckle measuring device 15 will be described with reference to FIGS. 3 (a) to 3 (c) together with FIGS. 2 (a) and 2 (b). An example of the configuration will be described. FIG. 3A is a block diagram illustrating an example of the configuration of the speckle measurement device 15. FIG. 3B is a cross-sectional view showing the optical member 152 provided in the speckle measuring device 15. FIG. 3C is a top view showing the optical member 152 provided in the speckle measuring device 15.

  As shown in FIG. 2A, the five speckle measuring devices 15 are arranged so as to be separated from each other along the X-axis direction. The speckle measuring devices 15L2 and 15R2 located at both ends along the X-axis direction are arranged at positions where they can overlap with the pair of reticle alignment marks 111RA arranged along the Y-axis direction along the Z-axis direction. Has been. As shown in FIG. 2B, the five speckle measuring devices 15 are arranged at positions shifted from the optical axis AX by a predetermined amount along the Y-axis direction. The five speckle measuring devices 15 are not arranged in the opening 113 a of the reticle stage surface plate 113. The five speckle measuring devices 15 are arranged outside the optical path of the exposure light EL.

  The speckle measurement device 15 irradiates the measurement target with the measurement light LB2, and acquires speckles generated by the irradiation of the measurement light LB2. The measurement target may include at least a part of the reticle 111. The measurement target may include at least a part of the pattern surface of the reticle 111. The measurement target may include at least a part of an arbitrary surface other than the pattern surface of the reticle 111 (for example, a surface or side surface opposite to the pattern surface). The measurement target may include at least a part of the pattern region 111PA. The measurement target may include at least a part of the reticle fiducial plate 115.

  The speckle is a light / dark pattern generated by the measurement light LB2 scattered or reflected by the measurement target interfering with each other. Note that the light / dark pattern may change depending on the irradiation position of the measurement light LB2. For example, the light / dark pattern may be a spot-like light / dark pattern, or may be a grid-like or linear light / dark pattern. In any case, as long as the measurement light LB2 scattered or reflected by the measurement target is a light / dark pattern generated by interference with each other, the light / dark pattern can be said to be speckle.

  The speckle measurement device 15 irradiates the measurement light LB2 toward a region shifted in the Y-axis direction with respect to the optical axis AX of the projection optical system 13. The speckle measurement device 15 irradiates the measurement light LB2 toward the outside of the optical path of the exposure light EL among the measurement targets. Hereinafter, a region irradiated with the measurement light LB2 is referred to as a “measurement target region”.

  As shown in FIG. 3A, the speckle measuring device 15 includes a light source 151, an optical member 152, a condenser lens 153, a projection lens 154, a pinhole plate 155, and a light receiving element 156. Yes. The light source 151, the optical member 152, the condensing lens 153, the condensing lens 154, the pinhole plate 155, and the light receiving element 156 are accommodated in a housing 158.

  The light source 151 emits the reference light LB1 toward the optical member 152. The light source 151 emits the reference light LB1 toward the optical rough surface 152a of the optical member 152. The reference light LB1 is coherent light. An example of the reference light LB1 is a laser beam.

  The optical member 152 is a disk-like member in plan view (see FIG. 3C). The optical member 152 is a member that generates a plurality of measurement lights LB2 from the reference light LB1 emitted from the light source 151. The plurality of measurement lights LB2 are irradiated to the measurement target through openings (not shown) formed in the condenser lens 153 and the housing 158.

  The optical member 152 is a member that generates a plurality of measurement lights LB2 having different incident angles with respect to the measurement target (or including at least a part of the measurement target). The optical member 152 is a member that generates a plurality of measurement lights LB2 having different emission angles from the optical member 152. The optical member 152 is a member that speckles the reference light LB1. The optical member 152 is a member that generates a plurality of speckled measurement lights LB2. For example, in the example illustrated in FIG. 3A, the optical member 152 includes the measurement light LB2 (1) whose incident angle with respect to the measurement target is the first angle, and the measurement light LB2 whose incident angle with respect to the measurement target is the second angle. (2) and measurement light LB2 (3) whose incident angle with respect to the measurement target is the third angle and measurement light LB2 (4) whose incident angle with respect to the measurement target is the fourth angle are generated. However, the optical member 152 may generate an arbitrary number of measurement lights LB2 having different incident angles with respect to the measurement target.

  In order to generate such a plurality of measurement lights LB2, the optical member 152 includes an optical rough surface 152a that reflects the reference light LB1. The optical rough surface 152a is a surface that generates a plurality of measurement lights LB2 by reflecting (for example, diffuse reflection or irregular reflection) the reference light LB1. The optical rough surface 152a is a surface that reflects the reference light LB1 as a plurality of measurement lights LB2.

  As shown in FIG. 3B, the optical rough surface 152a is formed with a convex pattern 152b and a concave pattern 152c having different heights or steps. The convex pattern 152b is a pattern protruding toward the outside of the optical member 152 (upper side in FIG. 3B) as compared with the periphery of the convex pattern 152b. The recess pattern 152c is a pattern that is recessed toward the inside of the optical member 152 (lower side in FIG. 3B) as compared with the periphery of the recess pattern 152c. In addition, since the periphery of the convex part pattern 152b is depressed compared with the convex part pattern 152b, it can be said that it is the concave part pattern 152c. Similarly, since the periphery of the concave pattern 152c protrudes compared to the concave pattern 152c, it can be said that it is the convex pattern 152b. That is, it can be said that the distinction between the convex pattern 152b and the concave pattern 152c is a relative distinction.

  The size (substantially height in the example shown in FIG. 3B) h1 of the convex pattern 152b relative to the periphery of the convex pattern 152b is the optical roughness on which the convex pattern 152b is formed. The reference light LB1 irradiated on the surface 152a has a size that can be speckled. The size h1 of the convex pattern 152b based on the periphery of the convex pattern 152b is larger than the wavelength of the reference light LB1.

  The size of the concave pattern 152c with respect to the periphery of the concave pattern 152c (in the example shown in FIG. 3B, the size in the Z-axis direction, substantially the height) h2 The reference light LB1 irradiated to the formed optical rough surface 152a is of a size that can be speckled. The size h2 of the concave pattern 152c with respect to the periphery of the concave pattern 152c is larger than the wavelength of the reference light LB1.

  The reflectance of the optical rough surface 152a with respect to the reference light LB1 is larger than a predetermined amount (for example, 50%, 60%, 70%, 80%, 90%, 100%). The reflectance of the optical rough surface 152a is a reflectance that can reflect the reference light LB1 more than a desired amount. In order to make the reflectance larger than a predetermined amount, the optical rough surface 152a may be a surface made of a predetermined metal or alloy (for example, aluminum). The optical rough surface 152a may be a surface covered with a predetermined metal or alloy.

  As shown in FIG. 3C, the pattern shape in plan view of the convex pattern 152b (in the example shown in FIG. 3C, the pattern shape observed from the direction facing the optical rough surface 152a) is The shape is such that the reference light LB1 irradiated on the optical rough surface 152a on which the part pattern 152b is formed can be speckled. The pattern shape in plan view of the convex pattern 152b is not periodic or regular. The pattern shape in plan view of the convex pattern 152b is aperiodic, irregular or random. The pattern shape in plan view of the convex pattern 152b is different from the exposure pattern formed in the pattern area 111PA of the reticle 111. However, when the exposure pattern formed in the pattern area 111PA of the reticle 111 is aperiodic, irregular or random, at least a part of the pattern shape in plan view of the convex pattern 152b is an exposure pattern. May be the same.

  The pattern shape of the concave pattern 152c in plan view is a shape that can speckle the reference light LB1 irradiated to the optical rough surface 152a on which the concave pattern 152c is formed. The pattern shape in plan view of the concave pattern 152c is not periodic or regular. The pattern shape of the concave pattern 152c in plan view is aperiodic, irregular or random. The pattern shape of the concave pattern 152c in plan view is different from the exposure pattern formed in the pattern area 111PA of the reticle 111. However, when the exposure pattern formed in the pattern region 111PA of the reticle 111 is aperiodic, irregular, or random, at least a part of the pattern shape in plan view of the concave pattern 152c is an exposure pattern. It may be the same.

  The condenser lens 153 is a lens that guides the plurality of measurement lights LB2 generated by the optical member 152 to the measurement target. The condenser lens 153 is a lens that guides the plurality of measurement lights LB2 generated by the optical member 152 to the measurement target region. As a result, the plurality of measurement lights LB2 are irradiated onto the measurement target (or the measurement target region including at least a part of the measurement target) with different incident angles.

  The projection lens 154 includes a pinhole 155a of the pinhole plate 155 for the interference light LB3 generated by the measurement light LB2 reflected or scattered by the measurement target interfering with each other (that is, the interference light exhibiting the above-described light-dark pattern). A lens that projects onto an area.

  The pinhole plate 155 is a plate-like member provided with a pinhole 155a. The center of the pinhole 155a coincides with the optical axis of the condenser lens 154 (in other words, the optical axis of the speckle light receiving optical system including the condenser lens 154, the pinhole plate 155, and the light receiving element 156) AX2. The interference light LB3 that has passed through the pinhole 155a reaches the light receiving element 156.

  The light receiving element 156 detects the interference light LB3 that has passed through the pinhole 155a. As a result, the light receiving element 156 detects a light / dark pattern (that is, speckle) exhibited by the interference light LB3. The light receiving element 156 may include a CCD (Charge Coupled Device), or a CMOS (Complementary Metal Oxide Semiconductor) sensor.

  The detection result of the light receiving element 156 is output to the main controller 16. As a result, the main controller 16 acquires speckle information indicating the characteristics of the light / dark pattern (that is, speckle) generated by the measurement light LB2 scattered or reflected by the measurement target interfering with each other. The main controller 16 analyzes the speckle information to measure the amount of variation over time of the measurement target. For example, when the measurement target includes at least a part of the pattern area 111PA formed on the reticle 111, the main controller 16 can measure the amount of variation over time of the pattern area 111PA. The speckle information acquisition method based on the detection result of the light receiving element 156 is disclosed in, for example, US Patent Application Publication No. 2004/0218181.

  The optical axis AX2 of the speckle light receiving optical system including the condensing lens 154, the pinhole plate 155, and the light receiving element 156 coincides with the optical axis AX1 of the speckle irradiation optical system including the light source 151, the optical element 152, and the condensing lens 153. do not do. The optical axis AX2 of the speckle light receiving optical system is different from the optical axis AX1 of the speckle irradiation optical system. The optical axis AX2 of the speckle light receiving optical system intersects with the optical axis AX1 of the speckle irradiation optical system.

  Both the speckle light receiving optical system and the speckle irradiation optical system are located below the reticle 111 (or below the pattern surface of the reticle 111). That is, both the speckle light receiving optical system and the speckle irradiation optical system are located on the −Z side with respect to the reticle 111.

  The speckle light receiving optical system including the condenser lens 154, the pinhole plate 155, and the light receiving element 156 can be said to be a telecentric optical system. For this reason, the speckle measurement device 15 is sensitive to changes in the gap between the measurement target and the speckle measurement device 15 (for example, the gap between the upper surface of the stage surface plate 113 and the pattern surface of the reticle 111). is not. In other words, noise caused by a change in the gap between the measurement target and the speckle measurement device 15 is not easily superimposed on the detection result of the speckle measurement device 15. In addition, since the speckle light receiving optical system includes the pinhole plate 155, the speckle detection size depends on the size of the pinhole 155a, but hardly depends on the parameters of the condenser lens 154. .

  The five speckle measurement devices 15 are arranged so as to be separated from each other along the X-axis direction so as to irradiate the measurement light LB2 to different measurement target regions. Accordingly, five measurement target regions to which the five speckle measurement devices 15 irradiate the measurement light LB2 are located on the measurement target. The five measurement target regions are also separated from each other along the X-axis direction.

