JP2009054736A - Mark detecting method and equipment, position controlling method and equipment, exposing method and equipment, and device manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect a plurality of marks on objects efficiently at high precision. <P>SOLUTION: The method includes a process to detect different wafer marks WMB, WMC, WMD, WME on a wafer W by using a plurality of alignment systems (AL21 to AL24) of different detection areas, a process of moving the wafer to position the wafer marks WMB to WME in the detection areas of another alignment system (AL1) sequentially and detecting the marks while measuring the positional information of the wafer W, and a process of calculating the offset of the result of detection by the alignment systems (AL21 to AL24) from the result of detection by the alignment systems (AL21 to AL24) and the result of detection by the alignment system (AL1). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a mark detection technique for detecting a mark placed on an object such as a semiconductor wafer or a glass substrate, a position control technique for performing position control of the object using the mark detection technique, an exposure technique, and It relates to device manufacturing technology.

Conventionally, in a lithography process for manufacturing electronic devices (microdevices) such as semiconductor elements (integrated circuits, etc.) and liquid crystal display elements, a step-and-repeat type projection exposure apparatus (so-called stepper) or a step-and-scan type is used. An exposure apparatus such as a projection exposure apparatus (so-called scanning stepper (also called a scanner)) is used.
For example, in a lithography process for manufacturing a semiconductor element, a multilayer circuit pattern is superimposed on a wafer to form a desired element. However, if the overlay accuracy between layers is poor, the semiconductor element exhibits predetermined circuit characteristics. Cannot be achieved, and the yield decreases. For this reason, usually, a mark (alignment mark) is previously attached to each of a plurality of shot areas on the wafer, and the position (coordinate value) of the mark on the stage coordinate system of the exposure apparatus is measured using an alignment system. Then, wafer alignment is performed to obtain the array coordinates of each shot area on the wafer from the measurement result. Thereafter, each shot area on the wafer is sequentially patterned based on the arrangement coordinate information of each shot area on the wafer and the known (measured) position information of a newly formed pattern (for example, a reticle pattern). The pattern is transferred to the shot area while being aligned with respect to.

As a wafer alignment method, all of the alignment of shot areas is determined by detecting alignment marks in only a few shot areas (also called sample shots or alignment shots) on the wafer in consideration of throughput. The global alignment for obtaining the array coordinates of the shot area is mainly used. Among them, in particular, enhanced global alignment (EGA), which calculates the arrangement of shot areas on a wafer with high accuracy by a statistical method, has become the mainstream (see, for example, Patent Document 1).
JP-A 61-44429

  In the conventional wafer alignment, a plurality of predetermined alignment marks on a wafer are measured using one alignment system (an alignment system having one detection area), and the array coordinates of all shot areas are obtained based on the result. It was. Therefore, when increasing the number of alignment marks to be measured in order to increase the alignment accuracy, there is a problem that the time required for measuring the alignment marks becomes long and the throughput of the exposure process decreases.

In particular, recent wafers have increased in area and the number of shot areas on a single wafer has increased, so in order to improve alignment accuracy, it is required to measure as many alignment marks as efficiently as possible. Yes.
The present invention has been made under the circumstances described above, and an object of the present invention is to provide a mark detection technique capable of detecting a plurality of marks on an object such as a semiconductor wafer as efficiently as possible with high accuracy.

Another object of the present invention is to provide a position control technique for controlling the position of an object using the mark detection technique, an exposure technique using the position control technique, and a device manufacturing technique using the exposure technique.

A first mark detection method according to the present invention is a mark detection method for detecting a mark of an object having marks formed at a plurality of positions, and a plurality of mark detection systems (AL1) having detection areas arranged at different positions. , _AL2 1 AL24 ₄ mark detection system except for the predetermined mark detection system of) _(AL2 1 ~AL2 ₄₎ with the step of detecting the mark (WMB～WME) corresponding on the object (step 313 ) And; measuring the position information of the object, moving the object, and detecting the mark detected by a mark detection system other than the predetermined mark detection system on the object in the predetermined mark detection system (AL1) ) Sequentially detecting the mark and detecting the mark (step 314); a detection result by a mark detection system other than the predetermined mark detection system and the predetermined Those having; on the basis of the detection result by chromatography click detection system, process (step 315) for obtaining the correction information of the detection result by the mark detection system other than the predetermined mark detection system.

A first mark detection apparatus according to the present invention is a mark detection apparatus for detecting a mark of an object in which marks are formed at a plurality of different positions, and a moving body (WST) that moves while holding the object. A plurality of mark detection systems (AL1, AL2 _{1 to} AL2 ₄ ) arranged at different positions in the detection area; a measuring device (70A to 70F) for measuring position information of the moving body; and a control device (20 20a), and the control device uses a mark detection system (AL2 _{1 to} AL2 ₄ ) excluding a predetermined mark detection system among the plurality of mark detection systems, and the corresponding one on the object. The mark is detected, and the position information of the moving body is measured by the measuring device, and the moving body is moved and detected by a mark detection system other than the predetermined mark detection system on the object. The detected mark is sequentially moved to the detection area of the predetermined mark detection system (AL1) to detect the mark, and the detection result by a mark detection system other than the predetermined mark detection system and the predetermined mark detection system Is used to obtain correction information for a detection result by a mark detection system other than the predetermined mark detection system.

A second mark detection method according to the present invention is a mark detection method for detecting the mark of an object in which marks are formed at a plurality of different positions, and a plurality of detection regions (AL1f, A step (FIG. 3A) of detecting a mark (FM) on a predetermined object (WST) in a first detection region (AL1f) of a mark detection system having AL2 ₁ f to AL2 ₄ f); While measuring the position of the predetermined object with the measuring devices (70A to 70F) that measure the position information of the mark, the mark on the object detected in the first detection area is displayed in the second detection area (AL2 ₄ f). A step of moving and detecting the mark (FIG. 3B); position information of the object measured by the measuring device, a result of detecting the mark in the first detection region, and a second detection thereof Detect the mark in the area Results and using, is intended to include a step of determining the relative positional relationship between the first detection area and its second detection region (Step 303).

A second mark detection apparatus according to the present invention is a mark detection apparatus that detects a mark on an object in which marks are formed at a plurality of different positions, and a plurality of detection regions (AL1f, AL2 ₁ having different positions). f~AL2 ₄ f) mark detection system provided with a _{(AL1, AL2 1 ~AL2 4)} ; measurement device which measures positional information of the movable body and (70A to 70F); the control device and (20, 20a); the The control device detects a mark (FM) on a predetermined object (WST) in the first detection area (AL1f) of the mark detection system, and then measures the position of the object with the measurement device. The mark on the object detected in the first detection area is moved to the second detection area (AL2 ₄ f), the mark is detected, and the position information of the object measured by the measuring device, the first 1 detection Using the result of detecting the mark in the region and the result of detecting the mark in the second detection region, the relative positional relationship between the first detection region and the second detection region is obtained.

  In addition, although the reference numerals in parentheses attached to the predetermined elements of the present invention correspond to members in the drawings showing an embodiment of the present invention, each reference numeral of the present invention is provided for easy understanding of the present invention. The elements are merely illustrative, and the present invention is not limited to the configuration of the embodiment.

  According to the present invention, a plurality of mark detection systems having different detection areas (or a mark detection system having a plurality of detection areas different from each other) are used, and a plurality of mark detection systems (or two detection systems are substantially simultaneous). Since it is possible to detect a plurality of different marks in (region), a plurality of marks on the object can be detected efficiently.

  Furthermore, according to the present invention, while measuring the amount of movement of the object (predetermined object) on which the mark is formed, the mark is transferred to another mark detection system (first detection region) and a predetermined mark detection system (second Since the measurement is sequentially performed in the detection area), the relative position information of a plurality of mark detection systems (detection areas) can be accurately measured. Therefore, the measurement accuracy of subsequent marks is improved.

Hereinafter, an example of a preferred embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a schematic configuration of an exposure apparatus 100 according to the present embodiment. The exposure apparatus 100 is a so-called scanning stepper as a step-and-scan projection exposure apparatus (scanning exposure apparatus). As will be described later, in the present embodiment, a 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. The Y-axis is taken in the direction in which the lens is relatively scanned, the X-axis is taken in the direction perpendicular to the Z-axis and the Y-axis, and the rotation (tilt) directions around the X-axis, Y-axis, and Z-axis are respectively θx, θy, and θz The direction is described.

  In FIG. 1, an exposure apparatus 100 includes an illumination system 10, a reticle stage RST that holds a reticle R illuminated by illumination light (exposure light) IL for exposure from the illumination system 10, and illumination light emitted from the reticle R. A projection unit PU including a projection optical system PL for projecting IL onto the wafer W, a stage device 50 having a wafer stage WST and a measurement stage MST, and a control system thereof are provided. Wafer W is placed on wafer stage WST.

The illumination system 10 includes a light source, an optical integrator (fly eye lens, rod integrator (inner surface), as disclosed in, for example, Japanese Patent Application Laid-Open No. 2001-313250 (corresponding US Patent Application Publication No. 2003/0025890). And an illumination optical system having a reticle blind and the like (all not shown). The illumination system 10 illuminates a slit-shaped illumination area IAR on the reticle R defined by the reticle blind with illumination light IL with a substantially uniform illuminance. As the illumination light IL, for example, ArF excimer laser light (wavelength 193 nm) is used. Illumination light includes KrF excimer laser light (wavelength 247 nm), F ₂ laser light (wavelength 157 nm), harmonic of YAG laser, harmonic of solid-state laser (semiconductor laser, etc.), or emission line of mercury lamp (i-line) Etc.) can also be used.

On reticle stage RST, reticle R on which a circuit pattern or the like is formed on its pattern surface (lower surface) is fixed, for example, by vacuum suction. The reticle stage RST can be driven minutely in the XY plane by the reticle stage drive system 11 of FIG. 7 including a linear motor, for example, and can be driven at a scanning speed designated in the scanning direction (Y direction). Yes.

  Position information (including position information in the X direction, Y direction, and rotation information in the θz direction) in the movement plane of the reticle stage RST in FIG. 1 is transferred to the movable mirror 15 (stage by the reticle interferometer 116 made of a laser interferometer. For example, it may be detected with a resolution of about 0.5 to 0.1 nm through a reflection surface obtained by mirror-finishing the end surface of each other. The measurement value of reticle interferometer 116 is sent to main controller 20 in FIG. Main controller 20 calculates positions of reticle stage RST in at least the X direction, the Y direction, and the θz direction based on the measurement value of reticle interferometer 116, and controls reticle stage drive system 11 based on the calculation result. Thus, the position and speed of reticle stage RST are controlled.

  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. . As the projection optical system PL, for example, a refractive optical system including a plurality of lens elements arranged along the optical axis AX is used. The projection optical system PL is, for example, telecentric on both sides and has a predetermined projection magnification β (for example, a reduction magnification such as 1/4, 1/5, or 1/8). When the illumination area IAR is illuminated by the illumination light IL from the illumination system 10, the image of the circuit pattern of the reticle R in the illumination area IAR is projected via the projection optical system PL by the illumination light IL that has passed through the reticle R. It is formed in an exposure area IA (an area conjugate to the illumination area IAR) on one shot area of W. In the wafer W of this example, for example, a resist (photoresist) that is a photosensitive agent (photosensitive layer) is applied to a surface of a disk-shaped semiconductor wafer having a diameter of about 200 mm to 300 mm with a predetermined thickness (for example, about 200 nm). Including things. In each shot area of the wafer W of this example, a predetermined single layer or a plurality of layers of circuit patterns and corresponding alignment marks (wafer marks) are formed by the pattern forming process so far.

The exposure apparatus 100 performs exposure using a liquid immersion method. In this case, in order to avoid an increase in the size of the projection optical system, a catadioptric system including a mirror and a lens may be used as the projection optical system PL.
Further, in the exposure apparatus 100, the lower end of the lens barrel 40 that holds the tip lens 191 that is an optical element on the most image plane side (wafer W side) constituting the projection optical system PL is used to perform exposure using the liquid immersion method. A nozzle unit 32 constituting a part of the local liquid immersion device 8 is provided so as to surround the part periphery.

  In FIG. 1, 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. A porous member (mesh) is disposed at the recovery port. The lower surface of the nozzle unit that can face the surface of the wafer W includes a lower surface of the porous member and a flat surface disposed so as to surround an opening for allowing the illumination light IL to pass therethrough. Further, the supply port is connected to a liquid supply device 186 (see FIG. 7) capable of delivering the liquid Lq via a supply flow path formed inside the nozzle unit 32 and a supply pipe 31A. The recovery port is connected to a liquid recovery device 189 (see FIG. 7) capable of recovering at least the liquid Lq via a recovery flow path and a recovery pipe 31B formed inside the nozzle unit 32.

  The liquid supply device 186 includes a liquid tank, a pressure pump, a temperature control device, a flow rate control valve for controlling supply / stop of the liquid to the supply pipe 31A, etc. The liquid Lq can be delivered. The liquid recovery device 189 includes a liquid tank, a suction pump, and a flow rate control valve for controlling recovery / stop of the liquid via the recovery pipe 31B, and can recover the liquid Lq. Note that the liquid tank, the pressurization (suction) pump, the temperature control device, the control valve, and the like do not have to be all provided in the exposure apparatus 100, and at least a part of the factory such as a factory in which the exposure apparatus 100 is installed. It can be replaced by equipment.

