JPWO2007097350A1 - POSITION MEASURING DEVICE AND POSITION MEASURING METHOD, MOBILE BODY DRIVING SYSTEM, MOBILE BODY DRIVING METHOD, PATTERN FORMING APPARATUS, PATTERN FORMING METHOD, EXPOSURE APPARATUS AND EXPOSURE METHOD, AND DEVICE MANUFACTURING METHOD - Google Patents

Abstract

  Four moving scales (44A to 44D) that surround the wafer (W) and are fixed to the wafer stage (WST), and corresponding to each moving scale, the length in the longitudinal direction is the length in the direction perpendicular thereto. Linear encoders (50A to 50D) having head units (46A to 46D) that respectively emit substantially longer light. Then, based on the measurement result of each encoder, position information in the XY plane of the wafer stage (WST) is calculated. Thereby, the position of the moving body can be accurately measured without causing an increase in size.

Description

  The present invention relates to a position measuring apparatus and position measuring method, a moving body driving system and a moving body driving method, a pattern forming apparatus and a pattern forming method, an exposure apparatus and an exposure method, and a device manufacturing method. A position measuring device and a position measuring method for measuring position information, a moving body driving system and a moving body driving method for driving a moving body in a predetermined plane, and a pattern forming apparatus and a moving body driving method including the moving body driving system The present invention relates to a pattern forming method to be used, an exposure apparatus having a position measuring apparatus, an exposure method using the position measuring method, and a device manufacturing method using the pattern forming apparatus or the pattern forming method.

  Conventionally, in the lithography process in the manufacture of electronic devices (microdevices) such as semiconductor elements and liquid crystal display elements, step-and-repeat reduction projection exposure apparatuses (so-called steppers) or step-and-scan scanning projections are used. An exposure apparatus (a so-called scanning stepper (also called a scanner)) or the like is used relatively often.

  In this type of exposure apparatus, for example, a wafer that holds a wafer in order to transfer a reticle (or mask) pattern to a plurality of shot areas on a substrate to be exposed (hereinafter referred to as a wafer) such as a wafer or a glass plate. The stage is driven in, for example, a linear motor in the XY two-dimensional direction. Measurement of the position of the wafer stage is generally performed using a high-resolution laser interferometer with stable measurement values over a long period of time.

  However, due to the miniaturization of patterns accompanying higher integration of semiconductor elements, more precise position control of the stage is required, and now it is caused by temperature fluctuations in the atmosphere on the beam optical path of the laser interferometer. Short-term fluctuations in measured values are no longer negligible.

  On the other hand, recently, encoders that are a kind of position measuring apparatus have appeared that have a measurement resolution equal to or higher than that of a laser interferometer (for example, Patent Document 1, Patent Document 2 (especially, description of prior art), etc. reference).

  However, when an encoder is used for the wafer stage of the exposure apparatus, it is usually installed at a position far from the exposure position on the wafer stage (see, for example, Patent Document 2). For this reason, there is a disadvantage that the outer shape of the wafer stage becomes large.

US Pat. No. 6,639,686 JP 2004-101362 A

  The present invention has been made under the circumstances described above. From a first viewpoint, the present invention is a position measuring device that measures position information of a movable body that is movable within a predetermined plane, and is provided on the movable body. A first grating arranged and having a periodic direction in a direction parallel to the first axis in the plane; and a light beam extending substantially elongated in a direction perpendicular to the first axis in the plane. A first axis encoder head including a first irradiation system for irradiating the grating and a first light receiving element for receiving light from the first grating; based on a photoelectric conversion signal from the first light receiving element; And a calculation device that calculates position information relating to a direction parallel to the first axis of the movable body.

  According to this, for example, since the first axis encoder head can be arranged to face the first grating on the moving body, the optical path of the light beam can be shortened, and the desired position on the moving body can be achieved. Even if the grating is disposed on the substrate, position information relating to a direction parallel to the first axis of the movable body (hereinafter abbreviated as the first axis direction) can be obtained. Accordingly, it is possible to reduce the size of the moving body, and unlike the laser interferometer, it is possible to obtain position information regarding the first axis direction of the moving body without being substantially affected by fluctuation (refractive index change). it can.

  In this case, even if the moving body moves in a direction intersecting the first axis, for example, in a direction orthogonal to the first axis, the moving body substantially extends in the direction orthogonal to the first axis in the plane from the first irradiation system. An elongated light beam is applied to the first grating on the moving body. Thereby, the position information regarding the first axis direction of the moving body can be obtained without being affected by the movement of the moving body.

  From a second point of view, the present invention is a position measuring device that measures position information of a movable body that is movable in a direction parallel to the first and second axes within a predetermined plane, on the movable body. A first grating periodically disposed in a direction parallel to the first axis; at least as much as the first grating in a direction intersecting the first axis in the plane and parallel to the second axis And a first encoder head that irradiates the first grating with a light beam extending in a length of.

