JP2012195379A - Overlay accuracy measurement method, exposure device, and manufacturing method of device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure overlay accuracy with high accuracy, and to reduce time from completion of measurement to start of exposure by immersion method.SOLUTION: A measurement method of overlay accuracy includes steps 302, 306 for sequentially exposing images of first and second overlay measurement marks in a plurality of shot regions of a wafer by an immersion method, a step 316 for measuring the amount of displacement between the first and second overlay measurement marks in a first set of the plurality of shot regions of the wafer via an alignment system, a step 318 for rotating the wafer by 180° so that the wafer does not come into contact with the liquid, and a step 324 for measuring the amount of displacement between the first and second overlay measurement marks in a second set of the shot regions of the wafer via the alignment system.

Description

  The present invention relates to a measurement technique for overlay accuracy when a pattern is superimposed on a substrate for exposure, an exposure technique to which this measurement technique can be applied, and a device manufacturing technique using this exposure technique.

  Conventionally, for example, an exposure apparatus used in a lithography process for manufacturing a semiconductor device uses a plurality of alignment systems to maintain high overlay accuracy between a plurality of layers of a semiconductor wafer (hereinafter simply referred to as a wafer). The position of the mark (wafer mark) attached to the shot area (alignment shot) selected from the shot area is detected. Then, the detected mark position is statistically processed by, for example, the EGA method, the array coordinates of each shot area are obtained, and the wafer is driven based on the array coordinates, whereby the reticle pattern image is formed on each shot area of the wafer. Are overlaid with high precision. Further, by using the alignment system, by measuring the amount of displacement between the first layer overlay measurement mark and the second layer overlay measurement mark formed in a predetermined shot area of the wafer, the two layers It is also possible to measure the overlay accuracy.

  Recently, in order to efficiently perform wafer alignment, a multi-axis alignment system including a first alignment system in which a detection region is fixed and a second alignment system in which the detection region is variable is provided. The relative position of the wafer in a predetermined direction with respect to the system, and the position of the mark attached to the alignment shot in one row of the wafer by the multi-axis alignment system with the multi-axis alignment system stationary relative to the wafer An exposure apparatus has been developed that repeats the detection of (see, for example, Patent Document 1 and Patent Document 2). In this exposure apparatus, exposure using a liquid immersion method is performed following mark detection by the multi-axis alignment system.

International Publication No. 2007/097379 Pamphlet International Publication No. 2008/029757 Pamphlet

  In an exposure apparatus that performs exposure by a conventional liquid immersion method, in order to accurately measure the positional deviation amount of the two-layer overlay measurement mark formed on the wafer using the alignment system, a liquid is applied to the surface of the wafer. It may be preferred that no liquid be used in the immersion exposure. However, if the supply of the liquid between the projection optical system and the wafer is stopped for that purpose, it takes time until the flow rate and temperature of the liquid stabilize when the exposure is started next. Therefore, in order to shorten the time from the completion of the measurement of the overlay accuracy to the start of exposure, it is preferable not to stop the liquid supply.

  In view of such circumstances, an object of the present invention is to make it possible to measure the overlay accuracy with high accuracy and to shorten the time from the end of the overlay accuracy measurement to the start of exposure by the liquid immersion method.

  According to the first aspect of the present invention, there is provided a method for measuring overlay accuracy when exposing a substrate through exposure optical projection light and a liquid that transmits the exposure light. In this measurement method, the exposure light exposes the image of the first mark at a plurality of positions on the substrate through the projection optical system and the liquid, and the exposure light passes through the projection optical system and the liquid. Exposing the image of the second mark corresponding to the first mark at the plurality of positions on the substrate, and passing through the mark detection system disposed at a position away from the projection optical system. Measuring a first misalignment of the first mark and a corresponding second mark of a plurality of measurement positions in a first set of a part of the plurality of positions, and contacting the liquid with the substrate The second set including a plurality of positions different from the plurality of measurement positions of the first set among the plurality of positions of the substrate through the mark detection system. The first mark and multiple measurement positions of And measuring the second deviation amount of the second mark corresponding thereto, it is intended to include.

  Moreover, according to the 2nd aspect, the exposure apparatus which exposes a board | substrate via a projection optical system with exposure light is provided. The exposure apparatus supplies a liquid that transmits the exposure light between the projection optical system and the substrate during the exposure of the substrate and the stage that moves the substrate, and collects the supplied liquid. The liquid supply device and the projection optical system are arranged independently of each other, a mark detection system for detecting the position of the mark on the substrate, and the substrate received from the stage, rotated by a predetermined angle, and then received on the stage again. A substrate rotating device to be handed over.

  According to a third aspect, there is provided a device manufacturing method comprising: forming a photosensitive pattern on an object using the exposure apparatus of the present invention; and processing the exposed object based on the photosensitive pattern. Is provided.

  According to the present invention, the amount of positional deviation between two marks is measured at a plurality of measurement positions of the first set of substrates, the substrate is rotated so that the substrate does not contact the liquid, and then the second set of the substrates is set. The amount of positional deviation between the two marks is measured at a plurality of measurement positions. That is, the overlay accuracy can be measured with high accuracy in a state where the liquid is supplied between the projection optical system and the member facing the projection optical system, and in a state where the liquid is not supplied to the measurement position on the surface of the substrate. Furthermore, exposure using the liquid immersion method can be started immediately after the measurement is completed. Accordingly, it is possible to shorten the time from the completion of the measurement of the overlay accuracy to the start of exposure by the liquid immersion method.

It is a figure which shows schematic structure of the exposure apparatus which concerns on an example of embodiment. It is a figure which shows arrangement | positioning of the alignment system of FIG. 1, and the encoder for position measurement. FIG. 2 is a block diagram showing a main configuration of a control system of the exposure apparatus in FIG. 1. It is a flowchart which shows an example of the measuring method of superimposition precision. (A) is a figure which shows the state which measures the 1st alignment shot, (B) is a figure which shows the state which measures the 3rd alignment shot, (C) is a figure which shows an example of the arrangement | sequence of an alignment shot. (A) is an enlarged view showing the overlay measurement mark on the first layer, (B) is an enlarged view showing the overlay measurement mark on the first layer and the second layer, and (C) is FIG. 6 (B). ) Is an enlarged view showing the two-layer overlay measurement mark, and (D) is an enlarged sectional view showing the overlay measurement mark. (A) and (B) are diagrams showing an arrangement for detecting wafer marks by a three-eye and five-eye alignment system, respectively, and (C) and (D) are overlay measurement marks by a three-eye and five-eye alignment system, respectively. It is a figure which shows the arrangement | positioning which measures the amount of positional deviation between. (A) is a diagram showing an arrangement after the wafer is rotated 180 ° on wafer stage WST, and (B) and (C) are diagrams showing an arrangement for detecting a wafer mark with a three-eye and five-eye alignment system, respectively. is there. (A) and (B) are diagrams showing an arrangement for measuring the amount of positional deviation between overlay measurement marks in a three-eye and five-eye alignment system, respectively, and (C) is an overlay error measured before the wafer is rotated. FIG. 4D is a diagram showing an overlay error vector measured before and after the rotation of the wafer. It is a flowchart which shows an example of the manufacturing process of an electronic device.