  In FIG. 3, for convenience of explanation, the configuration of the speckle measuring device 15 is described using an XYZ orthogonal coordinate system. However, in FIG. 3, the arrangement of the light source 151, the optical member 152, the condenser lens 153, the projection lens 154, the pinhole plate 155, and the light receiving element 156 constituting the speckle measurement device 15 is limited to the arrangement shown in FIG. 3. There is no intention to do. Therefore, at least one of the light source 151, the optical member 152, the condensing lens 153, the projection lens 154, the pinhole plate 155, and the light receiving element 156 may be arranged in an arrangement manner different from the arrangement manner shown in FIG. .

(1-3) Measurement Operation Using Speckle Measurement Device 15 Subsequently, with reference to FIGS. 4 to 8, the measurement operation of the variation amount with time of the pattern region 111PA using the speckle measurement device 15 will be described. To do.

  First, at the timing when a certain reticle 111 is used for the first time, main controller 16 performs a first speckle acquisition operation (initial speckle acquisition operation). The timing at which the reticle 111 is used for the first time includes, for example, the timing at which the reticle 111 is held on the reticle stage 11 for the first time.

  Main controller 16 performs the first speckle acquisition operation during at least a part of the period in which exposure light EL is not applied to reticle 111. Main controller 16 performs the first speckle acquisition operation during at least part of the period after reticle 111 is held on reticle stage 11 and before exposure light EL is irradiated for the first time. Main controller 16 performs the first speckle acquisition operation during at least a part of the period when reticle 111 is not heated by exposure light EL. Main controller 16 does not thermally deform reticle 111 due to irradiation of exposure light EL (or only a minute amount that can be regarded as substantially not thermally deformed). The first speckle acquisition operation is performed for at least a part of the period.

  In the first speckle acquisition operation, each speckle measurement device 15 irradiates the measurement light LB2 to the measurement target region under the control of the main control device 16. When the temporal variation of the pattern area 111PA is measured, at least a part of the pattern area 111PA and at least a part of the exposure pattern are formed in the measurement target area as the reticle stage 11 moves. The region can include at least one of the regions. As a result of the irradiation of the measurement light LB2, each speckle measurement device 15 detects the interference light LB3 generated by the measurement light LB2 scattered or reflected in the measurement target region interfering with each other. As a result, main controller 16 can acquire speckle information of the measurement target region. This speckle information is stored in the memory 17 as speckle information in the first state (initial state).

  For example, as shown in FIG. 4A, it is assumed that the first speckle acquisition operation is performed while the reticle stage 11 moves along the Y-axis direction (scanning direction or scanning direction). In this case, the measurement target area SAR2 of the speckle measurement device 15R2 moves in the predetermined area AR2 including at least a part of each of the pattern area 111PA and the reticle fiducial plate 115 as the reticle stage 11 moves. Accordingly, the speckle measurement device 15R2 acquires the interference light LB3 from a part of the predetermined area AR2 that coincides with the measurement target area SAR2 when the light source 151 emits the reference light LB1. The measurement target area SAR1 of the speckle measurement device 15R1 moves in a predetermined area AR1 including at least a part of each of the pattern area 111PA and the reticle fiducial plate 115 as the reticle stage 11 moves. Accordingly, the speckle measurement device 15R1 acquires the interference light LB3 from a part of the predetermined area AR1 that coincides with the measurement target area SAR1 when the light source 151 emits the reference light LB1. The measurement target area SAC of the speckle measurement device 15 </ b> C moves within a predetermined area AC including at least a part of each of the pattern area 111 </ b> PA and the reticle fiducial plate 115 as the reticle stage 11 moves. Therefore, the speckle measurement device 15C acquires the interference light LB3 from a part of the predetermined area AC that coincides with the measurement target area SAC when the light source 151 emits the reference light LB1. The measurement target area SAL1 of the speckle measurement device 15L1 moves in a predetermined area AL1 including at least a part of the pattern area 111PA and the reticle fiducial plate 115 as the reticle stage 11 moves. Therefore, the speckle measurement device 15L1 acquires the interference light LB3 from a part of the predetermined area AL1 that coincides with the measurement target area SAL1 when the light source 151 emits the reference light LB1. The measurement target area SAL2 of the speckle measurement device 15L2 moves in the predetermined area AL2 including at least a part of the pattern area 111PA and the reticle fiducial plate 115 as the reticle stage 11 moves. Accordingly, the speckle measurement device 15L2 acquires the interference light LB3 from a part of the predetermined area AL2 that coincides with the measurement target area SAL2 when the light source 151 emits the reference light LB1. As can be seen from FIG. 4A, the measurement target area SAR2, the measurement target area SAR1, the measurement target area SAC, the measurement target area SAL1, and the measurement target area SAL2 are separated from each other along the X-axis direction.

  As a result, the main control device 16 acquires speckle information of the five measurement target areas. The speckle information is information associated with the Y coordinate (in other words, the position in the Y-axis direction) of the reticle stage 111 as shown in FIG. 4C, for example. In FIG. 4C, speckle information is shown as a scalar quantity for convenience of explanation, but the speckle information is multidimensional information. Since each measurement target area moves within an area including at least a part of each of the pattern area 111PA and the reticle fiducial plate 115, the speckle information is stored in the reticle fiducial as shown in FIG. The speckle information Sf0 of the plate 115 and the speckle information Sp0 of the pattern area 111PA are included.

  Here, as shown in FIG. 4B, the main control device 16 acquires speckle information based on the detection result in the detection region 156b that is at least a part of the light receiving surface 156a of the light receiving element 156. To do. For example, when the field of view of the entire light receiving surface 156a is 200 μm square, the main controller 16 may acquire speckle information based on the detection result in the detection region 156b having a size of 10 μm square. .

  At this time, main controller 16 may adjust at least one of the position and size of detection region 156b according to the acquired speckle information. For example, when the acquired speckle information is speckle information in which it is difficult to measure the amount of variation over time of the pattern area 111PA, the main controller 16 determines the position of the detection area 156b within the light receiving surface 156a. May be changed. For example, main controller 16 moves detection area 156b along light receiving surface 156a when the acquired speckle information is speckle information in which it is difficult to measure the amount of variation over time of pattern area 111PA. (Shift) may be used. For example, when the acquired speckle information is speckle information in which it is difficult to measure the amount of variation over time of the pattern area 111PA, the main controller 16 may change the size of the detection area 156b. Good. For example, when the acquired speckle information is speckle information in which it is difficult to measure the amount of variation over time of the pattern area 111PA, the main controller 16 increases or decreases the size of the detection area 156b. May be. As speckle information for which it is difficult to measure the amount of variation over time of the pattern region 111PA, for example, speckle information exhibiting a periodic or regular pattern (so-called regular diffracted light has a property. Speckle information acquired when the light receiving element 156 receives the relatively strong interference light LB3) is exemplified.

  A plurality of different detection areas 156b may be set on the irradiation surface 156a. A plurality of detection areas 156b at least partially overlapping may be set on the irradiation surface 156a. In this case, main controller 16 may acquire speckle information based on detection results in a plurality of detection areas 156b. However, a single detection region 156b may be set on the irradiation surface 156a.

  Each speckle measurement device 15 performs irradiation of the measurement light LB2 and detection of the interference light LB3 generated by the interference of the measurement light LB2 scattered or reflected in the measurement target region. In this sense, it can be said that at least part of the period in which the measurement light LB2 is irradiated and the period in which the interference light LB3 is detected (that is, the period in which speckle information is acquired) overlap. Strictly speaking, however, each speckle measuring device 15 detects the interference light LB3 from the measurement target region after irradiating the measurement light region LB2 with the measurement light LB2. However, the time from when the measurement light LB2 is irradiated to a certain measurement target area until the interference light LB3 from the measurement target area is detected is extremely short. For this reason, each speckle measuring device 15 detects the interference light LB3 generated by the interference of the measurement light LB2 scattered or reflected in the measurement target region substantially simultaneously with the irradiation of the measurement light LB2. It can also be said. Also in this sense, it can be said that at least part of the period in which the measurement light LB2 is irradiated and the period in which the interference light LB3 is detected (that is, the period in which speckle information is acquired) overlap.

  Main controller 16 acquires speckle information in synchronization with the timing of acquiring the measurement result of position of reticle stage 11 by reticle laser interferometer 116. As a result, the speckle information is stored in the memory 17 in a format associated with the measurement result of the reticle laser interferometer 116. That is, as described above, the speckle information is stored in the memory 17 in a format associated with the Y coordinate of the reticle stage 111 (in other words, the position in the Y axis direction).

  The speckle information acquired by the first speckle acquisition operation is speckle information unique to the exposure pattern formed on the reticle 111. Therefore, it is difficult to measure the temporal variation amount of the pattern area 111PA using only speckle information acquired by the first speckle acquisition operation. The speckle information acquired by the first speckle acquisition operation is speckle information that serves as a reference when measuring the temporal variation of the pattern region 111PA.

  The speckle information of the measurement target area is information unique to the measurement target area. Therefore, when the reticle 111 held by the reticle stage 11 changes, the acquired speckle information also changes. For this reason, the first speckle acquisition operation is performed at least once for each reticle 111. Therefore, each time the reticle stage 11 holds a new reticle 111, a first speckle acquisition operation is performed on the newly held reticle 111.

  Thereafter, immediately before the first wafer 141 of each lot is exposed, the main controller 16 forms a pair of reticle alignment detection systems 119, four reticle alignment marks 111RA, and a reference plate 144 fixed to the wafer stage 14. A reticle alignment operation is performed using the second reference mark.

  Further, in at least a part of the period during which the main control device 16 performs the reticle alignment operation, the main control unit 16 further performs a second speckle acquisition operation that is the same as the first speckle acquisition operation described above to be measured. Get speckle information for a region. That is, main controller 16 performs the second speckle acquisition operation in parallel with the reticle alignment operation. In other words, the main controller 16 performs the reticle alignment operation during at least a part of the period during which the main controller 16 performs the second speckle acquisition operation. That is, main controller 16 performs the reticle alignment operation in parallel with the second speckle acquisition operation. The speckle information acquired as a result is stored in the memory 17 as speckle information in the second state.

  For example, as shown in FIG. 5, in the reticle alignment operation, a pair of reticle alignment detection systems 119, two reticle alignment marks 111RA arranged along the X-axis direction, and a second reference mark are arranged along the optical axis AX. Done in Even in this case, as shown in FIG. 5, each speckle measuring device 15 is in an area including at least a part of each of the pattern area 111PA and the reticle fiducial plate 115 as the reticle stage 11 moves. It is possible to irradiate the measurement light LB2 to the measurement target region that moves through the area. Therefore, main controller 16 can acquire speckle information of the measurement target region at the same time as performing the reticle alignment operation.

  The main control device 16 controls the light source 151 so that the reference light LB1 is emitted at the same timing as the reference light LB1 is emitted in the first speckle acquisition operation. The main control device 16 controls each speckle measurement device 15 so as to acquire the speckle information at the same timing as the timing at which the speckle information is acquired by the first speckle acquisition operation. The main controller 16 irradiates the same region of the measurement target with the reference light LB1 and acquires speckle information from the same region in both the first speckle acquisition operation and the second speckle acquisition operation. Each speckle measuring device 15 is controlled.

  Thereafter, main controller 16 compares the speckle information in the second state acquired in the second speckle acquisition operation with the speckle information in the first state acquired in advance in the first speckle acquisition operation. . Based on the comparison result between the speckle information in the first state and the speckle information in the second state, main controller 16 determines pattern area 111PA (hereinafter, “ The variation amount of the pattern area PA with reference to the initial pattern area 111PA ″ is measured.