  The operations of the liquid supply device 186 and the liquid recovery device 189 in FIG. 7 are controlled by the main controller 20. The exposure liquid Lq sent from the liquid supply device 186 in FIG. 7 flows through the supply pipe 31A and the supply flow path of the nozzle unit 32 in FIG. 1, and then is supplied from the supply port to the optical path space of the illumination light IL. Is done. Further, the liquid Lq recovered from the recovery port by driving the liquid recovery device 189 of FIG. 7 flows through the recovery flow path of the nozzle unit 32 of FIG. 1 and then passes through the recovery pipe 31B to the liquid recovery device 189. To be recovered. The main controller 20 in FIG. 7 performs the liquid supply operation from the supply port of the nozzle unit 32 and the liquid recovery operation by the recovery port of the nozzle unit 32 in parallel, so that the tip lens 191 and the wafer W in FIG. The liquid immersion space of the liquid Lq is formed so that the liquid immersion region 14 (see FIG. 4) including the optical path space of the illumination light IL between the liquid Lq is filled with the liquid Lq.

  In the present embodiment, pure water (water) that transmits ArF excimer laser light (light having a wavelength of 193 nm) is used as the exposure liquid Lq. Pure water can be easily obtained in large quantities at a semiconductor manufacturing plant or the like, and has the advantage that it does not adversely affect the resist on the wafer, the optical lens, and the like. The refractive index n of water with respect to ArF excimer laser light is approximately 1.44. In this water, the wavelength of the illumination light IL is shortened to 193 nm × 1 / n = about 134 nm, so that the resolution is improved.

  Returning to FIG. 1, the stage apparatus 50 includes an interferometer including a wafer stage WST and a measurement stage MST disposed above the base board 12, and Y-axis interferometers 16 and 18 that measure positional information of these stages WST and MST. A system 118 (see FIG. 7), an encoder system (to be described later) used for measuring position information of wafer stage WST at the time of exposure, and a stage drive system for driving stages WST, MST and a Z / leveling mechanism (to be described later) 124 (see FIG. 7) and the like.

  On the bottom surfaces of wafer stage WST and measurement stage MST, non-contact bearings (not shown), for example, air pads constituting vacuum preload type aerostatic bearings are provided at a plurality of locations. The wafer stage WST and the measurement stage MST are supported in a non-contact manner above the base board 12 with a clearance of about several μm by the static pressure of the pressurized air ejected from the air pads toward the upper surface of the base board 12. ing. The stages WST and MST can be driven in a two-dimensional direction independently of the Y direction and the X direction by the stage drive system 124 of FIG.

  More specifically, on the floor surface, as shown in the plan view of FIG. 2, a pair of Y-axis stators extending in the Y direction on one side and the other side in the X direction across the base board 12. 86 and 87 are arranged, respectively. The Y-axis stators 86 and 87 are configured by, for example, a magnetic pole unit containing a permanent magnet group composed of a plurality of pairs of N-pole magnets and S-pole magnets arranged alternately at predetermined intervals along the Y direction. . The Y-axis stators 86 and 87 are provided with two Y-axis movers 82 and 84 and 83 and 85 in a non-contact state. That is, a total of four Y-axis movers 82, 84 and 83, 85 are inserted into the internal space of the U-shaped Y-axis stators 86 and 87 in the XZ cross section, and the corresponding Y-axis The stators 86 and 87 are supported in a non-contact manner through an air pad (not shown) with a clearance of about several μm, for example. Each of the Y-axis movers 82, 84, 83, 85 is configured by an armature unit that incorporates armature coils arranged at predetermined intervals along the Y direction, for example. That is, in the present embodiment, the moving-coil type Y-axis linear motor is constituted by the Y-axis movers 82 and 84 formed of armature units and the Y-axis stator 86 formed of a magnetic pole unit. Similarly, the Y-axis movers 83 and 85 and the Y-axis stator 87 constitute moving coil type Y-axis linear motors, respectively. In the following, each of the four Y-axis linear motors will be appropriately referred to as Y-axis linear motors 82, 84, 83, and 85 using the same reference numerals as the respective movers 82, 84, 83, and 85. And

  Among the four Y-axis linear motors, the movers 82 and 83 of the two Y-axis linear motors 82 and 83 are respectively fixed to one end and the other end of the X-axis stator 80 extending in the X direction. . Further, the movers 84 and 85 of the remaining two Y-axis linear motors 84 and 85 are fixed to one end and the other end of an X-axis stator 81 extending in the X direction. Accordingly, the X-axis stators 80 and 81 are driven along the Y-axis by the pair of Y-axis linear motors 82, 83, and 84, 85, respectively.

Each of the X-axis stators 80 and 81 is constituted by an armature unit that incorporates armature coils arranged at predetermined intervals along the X direction, for example.
One X-axis stator 81 is provided in an inserted state in an opening (not shown) formed in a stage main body 91 (see FIG. 1) constituting a part of wafer stage WST. Inside the opening of the stage body 91, for example, a magnetic pole unit having a permanent magnet group composed of a plurality of pairs of N-pole magnets and S-pole magnets arranged alternately at predetermined intervals along the X direction is provided. ing. The magnetic pole unit and the X-axis stator 81 constitute a moving magnet type X-axis linear motor that drives the stage main body 91 in the X direction. Similarly, the other X-axis stator 80 is provided in an inserted state in an opening formed in the stage main body 92 constituting the measurement stage MST. Inside the opening of the stage main body 92, a magnetic pole unit similar to the wafer stage WST side (stage main body 91 side) is provided. The magnetic pole unit and the X-axis stator 80 constitute a moving magnet type X-axis linear motor that drives the measurement stage MST in the X direction.

  In the present embodiment, each of the linear motors constituting the stage drive system 124 is controlled by the main controller 20 shown in FIG. Each linear motor is not limited to either a moving magnet type or a moving coil type, and can be appropriately selected as necessary. It should be noted that yawing (rotation in the θz direction) of wafer stage WST (and measurement stage MST) is controlled by making the thrust generated by the pair of Y-axis linear motors 84 and 85 (and 82 and 83) slightly different. Is possible.

  Wafer stage WST in FIG. 1 is provided in stage body 91 described above, wafer table WTB mounted on stage body 91, and stage body 91, and in the Z direction, θx direction, and stage body 91. and a Z-leveling mechanism that relatively finely drives the wafer table WTB (wafer W) in the θy direction. The Z / leveling mechanism includes, for example, a mechanism including a voice coil motor that applies displacement in the Z direction at three locations and sensors that measure the displacement in the Z direction at the three locations.

On wafer table WTB, a wafer holder (not shown) for holding wafer W by vacuum suction or the like is provided. Although the wafer holder may be formed integrally with wafer table WTB, in this embodiment, the wafer holder and wafer table WTB are separately configured, and the wafer holder is fixed in the recess of wafer table WTB by, for example, vacuum suction. In addition, the upper surface of wafer table WTB has a surface (liquid repellent surface) that has been subjected to a liquid repellent treatment with respect to liquid Lq and is substantially flush with the surface of the wafer placed on the wafer holder, and has an outer shape ( A plate (liquid repellent plate) 28 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. The plate 28 is made of a material having a low coefficient of thermal expansion, such as glass, glass ceramics, or ceramics (Shot Corporation's Zerodur (trade name), Al ₂ O _3, TiC, or the like). The liquid repellent film is formed of a fluorine resin material such as tetrafluoroethylene (Teflon (registered trademark)), an acrylic resin material, or a silicon resin material.

Further, the plate 28 is formed by the wafer table WTB (wafer stage WST) shown in FIG.
As shown in the plan view, the first liquid repellent area 28a having a rectangular outer shape (contour) surrounding the circular opening, and a rectangular frame-shaped (annular) first arranged around the first liquid repellent area 28a. 2 liquid repellent area 28b. The first liquid repellent area 28a is formed, for example, at least part of the liquid immersion area 14 (see FIG. 4) that protrudes from the wafer surface during the exposure operation, and the second liquid repellent area 28b is used for an encoder system described later. A scale is formed. It should be noted that at least a part of the surface of the plate 28 may not be flush with the surface of the wafer, that is, it may have a different height. Further, the plate 28 may be a single plate, but in the present embodiment, a plurality of plates, for example, first and second liquid repellent plates corresponding to the first and second liquid repellent areas 28a and 28b, respectively, are combined. .

  In this case, the illumination light IL is irradiated to the inner first liquid repellent region 28a, whereas the illumination light IL is hardly irradiated to the outer second liquid repellent region 28b. In view of this, in the present embodiment, the surface of the first liquid repellent region 28a is provided with a water repellent coat that is sufficiently resistant to the illumination light IL (in this case, light in the vacuum ultraviolet region). The second liquid repellent area 28b is provided with a water repellent coat on its surface that is less resistant to the illumination light IL than the first liquid repellent area 28a.

  Further, as is apparent from FIG. 5A, a rectangular notch is formed in the central portion in the X direction at the end portion on the + Y direction side of the first liquid repellent region 28a. A measurement plate 30 is embedded in a rectangular space surrounded by the liquid repellent region 28b (inside the cutout). At the center of the measurement plate 30 in the longitudinal direction (on the center line LL of the wafer table WTB), a reference mark FM for baseline measurement is formed, and on one side and the other side of the reference mark in the X direction, A pair of aerial image measurement slit patterns (slit-shaped measurement patterns) SL is formed in a symmetrical arrangement with respect to the center of the reference mark FM. As each slit pattern SL, for example, an L-shaped slit pattern having sides along the Y direction and the X direction, or two linear slit patterns extending in the X axis and the Y direction, respectively, may be used. it can.

  Then, inside the wafer stage WST below each of the slit patterns SL, as shown in FIG. 5B, a light transmission system 36 including an optical system including an objective lens, a mirror, a relay lens, and the like is housed. An L-shaped housing is attached in a partially embedded state in a state of penetrating a part of the inside of the stage main body 91 from the wafer table WTB. Although not shown, a pair of light transmission systems 36 are provided corresponding to the pair of aerial image measurement slit patterns SL. The light transmission system 36 guides the illumination light IL transmitted through the aerial image measurement slit pattern SL along the L-shaped path and emits it in the Y direction.

Further, a large number of lattice lines 37 and 38 are directly formed on the upper surface of the second liquid repellent region 28b at a predetermined pitch along each of the four sides. More specifically, Y scales 39Y ₁ and 39Y ₂ are respectively formed in regions on both sides in the X direction of the second liquid repellent region 28b. Each of the Y scales 39Y ₁ and 39Y ₂ is formed, for example, by forming lattice lines 38 having the X direction as a longitudinal direction along a direction (Y direction) parallel to the Y axis at a predetermined pitch. And a reflection type grating (for example, a phase type diffraction grating).

Similarly, X scales 39X ₁ and 39X ₂ are respectively formed in regions on both sides in the Y direction of the second liquid repellent region 28b. Each of the X scales 39X ₁ and 39X ₂ is formed, for example, by forming lattice lines 37 having a longitudinal direction in the Y direction along a direction (X direction) parallel to the X axis at a predetermined pitch. And a reflection type grating (for example, a phase type diffraction grating).

As each of the scales _{39Y 1, 39Y 2, 39X 1} , 39X 2, which diffraction grating of the reflection type by the surface for example a hologram or the like of the second liquid repellent area 28b is created are used.
In this case, each scale is provided with a grid made up of narrow slits or grooves as scales at a predetermined interval (pitch). The type of the diffraction grating used for each scale is not limited, and may be not only those in which grooves or the like are mechanically formed, but may also be created by baking interference fringes on a photosensitive resin, for example. . However, each scale is formed by, for example, engraving the scale of the diffraction grating on a thin glass plate at a pitch between 138 nm and 4 μm, for example, 1 μm pitch. These scales are covered with the liquid repellent film (water repellent film) described above. In FIG. 5A, for the convenience of illustration, the pitch of the lattice is shown to be much wider than the actual pitch. The same applies to the other drawings.

  Thus, in this embodiment, since the 2nd liquid repellent area | region 28b itself comprises a scale, we decided to use a low thermal expansion glass plate as a material of the 2nd liquid repellent area | region 28b. However, the present invention is not limited to this, and a scale member made of a low thermal expansion glass plate with a lattice formed thereon is placed on the upper surface of wafer table WTB by, for example, a leaf spring (or vacuum suction) so that local expansion and contraction does not occur. In this case, a water-repellent plate having the same water-repellent coating on the entire surface may be used in place of the plate 28.