  An exemplary embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of an exposure apparatus EX according to the present embodiment. The exposure apparatus EX is, for example, a scanning exposure type projection exposure apparatus (scanning type exposure apparatus) composed of a scanning stepper (scanner). As will be described later, in the present embodiment, the projection optical system PL is provided. In the following description, the Z-axis is taken in parallel to the optical axis AX of the projection optical system PL, and the reticle and wafer are aligned in a plane perpendicular to the Z-axis. Takes the Y axis in the direction relative to the projection optical system PL, the X axis in the direction perpendicular to the Z axis and the Y axis, and the rotation (tilt) direction around the X axis, Y axis, and Z axis Are described as θx, θy, and θz directions, respectively.

  In FIG. 1, an exposure apparatus EX includes an illumination system 10 that illuminates a reticle R with illumination light (exposure light) IL for exposure, a reticle stage RST that holds and moves the reticle R, and illumination light IL that has passed through the reticle R. A projection unit PU including a projection optical system PL that projects onto the surface of the wafer W, a wafer stage WST that holds and moves the wafer W, a control system thereof, and the like are provided. The exposure apparatus EX further includes a wafer alignment apparatus 80 that detects a wafer mark on the wafer W and a wafer loader system WL that transfers the wafer W to the wafer stage WST.

  The illumination system 10 includes a light source and an illumination optical system as disclosed in, for example, Japanese Patent Application Laid-Open No. 2001-313250 (corresponding US Patent Application Publication No. 2003/0025890), and the illumination optical system. Includes, for example, a light amount distribution forming optical system including a diffractive optical element or a spatial light modulator, an optical integrator (such as a fly-eye lens or a rod integrator), and a reticle blind (not shown). The illumination system 10 illuminates the slit-shaped illumination area IAR on the pattern surface (reticle surface) of the reticle R defined by the reticle blind with illumination light IL with a substantially uniform illuminance distribution. As the illumination light IL, for example, ArF excimer laser light (wavelength 193 nm) is used. As illumination light, KrF excimer laser light (wavelength 248 nm), harmonic of a YAG laser, harmonic of a solid laser (such as a semiconductor laser), or a bright line (such as i-line) of a mercury lamp can be used.

  On the upper surface of reticle stage RST, reticle R on which a circuit pattern or the like is formed is held, for example, by vacuum suction. The reticle stage RST can be driven minutely in the XY plane and can be driven at a scanning speed specified in the scanning direction (Y direction). Position information (including the position in the X direction, the Y direction, and the rotation angle in the θz direction) within the moving surface of the reticle stage RST is, for example, 0. 0 through the moving mirror 15 by the reticle interferometer 116 including a laser interferometer. It is always detected with a resolution of about 5 to 0.1 nm. The measurement value of reticle interferometer 116 is sent to main controller 20 in FIG. Main controller 20 controls reticle stage drive system 11 based on the measured value, thereby controlling the position and speed of reticle stage RST.

  In FIG. 1, the projection unit PU disposed below the reticle stage RST includes a lens barrel 40 and a projection optical system PL having a plurality of optical elements held in the lens barrel 40 in a predetermined positional relationship. . The projection optical system PL is, for example, telecentric on both sides (or one side on the wafer side) and has a predetermined projection magnification β (eg, 1/4 times, 1/5 times, etc.). An image of the circuit pattern of the reticle R in the illumination area IAR is formed in the exposure area IA (an area conjugate to the illumination area IAR) of one shot area of the wafer W via the projection optical system PL. Wafer W (semiconductor wafer) has a predetermined thickness (for example, several 10 to 10) of photoresist, which is a photosensitive agent (photosensitive layer), on the surface of a substrate made of, for example, disc-shaped silicon having a diameter of about 200 mm to 450 mm. (Approx. 200 nm). In each shot area of the wafer W of the present embodiment, a predetermined single layer or a plurality of layers of circuit patterns and corresponding wafer marks are formed by the pattern forming process so far.

  In the exposure apparatus EX, in order to perform exposure using the liquid immersion method, the lower end of the lens barrel 40 that holds the tip lens 191 that is the optical element on the most image plane side (wafer W side) constituting the projection optical system PL. A nozzle unit 32 constituting a part of the local liquid immersion device 8 is provided so as to surround the part periphery. The nozzle unit 32 has a supply port that can supply the exposure liquid Lq and a recovery port that can recover the liquid Lq. The supply port is connected to a liquid supply device 5 (see FIG. 3) capable of delivering the liquid Lq via a supply pipe 31A. The recovery port is connected to a liquid recovery apparatus 6 (see FIG. 3) that can recover the liquid Lq via a recovery pipe 31B.

  The exposure liquid Lq delivered from the liquid supply device 5 in FIG. 3 flows through the supply pipe 31A and the supply flow path of the nozzle unit 32 in FIG. 1 and then is supplied to the optical path space of the illumination light IL from the supply port. Is done. Further, the liquid Lq recovered from the recovery port of the nozzle unit 32 is recovered by the liquid recovery device 6 via the recovery pipe 31B. By this operation, during the scanning exposure, the liquid immersion region 14 (see FIG. 2) including the optical path space (local liquid immersion space) of the illumination light IL between the tip lens 191 and the wafer W is filled with the liquid Lq. During normal exposure, the surface of the wafer W is often provided with a liquid repellent coating (top coat) that repels the liquid Lq.

  When the supply of the liquid Lq is once stopped and then the supply of the liquid Lq is started again, a certain amount of time is required until the flow rate or temperature of the liquid Lq is stabilized. Therefore, in the present embodiment, the liquid immersion region 14 (in some cases, the illumination light IL may not be irradiated) may be used even during a period in which scanning exposure is not performed, for example, during wafer loading and unloading and during wafer alignment. The liquid Lq is always supplied and recovered. In this case, even if projection optical system PL is separated from wafer stage WST, measurement stage MST (not shown in FIG. 1, not shown in FIG. 1) is independent from wafer stage WST so that there is a member facing the tip of projection optical system PL. 5 (A)) is arranged.