  As an example, the description proceeds using speckle information acquired by the main control device 16 based on a detection result of a speckle measurement device 15. FIG. 6A shows speckle information in the first state acquired by the first speckle acquisition operation. FIG. 6B shows speckle information in the second state acquired by the second speckle acquisition operation. Based on the difference between the speckle information in the first state and the speckle information in the second state, main controller 16 determines the X-axis direction and the Y-axis direction of the measurement target region based on the measurement target region in the initial state. Is measured (in other words, calculated). For example, FIG. 6C shows the amount of variation ΔX in the X-axis direction of the measurement target region with the measurement target region in the initial state as a reference (that is, zero) in association with the Y coordinate of the measurement target region. . FIG. 6D shows the amount of variation ΔY in the Y-axis direction of the measurement target region with the measurement target region in the initial state as a reference (that is, zero) in association with the Y coordinate of the measurement target region.

  The main control device 16 can measure the fluctuation amounts ΔX and ΔY of the five measurement target regions based on the detection results of the five speckle measurement devices 15. As a result, the main controller 16 can recognize how the pattern area 111PA varies based on the variation amounts ΔX and ΔY of the five measurement target areas. The main controller 16 can measure the two-dimensional distortion of the pattern area 111PA based on the fluctuation amounts ΔX and ΔY of the five measurement target areas.

  On the other hand, the attachment position or attachment state of each speckle measurement device 15 may vary with long-time use. When the mounting position or mounting state of each speckle measuring device 15 varies, the output of each speckle measuring device 15 drifts. Such a drift may cause measurement errors of the above-described fluctuation amounts ΔX and ΔY. Therefore, main controller 16 uses the speckle information of reticle fiducial plate 115 in order to remove measurement errors of fluctuation amounts ΔX and ΔY caused by the drift of the output of each speckle measuring device 15. Specifically, because reticle exposure plate 115 is not irradiated with exposure light EL, unlike reticle 111, even if a long time has passed since exposure of the exposure pattern was started, There is no deformation. Therefore, the speckle information in the second state of the reticle fiducial plate 115 should be the same as the speckle information in the first state of the reticle fiducial plate 115. For this reason, the fluctuation amounts ΔX and ΔY (see FIGS. 6C and 6D) of each region portion of the reticle fiducial plate 115 are fluctuation amounts due to the drift of the output of each speckle measurement device 15. It is guessed. For this reason, the main control device 16 subtracts the variation amounts ΔX and ΔY of the respective region portions of the reticle fiducial plate 115 from the variation amounts ΔX and ΔY of the respective region portions of the pattern region 111PA. The measurement errors of the fluctuation amounts ΔX and ΔY caused by the 15 output drifts can be removed.

  For example, when the fluctuation amount ΔY as shown by the dotted line in FIG. 7 is measured, the fluctuation amount ΔY of the reticle fiducial plate 115 shown by the dotted line on the left side in FIG. 7 is shifted along the Y-axis direction by the variation amount ΔY of the pattern region 111PA indicated by the dotted line on the right side of FIG. As a result, the fluctuation amount ΔY of the pattern region 111PA from which the measurement error due to the drift of the output of each speckle measuring device 15 is shown, which is indicated by a solid line on the right side in FIG. 7, is acquired. The same applies to the fluctuation amount ΔX.

  The main controller 16 determines each of the fluctuation amounts ΔX and ΔY (see FIGS. 8A and 8B) of the five measurement target regions measured based on the detection results of the five speckle measurement devices 15. A measurement error caused by the drift of the output of the speckle measuring device 15 is removed. After that, the main control measure 16 determines the pattern based on the fluctuation amounts ΔX and ΔY from which the measurement error due to the drift is removed, and the position of each region portion of the pattern region 111PA with reference to the four reticle alignment marks 111RA. The two-dimensional distortion shape of the region 111PA can be measured (in other words, calculated). In particular, as described above, the speckle measuring devices 15L2 and 15R2 are arranged at positions where they can overlap with the pair of reticle alignment marks 111RA along the Z-axis direction. Therefore, main controller 16 can acquire speckle information of reticle alignment mark 111RA based on the detection results of speckle measurement devices 15R2 and 15L2. That is, main controller 16 can also measure the amount of variation in the position of reticle alignment mark 111RA. Therefore, main controller 16 measures the two-dimensional distortion of pattern area 111PA (for example, the amount of change in the XY plane of each area portion of pattern area 111PA) with reference to the positions of four reticle alignment marks 111RA. can do.

  Note that after the reticle alignment operation using the reticle alignment mark 111RA is performed, the position of the reticle 111 is measured by the reticle laser interferometer 116 that measures the position of the reticle stage 11. Furthermore, the installation position of each speckle measurement device 15 (and thus the measurement target region and the region irradiated with the measurement light LB2) is known. Therefore, the main controller 16 determines the position of the reticle 111 (particularly the position in the Y-axis direction) and the reticle based on the position of the reticle stage 11 (particularly the position in the Y-axis direction) measured by the reticle laser interferometer 116. The measurement target area on 111 can be recognized. Therefore, main controller 16 can recognize which information portion of the acquired speckle information is speckle information corresponding to reticle alignment mark 111RA.

  Thereafter, the wafer 141 is held by the wafer stage 14 in order to expose the wafer 141. When wafer 141 is newly held by wafer stage 14, main controller 16 uses wafer alignment detection system 149 to detect a wafer alignment operation (for example, a wafer alignment mark formed on wafer 141). , EGA: Enhanced Global Alignment). The wafer alignment operation is disclosed in, for example, US Pat. No. 4,780,617.

  Thereafter, under the control of the main controller 16, an exposure operation for transferring a reduced image of the exposure pattern formed on the reticle 111 to a plurality of shot areas on the wafer 141 is performed. When this exposure operation is performed, the main controller 16 determines the two-dimensional distortion of the pattern area 111PA measured based on the speckle information so that each shot area and the exposure pattern overlap optically. Based on the above, at least one of reticle stage drive system 112, wafer stage drive system 142, and imaging characteristic correction controller 131 is controlled. As a result, the main controller 16 can superimpose each shot area and the exposure pattern with high accuracy.

  When the exposure for a certain wafer 141 is completed, the wafer 141 that has been exposed is released from the wafer stage 141 and a new wafer 141 is held by the wafer stage 14. Thereafter, the operation after the wafer 141 described above is newly held by the wafer stage 14 is repeated. When exposure of all wafers 141 in a lot is completed, an operation performed immediately before the exposure of the first wafer 141 in each lot (the pattern region 111PA associated with the above-described reticle alignment operation and second speckle acquisition operation) is performed. Measurement of a two-dimensional distortion shape) is performed.

  As described above, according to the exposure apparatus 1 of the first embodiment, the main controller 16 can measure the two-dimensional distortion of the pattern region 111PA every time the reticle alignment operation is performed. For this reason, even if the reticle 111 is thermally deformed by the exposure light EL irradiation, the main controller 16 can measure the two-dimensional distortion of the pattern region 111PA due to the heat deformation. For example, main controller 16 can measure fluctuation amounts ΔX and ΔY along the direction intersecting optical axis AX of pattern region 111PA due to thermal deformation of reticle 111.

  Particularly in the first embodiment, the main controller 16 measures the fluctuation amounts ΔX and ΔY of the pattern area 111PA based on the speckle information. For this reason, the main control device 16 is compared with the case where the variation amounts ΔX and ΔY of the pattern area 111PA are measured based on the detection result of the image by the imaging sensor of the same image processing method as the FIA (Field Image Alignment) system. Thus, the variation amounts ΔX and ΔY of the pattern region 111PA can be measured with high accuracy. Therefore, main controller 16 measures the distortion (that is, fluctuation amounts ΔX and ΔY substantially indicating the distortion) even when the two-dimensional distortion of pattern area 111PA is a nonlinear distortion. be able to.

  Furthermore, in the first embodiment, each speckle measurement device 15 irradiates each measurement target region with a plurality of measurement lights LB2 having different incident angles with respect to each measurement target region. For this reason, compared with the case where the single measurement light LB2 is irradiated to each measurement target region, the main controller 16 can preferably acquire the speckle information and calculate the fluctuation amounts ΔX and ΔY. It can measure suitably.

  The technical effect of irradiating the plurality of measurement lights LB2 is particularly remarkable when the shape of the exposure pattern formed in the measurement target region is regular (or periodic). As an example of the regular exposure pattern, for example, a plurality of linear patterns each extending in one direction (for example, the X-axis direction) are arranged along the other direction (for example, the Y-axis direction). An exposure pattern is exemplified. When the single measurement light LB2 is irradiated to the measurement target region where such a regular exposure pattern is formed, the measurement light LB2 scattered or reflected in the measurement target region interferes with each other. The interference light LB3 generated in this way is highly likely to be regarded as being regularly diffracted light. Therefore, for example, even when the shape of the pattern region 111PA is changed, there is a possibility that no substantial change is observed in the obtained interference light LB3. As a result, even when the shape of the pattern region 111PA is changing, the fluctuation amounts ΔX and ΔY may not be measured (for example, measured as zero). However, in the first embodiment, since the plurality of measurement lights LB2 are irradiated, the plurality of measurement lights LB2 scattered or reflected in the measurement target region where the regular exposure pattern is formed are generated by interference with each other. The interference light LB3 is highly likely to be speckled interference light. Therefore, even when the region where the regular exposure pattern is formed is set as the measurement target region, the main controller 16 can preferably acquire the speckle information and the variation amount ΔX. And ΔY can be suitably measured.

  Furthermore, in the first embodiment, the optical axis AX2 of the speckle light receiving optical system is different from the optical axis AX1 of the speckle irradiation optical system. Accordingly, the interference light LB3 received by the light receiving element 156 does not include zeroth-order light. Or, compared with the case where the optical axis AX2 of the speckle light receiving optical system and the optical axis AX1 of the speckle irradiation optical system coincide with each other, the interference light LB3 received by the light receiving element 156 has a property as the measurement light LB2 itself. , Which is relatively strong (in other words, it is difficult to exhibit relatively strong speckle properties). For this reason, main controller 16 can suitably acquire speckle information and can suitably measure fluctuation amounts ΔX and ΔY.

  Further, main controller 16 determines reticle stage drive system 112, wafer stage drive system 142, and imaging characteristics based on the two-dimensional distortion (for example, variations ΔX and ΔY) of pattern area 111PA measured as described above. Control at least one of the correction controllers 131. For this reason, the main controller 16 does not receive the influence of the distortion even if two-dimensional distortion occurs in the pattern area 111PA, and each shot area and the reticle 111 on the wafer 141. The upper exposure pattern can be superimposed with high accuracy.

  The configuration of the speckle measurement device 15 described with reference to FIGS. 1 to 8 and the measurement operation using the speckle measurement device 15 (particularly, the measurement operation of the variation amount with time of the pattern region 111PA) are examples. is there. Therefore, at least a part of the configuration of the speckle measurement device 15 and the measurement operation using the speckle measurement device 15 may be appropriately modified. Hereinafter, the configuration of the speckle measurement device 15 and an example of modification of at least part of the measurement operation using the speckle measurement device 15 will be described.

  The exposure apparatus 1 may include four or fewer speckle measuring apparatuses 15. In this case, four or less or six or more measurement target regions to which the four or less or six or more speckle measurement devices 15 irradiate the measurement light LB2 may be located in the measurement target. At least one speckle measurement device 15 may be arranged on the reticle stage surface plate 113. At least one speckle measuring device 15 may be arranged in a structure or on a structure different from the reticle stage surface plate 113.