  The -Y end surface and -X end surface of wafer table WTB are each mirror-finished to form reflection surfaces 17a and 17b shown in FIG. The Y-axis interferometer 16 and the X-axis interferometer 126 (see FIG. 2) of the interferometer system 118 (see FIG. 7) project interferometer beams (measurement beams) on these reflecting surfaces 17a and 17b, respectively. Each reflected light is received. Interferometers 16 and 126 measure the displacement of each reflecting surface from the reference position (for example, the reference mirror disposed on the side surface of projection unit PU), that is, the position information of wafer stage WST in the XY plane. Is supplied to the main controller 20. In the present embodiment, a multi-axis interferometer having a plurality of optical axes is used as the Y-axis interferometer 16 and the X-axis interferometer 126, and the main control is performed based on the measurement values of these interferometers 16 and 126. In addition to the position of wafer table WTB in the X and Y directions, apparatus 20 can also measure θx direction rotation information (pitching), θy direction rotation information (rolling), and θz direction rotation information (yawing).

  However, in the present embodiment, position information (including rotation information in the θz direction) in the XY plane of wafer stage WST (wafer table WTB) mainly includes the Y scale, X scale, and the like described later. The measurement values of the interferometers 16 and 126 are used supplementarily when correcting (calibrating) long-term fluctuations in the measurement values of the encoder system (for example, due to deformation of the scale over time). . The Y-axis interferometer 16 is used for measuring the position in the Y direction of the wafer table WTB in the vicinity of an unloading position, which will be described later, and the loading position, for wafer replacement. Also, for example, in the movement of wafer stage WST between the loading operation and the alignment operation and / or between the exposure operation and the unloading operation, the measurement information of interferometer system 118, that is, the direction of 5 degrees of freedom (X direction) , Y direction, θx, θy, and θz directions). Note that the Y-axis interferometer 16, the X-axis interferometer 126, the Y-axis interferometer 18 for the measurement stage MST described later, and the X-axis interferometer 130 of the interferometer system 118 are, for example, a main frame that holds the projection unit PU. Is provided.

  Further, in the present embodiment, the position information of wafer stage WST measured by interferometer system 118 is not used in the exposure operation and alignment operation described later, and mainly the calibration operation of the encoder system (that is, the calibration of the measurement value). However, the measurement information of the interferometer system 118 (that is, at least one of position information in the direction of 5 degrees of freedom) may be used in, for example, an exposure operation and / or an alignment operation. In this case, the measurement information of the interferometer system 118 is also supplied to the alignment calculation system 20a. In the present embodiment, the encoder system measures position information of wafer stage WST in three degrees of freedom, that is, in the X axis, Y axis, and θz directions. Therefore, in an exposure operation or the like, out of the measurement information of the interferometer system 118, a direction different from the measurement direction (X direction, Y direction, and θz direction) of the position information of the wafer stage WST by the encoder system, for example, the θx direction and / or Only position information regarding the θy direction may be used, or in addition to position information regarding the different directions, a position regarding the same direction as the measurement direction of the encoder system (ie, at least one of the X direction, the Y direction, and the θz direction). Information may be used. Further, interferometer system 118 may be capable of measuring position information of wafer stage WST in the Z direction. In this case, position information in the Z direction may be used in the exposure operation or the like.

  The measurement stage MST of FIG. 1 is configured by mounting a flat measurement table MTB and a later-described CD bar 46 (see FIG. 6A) on a stage main body 92. The stage main body 92 incorporates a Z-leveling mechanism (for example, a mechanism including three voice coil motors) that controls the position of the measurement table MTB and the CD bar 46 in the Z direction and the inclination angle in the θx direction and the θy direction. It is. The measurement table MTB and the stage main body 92 are provided with various measurement members. As the measurement member, for example, as shown in FIGS. 2 and 6A, an illuminance unevenness sensor 94 having a pinhole-shaped light receiving unit, a spatial image of a pattern projected by the projection optical system PL (projection) An aerial image measuring device 96 for measuring the image), a wavefront aberration measuring device 98, and the like are employed.

In the present embodiment, it is used for the measurement using the illumination light IL corresponding to the immersion exposure for exposing the wafer W with the illumination light IL through the projection optical system PL and the liquid (water) Lq. The illuminance unevenness sensor 94 (and the illuminance monitor), the aerial image measuring instrument 96, and the wavefront aberration measuring instrument 98 described above receive the illumination light IL through the projection optical system PL and water.
As shown in FIG. 6B, a frame-shaped attachment member 42 is fixed to the end surface on the −Y direction side of the stage main body 92 of the measurement stage MST. Further, on the end surface on the −Y direction side of the stage main body 92, an arrangement is provided in the vicinity of the center position in the X direction inside the opening of the mounting member 42 so as to face the pair of light transmission systems 36 in FIG. A pair of light receiving systems 44 are fixed. Each light receiving system 44 includes an optical system such as a relay lens, a light receiving element, such as a photomultiplier tube, and a housing for housing these. As can be seen from FIGS. 5B and 6B and the description so far, in this embodiment, wafer stage WST and measurement stage MST are close to each other within a predetermined distance in the Y direction (contact state). , The illumination light IL transmitted through each slit pattern SL of the measurement plate 30 of the wafer stage WST is guided by the above-described light transmission systems 36 and received by the light receiving elements of the respective light reception systems 44 of the measurement stage MST. . That is, a space similar to that disclosed in Japanese Patent Laid-Open No. 2002-14005 (corresponding US Patent Application Publication No. 2002/0041377) or the like is measured by the measurement plate 30, the light transmission system 36, and the light reception system 44. An image measuring device 45 (see FIG. 7) is configured.

On the attachment member 42 in FIG. 6B, a confidential bar (hereinafter abbreviated as “CD bar”) 46 as a reference member made of a rod-shaped member having a rectangular cross section is extended in the X direction. The CD bar 46 is kinematically supported on the mounting member 42 of the measurement stage MST by a full kinematic mount structure.
Since the CD bar 46 is an original instrument (measurement standard), glass ceramics having a low coefficient of thermal expansion, for example, Zerodure (trade name) manufactured by Schott is used as the material. The upper surface (front surface) of the CD bar 46 is set to have a flatness as high as that of a so-called reference flat plate. In addition, a reference grating (for example, a diffraction grating) 52 having a periodic direction in the Y direction is provided near one end and the other end of the CD bar 46 in the longitudinal direction, as shown in FIG. Is formed. The pair of reference gratings 52 are formed in a symmetrical arrangement with respect to the center of the CD bar 46 in the X direction, that is, the center line CL, with a predetermined distance (L).

A plurality of reference marks M are formed on the upper surface of the CD bar 46 in the arrangement as shown in FIG. The plurality of reference marks M are formed in an array of, for example, three rows in the Y direction, and the plurality of marks in each row are formed with a predetermined distance from each other in the X direction. As each reference mark M, a two-dimensional mark having a size detectable by a primary alignment system and a secondary alignment system, which will be described later, is used. The shape (configuration) of the reference mark M may be different from the reference mark FM shown in FIG. In the present embodiment, the reference mark M for the primary alignment system has the same configuration as the reference mark FM and the same configuration as the alignment mark of the wafer W. On the other hand, since the detection area of the secondary alignment system is movable within a predetermined range in the X direction as will be described later, the reference marks M for the secondary alignment system are elongated in the X direction at a predetermined pitch in the X direction and the Y direction as an example. It is a dimension mark. Information on the shapes and positional relationships (intervals, etc.) of the plurality of reference marks M is stored in a storage device in the alignment calculation system 20 a connected to the main control device 20.
In the present embodiment, the surface of the CD bar 46 and the surface of the measurement table MTB (which may include the above-described measurement member) are also covered with a liquid repellent film (water repellent film).

  As shown in FIG. 2, reflection surfaces 19a and 19b similar to the wafer table WTB described above are also formed on the + Y end surface and the −X end surface of the measurement table MTB. The Y-axis interferometer 18 and the X-axis interferometer 130 of the interferometer system 118 (see FIG. 7) project interferometer beams (measurement beams) on these reflecting surfaces 19a and 19b and receive the reflected lights. Thus, the displacement of each reflecting surface from the reference position, that is, the position information of the measurement stage MST (for example, including at least position information in the X direction and Y direction and rotation information in the θz direction) is measured. Is supplied to the main controller 20.

  Meanwhile, as shown in FIG. 2, stopper mechanisms 48A and 48B are provided at both ends of the X-axis stators 81 and 80 in the X direction. The stopper mechanisms 48A and 48B are provided on the X-axis stator 81 at positions facing the shock absorbers 47A and 47B as shock absorbers made of, for example, an oil damper, and the shock absorbers 47A and 47B of the X-axis stator 80. And the shutters 49A and 49B for opening and closing the openings 51A and 51B. Opening / closing states of the openings 51A, 51B by the shutters 49A, 49B are detected by an opening / closing sensor (see FIG. 7) 101 provided in the vicinity of the shutters 49A, 49B, and the detection results are sent to the main controller 20.

Here, the action of the stopper mechanisms 48A and 48B will be described by taking the stopper mechanism 48A as a representative.
In FIG. 2, when the shutter 49A closes the opening 51A, the shock absorber 47A and the shutter 49A come into contact (contact) even when the X-axis stator 81 and the X-axis stator 80 approach each other. As a result, the X-axis stators 80 and 81 can no longer approach each other. On the other hand, when the shutter 49A is opened and the opening 51A is opened, when the X-axis stators 81 and 80 approach each other, at least a part of the tip of the shock absorber 47A can enter the opening 51A. The shaft stators 81 and 80 can be brought close to each other. As a result, wafer table WTB and measurement table MTB (CD bar 46) can be brought into contact (or close to a distance of about 300 μm).

In FIG. 2, interval detection sensors 43A and 43C and collision detection sensors 43B and 43D are provided on the −Y side of both ends of the X-axis stator 80, and on the + Y side of both ends of the X-axis stator 81. , Elongated plate-like members 41A and 41B are projected in the Y direction. The interval detection sensors 43A and 43C are composed of, for example, a transmissive photosensor (for example, a sensor made of an LED-phototransistor), and the X-axis stator 80 and the X-axis stator 81 come close to each other between the interval detection sensors 43A. Since the plate-like member 41A enters and the amount of received light decreases, it can be detected that the distance between the X-axis stators 80 and 81 is equal to or less than a predetermined distance.

  The collision detection sensors 43B and 43D are photoelectric sensors similar to the interval detection sensors 43A and 43C, but are further arranged in the back thereof. According to the collision detection sensors 43B and 43D, when the X-axis stators 81 and 80 are further approached and the wafer table WTB and the CD bar 46 (measurement table MTB) are in contact with each other (or a stage close to a distance of about 300 μm). Since the upper half of the plate-like member 41A is positioned between the sensors, the main controller 20 detects that the amount of light received by the sensor is zero, so that both tables are in contact (or about 300 μm). Can be detected.

In the exposure apparatus 100 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. 4, the center of the projection unit PU (of the projection optical system PL). The detection center is located at a position a predetermined distance away from the optical axis AX on the straight line LV that passes through the optical axis AX (in this embodiment, also coincides with the center of the exposure area IA described above) and is parallel to the Y axis. A primary alignment system AL1 is arranged. The primary alignment system AL1 is fixed to a main frame (not shown). Secondary alignment systems AL2 ₁ and AL2 ₂ and secondary alignment systems AL2 ₃ and AL2 _{4 in} which detection centers are arranged almost symmetrically with respect to the straight line LV on one side and the other side of the X direction across the primary alignment system AL1. And are provided respectively. That is, the five alignment systems AL1, AL2 _{1 to} AL2 ₄ are arranged at positions where their detection regions (detection centers) are different with respect to the X direction, that is, along the X direction.

Each secondary alignment system AL2 _n (n = 1 to 4) rotates in a predetermined angle range clockwise and counterclockwise in FIG. 4 around the rotation center O as representatively shown for the secondary alignment system AL2 ₄ . The movable arm 56 _n (n = 1 to 4) is fixed to the tip (rotating end). In the present embodiment, each secondary alignment system AL2 _n includes a part thereof (for example, at least an optical system that irradiates the detection region with the alignment light and guides the light generated from the target mark in the detection region to the light receiving element). It is fixed to the arm 56 _n and the remaining part is provided on the main frame (not shown). Each of the secondary alignment systems AL2 _{1 to} AL2 ₄ rotates about the rotation center O, thereby adjusting the position (X position) in the X direction of the detection region.

That is, the secondary alignment systems AL2 _{1 to} AL2 ₄ have their detection areas (or detection centers) movable independently in the X direction. In the present embodiment, the X position of the detection region of the secondary alignment systems AL2 _{1 to} AL2 ₄ is adjusted by rotating the arm. However, the present invention is not limited to this, for example, the optical system at the tip of the secondary alignment systems AL2 _{1 to} AL2 ₄ is moved in the X direction parallel to the Y axis by a linear motor or the like, and the change in the optical path length due to the movement is not shown. You may make it cancel by the optical system. According to this parallel movement method, the detection region of each secondary alignment system moves parallel to the X axis. Furthermore, as can be driven secondary alignment systems AL2 ₁ AL24 ₄ of the tip portion of the optical system (or the whole optical system of the secondary alignment systems AL2 ₁ ~AL2 ₄₎ X direction linear motor system or the like, independently in the Y direction Also good.

Further, at least one of the detection regions of the secondary alignment systems AL2 _{1 to} AL2 ₄ may be movable not only in the X direction but also in the Y direction. Since each optical system of each secondary alignment system AL2 _n is moved by the arm 56 _n , a part of the secondary alignment system AL2 _n is fixed to the arm 56 _n by a sensor (not shown) such as an interferometer or encoder. The position information of the optical system can be measured. This sensor may only measure position information in the X direction of the detection region of the secondary alignment system AL2 _n , but other directions, for example, the Y direction and / or the rotation direction (including at least one of the θx and θy directions). The position information may be measurable.