  In FIG. 1, a measurement stage MST (see FIG. 5A) having a wafer stage WST and an apparatus for measuring the imaging characteristics of the projection optical system PL is disposed on the upper surface of the base board 12. The measurement stage MST is disclosed in, for example, pamphlet of International Publication No. 2008/029757 (corresponding to US Patent Application Publication No. 2008/094593). An interferometer system 118 (see FIG. 3) including a Y-axis interferometer 16 that measures position information of wafer stage WST and measurement stage MST is provided. Wafer stage WST is provided in stage body 91 that moves in the X direction and Y direction, wafer table WTB mounted on the upper surface of stage body 91, and in stage body 91. A Z stage (not shown) that relatively finely drives the wafer table WTB (wafer W) in the θx direction and the θy direction is provided. The measurement stage MST is similarly configured. Wafer stage WST and measurement stage MST are driven by stage drive system 124 of FIG.

  At the center of wafer table WTB, a wafer holder (not shown) for holding wafer W by vacuum suction or the like is provided. Further, the upper surface of wafer table WTB has a surface (liquid repellent surface) that is liquid repellent with respect to liquid Lq and has the same height as the surface of the wafer placed on the wafer holder, and has an outer shape ( A plate (liquid repellent plate) 28 having a low thermal expansion coefficient having a rectangular outline and a circular opening that is slightly larger than the wafer holder (wafer mounting region) is provided at the center thereof. A part of the plate 28 is provided with a reference member FM (see FIG. 2) in which a reference mark for baseline measurement is formed and a slit for measuring the position of the pattern image of the reticle R is formed. ing. On the bottom surface of the reference member FM, an aerial image measuring device 45 (see FIG. 3) that receives the light beam that has passed through the slit is provided.

  As shown in FIG. 2, a pair of Y scales 39Y1 and 39Y2 and a pair of X scales 39X1 and 39X2 for an encoder system to be described later are formed in a frame-shaped region around the plate 28. The Y scales 39Y1 and 39Y2 and the X scales 39X1 and 39X2 are diffraction gratings having a predetermined pitch in the Y direction and the X direction, respectively. The predetermined pitch is, for example, about 138 nm to 4 μm.

  In FIG. 1, end surfaces in the −Y direction and −X direction of wafer table WTB are each mirror-finished to be reflecting surfaces. The interferometer 16 and the like project the measurement beams onto these reflecting surfaces, respectively, and position information (X direction, Y direction position, θx direction, θy direction, θz direction angle) of the wafer stage WST in the XY plane. For example, measurement is performed with a resolution of about 0.5 to 0.1 nm, and this measurement value is supplied to the main controller 20. The position information of the measurement stage MST is also measured in the same way.

  However, in this embodiment, the position information of wafer stage WST (wafer table WTB) in the XY plane is mainly measured by an encoder system described later including the above-described Y scale and X scale, and the interferometer 16 and the like. The measured value is used supplementarily when correcting long-term fluctuations in the measured value of the encoder system. The interferometer 16 is also used for measuring the position of the wafer table WTB in the Y direction in the vicinity of the unloading position and the loading position for wafer replacement. Further, the upper surface of wafer table WTB (or the upper surface of measurement stage MST) is elongated in the X direction in which a number of reference marks made up of two-dimensional marks are formed in order to measure a baseline of a secondary alignment system described later. A reference member (not shown) is provided.

  In the exposure apparatus EX of the present embodiment, illustration is omitted in FIG. 1 from the viewpoint of avoiding complication of the drawing, but actually, as shown in FIG. 2, it passes through the optical axis AX of the projection optical system PL and Y On the straight line LV parallel to the axis, a primary alignment system (hereinafter referred to as a main alignment system) AL1 having a detection center at a position spaced a predetermined distance from the optical axis AX in the −Y direction side is disposed. A two-lens secondary alignment system (hereinafter, referred to as “secondary alignment system”) in which detection centers are arranged almost symmetrically with respect to the straight line LV on both sides in the X direction with a main alignment system AL1 fixed to an unillustrated main frame via an arm 54. Sub-alignment system) AL21 and AL22, and two-lens sub-alignment systems AL23 and AL24 are provided. That is, the detection areas (detection centers) of the five-eye alignment systems AL1, AL21 to AL24 are arranged along the X direction.

  Each of the sub-alignment systems AL21 to AL24 is fixed to the tip (rotation end) of an arm 56 that can be rotated around a rotation center (for example, center O). Each arm 56 can be fixed to a main frame (not shown) via a vacuum pad 58. In the present embodiment, each of the sub-alignment systems AL21 to AL24 has at least a part thereof (for example, an optical system that irradiates a detection region with alignment light and guides light generated from a test mark in the detection region to a light receiving element). (Including the portion) is fixed to the arm 56 and the remaining part is provided on the main frame. Under the control of the main controller 20, the X position of each detection region is adjusted by rotating the arms 56 of the sub-alignment systems AL21 to AL24 via the rotation drive mechanism 60. The X position of each detection area is measured by an encoder (not shown).

  In the present embodiment, as the alignment systems AL1, AL21 to AL24, for example, an image processing type FIA (Field Image Alignment) system is used. In this FIA system, the test mark is irradiated with broadband light that does not expose the resist on the wafer or light of a selected wavelength range, and the test mark imaged on the light receiving surface by the reflected light from the test mark. An image is picked up using an image pickup device (CCD type or CMOS type), and those image pickup signals are output to a signal processing unit. In this case, for example, the position of the image of the test mark is detected based on the position of a predetermined pixel in the image sensor. The field of view on the test surface conjugate with the imaging surface of the image sensor is the detection region of the alignment systems AL1, AL22 to AL24, and the center thereof is the detection center. In the signal processing unit, the image pickup signal is sliced with a predetermined threshold, for example, and the amount of positional deviation in the X and Y directions with respect to the detection center of the corresponding mark is obtained. At the time of normal alignment, this misalignment amount is supplied to the EGA calculation unit 134 of FIG. 3 via the main controller 20. The EGA calculation unit 134 obtains the coordinates of the test mark in the stage coordinate system (X, Y) from the positional deviation amount, the baseline of each alignment system, and the coordinates (X, Y) of the wafer stage WST. Obtaining the coordinates of the test mark by the EGA calculation unit 134 in this manner is hereinafter referred to as detecting the position of the test mark using the alignment systems AL1, AL22 to AL24.

  At the time of overlay accuracy measurement, which will be described later, the alignment systems AL1, AL22 to AL24 measure the positional deviation amounts of the two marks in the X direction and Y direction, and the measured positional deviation amounts are displayed via the main controller 20. 3 to the superposition calculation unit 135. Each of the alignment systems AL1, AL22 to AL24 includes an AF system (not shown) that measures the defocus amount with respect to the best focus position. Wafer alignment apparatus 80 includes alignment systems AL1, AL21 to AL24, main controller 20, and wafer stage WST. In this embodiment, since the five-eye alignment systems AL1, AL21 to AL24 are provided, alignment can be performed efficiently. However, the number of alignment systems is not limited to five, and may be two or more and four or less, or six or more, or may be an even number instead of an odd number.