  All of the plurality of speckle measurement devices 15 may not be arranged along the X-axis direction. The position of at least some of the plurality of speckle measurement devices 15 in the Y-axis direction may be different from the position of at least some other portions of the plurality of speckle measurement devices 15 in the Y-axis direction. The plurality of speckle measurement devices 15 may be arranged along a direction intersecting with the Y-axis direction. At least one of the speckle measuring devices 15L2 and 15R2 located at both ends along the X-axis direction is arranged at a position where it does not overlap with the pair of reticle alignment marks 111RA arranged along the Y-axis direction along the Z-axis direction. May be. In order to measure the fluctuation amounts ΔX and ΔY of the pattern area 111PA, the plurality of speckle measurement devices 15 are configured to move at least each of the pattern area 111PA and the reticle fiducial plate 115 in accordance with the movement of the reticle stage 11. The measurement light region LB2 is disposed at a position where the measurement light region LB2 can be irradiated onto a measurement target region that can move in a region including a part.

  At least one speckle measurement device 15 may irradiate the measurement light LB2 toward the optical path of the exposure light EL. The measurement target region of at least one speckle measurement device 15 may be located in the optical path of the exposure light EL. The measurement target region of at least one speckle measurement device 15 may overlap with at least a part of the illumination region IR.

  When the measurement target region of at least one speckle measurement device 15 is located in the optical path of the exposure light EL, the measurement light LB2 is irradiated to the exposure pattern, and thus the main control device 16 determines the exposure pattern itself. It can be said that the position of is directly measured. In this case, the operation of controlling the reticle stage drive system 112 so that each shot area and the exposure pattern are superimposed with high accuracy based on the position of the exposure pattern itself is performed based on the position of the exposure pattern itself. This corresponds to the operation of positioning the stage 11. As a result, the main controller 16 can superimpose each shot area and the exposure pattern with higher accuracy using a relatively simple process. Further, in this case, unlike the case where the position of the reticle stage 11 is measured using an encoder system including a head that targets the grating portion, the change in the coordinate system of the reticle stage 11 caused by the variation in the grating portion is caused by exposure. Little or no effect on the measurement of the position of the working pattern. Also in this sense, the main controller 16 can superimpose each shot area and the exposure pattern with higher accuracy. However, even if each shot area and the exposure pattern are superimposed with high precision based on the position of the exposure pattern itself, in order to superimpose each shot area and the exposure pattern with higher precision, The main controller 16 may remove measurement errors caused by the drift of each speckle measuring device 15.

  The at least one speckle measurement device 15 may not include at least one of the condenser lens 153, the projection lens 154, and the pinhole plate 155. At least a part of the light source 151, the optical member 152, the condensing lens 153, the condensing lens 154, the pinhole plate 155, and the light receiving element 156 included in at least one speckle measurement device 15 is not accommodated in the housing 158. May be. At least one speckle measurement device 15 may not include the housing 158.

  The light source 151 may emit reference light LB1 used as the measurement light LB2 toward the measurement target in addition to or instead of emitting the reference light LB1 toward the optical member 152. The light source 151 may emit the reference light LB1 toward either the optical member 152 or the measurement target according to the exposure pattern included in the measurement target region. For example, when the exposure pattern included in the measurement target region is a regular or periodic pattern (particularly, a regular or periodic pattern lined up along the moving direction of the reticle stage 11), the light source 151. May emit the reference light LB1 toward the optical member 152. For example, when the exposure pattern included in the measurement target region is not a regular or periodic pattern (for example, an irregular, aperiodic, or random pattern), the light source 151 is used as the measurement target. Reference light LB1 used as measurement light LB2 may be emitted toward

  The optical member 152 may be a member having an arbitrary shape (for example, a plate shape) in a plan view. The optical rough surface 152a included in the optical member 152 may scatter the reference light LB1 in addition to or instead of reflecting the reference light LB1. The optical rough surface 152a may be a surface that generates the plurality of measurement lights LB2 by scattering the reference light LB1 in addition to or instead of reflecting the reference light LB1. The optical rough surface 152a may be a surface that reflects or scatters the reference light LB1 as a plurality of measurement lights LB2. In this case, when the optical rough surface 152a scatters the reference light LB1 to generate a plurality of measurement lights LB2, the reflectance of the optical rough surface 152a may be smaller than a predetermined amount of light.

  The size h1 of the convex pattern 152b formed on the optical rough surface 152a may be the same as the wavelength of the reference light LB1. The size h1 of the convex pattern 152b may be smaller than the wavelength of the reference light LB1. The size h2 of the concave pattern 152c formed on the optical rough surface 152a may be the same as the wavelength of the reference light LB1. The size h2 of the concave pattern 152c may be smaller than the wavelength of the reference light LB1.

  At least a part of the measurement target region of one speckle measurement device 15 of the plurality of speckle measurement devices 15 is at least a measurement target region of another speckle measurement device 15 of the plurality of speckle measurement devices 15. It may overlap with a part. For example, at least a part of the measurement target region SAR1 of the speckle measurement device 15R1 may overlap with at least a part of the measurement target region SAR2 of the speckle measurement device 15R2.

  The main controller 16 may change the beam diameter of the reference light LB1 emitted from the light source 15. The main controller 16 may change the beam diameter of the reference light LB1 emitted from the light source 15 according to the acquired speckle information. For example, main controller 16 may change the beam diameter of reference light LB1 when the acquired speckle information is speckle information in which it is difficult to measure the variation over time of pattern area 111PA. Good (for example, it may be larger or smaller). When the beam diameter of the reference light LB1 is changed, the size of the measurement target region that is the region irradiated with the reference light LB1 is also changed. For example, as the beam diameter of the reference light LB1 increases, the size of the measurement target region that is the region irradiated with the reference light LB1 also increases. As a result, the main controller 16 can easily acquire speckle information that can relatively easily measure the temporal variation of the pattern region 111PA.

  The at least one speckle measurement device 15 may not irradiate the measurement target region with the plurality of measurement lights LB2. At least one speckle measuring device 15 may not include the optical member 152 and the condenser lens 153. In this case, at least one speckle measurement device 15 may irradiate the measurement target region with the reference light LB1 emitted from the light source 151 as the measurement light LB2.

  Main controller 16 may perform the first speckle acquisition operation during at least a part of the period in which reticle stage 11 is not moving. Main controller 16 may perform the first speckle acquisition operation during at least a part of the period in which reticle stage 11 is stopped. In this case, main controller 16 may perform the first speckle acquisition operation at each of a plurality of timings when reticle stage 11 is stopped at different positions. In other words, main controller 16 may perform the first speckle acquisition operation for each of a plurality of regions intermittently distributed on the measurement target along the moving direction of reticle stage 11. As a result, the main control device 16 uses the speckle associated with the Y coordinate of the reticle stage 11 as in the case where the first speckle acquisition operation is performed during at least a part of the period during which the reticle stage 11 is moving. Information can be acquired. Furthermore, the amount of speckle information stored in the memory 17 is reduced as compared with the case where the first speckle acquisition operation is performed at least during a period during which the reticle stage 11 is moving. That is, speckle information stored in the memory 17 as compared with the case where the first speckle acquisition operation is performed on a series of regions continuously distributed on the measurement target along the movement direction of the reticle stage 11. The amount of information is reduced. The same applies to the second speckle acquisition operation.

  Main controller 16 may perform the second speckle acquisition operation in at least a part of another period different from the period in which the reticle alignment operation is performed. As a result, the main controller 16 does not have to perform the second speckle acquisition operation in accordance with the reticle alignment operation, so that the throughput of the exposure apparatus 1 is improved in some cases.

  For example, the main control device 16 may perform the second speckle acquisition operation during at least a part of the period when the exposure light EL is not irradiated on the reticle 111. The main controller 16 may perform the second speckle acquisition operation during at least a part of the period when the exposure pattern is not transferred to the wafer 141. Main controller 16 may perform the second speckle acquisition operation during at least a part of the period in which wafer 141 held by wafer stage 14 is replaced. The main controller 16 may perform the second speckle acquisition operation during at least a part of a period for measuring the state of the exposure apparatus 1 (for example, the transmittance with respect to the exposure light EL, the power of the exposure light EL, etc.). The main controller 16 replaces the wafer stage 14 with at least a part of a period in which a measurement stage (not shown) provided in the exposure apparatus 1 is located below the projection optical system 13 (in other words, on the optical axis AX). A second speckle acquisition operation may be performed. As a result, the main controller 16 can acquire speckle information with little or no influence on the transfer of the exposure pattern to the wafer 141.

  For example, the main controller 16 may perform the second speckle acquisition operation during at least a part of the period in which the exposure light EL is applied to the reticle 111. The main controller 16 may perform the second speckle acquisition operation during at least a part of the period during which the exposure pattern is transferred to the wafer 141. That is, main controller 16 may measure variation amounts ΔX and ΔY of pattern area 111PA in parallel with exposure of the exposure pattern. As a result, main controller 16 can acquire speckle information more frequently and can measure fluctuation amounts ΔX and ΔY more frequently. Therefore, main controller 16 can superimpose each shot area on wafer 141 and the exposure pattern on reticle 111 with higher accuracy.

  However, when the second speckle acquisition operation is performed during at least a part of the period in which the exposure light EL is applied to the reticle 111, the reticle stage 11 moves at a constant speed in the second speckle acquisition operation. This may be performed not only when the reticle stage 11 is accelerating / decelerating, but also when the reticle stage 11 is accelerating / decelerating. The acceleration / deceleration of the reticle stage 11 may cause temporary deformation of the reticle 111. Therefore, in this case, main controller 16 determines the influence of temporary deformation of reticle 111 due to acceleration / deceleration of reticle stage 11 with reference to speckle information in the first state (for example, pattern region 111PA in the initial state). May be eliminated.

  When the second speckle acquisition operation is performed during at least a part of the period during which the exposure light EL is applied to the reticle 111, the main controller 16 performs at least a period during which the reticle stage 11 is moving at a constant speed. While the second speckle acquisition operation is partially performed, the second speckle acquisition operation may not be performed during a period in which the reticle stage 11 is accelerating or decelerating. As a result, the influence of temporary deformation of the reticle 111 due to acceleration / deceleration of the reticle stage 11 is preferably eliminated without requiring special signal processing by the main controller 16.

  When the measurement target region is located in the optical path of the exposure light EL (that is, overlaps at least a part of the illumination region IR), the main control device 16 can relatively easily accelerate and decelerate the reticle stage 11. The second speckle acquisition operation can be performed during at least a part of the period during which the reticle stage 11 is moving at a constant speed without performing the second speckle acquisition operation during the period.

  Main controller 16 may repeatedly perform the second speckle acquisition operation in a cycle shorter than the cycle in which the reticle alignment operation is performed. As a result, main controller 16 can acquire speckle information more frequently and can measure fluctuation amounts ΔX and ΔY more frequently. Therefore, main controller 16 can superimpose each shot area on wafer 141 and the exposure pattern on reticle 111 with higher accuracy.

  Based on the speckle information, main controller 16 performs, in addition to or instead of measuring the two-dimensional distortion (that is, variations ΔX and ΔY) of pattern region 111PA in the Z-axis direction of pattern region 111PA. The fluctuation amount ΔZ may be measured. In this case, for example, as the speckle measuring device 15, an image correlation displacement meter disclosed in Japanese Patent Application Laid-Open No. 2006-184091 or the like (specifically, the position in the height direction of the measurement target surface is determined by the principle of triangulation). A displacement meter for measurement) may be employed.