A vacuum pad 58 _n (n = 1 to 4) composed of a differential exhaust type air bearing is provided on the upper surface of each arm 56 _n . Further, the arm 56 _n can be rotated in accordance with an instruction from the main controller 20 by a rotation driving mechanism 60 _n (n = 1 to 4, see FIG. 7) including a motor or the like, for example. After adjusting the rotation of arm 56 _n , main controller 20 operates each vacuum pad 58 _n to adsorb and fix each arm 56 _n to a main frame (not shown). Thereby, the state after adjusting the rotation angle of each arm 56 _n , that is, the desired positional relationship between the primary alignment system AL1 and the four secondary alignment systems AL2 _{1 to} AL2 ₄ is maintained. 7 simultaneously sets the X position of the detection area of secondary alignment system AL2 _n and the X positions of a plurality of alignment marks to be detected on the wafer near the detection center in those detection areas. To control.

A magnetic material may be fixed to a part of the measurement frame 21 facing the arm 56 _n and an electromagnet may be used instead of the vacuum pad 58 _n .
In the present embodiment, for example, an image processing type FIA (Field Image Alignment) system is used as each of the primary alignment system AL1 and the four secondary alignment systems AL2 _{1 to} AL2 ₄ . In this FIA system, an object mark formed on a light-receiving surface by irradiating a detection mark with a broadband detection light beam from a halogen lamp or a xenon lamp that does not sensitize a resist on a wafer, and reflected light from the inspection mark These images are picked up using an image pickup device (CCD type or CMOS type, etc.), and those image pickup signals are output. In this case, the position of the image of the test mark is detected with reference to the position of a predetermined pixel in the image sensor. Instead, an index mark is provided in the FIA system, and the position of the image of the index mark is used as a reference. As an example, an image of the test mark may be detected. Information on the amount of deviation from the reference position of the image of the test mark obtained via the alignment systems AL1 and AL2 _{1 to} AL2 ₄ is supplied to the main controller 20 in FIG.

FIG. 12A conceptually shows a schematic configuration of the five-eye alignment systems AL1 and AL2 _{1 to} AL2 ₄ . In FIG. 12A, alignment systems AL1 and AL2 _{1 to} AL2 ₄ each irradiate the test surface with light from a light source (not shown) and collect the reflected light from the test surface via the objective lens system. By doing so, an enlarged image of the test surface is formed on the image pickup surface of the image pickup element 5d in which pixels are two-dimensionally arranged. Then, the imaging signals (detection signals) read from the imaging elements 5d of the alignment systems AL1 and AL2 _{1 to} AL2 ₄ are processed by the detection signal processing units 131A, 131B, 131C, 131D, and 131E, respectively. The position of the mark is determined. Although not shown, each of the alignment systems AL1 and AL2 _{1 to} AL2 ₄ is provided with an autofocus system for generating a focus signal indicating the defocus amount from the best focus position on the surface to be tested. Using the detection result of the system, the test surface can be focused on the alignment systems AL1 and AL2 _{1 to} AL2 ₄ , respectively.

Further, the visual field on the test surface conjugate with the imaging surface of the imaging device 5d of the alignment systems AL1 and AL2 _{1 to} AL2 ₄ is detected regions AL1, AL2 ₁ f, AL2 ₂ f, AL2 ₃ shown in FIG. f, AL2 ₄ f. Furthermore, as an example, the point 3A on the surface to be measured corresponding to the center pixel (origin) of the image sensor 5d of the primary alignment system AL1 is the detection center of the primary alignment system AL1. As an example, the initial positions of the detection centers of the secondary alignment systems AL2 _{1 to} AL2 ₄ are points 3B, 3C, 3D, and 3E corresponding to the center pixel of the image sensor, but the detection centers of the secondary alignment systems AL2 _{1 to} AL2 ₄ Is set as described later after the detection areas of the secondary alignment systems AL2 _{1 to} AL2 ₄ are moved.

In the detection signal processing units 131A to 131E in FIG. 12A, as an example, the image pickup signals of the image pickup devices 5d are accumulated in a predetermined range in a direction corresponding to the Y direction and the X direction on the test surface, respectively. Image pickup signals SX and SY (see FIG. 3D) of mark images that are periodic in the direction and the Y direction are generated. Further, the detection signal processing units 131A to 131E slice the respective image pickup signals SX and SY with, for example, a predetermined threshold value to obtain the amount of positional deviation in the X direction and the Y direction with respect to the detection center of the corresponding mark. The quantity information is supplied to the main controller 20 and the alignment calculation system 20a shown in FIG. In the alignment calculation system 20a, the coordinate in the stage coordinate system (X, Y) of the test mark is obtained by adding each positional deviation amount to the coordinates of the detection center of each alignment system AL2 _{1 to} AL2 ₄ obtained in advance. The value can be determined.

The detection region AL2 ₁ f~AL2 ₄ f of secondary alignment systems AL2 ₁ AL24 ₄ is movable within a predetermined range in the X direction. Thus, for example, when the entire secondary alignment systems AL2 ₁ AL24 ₄ to move, since the optical path length within each secondary alignment systems AL2 ₁ AL24 ₄ is not changed, the configuration of the secondary alignment systems AL2 ₁ AL24 ₄ May have the same configuration as the primary alignment system AL1. On the other hand, for example, when only the optical system such as the tip of the secondary alignment systems AL2 _{1 to} AL2 ₄ is movable, it is necessary to incorporate an optical system for canceling the change in the optical path length thereafter.

  The alignment system is not limited to the FIA system. For example, the target mark is irradiated with coherent detection light to detect scattered light or diffracted light generated from the target mark, or 2 generated from the target mark. Of course, it is possible to use an alignment sensor that detects two diffracted lights (for example, diffracted lights of the same order or diffracted in the same direction) by interference alone or in appropriate combination. Also in these cases, it is preferable to provide an autofocus system for measuring the amount of deviation from the best focus position of the test surface.

In the present embodiment, since five alignment systems AL1, AL2 _{1 to} AL2 ₄ 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.
In the exposure apparatus 100 of the present embodiment, as shown in FIG. 4, the 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) as shown by a two-dot chain line in FIG.

In FIG. 4, head units 62A and 62C are arranged at predetermined intervals on a straight line LH that passes through the optical axis AX of the projection optical system PL along the X direction on the + X side and −X side of the projection unit PU, respectively, and is parallel to the X axis. A plurality of (here, six) Y heads 64 are provided. Y head 64 measures the position in the Y direction (Y position) of wafer stage WST (wafer table WTB) using Y scale 39Y ₁ or 39Y ₂ in FIG. Further, a plurality of head units 62B and 62D are arranged at substantially predetermined intervals on a straight line LV passing through the optical axis AX along the Y direction on the + Y side and the −Y side of the projection unit PU, respectively, and parallel to the Y axis. Here, seven and eleven X heads 66 (however, in FIG. 4, three of the eleven, which overlap with the primary alignment system AL1 are not shown) are provided. The X head 66 measures the position (X position) in the X direction of the wafer stage WST (wafer table WTB) using the X scale 39X ₁ or 39X ₂ in FIG.

Therefore, the head units 62A and 62C in FIG. 4 use the Y scales 39Y ₁ and 39Y ₂ in FIG. 5A, respectively, to measure the Y position of the wafer stage WST (wafer table WTB) (multiple eyes (here 6). Eye) Y-axis linear encoders (hereinafter abbreviated as Y encoder as appropriate) 70A and 70C (see FIG. 7). 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 (details will be described later). Here, the interval between adjacent Y heads 64 (that is, measurement beams emitted from the Y head 64) included in the head units 62A and 62C is the width of the Y scales 39Y ₁ and 39Y _{2 in} the X direction (more accurately, Is set narrower than the length of the grid line 38).

Further, head units 62B and 62D are using basically each X scales 39X ₁ and 39X ₂ described above, to measure the X-position of wafer stage WST (wafer table WTB), multiview (here, 7 eyes and Eleven eye) X-axis linear encoders (hereinafter abbreviated as X encoder as appropriate) 70B and 70D (see FIG. 7) are configured. 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. In the present embodiment, for example, two X heads 66 out of eleven X heads 66 included in the head unit 62D may face the X scales 39X ₁ and 39X ₂ at the time of alignment described later. . In this case, X linear encoders 70B and 70D are configured by the X scales 39X ₁ and 39X ₂ and the X head 66 facing the X scales 39X ₁ and 39X ₂ .

The distance between adjacent X heads 66 (measurement beams) included in each of the head units 62B and 62D is larger than the width in the Y direction of the X scales 39X ₁ and 39X ₂ (more precisely, the length of the grid line 37). It is set narrowly.
Furthermore, the secondary alignment systems AL2 ₁ on the -X side of Figure 4, the + X side of secondary alignment system AL2 _4, substantially against parallel straight line and the detection center in the X axis passing through the detection center of primary alignment system AL1 symmetry Y heads 64y ₁ and 64y ₂ in which detection points are arranged are respectively provided. The distance between the Y heads 64y ₁ and 64y ₂ is set to be approximately equal to the distance L described above (the distance in the Y direction of the reference grating 52 in FIG. 6A). The Y heads 64y ₁ and 64y ₂ face the Y scales 39Y ₂ and 39Y ₁ in the state shown in FIG. 4 where the center of the wafer W on the wafer stage WST is on the straight line LV. In case of an alignment operation and the like to be described later, Y heads 64y opposite to _1, 64y ₂ Y scales 39Y _2, 39Y ₁ are placed respectively, the Y heads 64y _1, 64y ₂ (i.e., they Y heads 64y _1, 64y ₂ ), the Y position (and the angle in the θz direction) of wafer stage WST is measured.

In the present embodiment, the pair of reference grids 52 and the Y heads 64y ₁ and 64y ₂ of the CD bar 46 in FIG. The Y position of the CD bar 46 is measured at the position of each reference grating 52 by the reference grating 52 facing the heads 64y ₁ and 64y ₂ . Hereinafter, linear encoders configured by Y heads 64y ₁ and 64y ₂ respectively facing the reference grating 52 are referred to as Y encoders 70E and 70F (see FIG. 7).

The measured values of the six encoders 70A to 70F described above are supplied to the main controller 20 and the alignment calculation system 20a. And the rotation of the CD bar 46 in the θz direction is controlled based on the measured values of the Y encoders 70E and 70F.
In the exposure apparatus 100 of this embodiment, as shown in FIG. 4, for example, Japanese Patent Laid-Open No. 6-283403 (corresponding US Pat. No. 5,448,332) comprising an irradiation system 90a and a light receiving system 90b. Are provided with a multi-point focal position detection system (hereinafter abbreviated as a multi-point AF system) of an oblique incidence system having the same configuration as that disclosed in the above. In the present embodiment, as an example, the irradiation system 90a is disposed on the −Y side of the −X end portion of the head unit 62C described above, and in the state facing this, the −Y side of the + X end portion of the head unit 62A described above. The light receiving system 90b is arranged in the front.

A plurality of detection points of the multipoint AF system (90a, 90b) in FIG. 4 are arranged at predetermined intervals along the X direction on the surface to be detected. In the present embodiment, for example, they are arranged in a row matrix of 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). In FIG. 4, a plurality of detection points irradiated with the detection beams are not shown individually, but are shown as elongated detection areas AF extending in the X direction between the irradiation system 90a and the light receiving system 90b. Since this detection area AF has a length in the X direction set to be approximately the same as the diameter of the wafer W, the position information in the Z direction can be obtained over almost the entire surface of the wafer W by scanning the wafer W once in the Y direction. (Surface position information) can be measured. The detection area AF is arranged between the liquid immersion area 14 (exposure area IA) and the detection areas of the alignment systems (AL1, AL2 _{1 to} AL2 ₄ ) in the Y direction. The detection operation can be performed in parallel between the AF system and the alignment system. The multipoint AF system may be provided on the main frame that holds the projection unit PU, but may be supported via another support member.

In addition, although the some detection point shall be arrange | positioned by 1 row M column or 2 rows N columns, the number of rows and / or the number of columns is not restricted to this.
The exposure apparatus 100 of the present embodiment is symmetric with respect to the straight line LV in the vicinity of detection points located at both ends of a plurality of detection points of the multipoint AF system (90a, 90b), that is, in the vicinity of both ends of the detection area AF. Each surface position sensor (hereinafter abbreviated as a Z sensor) 72a, 72b, 72c, 72d for Z position measurement is provided. These Z sensors 72a to 72d are fixed to the lower surface of the main frame, for example. Z sensors 72a to 72d irradiate wafer table WTB with light from above, receive the reflected light, and measure position information in the Z direction orthogonal to the XY plane of wafer table WTB surface at the light irradiation point. For example, an optical displacement sensor (CD pickup type sensor) configured like an optical pickup used in a CD drive device or the like is used.