  The wafer loader system WL includes a guide portion WL1 parallel to the X axis, a slide portion WL2 movable in the X direction along the guide portion WL1, and a wafer arm that is supported by the tip of the slide portion WL2 and sucks and holds the wafer. WL3 and a rotation part WL4 that rotates the wafer arm WL3 by 180 ° with respect to the slide part WL2. Main controller 20 controls the operation of wafer loader system WL via wafer loader drive system 125 (see FIG. 3) including position and angle sensors (not shown).

In the exposure apparatus EX of the present embodiment, as shown in FIG. 2, four head units 62 </ b> A to 62 </ b> D of the encoder system are arranged so as to surround the nozzle unit 32 from four directions. A plurality of Y heads 64 and X heads 66 constituting these head units 62A to 62D are fixed to the bottom surface of a main frame (not shown).
In FIG. 2, head units 62A and 62C are arranged at a predetermined interval in the X direction on a straight line LH passing through the optical axis AX of the projection optical system PL and parallel to the X axis on the ± X direction side of the projection unit PU. A plurality of Y heads 64 are provided. Y head 64 uses Y scale 39Y1 or 39Y2 to measure the position of wafer stage WST (wafer table WTB) in the Y direction with the same resolution as the laser interferometer. The head units 62B and 62D each include a plurality of X heads 66 arranged on the straight line LV passing through the optical axis AX on the ± Y direction side of the projection unit PU and parallel to the Y axis at substantially predetermined intervals in the Y direction. I have. X head 66 uses X scale 39X1 or 39X2 to measure the position of wafer stage WST (wafer table WTB) in the X direction with the same resolution as the laser interferometer. An example of the configuration of the Y head 64 and the X head 66 is disclosed in International Publication No. 2008/029757 (and the corresponding US Patent Application Publication No. 2008/094593).

  Head units 62A and 62C in FIG. 2 use multi-scale Y-axis linear encoders (hereinafter abbreviated as Y encoders) 70A and 70C that measure the Y position of wafer stage WST using Y scales 39Y1 and 39Y2, respectively. (See FIG. 3). Each of the Y encoders 70A and 70C includes a switching control unit that switches the measurement values of the plurality of Y heads 64.

  The head units 62B and 62D use X scales 39X1 and 39X2, respectively, to measure the X position of the wafer stage WST, and are multi-lens X-axis linear encoders (hereinafter abbreviated as X encoders) 70B and 70D. (See FIG. 3). Each of the X encoders 70B and 70D includes a switching control unit that switches the measurement values of the plurality of X heads 66. Furthermore, in the present embodiment, a Y-axis encoder 70E, which is a linear encoder configured by a Y head (not shown) for measuring the Y position of wafer stage WST, for example, during baseline measurement of a secondary alignment system described later. 70F (see FIG. 3) is also provided.

The measured values of the six encoders 70A to 70F described above are supplied to the main controller 20 and the EGA arithmetic unit 134, and the main controller 20 determines the XY plane of the wafer stage WST or the like based on the measured values of the encoders 70A to 70F. Control the position within.
As shown in FIG. 2, the exposure apparatus EX of the present embodiment comprises an irradiation system 90a and a light receiving system 90b, for example, Japanese Patent Laid-Open No. 6-283403 (corresponding US Pat. No. 5,448,332). The multi-point focal position detection system (hereinafter abbreviated as the multi-point AF system) of the oblique incidence method having the same configuration as that disclosed in FIG. In the present embodiment, as an example, the irradiation system 90a is disposed on the −Y direction side of the head unit 62C, and the light receiving system 90b is disposed on the −Y direction side of the head unit 62A in a state of facing the irradiation system 90a. ing.

  A plurality of detection points of the multi-point AF system (90a, 90b) in FIG. 2 are arranged at predetermined intervals along the X direction in an elongated detection area AF extending in the X direction on the test surface. In the present embodiment, the plurality of detection points are arranged in a matrix of, for example, 1 row and M columns (M is the total number of detection points) or 2 rows and N columns (N is 1/2 of the total number of detection points). Since the length of the detection area AF in the X direction is set to be approximately the same as the diameter of the wafer W, position information in the Z direction can be obtained on almost the entire surface of the wafer W by scanning the wafer W once in the Y direction. (Surface position information) can be measured. Since the detection area AF is arranged between the liquid immersion area 14 (exposure area IA) and the detection areas of the alignment systems (AL1, AL21 to AL24) in the Y direction, The detection operation can be performed in parallel with the alignment system. The multipoint AF system may be provided in the main frame that holds the projection unit PU.

  Further, the head units 62C and 62A described above include a plurality of Z sensors 74 and 76 disposed along two straight lines parallel to the X axis that sandwich the straight line LH connecting the plurality of Y heads 64 and at predetermined intervals. I have. As each of the Z sensors 74 and 76, for example, a CD pickup type sensor is used. Z sensors 74 and 76 are fixed to the bottom surface of the measurement frame 21. In FIG. 2, reference numeral 78 denotes dry air whose temperature is adjusted to a predetermined temperature in the vicinity of the beam path of the multipoint AF system (90a, 90b), as indicated by the white arrow in FIG. The local air-conditioning system which ventilates by a down flow is shown. Reference symbols UP and LP are arranged in parallel at a predetermined interval in the −Y direction with respect to the projection optical system PL, respectively, and have an unload position and a loading position at which the wafer is unloaded and loaded with respect to the wafer table WTB. Show.

FIG. 3 shows the main configuration of the control system of the exposure apparatus EX. This control system is mainly configured of a main control device 20 composed of a computer that performs overall control of the entire device.
The exposure apparatus EX of the present embodiment configured as described above employs the X scale and Y scale arrangement of the wafer table WTB as described above and the X head and Y head arrangement as described above. As exemplified in FIG. 5B and the like, in the effective stroke range of wafer stage WST, X scale 39X1 and 39X2 and head units 62B and 62D (X head 66) always face each other, and Y scale 39Y1. , 39Y2 and the head units 62A, 62C (Y head 64) or a Y head (not shown) are opposed to each other.

  For this reason, main controller 20 controls the respective motors constituting stage drive system 124 based on at least three measurement values of encoders 70A to 70F in the effective stroke range of wafer stage WST described above. The position of stage WST in the XY plane (including the rotation angle in the θz direction) can be controlled with high accuracy. Since the influence of the air fluctuations on the measurement values of the encoders 70A to 70F is negligibly small compared to the interferometer, the short-term stability of the measurement values caused by the air fluctuation is much better than that of the interferometer.