  In the above description, main controller 16 measures the two-dimensional distortion of pattern area 111PA based on speckle information. However, the present invention is not limited to that based on speckle information. For example, the main control device 16 adds the two-dimensional pattern area 111PA based on arbitrary information obtained from the measurement light LB2 (that is, the interference light LB3) scattered or reflected by the measurement target in addition to or instead of the speckle information. May be measured. For example, the exposure apparatus 1 may include at least one light detection device in addition to or instead of at least one speckle measurement device 15. The optical measurement device is a device that can detect the measurement light LB2 reflected from the measurement target (that is, the interference light LB3). The main control device 16 compares the detection result of the optical measurement device in addition to or instead of comparing the speckle information corresponding to the detection result of the speckle measurement device 15, so that the two-dimensional pattern region 111PA is compared. Simple distortion (that is, fluctuation amounts ΔX and ΔY) may be measured. For example, the main controller 16 detects the light detection information in the first state corresponding to the detection result of the optical measurement device at a timing when a certain reticle 111 is used for the first time, and at least a part of the period during which the reticle alignment operation is performed. The two-dimensional distortion of the pattern region 111PA may be measured by comparing the light detection information in the second state corresponding to the detection result of the optical measurement device.

  However, the main controller 16 may measure the two-dimensional distortion of the pattern region 111PA without being based on arbitrary information obtained from the measurement light LB2 (that is, the interference light LB3) scattered or reflected by the measurement target. Good. That is, the main controller 16 may measure the two-dimensional distortion of the pattern region 111PA using some method even when the measurement light LB2 is not irradiated on the measurement target. For example, the exposure apparatus 1 may include at least one pattern measurement device in addition to or instead of at least one speckle measurement device 15. The pattern measurement apparatus is an apparatus that can measure an exposure pattern formed in the pattern area 111PA of the reticle 111. As such a pattern measurement device, for example, an image sensor that acquires an image of the pattern area 111PA by imaging the pattern area 111PA (for example, an image sensor of the same image processing method as the FIA system described above) is exemplified. . In addition to or instead of comparing the speckle information corresponding to the detection result of the speckle measurement device 15, the main control device 16 compares the pattern information corresponding to the detection result of the pattern measurement device, thereby A two-dimensional distortion of 111 PA (that is, fluctuation amounts ΔX and ΔY) may be measured. For example, the main control device 16 determines the pattern information in the first state corresponding to the detection result of the pattern measurement device at a timing when a certain reticle 111 is used for the first time, and the pattern in at least a part of the period during which the reticle alignment operation is performed. The two-dimensional distortion of the pattern area 111PA may be measured by comparing with the pattern information in the second state corresponding to the detection result of the measurement device.

  In the above description, the formation error of the electron beam exposure apparatus for forming the exposure pattern and reticle alignment mark 111RA formed in the pattern area 111PA is zero. However, even if the formation error of the electron beam exposure apparatus is not zero, the main controller 16 can measure the formation error of the electron beam exposure apparatus based on the speckle information described above. For example, the main controller 16 performs an operation similar to the first speckle acquisition operation described above on the reticle 111 serving as a reference on which an exposure pattern having a formation error of zero is formed, and the acquired speckle information. Is stored in the memory 17 as speckle information serving as a reference. Further, the main control device 16 performs the same operation as the first speckle acquisition operation described above on the reticle 111 serving as a reference on which an exposure pattern with a non-zero formation error is formed, and acquires the acquired speckle information. It is stored in the memory 17 as speckle information that is a measurement error measurement target. Thereafter, the main control device 16 can measure the formation error corresponding to the difference between the reference speckle information and the speckle information to be measured.

(1-4) Modified Examples Next, various modified examples of the exposure apparatus 1 of the first embodiment will be described with reference to FIGS. In the following, the description will be made focusing on differences between the exposure apparatus 1 of the first embodiment and various modifications. Therefore, the same components as those in the exposure apparatus 1 of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. Further, at least some of the various components of the various modifications described below can be combined with each other.

(1-4-1) First Modification First , an exposure apparatus 1-1 according to a first modification will be described with reference to FIG. Note that, in the exposure apparatus 1-1 of the first modification, a part of the configuration of each speckle measurement apparatus 15-1 is the configuration of the speckle measurement apparatus 15 described above, compared to the exposure apparatus 1 of the first embodiment. Different from some of them. Therefore, in the following, the description will be focused on the configuration of each speckle measurement apparatus 15-1 provided in the exposure apparatus 1-1 of the first modification. FIG. 9 is a block diagram showing an example of the configuration of each speckle measurement apparatus 15-1 provided in the exposure apparatus 1-1 of the first modification.

  As shown in FIG. 9, the speckle measurement device 15-1 of the first modified example does not include the optical member 152 and the condenser lens 153 as compared with the speckle measurement device 15 of the first embodiment. The difference is that a plurality of light sources 151 are provided. In the example shown in FIG. 9, the speckle measuring device 15-1 includes four light sources 151 (specifically, the light source 151 (1), the light source 151 (1), the light source 151 (1), and the light source 151 (4)). It has. The other components of the speckle measurement device 15-1 of the first modification may be the same as the other components of the speckle measurement device 15 of the first embodiment.

  The plurality of light sources 151 each emit a plurality of measurement lights LB2 having different incident angles with respect to the measurement target. For example, the light source 151 (1) emits the measurement light LB2 (1) whose incident angle with respect to the measurement target is the first angle. For example, the light source 151 (2) emits the measurement light LB2 (2) whose incident angle with respect to the measurement target is the second angle. For example, the light source 151 (3) emits the measurement light LB2 (3) whose incident angle with respect to the measurement target is the third angle. For example, the light source 151 (4) emits measurement light LB2 (4) whose incident angle with respect to the measurement target is the fourth angle.

  Each of the plurality of light sources 151 emits a plurality of measurement lights LB2 having the same irradiation position on the measurement target. The plurality of light sources 151 each emit a plurality of measurement lights LB2 that are irradiated onto the same measurement target region. Each of the plurality of light sources 151 emits a plurality of measurement lights LB2 having the same measurement target region. The characteristics of the plurality of measurement lights LB2 emitted from the plurality of light sources 151 are the same except for the incident angle with respect to the measurement target.

  Also in the exposure apparatus 1-1 of such a 1st modification, the various effects which can be enjoyed in the exposure apparatus 1 of 1st Embodiment mentioned above are enjoyed. For example, the main controller 16 can measure the two-dimensional distortion of the pattern area 111PA, and has little or no influence of the distortion, and each shot area on the wafer 141 and the reticle 111 The exposure pattern can be overlaid with high accuracy.

  Note that the speckle measurement device 15-1 may include three or less light sources 151 or five or more light sources 151. At least some of the plurality of measurement lights LB2 emitted from the plurality of light sources 151 may be irradiated to the measurement target after being reflected by the optical member 152 of the first embodiment. At least one speckle measurement device 15-1 irradiates the reference light LB1 to one or more first light sources 151 that directly irradiate the measurement target LB2 to the measurement target and the optical member 152 of the first embodiment. One or a plurality of second light sources 151 may be provided. At least some of the characteristics of the plurality of measurement lights LB2 emitted from the plurality of light sources 151 may not be the same.

(1-4-2) Second Modification Next, an exposure apparatus 1-2 of a second modification will be described with reference to FIG. Note that, in the exposure apparatus 1-2 of the second modification, a part of the configuration of each speckle measurement apparatus 15-2 is the configuration of the speckle measurement apparatus 15 described above, compared to the exposure apparatus 1 of the first embodiment. Different from some of them. Therefore, hereinafter, the description will be focused on the configuration of each speckle measurement device 15-2 included in the exposure apparatus 1-1 of the second modification. FIG. 10 is a block diagram showing an example of the configuration of each speckle measurement apparatus 15-2 provided in the exposure apparatus 1-2 of the second modification.

  As shown in FIG. 10, the speckle measuring device 15-2 of the second modified example does not include the optical member 152 and the condenser lens 153 as compared with the speckle measuring device 15 of the first embodiment. The optical branching member 157-2 is different in that it is provided. The other components of the speckle measuring device 15-2 of the second modification may be the same as the other components of the speckle measuring device 15 of the first embodiment.

  Similar to the optical member 152, the light branching member 157-2 is a member that generates a plurality of measurement lights LB2 having different incident angles with respect to the measurement target. Similarly to the optical member 152, the light branching member 157-2 is a member that generates a plurality of measurement beams LB2 having different emission angles from the light branching member 157-2. Similar to the optical member 152, the light branching member 157-2 is a member that speckles the reference light LB1. Similar to the optical member 152, the light branching member 157-2 is a member that generates a plurality of speckled measurement light beams LB2.

  The light branching member 157-2 includes, for example, a half mirror 157-2 (1), a half mirror 157-2 (2), a half mirror 157-2 (3), and a mirror 157-2 (4). ing.

  The half mirror 157-2 (1) transmits a part of the reference light LB1 emitted from the light source 151 and uses another part of the reference light LB1 emitted from the light source 151 as a measurement light LB2 (1). Reflect towards The half mirror 157-2 (2) transmits a part of the reference light LB1 transmitted through the half mirror 157-2 (1) and other than the reference light LB1 transmitted through the half mirror 157-2 (1). Is reflected toward the measurement target as measurement light LB2 (2). The half mirror 157-2 (3) transmits a part of the reference light LB1 transmitted through the half mirror 157-2 (2) and other than the reference light LB1 transmitted through the half mirror 157-2 (2). Is reflected toward the measurement target as measurement light LB2 (2). The mirror 157-2 (4) reflects the reference light LB1 transmitted through the half mirror 157-2 (3) toward the measurement target as measurement light LB2 (4). In this case, the optical branching member 157-2 measures the measurement light LB2 (1) whose incident angle with respect to the measurement target is the first angle, the measurement light LB2 (2) whose incident angle with respect to the measurement target is the second angle, and measurement. Measurement light LB2 (3) whose incident angle to the target is the third angle and measurement light LB2 (4) whose incident angle to the measurement target is the fourth angle are generated.

  However, the light branching member 157-2 may generate an arbitrary number of measurement lights LB2 having different incident angles with respect to the measurement target. In this case, the light branching member 157-2 may include more half mirrors and the like.

  The light branching member 157-2 generates a plurality of measurement lights LB2 having the same irradiation position on the measurement target. Each of the light branching members 157-2 generates a plurality of measurement lights LB2 that are irradiated onto the same measurement target region. The light branching member 157-2 generates a plurality of measurement lights LB2 having the same measurement target region. The characteristics of the plurality of measurement lights LB2 generated by the light branching member 157-2 are the same except for the incident angle with respect to the measurement target.

  In the exposure apparatus 1-2 of the second modification example as described above, various effects that can be enjoyed in the exposure apparatus 1 of the first embodiment described above are enjoyed. For example, the main control device 16 can measure the two-dimensional distortion of the pattern area 111PA, and has little or no influence on the distortion, and each shot area on the wafer 141 and the reticle 111 are affected. The exposure pattern can be overlaid with high accuracy.

  The light branching member 157-2 may include an optical element different from the half mirror and the mirror in addition to or instead of at least one of the half mirror and the mirror. For example, the light branching member 157-2 may include a beam splitter.

(1-4-3) Third Modification Next, an exposure apparatus 1-3 according to a third modification will be described with reference to FIG. Note that, in the exposure apparatus 1-3 of the third modification, compared to the exposure apparatus 1 of the first embodiment, a part of the configuration of each speckle measurement apparatus 15-3 is the configuration of the speckle measurement apparatus 15 described above. Different from some of them. Accordingly, the following description will be focused on the configuration of each speckle measurement apparatus 15-3 included in the exposure apparatus 1-3 of the third modification. FIG. 11 is a block diagram showing an example of the configuration of each speckle measurement apparatus 15-3 provided in the exposure apparatus 1-3 of the third modification.