Furthermore, the above-described head unit 62C is arranged along two straight lines parallel to the straight line LH, which are located on one side and the other side across the straight line LH in the X direction connecting the plurality of Y heads 64, and at predetermined intervals. A plurality of (here, 6 each, 12 in total) Z sensors 74 _{i, j} (i = 1, 2, j = 1, 2,..., 6) are provided. In this case, the paired Z sensors 74 _{1, j} and 74 _{2, j} are disposed symmetrically with respect to the straight line LH. Further, a plurality of pairs (here, six pairs) of Z sensors 74 _{1, j} , 742 _{, j} and a plurality of Y heads 64 are alternately arranged in the X direction. As each Z sensor 74 _{i, j} , for example, a CD pickup type sensor similar to the aforementioned Z sensors 72 a to 72 d is used.

Here, 1 Z sensor 74 of each pair in a symmetrical _{position, j,} 74 2, interval _j with respect to straight line LH, Z sensor 72c described above, are set to the same interval as the 72d. Further, the pair of Z sensors 74 _1,4 , 74 _2,4 are located on the same straight line parallel to the Y direction as the Z sensors 72a, 72b.
Further, the head unit 62A described above has a plurality of, in this case, twelve Z sensors 76 _{p, q} (p = 1, 2) arranged symmetrically with the plurality of Z sensors 74 _{i, j} with respect to the straight line LV. Q = 1, 2,..., 6). As each Z sensor 76 _{p, q} , for example, a CD pickup type sensor similar to the Z sensors 72a to 72d described above is used. Further, a pair of Z sensors 76 _1,3, 76 _2,3 is positioned in the Z sensors 72c, the same Y-direction on a straight line and 72d. The Z sensors 74 _{i, j} and 76 _{p, q} are fixed to the bottom surface of the measurement frame 21.

In FIG. 4, illustration of the measurement stage MST is omitted, and an immersion region 14 formed by water Lq held between the measurement stage MST and the tip lens 191 is shown. In FIG. 4, 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 blows in a down flow is shown. Reference sign UP indicates an unload position where the wafer is unloaded on the wafer table WTB, and reference sign LP indicates a loading position where the wafer is loaded on the wafer table WTB. In the present embodiment, the unload position UP and the loading position LP are set symmetrically with respect to the straight line LV. Note that the unload position UP and the loading position LP may be the same position.

  FIG. 7 shows the main configuration of the control system of the exposure apparatus 100. This control system is mainly configured of a main control device 20 composed of a microcomputer (or a workstation) for overall control of the entire apparatus. In FIG. 7, various sensors provided on the measurement stage MST such as the uneven illuminance sensor 94, the aerial image measuring device 96, and the wavefront aberration measuring device 98 are collectively shown as a sensor group 9.

The exposure apparatus 100 of the present embodiment configured as described above employs the X scale and Y scale arrangement on the wafer table WTB as described above and the X head and Y head arrangement as described above. As illustrated in FIGS. 8A and 8B and the like, in the effective stroke range of wafer stage WST (that is, in the present embodiment, the range moved for alignment and exposure operation), The X scales 39X ₁ and 39X ₂ and the head units 62B and 62D (X head 66) face each other, and the Y scales 39Y ₁ and 39Y ₂ and the head units 62A and 62C (Y head 64) or the Y heads 64y ₁ and 64y. _{The two} are facing each other. In FIGS. 8A and 8B, the head facing the corresponding X scale or Y scale is circled.

Therefore, main controller 20 controls each motor constituting stage drive system 124 based on at least three measurement values of encoders 70A to 70D in the above-described effective stroke range of wafer stage WST, so that the wafer is controlled. Position information (including rotation information in the θz direction) in the XY plane of stage WST can be controlled with high accuracy. Since the influence of the air fluctuations on the measurement values of the encoders 70A to 70D 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. In the present embodiment, the sizes of the head units 62B, 62D, 62A, 62C (for example, the number of heads and / Or interval). Accordingly, in the effective stroke range of wafer stage WST, four scales 39X ₁ , 39X ₂ , 39Y ₁ , 39Y ₂ are all opposed to head units 62B, 62D, 62A, 62C, respectively, but the heads to which all four scales correspond. It does not have to face the unit.

For example, one of the X scales 39X ₁ and 39X ₂ and / or one of the Y scales 39Y ₁ and 39Y ₂ may be detached from the head unit. When one of the X scales 39X ₁ and 39X ₂ or one of the Y scales 39Y ₁ and 39Y ₂ deviates from the head unit, the three scales face the head unit in the effective stroke range of the wafer stage WST. Position information in the X axis, Y axis, and θz directions can always be measured. Further, when one of the X scales 39X ₁ and 39X ₂ and one of the Y scales 39Y ₁ and 39Y ₂ are out of the head unit, the _two scales face the head unit in the effective stroke range of the wafer stage WST. Although the position information of the WST in the θz direction cannot always be measured, the position information in the X axis and the Y direction can always be measured. In this case, position control of wafer stage WST may be performed using the position information of wafer stage WST in the θz direction measured by interferometer system 118 in combination.

In addition, when the wafer stage WST is driven in the X direction as indicated by a white arrow in FIG. 8A, the Y head 64 that measures the position of the wafer stage WST in the Y direction is indicated by the arrow in the figure. As indicated by e ₁ and e ₂ , the adjacent Y heads 64 are sequentially switched. For example, the Y head 64 surrounded by a solid circle is switched to the Y head 64 surrounded by a dotted circle. Therefore, the measurement value is taken over by the switching control unit in the Y encoders 70A and 70C in FIG. 7 before and after the switching. That is, in this embodiment, in order to smoothly switch the Y head 64 and take over the measurement value, as described above, the interval between the adjacent Y heads 64 included in the head units 62A and 62C is set to the Y scale 39Y ₁ , it is obtained by set narrower than the width of the X direction 39Y _2.

In the present embodiment, as described above, the interval between adjacent X heads 66 included in the head units 62B and 62D is set to be narrower than the width of the X scales 39X ₁ and 39X _{2 in} the Y direction. Accordingly, as described above, when the wafer stage WST is driven in the Y direction as indicated by the white arrow in FIG. 8B, the X head 66 that measures the position of the wafer stage WST in the X direction is The X heads 66 are sequentially switched to the adjacent X heads 66 (for example, the X heads 66 surrounded by the solid circles are switched to the X heads 66 surrounded by the dotted circles), before and after the switching, in the X encoders 70B and 70D in FIG. The switching value is taken over by the switching control unit.

In addition, the Y head 64 of the encoders 70A to 70F, as an example, coaxially irradiates a pair of laser beams to the corresponding Y scales 39Y ₁ and 39Y ₂ and a pair of diffracted lights generated from these scales. And a light receiving system that detects the interference light as combined light. Further, the Y head 64 also incorporates an optical system that detects interference light having a phase difference of 90 °, and is interpolated using two-phase detection signals, thereby halving the pitch of those scales. Displacement measurement can be performed with considerably finer resolution. The X heads 66 of the encoders 70A to 70F are similarly configured.

Hereinafter, in the exposure apparatus 100 of FIG. 1 of the present embodiment, an example of the operation when sequentially exposing the pattern image of the reticle R on one lot of wafers under the control of the main controller 20 of FIG. This will be described with reference to FIGS. 17 and 18.
First, in step 301 of FIG. 17, the reticle R is loaded onto the reticle stage RST of FIG. 1, and the main controller 20 determines the illumination conditions of the reticle R, the numerical aperture of the projection optical system PL, etc. from the exposure data file (not shown). The exposure conditions are read and the illumination system 10 and the like are set. Further, main controller 20 reads information on the shot arrangement of the wafer to be exposed from the exposure data file, and from this shot arrangement information, the arrangement pitch in the X direction of the shot area on the wafer, that is, each shot on the wafer. An X-direction interval (design interval) between the wafer marks attached to the region is obtained.

The wafer shot arrangement is set as shown in FIG. 13C as an example, and an alignment shot (sample shot) consisting of 16 shot areas distinguished from, for example, black selected from all shot areas on the wafer W. ) The wafer mark attached to the AS is measured by the alignment systems AL1, AL2 _{1 to} AL2 ₄ . In this case, the alignment shot AS on the wafer W has three alignment shots, five alignment shots, five alignment shots, and three alignment shots in the order of the width of four shot regions in the X direction from the + Y direction. It is composed of The wafer mark may be formed in the shot area, but in the present embodiment, the wafer mark is formed on a street line between the shot areas. The wafer mark includes a search alignment mark for searching the position of the wafer and a fine alignment mark for alignment of each shot area. Except for the case of step 311 described later, this embodiment Fine alignment marks are measured by the alignment systems AL1, AL2 _{1 to} AL2 ₄ .

Further, it is assumed that the alignment systems AL1, AL2 _{1 to} AL2 ₄ are arranged in the state shown in FIG. The intervals in the X direction of the detection centers of the secondary alignment systems AL2 ₁ , AL2 ₂ , AL2 ₃ , AL2 ₄ with respect to the detection center of the primary alignment system AL1, that is, secondary base lines SBL1, SBL2, SBL3, SBL4 are shown in FIG. As described above, the secondary alignment systems AL2 _{1 to} AL2 ₄ are driven and fixed so as to be a predetermined integer multiple of the interval between the wafer marks in the X direction. As an example, the initial values of the secondary baselines SBL1, SBL2, SBL3, and SBL4 are 8 times, 4 times, 4 times, and 8 times the interval in the X direction of the wafer mark (see FIG. 13C). Information on these values is also supplied to the alignment calculation system 20a. As a result, the primary alignment system AL1 and the secondary alignment systems AL2 _{1 to} AL2 ₄ are adjusted in position in the X direction in accordance with the arrangement of the measurement target wafer mark of the alignment shot AS on the wafer W. . At this stage, a setting error is included in the X-direction interval between the detection centers of the secondary alignment systems AL2 _{1 to} AL2 ₄ .

In the next step 302, calibration of the autofocus system (AF system) (not shown) for the alignment systems AL1, AL2 _{1 to} AL2 ₄ in FIG. For this purpose, as an example, the measurement stage MST is driven from the state of FIG. 2 (however, the wafer W is not placed), and as shown in FIG. 12A, the CD bar 46 of the measurement stage MST. The plurality of reference marks M1, M2 _{1 to} M2 ₄ are moved to the detection areas of the alignment systems AL1, AL2 _{1 to} AL2 ₄ . Then, the CD bar 46 is scanned in the Z direction via the Z / leveling mechanism of the measurement stage MST, and the position where the contrast of the imaging signal from the imaging device 5d is the highest may be set as the best focus position.

In the next step 303, by using the measured values of the encoders 70A to 70F in FIG. 7 including the Y heads 64, 64y ₁ , 64y ₂ and the X head 66 in FIG. 4, that is, by driving the wafer stage WST on the basis of the encoders. The origins of the image sensors of the alignment systems AL1, AL2 _{1 to} AL2 ₄ are set. It should be noted that wafer stage WST is driven based on an encoder during subsequent alignment and exposure. That is, first, as shown in FIG. 3A, the centers of the X mark FMX and the Y mark FMY of the reference mark FM are aligned with the detection center (conjugate point of the center of the image sensor) 3A of the primary alignment system AL1. As an example, the X mark FMX is a line-and-space pattern arranged at a predetermined interval in the X direction at two locations, and the Y mark FMY is arranged at a predetermined pitch in the Y direction between the X marks FMX. Line and space pattern.

Thereafter, as shown at the position A2 of the two-dot chain line in FIG. 11 (A), the wafer stage WST by a secondary baseline SBL2 + X direction by driving, for detecting the reference mark FM by secondary alignment systems AL2 _2. Center on the imaging element of the reference mark FM of the image at that time is the origin of the imaging surface, the detection center of the secondary alignment systems AL2 ₂ to a point on the object surface corresponding to the origin shown in FIG. 3 (B) 4C. FIG. 3B shows a state in which the reference mark FM is present in the detection area AL2 ₄ f of the secondary alignment system AL2 ₄ . Similarly, by moving the secondary baseline SBL1, SBL3, SBL4 only wafer stage WST + X direction or -X direction in FIG. 10, for detecting the reference mark FM by secondary alignment systems AL2 _1, AL2 _3, AL2 ₄ respectively. The pixel of the image sensor at the center of the image of the reference mark FM at that time is the origin of the imaging surface, and the points in the detection areas AL2 ₁ f to AL2 ₄ f in FIG. 3B corresponding to the origin are the detection centers 4B, 4D, 4E. The origin on the image sensor may be the center of the mark image obtained by interpolating the image signal.

Thereafter, the detection signal processing units 131A to 13E of FIG. 12A detect the origin on the imaging surface corrected for the offset corresponding to the detection center 3A (detection center of the primary alignment system AL1) and 4B to 4E (this is 3a). 4b to 4e (refer to FIG. 3D), a positional deviation amount in the direction corresponding to the X direction and the Y direction of the center of the image of the test mark is obtained, and for example, the image is enlarged to the positional deviation amount. By multiplying the reciprocal of the magnification, the amount of displacement on the surface to be measured is obtained.
When there is one alignment system, the center of the test mark can be placed near the position corresponding to the center pixel of the image sensor. However, when a plurality of test marks are detected substantially simultaneously using a plurality of alignment systems as in this embodiment, for example, the first test mark is installed in the vicinity of the detection center of the primary alignment system AL1. Then, in the other secondary alignment systems AL2 _{1 to} AL2 ₄ , the test mark is detected at a position substantially away from the first test mark by the secondary base line, that is, in the vicinity of the offset detection centers 4B to 4E. The Accordingly, even when the linearity of the image sensor is inferior as described later, by measuring the positional deviation amount of the test mark image with respect to the offset origins 4b to 4e on the image sensor corresponding to the detection centers 4B to 4E, a plurality of Can be detected with high accuracy substantially simultaneously.