  When the wafer W is exposed by the exposure apparatus EX, the alignment of the wafer W is performed by first detecting the wafer mark on the wafer W using the alignment systems AL1, AL22 to AL24. Subsequently, the wafer W moves to the scanning start position by moving the wafer stage WST (step movement). The liquid Lq is continuously supplied and recovered in the liquid immersion area 14 between the projection optical system PL and the wafer W. In this state, irradiation of the illumination light IL is started, and the reticle R and the wafer W are projected through the reticle stage RST and the wafer stage WST while exposing the wafer W with an image of the pattern of the reticle R by the projection optical system PL. By synchronously moving the magnification as the speed ratio, the pattern image of the reticle R is scanned and exposed on one shot area of the wafer W. Thus, the image of the pattern of the reticle R is exposed on the entire shot area of the wafer W by the step-and-scan operation in which the step movement and the scanning exposure are repeated.

  Hereinafter, an example of a method for measuring the overlay accuracy under the control of the main controller 20 in the exposure apparatus EX of the present embodiment will be described with reference to the flowchart of FIG. First, in step 302 of FIG. 4, a reticle R1 on which a pattern (first pattern) for overlay measurement marks of the first layer and a pattern for wafer marks are formed is loaded on the reticle stage RST, and the wafer stage WST is loaded. A wafer (referred to as wafer W) having a thin film and a photoresist layer formed on the surface of the substrate is loaded. Then, the pattern image of the reticle R1 is scanned and exposed to each shot area of the wafer W by a liquid immersion method. In the next step 304, the wafer W is developed by a coater / developer (not shown) and etched by an etching apparatus (not shown). Thereby, as shown in FIG. 6A, two line and space patterns (hereinafter referred to as L & S patterns) 50X arranged in the X direction on the first layer of each shot area SA of the wafer W, respectively. And two overlapping L & S patterns 50Y) (50Y) are formed. Further, a two-dimensional wafer mark WM is formed in a predetermined positional relationship with the first overlay measurement mark 50 in each scribe line area SLA between adjacent shot areas SA. In FIGS. 6A and 6B, the wafer mark WM, the first overlay measurement mark 50, and the like are shown enlarged.

  In the next step 306, reticle R2 on which a second layer overlay measurement mark pattern (second pattern) is formed is loaded on reticle stage RST, and wafer W on which photoresist layer is formed on wafer stage WST. To load. As an example, as shown in FIG. 5C, alignment shots AS for measuring wafer marks in a shot array of wafers W are arranged from the first row to the fourth row arranged with three shot regions separated in the X direction. It is assumed that there are 16 shot areas up to the column. In this case, first, as shown in FIG. 5A, wafer stage WST is moved in the + Y direction, and wafer marks WM of three first-row alignment shots AS in three-lens alignment systems AL1, AL22, AL23 are used. The position of (see FIG. 6A) is detected. In FIG. 5A and the like, an asterisk is attached to the alignment system that detects the wafer mark in the alignment systems AL1, AL22 to AL24. 5A and 5B, the wafer mark is shown inside the shot area for convenience of explanation.

  Next, wafer stage WST is moved in the + Y direction, and the positions of wafer marks of five second-row alignment shots AS are detected by five-lens alignment systems AL1, AL22 to AL24. Thus, at the stage of detecting the position of the wafer mark WM attached to the alignment shots AS in the first and second rows, the measurement stage MST is positioned below the projection optical system PL, and the immersion area 14 Is formed between the measurement stage MST and the projection optical system PL.

  Thereafter, wafer stage WST (wafer W) is further moved in the + Y direction, and as shown in FIG. 5 (B), five third-row alignment shots AS are obtained by alignment systems AL1 and AL22 to AL24 of five eyes. When detecting the position of the wafer mark, wafer stage WST is positioned below projection optical system PL, and liquid immersion region 14 is formed between wafer stage WST and projection optical system PL. Accordingly, the liquid Lq is applied to the surface of the end portion in the + Y direction of the wafer W.

  Further, when wafer stage WST (wafer W) is moved in the + Y direction and the positions of wafer marks of three fourth-row alignment shots AS are detected by three-lens alignment systems AL1, AL22, AL23, wafer W The liquid Lq is applied to a region of about 1/3 in the + Y direction on the surface of the surface. However, since the detection of the wafer mark by the alignment systems AL1, AL22 to AL24 has been completed, the alignment accuracy does not decrease. The EGA calculation unit 134 calculates the shot arrangement of the wafer W from the coordinates of the 16 wafer marks by, for example, the EGA method, and sends the calculation result to the main controller 20. By moving the wafer W based on the shot arrangement, the pattern image of the reticle R2 is scanned and exposed to each shot area of the wafer W by the liquid immersion method. In the next step 308, the wafer W is developed by a coater / developer (not shown). In the next step 310, the developed wafer W is loaded onto wafer stage WST.

  As shown in FIG. 6B, in each shot area SA of the wafer W, in addition to the first overlay measurement mark 50 (main scale) of the first layer, an L & S pattern 52X arranged in the X direction and A second overlay measurement mark 52 (a resist pattern in this case) (sub-scale) is formed as a second layer made of the L & S pattern 52Y arranged in the Y direction. As an example, the L & S pattern 52X is formed between the X-axis L & S pattern 50X of the first overlay measurement mark 50, and the L & S pattern 52Y is between the Y-axis L & S pattern 50Y of the first overlay measurement mark 50. Is formed. In the present embodiment, in order to measure the overlay accuracy of the exposure apparatus EX, the alignment systems AL1, AL22 to AL24 are used, and within a predetermined plurality of measurement target shot areas selected from all shot areas of the wafer W. The displacement amounts ΔX and ΔY in the X and Y directions between the first overlay measurement mark 50 and the second overlay measurement mark 52 are measured. The shot area to be measured is preferably the entire shot area of the wafer W. Further, the shot area to be measured may be a plurality of shot areas of an arbitrary arrangement selected from all the shot areas. Here, for convenience of explanation, as an example, the alignment shot AS is a shot area to be measured.

  Further, as shown in FIG. 6C, the positional deviation amount ΔX is the positional deviation amount in the X direction between the two L & S patterns 50X and the L & S pattern 52X, and the positional deviation amount ΔY is the two L & S patterns. This is the amount of positional deviation in the Y direction between 50Y and the L & S pattern 52Y. In order to measure these misregistration amounts ΔX and ΔY, the wafer W is aligned, and the overlay measurement marks 50 and 52 in the shot area to be measured (alignment shot AS) are aligned with the alignment systems AL1, AL22 to AL24. It is necessary to move into one of the detection areas.