  As shown in FIG. 11, the speckle measuring device 15-3 of the third modified example is different from the speckle measuring device 15 of the first embodiment in the arrangement position of the speckle light receiving system 15-3b. It is different in point. In the example shown in FIG. 11, the speckle light receiving system 15-3b accommodated in the housing 158-3b is located above the reticle 111 (that is, on the + Z side with respect to the reticle 111). In this case, the housing 158-3b may be fixed to the frame of the exposure apparatus 3-3 or may be fixed to the reticle stage 11. On the other hand, the speckle irradiation system 15-3a accommodated in the housing 158-3a is located below the reticle 111 (that is, on the −Z side with respect to the reticle 111). In this case, casing 158-3a may be fixed to reticle stage surface plate 113. The other components of the speckle measurement device 15-3 of the third modification may be the same as the other components of the speckle measurement device 15 of the first embodiment.

  In the exposure apparatus 1-3 of the third modified example, various effects that can be enjoyed in the exposure apparatus 1 of the first embodiment described above are also enjoyed. For example, the main control device 16 can measure the two-dimensional distortion of the pattern area 111PA, and has little or no influence on the distortion, and each shot area on the wafer 141 and the reticle 111 are affected. The exposure pattern can be overlaid with high accuracy.

  The speckle irradiation system 15-3a may be located above the reticle 111. The speckle light receiving system 15-3b may be positioned below the reticle 111.

  At least one speckle measuring device 15-3 may include a plurality of speckle light receiving systems 15-3b. In this case, a part of the plurality of speckle light receiving systems 15-3b is located above the reticle 111 (that is, + Z side from the reticle 111), and the other part of the plurality of speckle light receiving systems 15-3b is the reticle. It may be located below 111 (that is, on the −Z side with respect to reticle 111).

(1-4-4) Fourth Modification Next, an exposure apparatus 1-4 according to a fourth modification will be described with reference to FIG. Note that, in the exposure apparatus 1-4 of the fourth modification, a part of the configuration of each speckle measurement apparatus 15-4 is the configuration of the speckle measurement apparatus 15 described above, compared to the exposure apparatus 1 of the first embodiment. Different from some of them. Accordingly, the following description will be focused on the configuration of each speckle measurement device 15-4 included in the exposure apparatus 1-4 of the fourth modification. FIG. 12 is a block diagram showing an example of the configuration of each speckle measurement device 15-4 included in the exposure apparatus 1-4 according to the fourth modification.

  As shown in FIG. 12, the speckle measuring device 15-4 of the fourth modified example has an optical member 152, a condensing lens 153, a projection lens 154, a pin, as compared with the speckle measuring device 15 of the first embodiment. The difference is that the Hall plate 155 and the light receiving element 156 are arranged on the slider 114SL of the reticle stage 11. In the example shown in FIG. 12, the optical member 152, the condensing lens 153, the projection lens 154, the pinhole plate 155, and the light receiving element 156 housed in the housing 158 are positioned between the slider 114SL and the reticle 111. Further, it is disposed on the slider 114SL. Further, the housing 158 further accommodates a light guide member (for example, a mirror) 159 for guiding the reference light LB1 emitted from the light source 151 disposed in the slider surface plate 113 to the optical member 152. . The reticle 111 is vacuum-sucked to the slider 114SL (that is, the reticle stage 11) via a suction part 114b formed on the upper surface of the slider 114SL. The other components of the speckle measuring device 15-4 of the fourth modification may be the same as the other components of the speckle measuring device 15 of the first embodiment.

  Also in the exposure apparatus 1-4 of the fourth modified example, various effects that can be enjoyed in the exposure apparatus 1 of the first embodiment described above are enjoyed. For example, the main control device 16 can measure the two-dimensional distortion of the pattern area 111PA, and has little or no influence on the distortion, and each shot area on the wafer 141 and the reticle 111 are affected. The exposure pattern can be overlaid with high accuracy.

  In addition, in the fourth modification, the light source 151 is separated from components other than the light source 151 (that is, the optical member 152, the condensing lens 153, the projection lens 154, the pinhole plate 155, and the light receiving element 156). For this reason, there is little or no influence of the heat generated by the light source 151 on the components other than the light source. Therefore, a high output light source 151 can be employed. As a result, main controller 16 can measure the two-dimensional distortion of pattern region 111PA with higher accuracy.

  The optical member 152, the condensing lens 153, the projection lens 154, the pinhole plate 155, and a part of the light receiving element 156 are disposed on the slider 114SL, while the condensing lens 153, the projection lens 154, and the pinhole plate 155. The other part of the light receiving element 156 may not be disposed on the slider 114SL.

  In the fourth modification, speckle information is acquired from a part of the pattern formed on the reticle 111 after the housing 158 is fixed on the slider 114SL. However, it is not particularly limited to this aspect. For example, the number of peaks of the detection signal (for example, information from the pattern of the reticle 111 including speckle) and the contrast height are measured for each reticle 111, and the measurement position of the reticle 111 is optimized based on the measurement result. Alternatively, the position of the reticle stage 11 may be adjusted. Alternatively, the housing 158 may be movable and the housing 158 may be moved to an optimal position for each reticle 111.

(2) Exposure apparatus 2 of the second embodiment
Subsequently, the exposure apparatus 2 of the second embodiment will be described with reference to FIGS. 13 and 14. The exposure apparatus 2 of the second embodiment is different from the exposure apparatus 1 of the first embodiment in that each speckle measurement device 15 is movable. Therefore, in the following, the description will be focused on the configuration requirements for moving each speckle measurement device 15 included in the exposure apparatus 2 of the second embodiment. FIG. 13 is a top view showing the configuration around the reticle stage 11 provided in the exposure apparatus 2 of the second embodiment. FIG. 14 is a top view showing an example of the movement mode of the speckle measuring device 15. In addition, about the component same as the exposure apparatus 1 of 1st Embodiment, the detailed description is abbreviate | omitted by attaching | subjecting the same referential mark.

  As shown in FIG. 13, the exposure apparatus 2 according to the second embodiment is different in that each speckle measurement apparatus 15 is movable. Other components of the exposure apparatus 2 of the second embodiment may be the same as other components of the exposure apparatus 1 of the first embodiment.

  Each speckle measuring device 15 is movable along a direction that intersects the moving direction of the reticle stage 11. Each speckle measuring device 15 is movable along a direction intersecting with the Y-axis direction. Each speckle measuring device 15 is movable along the X-axis direction. Each speckle measuring device 15 is movable along the XY plane. Each speckle device 15 is movable on the order of centimeters or millimeters.

  As a result of the movement of each speckle measurement device 15, the measurement target area of each speckle measurement device 15 also moves along the movement direction of each speckle measurement device 15. That is, the measurement target region can move along a direction that intersects the movement direction of the reticle stage 11. The measurement target region is movable along a direction intersecting with the Y-axis direction. The measurement target area is movable along the X-axis direction. The measurement target area is movable along the XY plane.

  In order to move each speckle measurement device 15, the exposure apparatus 2 further includes a plurality of drive mechanisms 25 that respectively move the plurality of speckle measurement devices 15. For example, in the example shown in FIG. 13, the exposure apparatus 2 includes a drive mechanism 25R2 that moves the speckle measurement apparatus 15R2, a drive mechanism 25R1 that moves the speckle measurement apparatus 15R1, and a drive mechanism that moves the speckle measurement apparatus 15C. 25C, a drive mechanism 25L1 that moves the speckle measurement device 15L1, and a drive mechanism 25L2 that moves the speckle measurement device 15L2. The five drive mechanisms 25 are the same except that the movement targets are different.

  Each drive mechanism 25 includes, for example, an arbitrary motor (for example, a planar motor or a linear motor). In this case, each speckle measuring device 15 moves using the driving force of the motor as a power source. However, each drive mechanism 25 may include an arbitrary power source capable of generating or supplying power when each speckle measuring device 15 moves in addition to or instead of an arbitrary motor.

  For example, each drive mechanism 25 may include a pair of electrodes arranged to face each other. In this case, when a voltage is applied to the pair of electrodes, an electrostatic force is generated in the pair of electrodes. As a result, electrostatic force is adopted as power when each speckle measuring device 15 moves.

  For example, each drive mechanism 25 may include a magnetic pole and a coil disposed in a magnetic field generated by the magnetic pole. In this case, when a current is supplied to the coil, an electromagnetic force is generated in the coil. As a result, for example, electromagnetic force is employed as power when each speckle measuring device 15 moves.

  For example, each drive mechanism 25 may include a piezoelectric element. In this case, when a current is supplied to the piezoelectric element, the piezoelectric element is distorted. As a result, for example, a force resulting from distortion of the piezoelectric element is employed as power when each speckle measuring device 15 moves.

  The main control device 16 controls each drive mechanism 25 so that each speckle measurement device 15 moves in the above-described manner. The main controller 16 controls each drive mechanism 25 according to the exposure pattern formed in the pattern area 111PA. The main controller 16 controls each drive mechanism 25 according to the state of the exposure pattern formed in the pattern area 111PA.

  For example, the main controller 16 determines each part of the pattern area 111PA in which the exposure pattern actually transferred to the wafer 141 is formed based on the relative position in the pattern area 111PA. The drive mechanism 25 is controlled. Specifically, the main control device 16 controls each drive mechanism 25 so that as many measurement target regions as possible overlap the exposure pattern actually transferred to the wafer 141. The main controller 16 controls each drive mechanism 25 so that as many measurement target areas as possible overlap with a part of the pattern area 111PA where an exposure pattern that is actually transferred to the wafer 141 is formed. To do. For example, as shown in FIG. 14A, when all of the exposure patterns formed in the pattern area 111PA are actually transferred to the wafer 141, the main controller 16 has five speckle measuring devices. Each drive mechanism 25 may be controlled so that 15 are arranged at equal intervals along the X-axis direction. That is, the main control device 16 may control each drive mechanism 25 so that the five speckle measurement devices 15 are arranged substantially evenly with respect to the pattern region 111PA. On the other hand, for example, as shown in FIG. 14B, when the exposure pattern formed in the partial region portion 111PA-1 of the pattern region 111PA is actually transferred to the wafer 141, The main control device 16 may control each drive mechanism 25 so that the five measurement target regions of the five speckle measurement devices 15 overlap with a part of the pattern region 111PA-1.

  When the speckle measurement device 15 moves, the measurement target region irradiated with the measurement light LB2 also moves. Therefore, every time the speckle measuring device 15 moves, the main control device 16 newly performs a first speckle measuring operation.

  The main control device 16 may acquire position information indicating the position (for example, a position along the X-axis direction) of each speckle measurement device 15 based on the control amount of each drive mechanism 25. The position information acquired by the main controller 16 is stored in the memory 17. When each speckle measuring device 15 is moved by controlling each drive mechanism 25, the position information is also updated.

  However, the exposure apparatus 2 may include a position sensor that can detect the position of each speckle measurement device 15 (for example, a position along the X-axis direction that is the direction in which each speckle device 15 moves). In this case, in the mark region 115MA of the reticle fiducial plate 115, a plurality of position marks having unique characteristics (for example, shape and pattern) are formed along the X-axis direction according to the position in the X-axis direction. Yes. As a result, the position sensor can detect the position of each speckle measuring device 15 based on the position mark formed on the reticle fiducial plate 115.

  Such an exposure apparatus 2 of the second embodiment also enjoys various effects that can be enjoyed by the exposure apparatus 1 of the first embodiment described above. For example, the main control device 16 can measure the two-dimensional distortion of the pattern area 111PA, and has little or no influence on the distortion, and each shot area on the wafer 141 and the reticle 111 are affected. The exposure pattern can be overlaid with high accuracy.