Each way of example, FIG. 3 (C) and (D) shows the imaging surface 150E of the imaging element of the secondary alignment system AL2 _4, X direction on the surface to be detected, even direction on the imaging surface corresponding to the Y-direction Expressed in the X and Y directions. 3C shows the center pixel of the image sensor as the imaging center 3e, and FIG. 3D shows the origin 4e after offset correction obtained in step 303. In this case, assuming that the test mark is a reference mark FM (this image is FMP), in the image processing, the X direction of the X mark image FMXP and the Y mark image FMYP with respect to the origin 4e in FIG. A displacement amount in the Y direction is detected. When the offset corrected origin 4e is used, the position of the mark image can be detected with high accuracy even when the linearity of the high range of the image sensor is inferior.

  That is, the curve 162 in FIG. 15C changes an example of the correspondence relationship between the X-direction position CX of the pixel of the CCD type image sensor and the X-direction position WX on the test surface corresponding thereto. Is exaggerated. From the curve 162 in FIG. 15C, it can be seen that there is a portion where the linearity is inferior in a wide range between the position CX on the image sensor and the position WX on the test surface. However, as shown in FIG. 15C, linearity is relatively good in the region 160 (near the center of the image sensor) and the region 161 (region a predetermined distance from the center of the image sensor). The mark position can be detected with high accuracy by measuring the positional deviation amount of the image using these areas and converting the positional deviation amount into the positional deviation amount on the surface to be measured.

In the next step 304, the detection signal processing units 131A to 131E in FIG. 12A set an integration region (predetermined region) of imaging signals having a predetermined width on the imaging surfaces of the alignment systems AL1, AL2 _{1 to} AL2 ₄ . Specifically, on the imaging surface 150E in FIG. 3D, an integration region 151Y having a width in the X direction of ΔX and an integration region 151X having a width in the Y direction of ΔY are set around the corrected origin 4e. Then, the detection signal processing unit 131E integrates the imaging signals in the integration area 151X in the X direction (non-measurement direction) to obtain the imaging signal SY corresponding to the Y mark image FMYP, and the imaging signal in the integration area 151Y is obtained. An image pickup signal SX corresponding to the X mark image FMXP is obtained by integration in the Y direction (non-measurement direction).

As an example, the widths ΔX and ΔY of the integration regions 151X and 151Y are about 30 μm, and the offset amount of the origin 4e with respect to the imaging center 3e in the X and Y directions is within about 20 μm (± 10 μm). If the widths ΔX and ΔY are about 30 μm, a sufficiently large signal can be obtained. Further, it is possible to cancel the inconvenience due to the visual field shift when the detection region of the secondary alignment system is moved with such an offset amount.
As described above, by using only the imaging signals in the integration regions 151X and 151Y, the noise component in the region without the mark image can be reduced, so that the S / N ratio is improved and the test mark can be detected with high accuracy.

For example, as shown in FIG. 3C, when the integration regions 151X and 151Y are set around the imaging center 3e, a part of the image FMP of the reference mark deviates from the integration regions 151X and 151Y and the position thereof is changed. There is a possibility that it cannot be detected with high accuracy. Thus, in the present embodiment, in step 303, by actually detecting the reference mark FM, the imaging of the secondary alignment systems AL2 _{1 to} AL2 ₄ with reference to the imaging surface of the primary alignment system AL1 in which the detection area is fixed. The origin on the surface is set. As a result, the image of the test mark measured thereafter can be driven into the integrated areas 151X and 151Y of the imaging surfaces of the alignment systems AL1, AL2 _{1 to} AL2 ₄ .

Thereafter, assuming that there is no change over time, on the test surface (the upper surface of the wafer, etc.) corresponding to the origin of the imaging surface of the primary alignment system AL1 and the origin of the imaging surfaces of the secondary alignment systems AL2 _{1 to} AL2 ₄ The interval in the X direction at the point (detection center) accurately becomes the initial value of the secondary baselines SBL1 to SBL4.
However, in practice, since a slight change with time may occur, the secondary baseline is determined based on the known phase (interval information) of the reference mark on the CD bar 46 before exposure of each wafer in steps 306 to 308. The amount of change in SBL1 to SBL4 is measured. That is, after wafer stage WST is directed to the loading position, in step 306, measurement stage MST is driven to align reference marks M1, M2 _{1 to} M2 ₄ on CD bar 46 as shown in FIG. It moves to the detection area of the systems AL1, AL2 _{1 to} AL2 ₄ . Then, the reference mark M2 ₁ is detected by the secondary alignment system AL2 ₁ , and at the same time, using the focus signal from the autofocus system, the CD bar 46 is positioned so that the test surface is at the best focus position in the alignment systems AL1 and AL2 _1. The reference mark M1 is also detected in the primary alignment system AL1 while leveling is performed. Two reference marks M1, M2 ₁ detection result (position shift amount from the detection center) are supplied to the alignment calculation system 20a in FIG.

In the next step 307, as shown in FIG. 12 (B), while leveling of CD bar 46 as the test surface by the alignment systems AL1 and AL2 ₂ comes into best focus position, respectively, at the same time, alignment systems AL1 and detecting the reference marks M1 and M2 ₂ in AL2 _2, and supplies the two reference marks M1, M2 ₂ detection result (position shift amount from the detection center) in the alignment calculation system 20a in FIG. Similarly, with respect to the other secondary alignment systems AL2 ₃ and AL2 ₄ , in a state where the CD bar 46 is leveled and focused, the corresponding reference marks are detected simultaneously with the primary alignment system AL1, and the detection results are subjected to alignment calculation. Supply to system 20a.

In the next step 308, the alignment calculation system 20a obtains information on the known distance between the two reference marks M1 and M2 ₁ (or M2 _{2 to} M2 ₄ ) and the measured positional deviation amount of the two reference marks. Using the information, values after time-dependent changes of the secondary baselines SBL1 to SBL4 in FIG. 10 are obtained and stored. In this case, the position of the measurement stage MST (CD bar 46) slightly varies due to disturbance or the like. However, as in this embodiment, the primary alignment system AL1 (an alignment system in which the detection area is fixed) is simultaneously provided with one secondary alignment system (any one of AL2 _{1 to} AL2 ₄ ) in which the detection area is variable while always performing leveling. However, by detecting the reference mark, the secondary baseline can be measured with high accuracy at the best focus position without being affected by the position fluctuation of the CD bar 46.

For example, in FIG. 12A, when it is known that the best focus positions of the three alignment systems AL1, AL2 ₁ and AL2 ₂ are on a straight line, the upper surface of the CD bar 46 is brought to the straight line by leveling. combined by inclining the three alignment systems AL1, AL2 _1, AL2 ₂ in may detect the position of the corresponding reference mark simultaneously. In this case,
With one measurement, the two secondary baselines SBL1 and SBL2 can be measured with high accuracy at the best focus position.

  Next, in step 309 in FIG. 17, at the loading position LP in FIG. 13A, the first wafer (referred to as wafer W) of one lot is loaded onto wafer stage WST. The shot arrangement of the wafer W is as shown in FIG. Thereafter, main controller 20 moves wafer stage WST obliquely upward to the left in FIG. 13A to a predetermined position (alignment start position) where the center of wafer W is located on straight line LV. Position. In the state positioned at the alignment start position, a straight line that passes through the center of the wafer W and passes through the center of the wafer mark attached to the shot region arranged parallel to the Y axis passes through the detection center of the primary alignment system AL1. During the following alignment, wafer stage WST moves substantially along the Y axis. For this reason, alignment can be performed efficiently.

In the next step 310, as one process for measuring the baseline BL, which is the distance in the Y direction between the detection center of the primary alignment system AL1 and the center of the image by the projection optical system PL of the reticle R in FIG. Wafer stage WST is driven in the Y direction, and as shown in FIG. 11A, reference mark FM on measurement plate 30 on wafer stage WST is detected by primary alignment system AL1. This detection result (position shift amount from the detection center) and the coordinates measured by the encoders 70A to 70F of wafer stage WST at this time are supplied to alignment calculation system 20a.
Note that the origin setting operation in steps 303 and 304 may be executed before and after the operation in step 310 for the first wafer in one lot.

In the next step 311, for example, two search alignment marks on the wafer W are detected by the two secondary alignment systems AL _{2 2} and AL _{2 3} , and the rotation angle around the Z axis of the wafer W is corrected using this result. For example, when the wafer W is placed on the wafer stage WST from the wafer loader system (not shown), the operation of this step 311 can be omitted if the rotation angle of the wafer W can be controlled with high accuracy.

Next, in step 312 of FIG. 18, main controller 20 determines whether or not wafer W on wafer stage WST is the first wafer of one lot, and if it is the first wafer, it proceeds to step 313 and is not the first wafer. If so, the process proceeds to step 320. At this stage, since the wafer W is the leading wafer, the operation moves to step 313. Then, in order to correct TIS (Tool Induced Shift), which is an error caused by aberrations of the optical system of alignment systems AL1, AL2 _{1 to} AL2 ₄ , and an error caused by the wafer mark, main controller 20 performs a wafer stage. By driving the WST in the Y direction, as shown in FIG. 14A, as an example, five wafer marks WMA, WMB, WMC, WMD, and WME of five alignment shots arranged in the X direction on the wafer W Moving to the detection area of alignment systems AL1, AL2 _{2 to} AL2 ₄ , the amount of displacement from the detection center of wafer marks WMA to WME is detected. At this time, the wafer marks WMA to WME are concave and convex marks and may be asymmetric in the measurement direction (here, the X direction). As an example, wafer stage WST is controlled by primary alignment system AL1 so that the center of wafer mark WMA is as close to the detection center as possible, but it is not always necessary to detect wafer mark WMA by primary alignment system AL1. 14A to 14E, an asterisk indicates an alignment system that is measuring a wafer mark.

In the next step 314, as shown in FIG. 14B, wafer stage WST is moved in the -X direction by secondary base line SBL3, and wafer mark WMD (detected by secondary alignment system AL2 ₃₎ is detected by primary alignment system AL1. The amount of positional deviation with respect to the detection center of the mark) is detected. Similarly, as shown in FIGS. 14 (C), 14 (D), and 14 (E), wafer stage WST is moved to secondary base lines SBL4, SBL2, and SBL1, respectively, in the case of FIG. 14 (A). Positions with respect to the detection center of wafer marks WME, WMC, and WMB (marks detected by secondary alignment systems AL2 ₄ , AL2 ₂ , AL2 ₁ ) in primary alignment system AL 1, respectively, by moving in −X direction, + X direction, and + X direction The amount of deviation is detected.

In the next step 315, the alignment calculation system 20a obtains an offset of the detection result of the wafer mark in steps 313 and 314. Taking the secondary alignment system AL2 ₄ as an example, in the step 313, as shown in FIG. 15A, the secondary alignment system AL2 ₄ uses the X direction with respect to the origin 4e of the wafer mark image WMEP on the imaging surface 150E. The positional deviation amounts TIXR2, TIYR2 in the direction are detected. On the other hand, in step 314, as shown in FIG. 15B, the primary alignment system AL1 moves the wafer mark image WMEP on the imaging surface 150A in the X and Y directions with respect to the imaging center 3a (this is also the origin). The displacement amounts TIXPr and TIYPr are detected. In practice, these misregistration amounts are multiplied by a reciprocal of the magnification, but this is omitted here.

In this case, offsets XTOFF and YTOFF caused by TIS in the X direction and Y direction are as follows.
XTOFF = TIXPr−TIXR2 (1)
YTOFF = TIYPr−TIYR2 (2)
The offsets of the other secondary alignment systems AL2 _{1 to} AL2 ₃ can be calculated similarly. After that, when the wafer marks of the wafers in the same lot are detected by the secondary alignment systems AL2 _{1 to} AL2 ₄ , the alignment calculation system 20a adds the offsets of the expressions (1) and (2) to the measured values of the marks. By performing the above, errors due to TIS and the like can be reduced.

Further, as in the present embodiment, by detecting the wafer mark detected by the secondary alignment system by the primary alignment system, it is possible to cancel the influence of the measurement error of the measuring apparatus that measures the position of wafer stage WST.
For example, when the offsets of the equations (1) and (2) are known as device constants in advance, the operations in steps 313 to 315 may be omitted. In this case, the wafer mark detection operation from step 320 is immediately performed on the first wafer.