  According to this, for example, the first encoder head can be arranged to face the first grating on the moving body, so that the optical path of the light beam can be shortened, and the moving body is parallel to the second axis. Even if it moves about the same direction as the length of the first grating with respect to the direction, it is possible to obtain position information about the direction parallel to the first axis of the moving body. Therefore, it is possible to reduce the size of the moving body, and unlike the laser interferometer, the position information regarding the direction parallel to the first axis of the moving body can be obtained without being substantially affected by fluctuation (refractive index change). Obtainable.

  According to a third aspect of the present invention, either one of the first and second position measuring devices of the present invention; and a driving device that drives the movable body in the plane based on a measurement result of the position measuring device. And a moving body drive system.

  According to this, since any one of the first and second position measuring devices of the present invention is provided, the position of the moving body in the first axis direction can be accurately measured, and based on this measurement result The moving body is driven in the plane by the driving device. Therefore, it becomes possible to drive the moving body with high accuracy in at least the first axis direction in the plane.

  According to a fourth aspect of the present invention, there is provided a first pattern including: a moving body drive system according to the present invention in which an object is placed on the moving body; and a generation device that generates a pattern formed on the object. Forming device.

  According to this, the pattern generated by the pattern generation device is formed on the object driven with high accuracy by the moving body drive system of the present invention. This makes it possible to form a pattern on the object with high accuracy.

  The present invention relates to a moving body that holds an object; one of the first and second position measuring devices of the present invention that measures position information of the moving body; and a pattern generation device that generates a pattern on the object; And a second pattern forming apparatus that moves the movable body using the position measuring apparatus.

  According to this, for example, when the pattern generation device generates a pattern on the object, the moving body that holds the object is moved using either the first or second position measurement device of the present invention.

  According to a fifth aspect of the present invention, there is provided a step of forming a pattern on an object using either the first or second pattern forming apparatus of the present invention; and processing the object on which the pattern is formed. And a step of applying the device.

  According to a sixth aspect of the present invention, there is provided an exposure apparatus that exposes an object, the moving body that holds the object, and the first and second position measurements of the present invention that measure position information of the moving body. An exposure apparatus comprising any one of the apparatuses.

  According to this, for example, when the object is exposed, the position information of the moving body that holds the object is measured using either the first or second position measuring device of the present invention.

  According to a seventh aspect of the present invention, there is provided a position measurement method for measuring position information of a movable body movable in a predetermined plane, wherein the direction parallel to the first axis in the plane is the periodic direction. Irradiating the first grating disposed on the moving body with a light beam extending substantially elongated in a direction perpendicular to the first axis in the plane, receiving light from the first grating, It is a 1st position measuring method including the process of measuring the positional information regarding the direction parallel to the said 1st axis | shaft of a moving body.

  According to this, for example, it is possible to employ a configuration in which the first grating disposed on the moving body is irradiated with the light beam from the facing direction, so that the optical path of the light beam can be shortened and moved. Even if the grating is arranged at a desired position on the body, position information regarding the first axis direction of the moving body can be obtained. Accordingly, it is possible to reduce the size of the moving body, and unlike the laser interferometer, it is possible to obtain position information regarding the first axis direction of the moving body without being substantially affected by fluctuation (refractive index change). it can.

  In this case, even if the moving body moves in a direction intersecting the first axis, for example, in a direction perpendicular to the first axis, a light beam extending substantially elongated in the direction perpendicular to the first axis in the plane is generated. The first grating on the moving body is irradiated. Thereby, the position information regarding the first axis direction of the moving body can be obtained without being affected by the movement of the moving body.

  From an eighth aspect, the present invention is a position measurement method for measuring position information of a movable body movable in a direction parallel to the first and second axes within a predetermined plane, A light beam that intersects the first axis and extends in a direction that is at least as long as the first grating in a direction parallel to the second axis is periodically formed in a direction parallel to the first axis on the moving body. Irradiating the first grating disposed on the first grating, receiving light from the first grating, and measuring position information relating to a direction parallel to the first axis of the movable body. Is the method.

  According to this, for example, the first grating on the moving body can be irradiated with the light beam from the opposite direction, so that the optical path of the light beam can be shortened, and the moving body is parallel to the second axis. Even if it moves about the same direction as the length of the first grating with respect to the direction, it is possible to obtain position information about the direction parallel to the first axis of the moving body. Therefore, it is possible to reduce the size of the moving body, and unlike the laser interferometer, the position information regarding the direction parallel to the first axis of the moving body can be obtained without being substantially affected by fluctuation (refractive index change). Obtainable.