  Furthermore, in the second embodiment, the main controller 16 makes a relative comparison within the pattern area 111PA of the area portion 111PA-1 in which the exposure pattern actually transferred to the wafer 141 is formed in the pattern area 111PA. Each drive mechanism 25 can be controlled based on the position. As a result, the main controller 16 can measure the two-dimensional distortion of the region portion 111PA-1 where the exposure pattern actually transferred to the wafer 141 is formed with relatively high accuracy. Therefore, main controller 16 can superimpose each shot area on wafer 141 and the exposure pattern on reticle 111 (in particular, the exposure pattern actually transferred to wafer 141) with high accuracy. Even if the main control device 16 is thermally deformed in the region portion 111PA-1 where the exposure pattern actually transferred to the wafer 141 is formed in the pattern region 111PA, The shot area and the exposure pattern on the reticle 111 can be overlaid with high accuracy.

  The speckle measurement device 15 may be movable in addition to or instead of being movable, the irradiation position (that is, the measurement target region) of the measurement light LB2. For example, the speckle measurement device 15 includes various components (that is, the light source 151, the optical member 152, the condensing lens 153, the projection lens 154, the pinhole plate 155, and the light receiving element 156) that constitute the speckle measurement device 15. The measurement target region may be moved by dynamically changing at least a part of the arrangement position or the arrangement angle or at least a part of the various components. Even in this case, various effects that can be enjoyed when the speckle measuring device 15 is movable are favorably enjoyed.

  In the exposure apparatus 2 of the second embodiment, at least one speckle measurement apparatus 15 may not irradiate the measurement target region with the plurality of measurement lights LB2. At least one speckle measuring device 15 may not include the optical member 152 and the condenser lens 153. In this case, at least one speckle measurement device 15 may irradiate the measurement target region with the reference light LB1 emitted from the light source 151 as the measurement light LB2.

  The main controller 16 may control each drive mechanism 25 based on the density of the exposure pattern. Specifically, the main control device 16 controls each drive mechanism 25 so that the number of measurement target regions that overlap the region portion of the pattern region 111PA in which the density of the exposure pattern is relatively high becomes relatively large. May be. The main control device 16 may control each drive mechanism 25 so that the number of measurement target regions overlapping the region portion where the density of the exposure pattern in the pattern region 111PA is relatively low. The main controller 16 determines that the number of measurement target regions overlapping the region portion where the exposure pattern density is relatively high in the pattern region 111PA is the region portion where the exposure pattern density is relatively low in the pattern region 111PA. Each drive mechanism 25 may be controlled so as to be larger than the number of overlapping measurement target regions. As a result, the main controller 16 determines the two-dimensional area of the pattern area 111PA in which the density of the exposure pattern is relatively high and the influence on the transfer of the exposure pattern due to thermal deformation is relatively large. Accurate distortion can be measured with relatively high accuracy. Therefore, main controller 16 can superimpose each shot area on wafer 141 and the exposure pattern on reticle 111 (in particular, the exposure pattern having a relatively high density) with high accuracy. Even if the main control device 16 is thermally deformed in a region where an exposure pattern having a relatively high density is formed in the pattern region 111PA, the main control device 16 and the reticle 111 and each shot region on the wafer 141. The upper exposure pattern can be superimposed with high accuracy.

  The main controller 16 may control each drive mechanism 25 based on the magnitude of the influence of the exposure pattern on the thermal deformation of the pattern area 111PA. Specifically, the main control device 16 has a relatively large number of measurement target areas that overlap the area portion where the pattern for exposure that is relatively likely to cause thermal deformation is formed in the pattern area 111PA. Each drive mechanism 25 may be controlled. The main controller 16 controls each drive mechanism 25 so that the number of measurement target regions overlapping the region of the pattern region 111PA where the exposure pattern that is relatively unlikely to cause thermal deformation is relatively small. You may control. The main controller 16 determines that the number of measurement target regions overlapping the region of the pattern region 111PA where an exposure pattern that is relatively likely to cause thermal deformation is relatively caused by thermal deformation in the pattern region 111PA. Each drive mechanism 25 may be controlled so as to be larger than the number of measurement target regions that overlap the region where the difficult exposure pattern is formed. As a result, main controller 16 can measure the two-dimensional distortion of the region of pattern area 111PA, which is relatively susceptible to thermal deformation, with relatively high accuracy. Therefore, main controller 16 can superimpose each shot area on wafer 141 and the exposure pattern on reticle 111 (particularly, the exposure pattern that is relatively likely to cause thermal deformation) with high accuracy. Even if the main control device 16 is thermally deformed in an area where an exposure pattern that is relatively likely to cause thermal deformation is formed in the pattern area 111PA, The exposure pattern on the reticle 111 can be overlaid with high accuracy.

  Also in the exposure apparatus 2 of the second embodiment, at least a part of various aspects that can be adopted by the exposure apparatus 1 of the first embodiment described above may be appropriately adopted. For example, in the exposure apparatus 2 of the second embodiment, at least a part of the various aspects employed in the first to fourth modifications described above may be employed as appropriate.

  The configurations and operations of the exposure apparatuses 1 and 2 described with reference to FIGS. 1 to 14 are examples. Therefore, at least a part of the configuration and operation of the exposure apparatuses 1 and 2 may be modified as appropriate. Hereinafter, an example of modification of at least a part of the configuration and operation of the exposure apparatuses 1 and 2 will be described.

  The exposure apparatus 1 may be a step-and-scan type scanning exposure apparatus (so-called scanning stepper) that scans and exposes an exposure pattern formed on the reticle 111 by moving the reticle 111 and the wafer 141. Good. The exposure apparatus 1 performs batch exposure of the exposure pattern formed on the reticle 111 while the reticle 111 and the wafer 141 are stationary, and step-and-step moves the wafer 141 every time the batch exposure is completed. It may be a repeat type projection exposure apparatus (so-called stepper). In the step-and-repeat type projection exposure apparatus, a reduced image of the first exposure pattern formed on the first reticle 111 is placed on the wafer 141 in a state where the first reticle 111 and the wafer 141 are substantially stationary. After the exposure, the reduced image of the second exposure pattern formed on the second reticle 111 with the second reticle 111 and the wafer 141 substantially stationary is converted into a reduced image of the first exposure pattern. An exposure apparatus (so-called stitch-type exposure apparatus) that exposes the wafer 141 in a stacked manner may be used. The stitch type exposure apparatus may be a step-and-stitch type exposure apparatus that partially exposes two or more exposure patterns on the wafer 141 and moves the wafer 141 sequentially.

  The exposure apparatus 1 synthesizes the exposure patterns of the two reticles 111 on the wafer 141 via the projection optical system 13 and simultaneously double-exposes the shot area on the wafer 141 by one scanning exposure. It may be. An example of such an exposure apparatus is disclosed in, for example, US Pat. No. 6,611,316. The exposure apparatus 1 may be a proximity type exposure apparatus that does not include the projection optical system 13. The exposure apparatus 1 may be a mirror projection aligner or the like.

  In the above description, the exposure apparatus 1 is a dry-type exposure apparatus that exposes the wafer 141 without using a liquid. However, in the exposure apparatus 1, the exposure apparatus 1 forms an immersion space including the optical path of the exposure light EL between the projection optical system 13 and the wafer 141, and the wafer through the projection optical system 13 and the immersion space. 141 may be an immersion exposure apparatus that performs the exposure of 141. An example of the immersion exposure apparatus is disclosed in, for example, European Patent Application Publication No. 1,420,298, International Publication No. 2004/055803 and US Pat. No. 6,952,253. Yes.

  The exposure apparatus 1 may be a twin stage type or multistage type exposure apparatus including a plurality of wafer stages 14. The exposure apparatus 1 may be a twin-stage type or multi-stage type exposure apparatus that includes a plurality of wafer stages 14 and measurement stages. Examples of the twin stage type exposure apparatus are disclosed in, for example, US Pat. No. 6,341,007, US Pat. No. 6,208,407 and US Pat. No. 6,262,796.

  The projection optical system 13 may be a unity magnification system or an enlargement system. The projection optical system 13 may be a reflective system that does not include a refractive optical element but includes a reflective optical element. The projection optical system 13 may be a refractive / reflective system including both a refractive optical element and a reflective optical element. The image projected by the projection optical system 13 may be an inverted image or an erect image. The shapes of the illumination region IR and the projection region PR are not limited to the slit shape, and may be any shape (for example, an arc, a trapezoid, a rectangle, or the like).

The exposure light EL may be, for example, a bright line (for example, g line, h line, or i line) emitted from a mercury lamp. The exposure light EL may be far ultraviolet light (DUV light: Deep Ultra Violet light) such as KrF excimer laser light (wavelength 248 nm). The exposure light EL may be vacuum ultraviolet light (VUV light: Vacuum Ultra Violet light) such as F ₂ laser light (wavelength 157 nm). As the exposure light EL, for example, as disclosed in US Pat. No. 7,023,610, a single wavelength laser beam in an infrared region or a visible region oscillated from a DFB semiconductor laser or a fiber laser is used. It may be a harmonic obtained by amplifying with a fiber amplifier doped with erbium (or both erbium and yttrium) and converting the wavelength into ultraviolet light using a nonlinear optical crystal.

  The exposure light EL is not limited to light having a wavelength of 100 nm or more, and light having a wavelength of less than 100 nm may be used. For example, the exposure light EL may be EUV (Extreme Ultra Violet) light in a soft X-ray region (for example, a wavelength region of 5 to 15 nm). Instead of the exposure light EL, a charged particle beam such as an electron beam or an ion beam may be used for exposing the exposure pattern.

  The object to which the exposure pattern is exposed (that is, transferred) is not limited to the wafer 141, and may be any object such as a glass plate, a ceramic substrate, a film member, and mask blanks.

  The position of the reticle stage 11 in the XY plane may be measured by an encoder in addition to or instead of the reticle laser interferometer 116. The position of the wafer stage 14 in the XY plane may be measured by an encoder in addition to or instead of the wafer laser interferometer 146.

  The exposure apparatus 1 may be an exposure apparatus for manufacturing a semiconductor element that exposes a semiconductor element pattern onto the wafer 141. The exposure apparatus X1 may be an exposure apparatus for manufacturing a liquid crystal display element or for manufacturing a display. The exposure apparatus 1 may be an exposure apparatus for manufacturing at least one of a thin film magnetic head, an image sensor (for example, CCD), a micromachine, a MEMS, a DNA chip, and a reticle 111.

  The reticle 111 may be a transmissive reticle in which a predetermined light-shielding pattern (or a moving pattern or a dimming pattern) is formed on a light transmissive transparent plate. The reticle 111 may be a variable shaping mask (so-called electronic mask, active mask or image generator) that forms a transmission pattern, a reflection pattern, or a light emission pattern based on electronic data of an exposure pattern. An example of a variable shaped mask is disclosed in US Pat. No. 6,778,257. The reticle 111 may be a pattern forming apparatus including a self-luminous image display element instead of a variable shaping mask including a non-luminous image display element.

  The exposure apparatus 1 may be an exposure apparatus (so-called lithography system) that exposes a line-and-space pattern on the wafer 141 by forming interference fringes on the wafer 141. An example of such an exposure apparatus is disclosed in, for example, International Publication No. 2001/035168 pamphlet.

  The above-described exposure apparatus 1 may be manufactured by combining various subsystems including the above-described various components so as to maintain predetermined mechanical accuracy, electrical accuracy, and optical accuracy. In order to maintain mechanical accuracy, adjustment processing for achieving mechanical accuracy may be performed on various mechanical systems before and after the combination. In order to maintain electrical accuracy, adjustment processing for achieving electrical accuracy may be performed on various electrical systems before and after the combination. In order to maintain optical accuracy, adjustment processing for achieving optical accuracy may be performed on various optical systems before and after assembly. The step of combining the various subsystems may include a step of making a mechanical connection between the various subsystems. The step of combining various subsystems may include a step of wiring connection of electric circuits between the various subsystems. The step of combining various subsystems may include a step of connecting the piping of the atmospheric pressure circuit between the various subsystems. In addition, the process of assembling each of the various subsystems is performed before the process of combining the various subsystems. After the process of combining the various subsystems is completed, the overall adjustment of the exposure apparatus 1 is ensured by performing overall adjustment. The exposure apparatus 1 may be manufactured in a clean room in which temperature, cleanliness, etc. are controlled.