  Further, as shown in the enlarged sectional view of FIG. 6D, the L & S patterns 50X, 52X and the like of the overlay measurement marks 50, 52 are formed as an uneven pattern on the upper surface of the substrate Wa of the wafer W. In order to simplify the measurement process, a liquid-repellent coating (top coat) that repels the liquid Lq used for exposure by the immersion method is not formed on the surface of the wafer W to be measured. Therefore, in order to measure the positional deviation amount between the overlay measurement marks 50 and 52 with high accuracy, it is preferable that the liquid Lq is not applied to the surfaces of the overlay measurement marks 50 and 52.

  In this regard, as shown in FIGS. 5A and 5B, the wafer marks of the 16 alignment shots AS of the wafer W are simply used by using the alignment systems AL1, AL22 to AL24 while moving the wafer W in the + Y direction. When the position is detected, the liquid Lq in the liquid immersion region 14 is applied to the end of the wafer W in the + Y direction. Since the liquid Lq gradually flows on the surface of the wafer W, there is a possibility that the displacement amount of the overlay measurement marks 50 and 52 cannot be measured with high accuracy in the portion where the liquid Lq is applied. Therefore, in the present embodiment, the overlay measurement marks 50 and 52 in these shot areas are reliably applied to the entire shot target area (here, the alignment shot AS) without being exposed to the liquid Lq as follows. The amount of misalignment is measured.

  That is, in the next step 312, as shown in FIG. 7A, the wafer stage WST is driven to move the wafer W in the + Y direction from the loading position, and the three-lens alignment systems AL1, AL22, AL23 The positions of wafer marks WMA1, MWC1, and WMD1 attached to the alignment shots AS in the first row are detected. Wafer mark WMA1 and the like have the same shape as wafer mark WM in FIG. Next, as shown in FIG. 7B, the wafer mark is moved in the + Y direction, and the wafer marks attached to the five second-row alignment shots AS by the five-lens alignment systems AL1, AL22 to AL24. The positions of WMA2, MWB2 to WME2 are detected. At this stage, the immersion area 14 of the projection optical system PL is formed on the measurement stage MST, and the liquid Lq used when performing exposure by the immersion method is not applied to the wafer stage WST and the wafer W. . In the next step 314, the EGA calculation unit 134 calculates the array coordinates of the shot area of the almost half surface of the wafer W in the + Y direction by, for example, the EGA method from the coordinates of the detected eight wafer marks. If the number of shot areas in the Y direction of the wafer W is an odd number, the array coordinates of shot areas arranged in a line in the X direction in the center of the wafer W are also calculated.

  In the next step 316, wafer stage WST is driven based on the arrangement coordinates calculated in step 314, and the wafer is placed in the detection area of trinocular alignment systems AL1, AL22, AL23 as shown in FIG. The first overlay measurement marks 50A1, 50C1, and 50D1 and the second overlay measurement marks 52A1, 52C1, and 52D1 in the three first-row alignment shots AS of W are moved. The overlay measurement mark 50A1 and the like have the same shape as the first overlay measurement mark 50 in FIG. 6C, and the overlay measurement mark 52A1 and the like have the same shape as the second overlay measurement mark 52 in FIG. 6C. is there. Then, the displacement amounts in the X and Y directions between the overlay measurement marks 50A1, 50C1, 50D1 and 52A1, 52C1, 52D1 are measured by the alignment systems AL1, AL22, AL23. The measurement result is supplied to the overlay calculation unit 135 in FIG. 3 via the main controller 20. Note that the amount of positional deviation in the X and Y directions may be measured individually.

  Further, the wafer stage WST is driven, and as shown in FIG. 7D, the first in the alignment shots AS in the five second rows of the wafer W in the detection areas of the five-lens alignment systems AL1, AL22 to AL24. The overlay measurement marks 50A2 to 50E2 and the second overlay measurement marks 52A2 to 52E2 are moved. Then, the misalignment amounts in the X direction and Y direction between the overlay measurement marks 50A2 to 50E2 and 52A2 to 52E2 are measured by the alignment systems AL1, AL22 to AL24. The measurement result is supplied to the overlay calculation unit 135. At this stage, the immersion area 14 of the projection optical system PL is formed on the measurement stage MST, and the liquid Lq used in the immersion method is not applied to the surface of the wafer W at all. As shown in FIG. 9C, the amount of misalignment between the overlay measurement marks 50 and 52 in the alignment shot AS in the first row 54A and the second row 54B of the wafer W measured in step 316 is the overlay. Error vectors OEV <b> 1 to OEV <b> 8 are stored in the storage unit in the overlay calculation unit 135.

  In the next step 318, the center of wafer stage WST is moved to loading position LP in FIG. 2, and wafer W is transferred to wafer arm WL3 of wafer loader system WL. Then, wafer arm WL3 (wafer W) is rotated 180 ° by rotating unit WL4. To do. Thereafter, the slide part WL2 is moved in the + X direction, and the wafer W is loaded from the wafer arm WL3 onto the wafer stage WST. As a result, as shown in FIG. 8A, the wafer W is rotated by 180 ° in the θz direction with respect to the arrangement of FIG.

  In the next step 320, as shown in FIG. 8B, the wafer stage WST is driven to move the wafer W in the + Y direction, and three fourth columns are formed by the three-lens alignment systems AL1, AL22, AL23. The positions of wafer marks WMA4, MWD4, WMC4 attached to the alignment shot AS are detected. Next, as shown in FIG. 8C, the wafer W is moved in the + Y direction, and the wafer marks attached to the five third-row alignment shots AS by the five-lens alignment systems AL1, AL22 to AL24. The positions of WMA3, MWE3 to WMB3 are detected. Even at this stage, the immersion area 14 of the projection optical system PL is formed on the measurement stage MST, and the liquid Lq used when performing exposure by the immersion method is not applied to the wafer stage WST and the wafer W. . In the next step 322, the EGA calculation unit 134 calculates the array coordinates of the shot area on the almost half surface of the wafer W in the + Y direction (−Y direction before rotation) of the wafer W by the EGA method, for example, from the detected coordinates of the eight wafer marks. calculate. If the number of shot areas in the Y direction of the wafer W is an odd number, the array coordinates of shot areas arranged in a line in the X direction in the center of the wafer W are also calculated.

  In the next step 324, wafer stage WST is driven based on the array coordinates calculated in step 322, and the wafer is placed in the detection area of trinocular alignment systems AL1, AL22, AL23 as shown in FIG. 9A. The first overlay measurement marks 50A4, 50D4, and 50C4 and the second overlay measurement marks 52A4, 52D4, and 52C4 in the alignment shots AS in the fourth row of the third W are moved. Then, the misalignment amounts in the X direction and Y direction between the overlay measurement marks 50A4, 50D4, 50C4 and 52A4, 52D4, 52C4 are measured by the alignment systems AL1, AL22, AL23. The measurement result is supplied to the overlay calculation unit 135.