  From a ninth aspect, the present invention provides a step of measuring the position information of the moving body using either the first or second position measurement method of the present invention; based on the measured position information, Driving the moving body within the plane.

  According to this, since the position information of the moving body is measured using either the first or second position measuring method of the present invention, the position of the moving body in the first axis direction can be accurately measured. Based on the measured position information, the moving body is driven in the plane. Therefore, it becomes possible to drive the moving body with high accuracy in a direction parallel to at least the first axis in the plane.

  From a tenth aspect, the present invention includes a step of driving a moving body on which an object is placed using the moving body driving method of the present invention; and a step of generating a pattern on the object. 1 is a pattern forming method.

  According to this, a pattern is generated on an object driven with high accuracy using the moving body driving method of the present invention. This makes it possible to form a pattern on the object with high accuracy.

  According to an eleventh aspect of the present invention, there is provided a pattern forming method for forming a pattern on an object. When the pattern is generated on the object, any one of the first and second position measuring methods of the present invention is used. This is a second pattern forming method including a step of measuring position information of the moving body that holds the object using the method.

  According to this, for example, when generating a pattern on an object, the position information of the moving body holding the object is measured using either the first or second position measurement method of the present invention.

  According to a twelfth aspect of the present invention, a process of forming a pattern on an object using any one of the first and second pattern forming methods of the present invention; and processing the object on which the pattern is formed. And a step of applying the device.

  According to a thirteenth aspect of the present invention, there is provided an exposure method for exposing an object, the position information of a moving body that holds the object using either the first or second position measurement method of the present invention. It is the exposure method including the process of measuring.

  According to this, for example, when the object is exposed, the position information of the moving body that holds the object is measured using either the first or second position measuring method of the present invention.

It is a figure which shows schematically the structure of the exposure apparatus which concerns on one Embodiment. It is a figure for demonstrating the encoder system and interferometer system which are used with the exposure apparatus which concerns on one Embodiment. 3A and 3B are diagrams for explaining the encoder head of the encoder in FIG. FIGS. 4A and 4B are diagrams for explaining light emitted from the light source unit of the encoder head of FIG. 5A to 5D are diagrams for explaining the operation of the encoder head of FIG. It is a block diagram which abbreviate | omits and shows some control systems relevant to the stage control of the exposure apparatus which concerns on one Embodiment. It is a figure for demonstrating the modification of the encoder head used with the exposure apparatus which concerns on one Embodiment. 8A is a timing chart for explaining an output signal of the encoder when the encoder head of FIG. 7 is used, and FIG. 8B is a diagram for explaining a signal restored from the output signal of the encoder. It is a timing chart. It is a figure which shows the modification of the wafer stage used with an immersion exposure apparatus.

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

  FIG. 1 shows a schematic configuration of an exposure apparatus 100 according to an embodiment. The exposure apparatus 100 is a step-and-scan type scanning exposure apparatus, that is, a so-called scanning stepper. As will be described later, in the present embodiment, a projection optical system PL is provided. In the following description, a direction parallel to the optical axis AX of the projection optical system PL is a Z-axis direction, and a reticle in a plane perpendicular to the Z-axis direction. The direction in which the wafer is relatively scanned (the left-right direction in the drawing in FIG. 1) is the Y-axis direction, and the direction perpendicular to the Z-axis and the Y-axis (the direction orthogonal to the drawing in FIG. 1) is the X-axis direction. The rotation (inclination) directions around the Z axis will be described as θx, θy, and θz directions, respectively.

  The exposure apparatus 100 includes a light source and an illumination optical system, and an illumination system 10 that illuminates the reticle R with illumination light (exposure light) IL, a reticle stage RST that holds the reticle R, a projection unit PU, and a wafer W are placed thereon. A wafer stage device 12 including a wafer stage WST, a body BD on which a reticle stage RST, a projection unit PU, and the like are mounted, a control system for these, and the like are provided.

  The illumination system 10 illuminates a slit-shaped illumination area extending in the X-axis direction on the reticle R defined by a reticle blind (masking system) (not shown) with illumination light IL with a substantially uniform illuminance. Here, as the illumination light IL, for example, ArF excimer laser light (wavelength 193 nm) is used.

  Reticle stage RST is supported on a reticle base 36 constituting a top plate of second column 34 (described later) by an air bearing (not shown) provided on the bottom surface of the reticle stage RST through a clearance of about several μm, for example. .

  Here, the reticle stage RST is two-dimensionally (X-axis direction, Y-axis direction and θz) in an XY plane perpendicular to the optical axis AX of the projection optical system PL by a reticle stage drive system 11 including, for example, a linear motor. (In the direction) and can be driven at a speed specified in the scanning direction (Y-axis direction). The reticle stage RST may be a coarse / fine movement structure disclosed in, for example, Japanese Patent Application Laid-Open No. 8-130179 (corresponding to US Pat. No. 6,721,034). ) Is not limited to.