Next, at step 320, main controller 20 moves wafer stage WST by a predetermined distance in the Y direction based on the measurement values of encoders 70A to 70F, and positions it at the position shown in FIG. Using the alignment system AL1 and the secondary alignment systems AL2 ₂ and AL2 ₃ , the wafer marks attached to the three first alignment shots AS are imaged almost simultaneously and individually (see the star mark in FIG. 13A). At this time, for example, the wafer mark is first imaged while leveling the wafer W so that the defocus amount becomes zero with the two-lens secondary alignment systems AL2 ₂ and AL2 ₃ and the next remaining primary alignment system AL1. Is used to image the wafer mark in a focused state. Thereafter, in step 321, the position of the wafer mark is obtained by integrating the imaging signals in the integration areas 151 </ b> X and 151 </ b> Y (see FIG. 13D) of the imaging surface of each alignment system.

Next, in step 322, main controller 20 determines whether or not there is a wafer mark to be measured. If the measurement target remains, the process returns to step 320. At this stage, main controller 20 moves wafer stage WST by a predetermined distance in the + Y direction based on the measurement values of encoders 70A-70E, so that five alignment systems AL1, AL2 ₁ -AL2 ₄ are shown in FIG.
The wafer marks attached to the five second alignment shots AS on the wafer W shown in (C) are positioned at positions where they can be detected almost simultaneously and individually.

In steps 320 and 321, the wafer mark is detected while leveling for each of the two-lens secondary alignment systems, and finally the wafer mark is detected by the primary alignment system, so that the positions of the five wafer marks are substantially simultaneously detected. Is detected.
At the time of detecting these five wafer marks, the wafer mark detection for obtaining the offset shown in steps 313 to 315 may be executed. Instead, at the time of detecting the wafer mark in the three first alignment shot areas AS shown in FIG. 13A, an operation for obtaining the offsets of the corresponding secondary alignment systems AL2 ₂ and AL2 ₃ is executed, and the next FIG. during the five second wafer marks of the alignment shots AS detection may perform operation for obtaining the sides of the secondary alignment systems AL2 _1, AL2 ₄ offset.

Next, the operation returns from step 322 to step 320 again, and main controller 20 moves wafer stage WST by a predetermined distance in the + Y direction, and as shown in FIG. 13B, five alignment systems AL1, AL2 _{1 to} AL2 ₄ position the wafer marks attached to the five third alignment shots AS on the wafer W at positions where they can be detected almost simultaneously and individually. Then, Steps 320 and 321 are executed, and the detection results of the five wafer marks by the alignment systems AL1, AL2 _{1 to} AL2 ₄ are associated with the measurement values of the encoders 70A to 70F at the time of detection, and supplied to the alignment calculation system 20a. To do.

Next, the operation returns from step 322 to step 320, and main controller 20 moves wafer stage WST by a predetermined distance in the + Y direction and uses primary alignment system AL1, secondary alignment systems AL2 ₂ and AL2 ₃ to perform wafer W. The wafer marks attached to the above three force alignment shots AS are positioned at positions where they can be detected almost simultaneously and individually. Then, Steps 320 and 321 are executed to associate the detection results of the three wafer marks by the three alignment systems AL1, AL2 ₂ and AL2 ₃ with the measurement values of the encoders 70A to 70E at the time of the detection, and the alignment calculation system 20a. To supply. Since measurement of the wafer mark is completed at this stage, the operation shifts from step 322 to step 323, and main controller 20 drives wafer stage WST in the Y direction, as shown in FIG. Wafer stage WST and measurement stage MST are connected.

  Next, the slit pattern SL (see FIG. 5A) of the measurement plate 30 of the wafer stage WST is moved below the projection optical system PL, and the reticle stage RST of FIG. 1 is driven to light the center of the reticle R. Irradiation light IL is irradiated in accordance with the axis AX. Then, the image of the alignment mark on the reticle R is scanned with the slit pattern SL, the position is detected using the aerial image measurement device in the measurement stage MST, and the position information of the image (measured values of the encoders 70A to 70F). ) Is supplied to the alignment calculation system 20a. The alignment calculation system 20a can obtain the baseline BL shown in FIG. 11A from the detection result of step 310 and the detection result of step 323.

The operation of step 323 can be executed when the tip of the projection optical system PL approaches the measurement plate 30 during the measurement of the wafer marks of the four alignment shots in FIG. . This reduces the amount of movement of wafer stage WST and improves the exposure process throughput.
In the next step 324, the alignment calculation system 20a performs the encoder 70A corresponding to the detection results of the secondary baselines SBL1 to SBL4 obtained in step 308, the baseline BL obtained in step 323, and the total of 16 wafer marks. Statistical calculation is performed by using the EGA method disclosed in, for example, Japanese Patent Application Laid-Open No. 61-44429 (corresponding US Pat. No. 4,780,617) and the like using the measured values of ˜70E. Then, the arrangement of all shot regions on the wafer W on the stage coordinate system (for example, the XY coordinate system having the optical axis of the projection optical system PL as the origin) defined by the measurement axes of the encoders 70A to 70E is calculated. To do.

  Next, in step 325, as shown in FIGS. 13A and 13B, wafer stage WST is driven in the + Y direction, and the oblique incidence type multi-point AF system (90a, 90b) is used. Then, the Z position distribution (unevenness distribution) on the surface of the wafer W is measured. Then, in step 326, under the control of main controller 20, as shown in FIG. 16, wafer stage WST is measured using the measurement values of encoders 70A to 70F based on the array coordinates supplied from alignment calculation system 20a. , The pattern image of the reticle R is exposed on the entire shot area on the wafer W by the liquid immersion method and the step-and-scan method. The exposed wafer W is unloaded from wafer stage WST.

  In the next step 327, it is determined whether or not there is an unexposed wafer in one lot. If there is an unexposed wafer, the operation proceeds to step 306 in FIG. Measurement of a secondary baseline using marks, loading of a new wafer, and the like are executed. Since this time is the second and subsequent wafers, the operation shifts from step 311 to step 320, the wafer mark on the wafer is detected, and then the wafer scanning exposure is performed. Then, when there are no unexposed wafers in step 327, the exposure process for one lot of wafers ends.

As described above, in this embodiment, the five-stage alignment systems AL1, AL2 _{1 to} AL2 ₄ are used by moving the wafer stage WST in the Y direction and positioning the wafer stage WST at four positions on the movement path. Thus, it is possible to detect wafer mark position information in a total of 16 alignment shots AS. At this time, since it is not necessary to move wafer stage WST in the X direction, the wafer stage is driven in the X direction and the Y direction using a single alignment system to sequentially detect the wafer marks. Position information of a large number of wafer marks can be obtained in a very short time. Therefore, alignment can be performed in a short time.

The five-eye alignment systems AL1, AL2 _{1 to} AL2 ₄ in the above embodiment can be regarded as one alignment system (mark detection system, image detection system) having at least five detection areas separated in the X direction. It is.
The effect of this embodiment is as follows.
(1) The alignment method by the exposure apparatus 100 of the present embodiment is a mark detection method for detecting a wafer mark of a wafer W on which wafer marks are formed at a plurality of positions, and a plurality of detection regions arranged at different positions. alignment systems _AL1, AL2 1 AL24 primary alignment system of ₄ AL1 detects the corresponding wafer marks WMB~WME on the wafer W using a secondary alignment systems _AL2 1 AL24 ₄ except (predetermined mark detection system) Step 313 (FIG. 14A) is performed. Further, while measuring the position information of wafer stage WST holding wafer W, while moving wafer W, wafer marks WMB to WME on wafer W are sequentially moved to the detection area of primary alignment system AL1, and the wafer mark is moved. Based on the detection results of step 314 (FIGS. 14B to 14E) for detecting WMB to WME and the primary alignment system AL1 and the secondary alignment systems AL2 _{1 to} AL2R ₄ , the secondary alignment system AL2 ₁ to step 315 to determine the offset (correction information) resulting from the AL2R ₄ of the detection result TIS (Tool Induced Shift) (FIG. 15 (a), (B)) and a.

The alignment apparatus of the exposure apparatus 100 of the present embodiment is a mark detection apparatus that detects a wafer mark of a wafer W having wafer marks formed at a plurality of positions, and is a wafer stage WST that holds and moves the wafer W. A plurality of alignment systems AL1, AL2 _{1 to} AL2 ₄ arranged at different positions in the detection area, encoders 70A to 70F for measuring position information of wafer stage WST, main controller 20 and alignment calculation system 20a It has. Then, the main controller 20 and the alignment calculation system 20a detect the corresponding wafer marks WMB to WME on the wafer W using the secondary alignment systems AL2 _{1 to} AL2 ₄ , and the encoders 70A to 70F detect the wafer stage WST. While moving the wafer stage WST while measuring the position information, the wafer marks WMB to WME on the wafer W are sequentially moved to the detection area of the primary alignment system AL1, the marks are detected, and the alignment systems AL1, AL2 ₁ AL24 ₄ based on the detection results of those wafer mark by seeking an offset detection result of the secondary alignment systems _AL2 1 AL24 _4.

According to this embodiment, a plurality of alignment systems AL1, AL2 _{1 to} AL2 ₄ are used, and a plurality of wafer marks can be detected substantially simultaneously. Can be detected.
Since the wafer mark (wafer W) is measured while the wafer mark is sequentially measured by the two alignment systems, even if there is a measurement error of the encoders 70A to 70F, the two alignment systems are measured. The offset between them can be measured accurately. Accordingly, the accuracy of wafer mark measurement thereafter is improved.

(2) Further, another alignment method of the above embodiment is a mark detection method for detecting a wafer mark on the wafer W, and a plurality of detection areas AL1f, AL2 ₁ f to AL2 ₄ f having different positions are arranged. A step of detecting a reference mark FM on wafer stage WST in first detection area AL1f of alignment systems AL1, AL2 _{1 to} AL2 ₄ provided (part of step 303, FIG. 3A), and encoders 70A to 70F. The step of detecting the mark by moving the reference mark FM detected in the first detection area to the second detection area AL2 ₄ f while measuring the position of the wafer stage WST using (step 303) 3 (B)), the movement amount (position information) of wafer stage WST measured by encoders 70A to 70F, and the two detection areas. By using the result of detecting click FM, it is intended to include a step of determining a secondary baseline SBL4 (relative positional relationship) (part of step 303) is the distance of the detection center of the two detection regions.

Further, another alignment apparatus of the above embodiment is a mark detection apparatus that detects a wafer mark on the wafer W, and includes a plurality of detection areas AL1f, AL2 ₁ f to AL2 ₄ f having different positions. The systems AL1, AL2 _{1 to} AL2 ₄ , encoders 70A to 70F that measure position information of the moving body, a main controller 20 and an alignment calculation system 20a are provided. The main controller 20 and the alignment calculation system 20a detect the reference mark FM on the wafer stage WST in the first detection area AL1f of the alignment system, and then measure the position of the wafer stage WST with the encoders 70A to 70F. Meanwhile, the reference mark FM is moved to the second detection area AL2 ₄ f to detect the reference mark FM, and the movement amount of the wafer stage WST measured by the encoders 70A to 70F, and the reference mark FM in the two detection areas. The secondary baseline SBL4 is obtained using the result of detecting.

Thus, while measuring the movement amount of the reference mark FM by encoder 70A to 70F, since the sequentially measured fiducial mark FM in the detection region AL1f, AL2 ₄ f, the secondary baseline between the two detection regions accurately It can be measured. Accordingly, the accuracy of wafer mark measurement thereafter is improved.

(3) In the above embodiment, the wafer stage WST that holds the wafer W and can move in the X direction and the Y direction intersecting the wafer W is provided on one surface of the wafer stage WST. Scales 39X ₁ , 39X ₂ and 39Y ₁ , 3 in which lattices are periodically arranged in the direction
9Y ₂ (first and second grating portions), encoders 70B and 70D having a plurality of X heads 66 having different positions in the Y direction, and encoders 70A and 70C having a plurality of Y heads 64 having different positions in the X direction The X stage 66 measures the positional information of the wafer stage WST in the X direction with the X head 66 facing the scales 39X ₁ and 39X _2, and the wafer stage WST with the Y head 64 facing the scales 39Y ₁ and 39Y _2. The position information in the Y direction is measured.

Therefore, since the optical path length of the detection light of encoders 70A to 70D is short, the position of wafer stage WST can be measured with high accuracy with almost no influence of fluctuation compared to the case of using a laser interferometer.
As the encoders 70A to 70D, 70E, and 70F, a magnetic linear encoder or the like including a periodic magnetic scale in which a magnetism whose polarity is reversed is formed at a minute pitch and a magnetic head that reads the magnetic scale is used. It is also possible to do. Further, when the influence of the fluctuation of the optical path is small, the position of wafer stage WST may be measured using only the laser interferometer.

(4) The exposure apparatus of the above embodiment is an exposure apparatus that exposes the wafer W (object) with the illumination light IL (energy beam), and is a wafer stage WST (moving body) that holds and moves the wafer W. ) And a mark detection device including a plurality of alignment systems AL1, AL2 _{1 to} AL2 ₄ of the above-described embodiment, and using the mark detection device, a predetermined plurality of wafer marks on the wafer W are detected, Based on the detection result of the wafer mark, the illumination light is driven while driving the wafer W via the wafer stage WST in order to align the irradiation position of the illumination light IL (pattern image of the reticle R) with the wafer W. The wafer W is exposed with IL.