  Further, by driving wafer stage WST, as shown in FIG. 9 (B), the first in alignment shots AS in five third rows of wafer W in the detection areas of alignment systems AL1, AL22 to AL24 of five eyes. The overlay measurement marks 50A3 and 50E3 to 50B3 and the second overlay measurement marks 52A3 and 52E3 to 52B3 are moved. Then, the misalignment amounts in the X direction and Y direction between the overlay measurement marks 50A3 to 50B3 and 52A3 to 52B3 are measured by the alignment systems AL1, AL22 to AL24. The measurement result is supplied to the overlay calculation unit 135. At this stage, the immersion area 14 of the projection optical system PL is formed on the measurement stage MST, and the liquid Lq used in the immersion method is not applied to the surface of the wafer W at all. As shown in FIG. 9D, the positional deviation amount between the overlay measurement marks 50 and 52 in the alignment shots AS in the third row 54C and the fourth row 54D after the rotation of the wafer W measured in step 324 is as follows. Are stored in the storage unit in the overlay calculation unit 135 as overlay error vectors OEV9 to OEV16.

  In the next step 326, the overlay calculator 135 statistically processes the 16 overlay error vectors OEV1 to OEV16 measured in steps 316 and 324 (for example, calculates an average value and a standard deviation) and performs the exposure apparatus EX. Find the overlay error. The obtained overlay error is sent to the main controller 20, and the master controller 20 compares the overlay error with an allowable value, for example, and outputs the comparison result to the operator via the input / output device. Thereafter, unloading of the wafer W is performed (step 328), and measurement of overlay accuracy is completed.

At this time, the liquid is continuously supplied to the liquid immersion region 14 between the projection optical system PL and the measurement stage MST. Accordingly, immediately after this, the pattern image of the reticle R can be exposed to a predetermined number of wafers by the immersion method.
As described above, the exposure apparatus EX of the present embodiment is an exposure apparatus that exposes the wafer W with the illumination light IL for exposure via the projection optical system PL. The exposure apparatus EX supplies the wafer stage WST that moves the wafer W and the liquid Lq that transmits the illumination light IL between the projection optical system PL and the wafer W during the exposure of the wafer W, and the supplied liquid Alignment systems AL1, AL22 to AL24 for detecting the position of a mark such as a wafer mark on the wafer W, which are arranged independently of the liquid supply device 5 and the liquid recovery device 6 for collecting the liquid and the projection optical system PL, and the wafer mark Is loaded from wafer stage WST and rotated, for example, 180 °, and then transferred to wafer stage WST again. Further, the exposure apparatus EX includes a main controller 20 that controls operations of the wafer stage WST, the alignment systems AL1, AL22 to AL24, and the wafer loader system WL.

  In addition, the overlay accuracy measurement method using the exposure apparatus EX is a liquid immersion method that sequentially exposes pattern images for the first and second overlay measurement marks 50 and 52 onto a plurality of shot regions of the wafer W 302, Step 316 of measuring the amount of misalignment between the overlay measurement marks 50 and 52 at the measurement position in the alignment shot AS of the first row and the second row of the wafer W via 306 and the alignment systems AL1, AL22 to AL24. Step 318 for rotating the wafer W by 180 ° so that the wafer W does not come into contact with the liquid, and measurement positions in the alignment shots AS in the third and fourth rows of the wafer W via the alignment systems AL1 and AL22 to AL24. Step 324 of measuring the amount of misalignment between the overlay measurement marks 50 and 52.

  According to this embodiment, the amount of positional deviation between the overlay measurement marks 50 and 52 is measured in the alignment shots AS in the first and second rows of the wafer W, so that the wafer W does not come into contact with the liquid. , The amount of positional deviation between the overlay measurement marks 50 and 52 in the third and fourth alignment shots AS of the wafer W is measured. That is, in the state where the liquid Lq is supplied between the projection optical system PL and the measurement stage MST which is a member facing the projection optical system PL, and the liquid Lq is not supplied to the measurement position on the surface of the wafer W, the overlay accuracy is increased. It can measure with high accuracy. Furthermore, exposure using the liquid immersion method can be started immediately after the measurement is completed. Accordingly, it is possible to shorten the time from the completion of the measurement of the overlay accuracy to the start of exposure by the liquid immersion method.

In this embodiment, the wafer W is rotated 180 ° in step 318, but the rotation angle of the wafer W may be about 90 °, for example.
In this embodiment, different wafer marks are detected when the wafer mark of the wafer W is detected in step 312 and when the wafer mark of the wafer W is detected in step 320. However, when the distance between the projection optical system PL and the alignment systems AL1, AL22 to AL24 is longer, for example, in step 320, a part of the wafer mark detected in step 312 by the alignment systems AL1, AL22 to AL24 ( For example, the positions of the wafer marks attached to at least two alignment shots AS in the second row may be detected redundantly. In this case, the shot arrangement calculated in step 314 and the shot arrangement calculated in step 322 are spliced together so that the positions of the wafer marks detected in duplicate coincide with each other. Thus, the two shot arrays can be stitched together with high accuracy.

Further, in the present embodiment, the overlay measurement marks 50 and 52 are concave and convex patterns, but the positional deviation amount of the overlay measurement marks 50 and 52 may be measured at the latent image stage of the photoresist.
In this embodiment, the misalignment amounts of the overlay measurement marks 50 and 52 are also measured by the sub-alignment systems AL21 to AL24. For example, the misalignment amounts of all the overlay measurement marks 50 and 52 are used as the main alignment system. You may measure only with AL1.

Therefore, it is not always necessary to provide the sub-alignment systems AL21 to AL24, and the number of alignment systems is arbitrary.
Although the number of wafer alignment shots in this embodiment is 16, the number and arrangement of wafer alignment shots (wafer marks to be measured) are arbitrary.
Furthermore, the arrangement and the number of shot areas for measuring the amount of misalignment of the overlay measurement marks 50 and 52 are also arbitrary.

  Further, when an electronic device (microdevice) such as a semiconductor device is manufactured using the exposure apparatus of each of the above embodiments, the electronic device performs function / performance design of the electronic device as shown in FIG. Step 222 for manufacturing a mask (reticle) based on this design step, Step 223 for manufacturing a substrate (wafer) as a base material of the device, and exposing the reticle pattern onto the substrate by the exposure apparatus EX of the above-described embodiment. A substrate processing step 224 including a process, a process of developing the exposed substrate, a heating (curing) and etching process of the developed substrate, a device assembly step (including processing processes such as a dicing process, a bonding process, and a packaging process) 225, In addition, it is manufactured through an inspection step 226 and the like.