  A microdevice such as a semiconductor device may be manufactured through the steps shown in FIG. The steps for manufacturing the microdevice include: step S201 for performing the function and performance design of the microdevice; step S202 for manufacturing the reticle 111 based on the function and performance design; and step S203 for manufacturing the wafer 141 which is the substrate of the device. In accordance with the above-described embodiment, step S204 for exposing the wafer 141 with the exposure light EL from the exposure pattern of the reticle 111 and developing the exposed wafer 141, device assembly processing (dicing processing, bonding processing, package processing, etc.) Step S205 including processing) and inspection step S206 may be included.

  At least a part of the configuration requirements of each embodiment described above can be appropriately combined with at least another part of the configuration requirements of each embodiment described above. Some of the configuration requirements of the above-described embodiments may not be used. In addition, as long as it is permitted by law, the disclosure of all published publications and US patents related to the exposure apparatus and the like cited in each of the above-described embodiments is incorporated as part of the description of the text.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit or concept of the invention that can be read from the claims and the entire specification. An exposure method and a device manufacturing method are also included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Exposure apparatus 11 Reticle stage 111 Reticle 111PA Pattern area | region 111RA Reticle alignment mark 112 Reticle stage drive system 113 Reticle stage surface plate 113a Opening 114 Recession 114a Opening 114SL Slider 115 Reticle fiducial plate 115FA Alignment mark 115MA Mark area 116 Reticle laser interferometer 116a moving mirror 119 reticle alignment detection system 12 illumination system 13 projection optical system 14 wafer stage 141 wafer 142 wafer stage driving system 144 reference plate 146 wafer laser interferometer 146a moving mirror 15 speckle measuring device 151 light source 152 optical member 153 condensing lens 154 Projection lens 155 Pinhole plate 156 Light-receiving element 16 Main controller 17 Memory 25 Drive mechanism

Claims (42)

An exposure apparatus that irradiates a mask with an energy beam and transfers a mask pattern formed on the pattern surface of the mask to an object,
A light irradiation unit configured to irradiate a plurality of measurement lights having different incidence angles with respect to the predetermined surface of the mask;
An exposure apparatus comprising: a sensor unit that detects at least some of the plurality of measurement lights reflected or scattered by the predetermined surface. The exposure apparatus according to claim 1, wherein the light irradiation unit includes a light source that emits reference light, and an optical member that can generate the plurality of measurement lights from the reference light. The exposure apparatus according to claim 2, wherein the optical member includes a first member that can generate the plurality of measurement lights by scattering or reflecting the reference light in a plurality of different directions. The exposure according to claim 3, wherein the first member includes an irradiation surface that is irradiated with the reference light and can generate the plurality of measurement lights by scattering or reflecting the reference light toward a plurality of different directions. apparatus. The exposure apparatus according to claim 4, wherein a random or irregular first uneven pattern is formed on the irradiation surface. The exposure according to claim 5, wherein the first concavo-convex pattern includes at least one of a first convex pattern protruding from the periphery along a direction intersecting the irradiation surface and a first concave pattern recessed from the periphery. apparatus. The exposure apparatus according to claim 6, wherein a size along a direction intersecting the irradiation surface of at least one of the first convex pattern and the first concave pattern is larger than a wavelength of the reference light. The exposure apparatus according to claim 5, wherein the first uneven pattern includes a second uneven pattern different from the mask pattern. The exposure apparatus according to any one of claims 4 to 8, wherein a reflectance of the irradiation surface with respect to the reference light is a predetermined value or more. The exposure apparatus according to claim 2, wherein the optical member includes a second member capable of branching the reference light into the plurality of measurement lights. A movable stage part holding the mask;
The exposure apparatus according to claim 2, wherein the optical member is fixed to the stage unit. The exposure apparatus according to claim 1, wherein the light irradiation unit includes a plurality of light sources that respectively irradiate the plurality of measurement lights. The light irradiation unit irradiates the plurality of irradiation lights toward one of the two opposing surfaces of the mask,
The said sensor part detects at least one part of these measurement light which propagates from the surface of the other side of the two surfaces where the said mask mutually opposes. Exposure equipment. The light irradiation unit irradiates the plurality of irradiation lights toward one of the two opposing surfaces of the mask,
The said sensor part detects at least one part of these measurement light which propagates from the surface of the said one side of the two surfaces where the said mask mutually opposes. The exposure apparatus described. The exposure apparatus according to claim 1, wherein an optical axis of an irradiation optical system including the light irradiation unit is different from an optical axis of a sensor optical system including the sensor unit. A movable stage part holding the mask;
The exposure apparatus according to any one of claims 1 to 15, wherein the sensor unit is fixed to the stage unit. 2. The sensor unit acquires information on speckles generated by irradiating the predetermined surface with at least some of the plurality of measurement lights by detecting at least some of the plurality of measurement lights. The exposure apparatus according to any one of items 16 to 16. The predetermined surface is formed with a third concavo-convex pattern regularly arranged along the first direction,
The exposure apparatus according to claim 1, wherein the light irradiation unit irradiates the third uneven pattern with a plurality of measurement lights having different incident angles with respect to the predetermined surface. The exposure apparatus according to any one of claims 1 to 18, further comprising a moving unit that moves at least one of the light irradiation unit and the sensor unit. An exposure apparatus that irradiates a mask with an energy beam and transfers a mask pattern formed on the pattern surface of the mask to an object,
A light irradiation unit for irradiating measurement light to a predetermined surface of the mask;
A sensor unit for detecting at least a part of the measurement light reflected or scattered by the predetermined surface;
An exposure apparatus comprising: a moving unit that moves at least one of the light irradiation unit and the sensor unit. A movable stage part holding the mask;
The exposure according to claim 19 or 20, wherein the moving unit moves at least one of the light irradiation unit and the sensor unit along a direction parallel to the pattern surface and intersecting a moving direction of the stage unit. apparatus. A movable stage part holding the mask;
The moving unit is configured to irradiate the light such that the predetermined surface on which the light irradiating unit irradiates the measurement light moves in a direction parallel to the pattern surface and intersecting the moving direction of the stage unit. The exposure apparatus according to any one of claims 19 to 21, wherein the part is moved. A movable stage part holding the mask;
The moving unit moves so that the predetermined surface on which the measurement light detected by the sensor unit is reflected or scattered is parallel to the pattern surface and intersects the moving direction of the stage unit. The exposure apparatus according to claim 19, wherein the sensor unit is moved. The moving unit includes the light irradiation unit and the sensor based on a position of a part of the pattern surface on which the part of the pattern surface actually used for the exposure is formed in the pattern surface. The exposure apparatus according to any one of claims 19 to 22, wherein at least one of the parts is moved. The exposure apparatus according to claim 24, wherein the moving unit moves at least one of the light irradiation unit and the sensor unit such that the predetermined surface is included in the partial pattern surface. A plurality of sensor units that detect measurement light reflected or scattered by the predetermined surfaces that are different from each other,
The exposure apparatus according to any one of claims 19 to 25, wherein the moving unit moves each of the plurality of sensor units. The light irradiation unit irradiates the predetermined surface with the measurement light at a second timing different from the first timing at which the mask pattern is transferred to the object,
The exposure apparatus according to any one of claims 1 to 25, wherein the sensor unit detects at least a part of the measurement light at a third timing different from the first timing. An exposure apparatus that irradiates a mask with an energy beam and transfers a mask pattern formed on the pattern surface of the mask to an object,
A light irradiating unit that irradiates a predetermined surface of the mask with measurement light at a second timing different from the first timing at which the mask pattern is transferred to the object;
An exposure apparatus comprising: a sensor unit that detects at least a part of the measurement light reflected or scattered by the predetermined surface at a third timing different from the first timing. A movable object stage unit for holding the object;
The exposure apparatus according to claim 27 or 28, wherein at least one of the second timing and the third timing includes at least a part of a timing at which the object held by the object stage unit is replaced. 30. The exposure apparatus according to any one of claims 27 to 29, wherein at least one of the second timing and the third timing includes at least a part of a timing for measuring an operation parameter or a state parameter of the exposure apparatus. . The exposure according to any one of claims 27 to 30, wherein at least one of the second timing and the third timing includes at least a part of a timing at which the predetermined surface is positioned outside an optical path of the energy beam. apparatus. A first measurement unit that measures the position of the mask using a mask alignment mark formed on the mask;
32. At least one of the second timing and the third timing includes at least a part of timing at which the first measurement unit measures the position of the mask using the mask alignment mark. An exposure apparatus according to claim 1. The exposure apparatus according to any one of claims 27 to 32, wherein at least a part of the second timing overlaps at least a part of the third timing. A movable mask stage portion for holding the mask;
Calculation for calculating a variation amount of a predetermined region on the pattern surface based on at least a part of the measurement light detected by the sensor unit and reflected or scattered by the predetermined surface And further comprising
The mask stage portion is provided with a reference member on which a reference pattern is formed,
The light irradiation unit irradiates the measurement light to the reference member at a fourth timing different from the first timing,
The sensor unit detects at least a part of the measurement light reflected or scattered by the reference member at a fifth timing different from the first timing,
The calculation unit is caused by a drift of the sensor unit based on at least a part of the measurement light detected by the sensor unit and reflected or scattered by the reference member. The exposure apparatus according to any one of claims 27 to 33, wherein a measurement error of the fluctuation amount is calculated. A movable object stage unit for holding the object;
35. The exposure apparatus according to claim 34, wherein at least one of the fourth timing and the fifth timing includes at least a part of a timing at which the object held by the object stage unit is replaced. 36. The exposure apparatus according to claim 34 or 35, wherein at least one of the fourth timing and the fifth timing includes at least a part of a timing for measuring an operation parameter or a state parameter of the exposure apparatus. 37. The exposure according to any one of claims 34 to 36, wherein at least one of the fourth timing and the fifth timing includes at least a part of a timing at which the predetermined surface is located outside an optical path of the energy beam. apparatus. A measuring unit that measures the position of the mask using a mask alignment mark formed on the mask;
38. At least one of the fourth timing and the fifth timing includes at least a part of timing at which the measurement unit measures the position of the mask using the mask alignment mark. The exposure apparatus according to item. An exposure method for irradiating a mask with an energy beam and transferring a mask pattern formed on the pattern surface of the mask to an object,
Irradiating a predetermined surface of the mask with a plurality of measurement lights having different incident angles with respect to the predetermined surface;
An exposure method for detecting at least a part of the plurality of measurement lights reflected or scattered by the predetermined surface. An exposure method for irradiating a mask with an energy beam and transferring a mask pattern formed on the pattern surface of the mask to an object,
Using a light irradiation unit, irradiate measurement light to a predetermined surface of the mask,
Using a sensor unit, detect at least a part of the measurement light reflected or scattered by the predetermined surface,
An exposure method for moving at least one of the light irradiation unit and the sensor unit. An exposure method for irradiating a mask with an energy beam and transferring a mask pattern formed on the pattern surface of the mask to an object,
Irradiating the predetermined surface of the mask with measurement light at a second timing different from the first timing at which the mask pattern is transferred to the object;
An exposure method that detects at least a part of the measurement light reflected or scattered by the predetermined surface at a third timing different from the first timing. The mask pattern is transferred to a sensitive substrate by the exposure method according to any one of claims 39 to 41,
A device manufacturing method for developing the sensitive substrate to which the mask pattern is transferred.

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