In addition, the exposure apparatus of the above embodiment includes a position control device including the plurality of alignment systems AL1, AL2 _{1 to} AL2 ₄ of the above embodiment, and the position is controlled on the wafer using the position control device. It is also an exposure apparatus that exposes a device pattern.
Further, the alignment method or apparatus of the above embodiment uses the position information of the wafer mark on the wafer W obtained by using the mark detection method using the plurality of alignment systems AL1, AL2 _{1 to} AL2 ₄ of the above embodiment. It is also an object position control method or apparatus for controlling the position of the wafer W.

In these cases, by using the alignment systems AL1, AL2 _{1 to} AL2 _{4 in} which the offset adjustment of a plurality of best focus positions is performed, a plurality of marks can be measured efficiently and with high accuracy, so that position control and exposure are efficient. And with high accuracy.
When a microdevice such as a semiconductor device is manufactured using the exposure apparatus according to the above-described embodiment, the microdevice is designed in step 221 for designing the function / performance of the microdevice, as shown in FIG. Step 222 for producing a mask (reticle) based on the above, step 223 for producing a substrate (wafer) as a base material of the device, and exposing the reticle pattern onto the substrate by the exposure apparatus 100 (projection exposure apparatus) 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, this device manufacturing method includes exposing a substrate (object) using the exposure apparatus of the above-described embodiment, and developing the exposed substrate. In addition, the device manufacturing method includes exposing a device pattern on a substrate (object) whose position is controlled using the alignment method (position control method) of the above-described embodiment.
At this time, since the substrate can be efficiently aligned (detection of alignment marks) using a plurality of alignment systems, the device can be mass-produced with high throughput.

The present invention can be applied to a step-and-repeat type projection exposure apparatus (stepper or the like) in addition to the above-described step-and-scan type scanning exposure type projection exposure apparatus (scanner). Further, the present invention can be similarly applied to a dry exposure type exposure apparatus other than the immersion type exposure apparatus.
The present invention 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 and a plasma display. Applicable to exposure equipment that transfers device patterns used in ceramics onto ceramic wafers, as well as exposure equipment used to manufacture imaging devices (CCD, etc.), organic EL, micromachines, MEMS (Microelectromechanical Systems), and DNA chips. can do. Further, the present invention is applied not only to a micro device such as a semiconductor element but also to an exposure apparatus that transfers a circuit pattern to a glass substrate or a silicon wafer in order to manufacture a mask used in an optical exposure apparatus and an EUV exposure apparatus. Applicable. 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.

It is a figure which shows schematic structure of the exposure apparatus which concerns on an example of embodiment of this invention. It is a top view which shows the stage apparatus of FIG. 3A is a diagram showing a detection area of a five-eye alignment system as an example of the embodiment, FIG. 3B is a diagram showing a detection center of the five-eye alignment system, and FIG. 3C is a secondary alignment system. FIG. 3D is a diagram showing the imaging center of AL2 ₄ , and FIG. 3D is a diagram showing the origin and integration area of the imaging surface of secondary alignment system AL2 ₄ . It is a figure which shows arrangement | positioning of alignment system AL1, AL2 ₁ -AL2 _{4 of} FIG. 1, and the encoder for position measurement. FIG. 5A is a plan view showing the wafer stage, and FIG. 5B is a side view showing a part of the wafer stage WST. FIG. 6A is a plan view showing the measurement stage, and FIG. 6B is a side view with a part of the cross section showing the measurement stage. FIG. 2 is a block diagram showing a main configuration of a control system of the exposure apparatus in FIG. 1. 8A and 8B are diagrams for explaining the position measurement in the XY plane of the wafer table and the takeover of the measurement value between the heads by a plurality of encoders each including a plurality of heads arranged in an array. FIG. It is a figure which shows an example of arrangement | positioning of alignment system AL1, AL2 ₁ -AL2 ₄ . It is a figure which shows the state which driven secondary alignment system AL2 ₁ -AL2 ₄ . FIG. 11A is a diagram showing a state in which the reference mark FM is measured by the primary alignment system AL1, and FIG. 11B is a diagram showing a state in which an image of the reticle pattern is scanned with a slit pattern. 12A shows a state in which the fiducial mark on the CD bar 46 is detected by the two-lens alignment systems AL1 and AL2 ₁ , and FIG. 12B shows the CD bar 46 by the two-lens alignment systems AL1 and AL2 _2. It is a figure which shows the state which detects the upper reference mark. FIG. 13A shows a state in which the first alignment shot AS is measured, FIG. 13B shows a state in which the third alignment shot AS is measured, and FIG. 13C shows a wafer alignment shot AS. It is a figure which shows an example of the arrangement | sequence of. FIG. 14A is a diagram showing a state in which wafer marks are detected by alignment systems AL2 _{1 to} AL2 ₄ , and FIGS. 14B, 14C, 14D, and 14E are respectively shown. It is a figure which shows the state which detects the wafer mark detected by the secondary alignment system by primary alignment system AL1. FIG 15 (A) is a diagram showing an image pickup surface of the secondary alignment system AL2 _4, FIG. 15 (B) is a diagram showing an image pickup surface of the primary alignment system AL1, FIG 15 (C) is the linearity of the imaging signal of the imaging device described FIG. It is a top view which shows the state which scans a wafer while driving the wafer stage WST and moving a wafer. It is a flowchart which shows a part of example of the exposure operation | movement of embodiment. It is a flowchart which shows the exposure operation | movement following FIG. It is a flowchart which shows an example of the manufacturing process of a microdevice.

Explanation of symbols

AL1 ... primary alignment system, AL2 _{1 to} AL2 ₄ ... secondary alignment system, R ... reticle, W ... wafer, WTB ... wafer table, WST ... wafer stage, MTB ... measurement table, MST ... measurement stage, 20 ... main controller, 32 ... nozzle unit, 39X _1, 39X ₂ ... X scales, 39Y _1, 39Y ₂ ... Y scale, 46 ... CD bar, 62A to 62D ... head unit, 64 ... Y head, 66 ... X heads, 70A, 70C ... Y Encoder, 70B, 70D ... X encoder

Claims (26)

A mark detection method for detecting the mark of an object having marks formed at a plurality of positions,
Detecting the corresponding mark on the object using a mark detection system excluding a predetermined mark detection system among a plurality of mark detection systems arranged at different positions in the detection area;
The mark detected by the mark detection system other than the predetermined mark detection system on the object is sequentially moved to the detection area of the predetermined mark detection system while moving the object while measuring the position information of the object. Moving to detect the mark;
Obtaining correction information of a detection result by a mark detection system other than the predetermined mark detection system based on a detection result by a mark detection system other than the predetermined mark detection system and a detection result by the predetermined mark detection system; A mark detection method. The detection area of the predetermined mark detection system is fixed,
The mark detection method according to claim 1, wherein a detection area of a mark detection system other than the predetermined mark detection system among the plurality of mark detection systems is movable. When detecting a mark on the object by a mark detection system other than the predetermined mark detection system,
3. The mark detection method according to claim 1, wherein an amount of positional deviation of the mark from a detection center determined based on the correction information is obtained. Placing the object on a movable body movable in a first direction and a second direction crossing the first direction;
First and second grating portions on which gratings are periodically arranged in the first direction and the second direction are provided on the moving body,
Using a measuring device having a first encoder having a plurality of first heads having different positions with respect to the second direction and a second encoder having a plurality of second heads having different positions with respect to the first direction;
When moving the moving body, position information of the moving body in the first direction is measured by the first head facing the first grating portion, and the moving is performed by the second head facing the second grating portion. The mark detection method according to claim 1, wherein position information of the body in the second direction is measured. An exposure method for exposing an object with an energy beam,
Detecting a plurality of predetermined marks on the object using the mark detection method according to any one of claims 1 to 4;
A step of exposing the object with the energy beam while driving the moving body to align the irradiation position of the energy beam and the object based on a detection result of the predetermined mark on the object; And an exposure method comprising: Exposing an object using the exposure method of claim 5;
Developing the exposed object. A mark detection device for detecting the mark of an object in which marks are formed at a plurality of different positions,
A moving body that holds and moves the object;
A plurality of mark detection systems in which detection areas are arranged at different positions;
A measuring device for measuring position information of the moving body;
A control device;
The controller is
Among the plurality of mark detection systems, using a mark detection system excluding a predetermined mark detection system, the corresponding mark on the object is detected,
While measuring the position information of the moving body by the measuring device, moving the moving body, the mark detected by the mark detection system other than the predetermined mark detection system on the object is detected by the predetermined mark. Move sequentially to the detection area of the system, detect the mark,
Mark detection for obtaining correction information of a detection result by a mark detection system other than the predetermined mark detection system based on a detection result by a mark detection system other than the predetermined mark detection system and a detection result by the predetermined mark detection system apparatus. The detection area of the predetermined mark detection system is fixed,
The mark detection apparatus according to claim 7, wherein a detection area of a mark detection system other than the predetermined mark detection system among the plurality of mark detection systems is movable. When detecting a mark on the object by a mark detection system other than the predetermined mark detection system,
The mark detection apparatus according to claim 7 or 8, wherein an amount of positional deviation of the mark from a detection center determined based on the correction information is obtained. On one surface of the moving body, there are provided first and second grating portions in which gratings are periodically arranged in a first direction and a second direction intersecting therewith,
A measuring device having a first encoder having a plurality of first heads having different positions with respect to the second direction, and a second encoder having a plurality of second heads having different positions with respect to the first direction;
When the movable body is moved, position information of the movable body in the first direction is measured by the first head facing the first lattice portion, and the movement is performed by the second head facing the second lattice portion. The mark detection apparatus according to any one of claims 7 to 9, which measures position information of the body in the second direction. An exposure apparatus that exposes an object with an energy beam,
A plurality of predetermined marks on the object are detected using the mark detection device according to any one of claims 7 to 10,
Exposure that exposes the object with the energy beam while driving the moving body to align the irradiation position of the energy beam and the object based on the detection result of the predetermined mark on the object apparatus. Exposing an object using the exposure apparatus of claim 11;
Developing the exposed object. A mark detection method for detecting the mark of an object in which marks are formed at a plurality of different positions,
Detecting a mark on a predetermined object in a first detection region of a mark detection system having a plurality of detection regions with different positions;
The mark on the predetermined object detected in the first detection area is moved to the second detection area while measuring the position of the predetermined object with a measuring device that measures the position information of the moving body, and the mark Detecting
Using the position information of the predetermined object measured by the measurement device, the result of detecting the mark in the first detection area, and the result of detecting the mark in the second detection area, the first detection Obtaining a relative positional relationship between a region and the second detection region.   The mark detection method according to claim 13, wherein the predetermined object is a reference mark member installed on a substrate stage that moves while holding a substrate on which a pattern is formed.   The mark detection method according to claim 13, wherein the predetermined object is a substrate on which a pattern is formed.   The mark detection method according to any one of claims 13 to 15, wherein the second detection area is fixedly disposed at a predetermined position, and the first detection area is movable with respect to the predetermined position. .   17. The measurement device according to claim 13, wherein the measurement device includes a lattice unit provided on a moving body that holds and moves the object, and a detection head unit disposed to face the lattice unit. The described mark detection method.   The mark detection method according to any one of claims 13 to 17, wherein the plurality of detection areas is three or more. A mark detection method according to any one of claims 13 to 18, comprising:
The position of the object is controlled while the position of the object is measured by the measurement device using the result of detecting the mark of the object on which the pattern is formed substantially simultaneously in the first detection area and the second detection area. An exposure method for exposing the pattern to the object. A mark detection device for detecting the mark of an object in which marks are formed at a plurality of different positions,
A mark detection system having a plurality of detection regions at different positions;
A measuring device for measuring position information of the moving body;
A control device;
The controller is
After detecting a mark on a predetermined object in the first detection area of the mark detection system, the position of the predetermined object is measured by the measurement device, and the position on the predetermined object detected in the first detection area is measured. Move the mark to the second detection area, detect the mark,
Using the position information of the predetermined object measured by the measurement device, the result of detecting the mark in the first detection area, and the result of detecting the mark in the second detection area, the first detection A mark detection apparatus for obtaining a relative positional relationship between a region and the second detection region.   21. The mark detection apparatus according to claim 20, wherein the predetermined object is a reference mark member installed on a substrate stage that moves while holding a substrate on which a pattern is formed.   The mark detection apparatus according to claim 20, wherein the predetermined object is a substrate on which a pattern is formed.   The mark detection device according to any one of claims 20 to 22, wherein the second detection area is fixedly disposed at a predetermined position, and the first detection area is movable with respect to the predetermined position. .   24. The measurement apparatus according to any one of claims 20 to 23, wherein the measurement device includes a lattice portion provided on a moving body that holds and moves the object, and a detection head portion that is disposed to face the lattice portion. The mark detection apparatus described.   The mark detection device according to any one of claims 20 to 24, wherein the plurality of detection regions is three or more. A mark detection device according to any one of claims 20 to 25,
The position of the object is controlled while the position of the object is measured by the measurement device using the result of detecting the mark of the object on which the pattern is formed substantially simultaneously in the first detection area and the second detection area. An exposure apparatus for exposing the pattern to the object.

Images