In other words, the device manufacturing method includes exposing the substrate using the exposure apparatus of the above-described embodiment and processing the exposed substrate (development or the like). At this time, since immersion exposure can be started immediately after measurement of overlay accuracy, electronic devices can be mass-produced with high throughput.
In the above embodiment, a step-and-repeat type projection exposure apparatus (stepper or the like) can be used in addition to the above-described scanning exposure type exposure apparatus (scanner).

  In addition, the above embodiment is not limited to an exposure apparatus for manufacturing a semiconductor device, but is used for manufacturing a display including a liquid crystal display element, a plasma display, and the like. For exposure apparatuses that transfer device patterns used in the manufacture of ceramics onto ceramic wafers, as well as exposure apparatuses that are used in the manufacture of imaging devices (CCD, etc.), organic EL, micromachines, MEMS (Microelectromechanical Systems), and DNA chips Can also be applied. In addition to an electronic device (microdevice) such as a semiconductor element, an exposure apparatus that transfers a circuit pattern onto a glass substrate or a silicon wafer to manufacture a mask used in an optical exposure apparatus and an EUV exposure apparatus. The present invention can also be applied.

  Thus, the present invention is not limited to the above-described embodiments, and various configurations can be taken without departing from the gist of the present invention.

  AL1 ... main alignment system (primary alignment system), AL21 to AL24 ... sub-alignment system (secondary alignment system), WL ... wafer loader system, R ... reticle, W ... wafer, WST ... wafer stage, WM, WMA1, WMC1, WMD1, WMA2 to WME2 ... wafer mark, 20 ... main controller, 50, 50A1 to 50D4 ... first overlay measurement mark, 52,52A1 to 52D4 ... second overlay measurement mark

Claims (13)

A method for measuring overlay accuracy when exposing a substrate through a projection optical system and liquid that transmits the exposure light with exposure light,
Exposing the image of the first mark to a plurality of positions on the substrate via the projection optical system and the liquid with the exposure light; and
Exposing the image of the second mark with the exposure light to correspond to the first mark at the plurality of positions of the substrate via the projection optical system and the liquid;
The first mark at the first set of the plurality of measurement positions of the plurality of positions on the substrate and the corresponding first mark via the mark detection system arranged at a position away from the projection optical system. Measuring the first misalignment of the two marks;
Rotating the substrate by a predetermined angle so that the substrate does not contact the liquid;
Corresponding to the first marks of the second set of measurement positions including a plurality of positions different from the first set of measurement positions among the plurality of positions of the substrate via the mark detection system Measuring a second misalignment amount of the second mark;
A method for measuring overlay accuracy, comprising: Before measuring the first displacement amount through the mark detection system,
Detecting a plurality of first alignment marks on the substrate via the mark detection system to calculate a shot arrangement of the substrate;
Before measuring the second displacement amount through the mark detection system,
Detecting a plurality of second alignment marks on the substrate via the mark detection system to calculate a shot arrangement on the substrate, and
2. The overlay accuracy measuring method according to claim 1, wherein at least some of the plurality of first alignment marks and the plurality of second alignment marks overlap each other. . The plurality of measurement positions of the first set are arranged in a region on substantially one half side of the surface of the substrate,
The plurality of measurement positions of the second set are arranged in a region on the other half surface side of the surface of the substrate,
The overlay accuracy measuring method according to claim 1, wherein the predetermined angle of rotating the substrate is 180 °. The mark detection system is plural,
4. The overlay accuracy measurement method according to claim 1, wherein the detection target areas of the plurality of mark detection systems are arranged in a line along the first direction. 5.   5. The overlay accuracy measurement according to claim 4, wherein the plurality of measurement positions of the first set and the second set are arranged in a plurality of rows along the first direction on the surface of the substrate, respectively. Method. When exposing the first mark and the second mark on the substrate, a coating film that is liquid-repellent to the liquid is formed on the surface of the substrate,
6. The liquid-repellent coating film is not formed on the surface of the substrate when measuring the amount of positional deviation between the first mark and the second mark corresponding to the first mark. The overlay accuracy measurement method according to one item. In an exposure apparatus that exposes a substrate with exposure light via a projection optical system,
A stage for moving the substrate;
A liquid supply device that supplies a liquid that transmits the exposure light between the projection optical system and the substrate during the exposure of the substrate, and collects the supplied liquid;
A mark detection system that is arranged independently of the projection optical system and detects the position of the mark on the substrate;
A substrate rotating device that receives the substrate from the stage and rotates the substrate by a predetermined angle, and then transfers the substrate to the stage again;
An exposure apparatus comprising: A control device for controlling the stage, the mark detection system, and the substrate rotation device;
The controller is
When the image of the first mark is exposed at a plurality of positions on the substrate, and the image of the second mark is exposed corresponding to the first mark at the plurality of positions on the substrate,
The mark detection system is configured to measure a first positional shift amount of the first mark and a second mark corresponding to the first mark at a first set of a plurality of measurement positions at a part of the plurality of positions on the substrate,
Via the substrate rotating device, the substrate is rotated by a predetermined angle so that the substrate does not come into contact with the liquid,
The mark detection system includes a second set of a plurality of measurement positions including a plurality of positions different from the first set of a plurality of measurement positions among the plurality of positions of the substrate, and the first mark corresponding thereto. The exposure apparatus according to claim 7, wherein a second positional shift amount of the second mark is measured. The controller is
Before the mark detection system measures the first displacement amount, the plurality of first alignment marks on the substrate are detected, and the shot arrangement of the substrate is calculated from the detection result,
Before the mark detection system measures the second misalignment amount, the plurality of second alignment marks on the substrate are detected, and the shot arrangement of the substrate is calculated from the detection result,
9. The exposure apparatus according to claim 8, wherein at least some of the plurality of first alignment marks and the plurality of second alignment marks overlap each other. The plurality of measurement positions of the first set are arranged in a region on substantially one half side of the surface of the substrate,
The plurality of measurement positions of the second set are arranged in a region on the other half surface side of the surface of the substrate,
The exposure apparatus according to claim 8 or 9, wherein the predetermined angle by which the substrate rotating device rotates the substrate is 180 °. The mark detection system is plural,
11. The exposure apparatus according to claim 7, wherein the detection target areas of the plurality of mark detection systems are arranged in a line along the first direction.   12. The exposure apparatus according to claim 11, wherein the plurality of measurement positions of the first set and the second set are arranged in a plurality of rows along the first direction on the surface of the substrate. Forming a photosensitive pattern on a substrate using the exposure apparatus according to any one of claims 7 to 12,
Processing the exposed substrate based on the photosensitive pattern;
A device manufacturing method including:

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