  Position information of reticle stage RST is measured by a reticle interferometer system including a reticle Y laser interferometer (hereinafter referred to as “reticle Y interferometer”) 16 y shown in FIG. As shown in FIG. 6, the reticle interferometer system actually includes a reticle Y interferometer 16y and a reticle X interferometer 16x.

  The reticle Y interferometer 16y uses the fixed mirror 14 (see FIG. 1) fixed to the side surface of the lens barrel 40 of the projection unit PU as a reference to move the Y position of the reticle stage RST to a movable mirror (such as a plane mirror or a retroreflector) 15 For example, it is always detected with a resolution of about 0.5 to 1 nm. At least a part of the reticle Y interferometer 16y (for example, an optical unit excluding the light source) is fixed to the reticle base 36, for example. The reticle X interferometer 16x irradiates a measurement surface with a measurement beam on a reflection surface formed extending in the Y-axis direction fixed (or formed) to the reticle stage RST, and the X position of the reflection surface is determined by the reticle. The X position of the stage RST is measured using a fixed mirror (not shown) fixed to the side surface of the lens barrel 40 as a reference. Note that the reticle interferometer system does not necessarily need to measure the position information of the reticle stage RST using a fixed mirror provided in the lens barrel 40.

  The X position information from the reticle X interferometer 16x and the Y position information from the reticle Y interferometer 16y are sent to the main controller 20 (see FIG. 6).

  Projection unit PU is held by a part of body BD below reticle stage RST in FIG. The body BD includes a first column 32 provided on the floor F of the clean room, for example, provided on the frame caster FC, and a second column 34 fixed on the first column 32. Yes.

  The frame caster FC includes a base plate BS placed horizontally on the floor surface F, and a plurality of, for example, three (or four) leg portions 39 (provided on the back of the page in FIG. 1) fixed on the base plate BS. The leg portion on the side is not shown).

  The first column 32 is a lens barrel supported substantially horizontally by a plurality of, for example, three (or four) first anti-vibration mechanisms 56 fixed individually to the upper ends of the plurality of legs 39. A surface plate (main frame) 38 is provided.

  The lens barrel base plate 38 is formed with a circular opening (not shown) at substantially the center thereof, and the projection unit PU is inserted into the circular opening from above, and the projection unit PU has a flange FLG provided on the outer periphery thereof. Is held through. On the upper surface of the lens barrel surface plate 38, one end (lower end) of a plurality of, for example, three legs 41 (however, the legs on the back side of the drawing in FIG. 1 are not shown) is fixed at a position surrounding the projection unit PU. ing. The other end (upper end) surface of each of these legs 41 is on substantially the same horizontal plane, and the above-mentioned reticle base 36 is fixed to these legs 41. In this way, the reticle base 36 is horizontally supported by the plurality of legs 41. That is, the second column 34 is configured by the reticle base 36 and the plurality of legs 41 that support the reticle base 36. The reticle base 36 is formed with an opening 36a serving as a passage for the illumination light IL at the center thereof. The second column 34 (that is, at least the reticle base 36) may be disposed on the first column 32 via a vibration isolation mechanism, or may be disposed on the base plate BS independently of the first column 32. Also good.

  The projection unit PU includes a lens barrel 40 that is cylindrical and provided with a flange FLG, and a projection optical system PL that includes a plurality of optical elements held by the lens barrel 40. In the present embodiment, the projection unit PU is placed on the lens barrel surface plate 38. However, as disclosed in, for example, International Publication No. 2006/038952 pamphlet, the projection unit PU is not disposed above the projection unit PU. The projection unit PU may be supported by being suspended from the illustrated main frame member, the reticle base 36, or the like.

  As the projection optical system PL, for example, a refractive optical system including a plurality of lenses (lens elements) arranged along an optical axis AX parallel to the Z-axis direction is used. This projection optical system PL is, for example, both-side telecentric and has a predetermined projection magnification (for example, 1/4 or 1/5). For this reason, when the above-mentioned illumination area is illuminated by the illumination light IL from the illumination system 10, the first surface (object surface) of the projection optical system PL and the pattern surface are passed through the reticle R, which is substantially aligned. With the illumination light IL, a reduced image of the circuit pattern of the reticle in the illumination area (a reduced image of a part of the circuit pattern) is arranged on the second surface (image surface) side via the projection optical system PL. It is formed in a region (exposure region) conjugate to the illumination region on the wafer W having a resist (photosensitive agent) coated on the surface. Then, by synchronous driving of reticle stage RST and wafer stage WST, reticle R is moved relative to the illumination area (illumination light IL) in the scanning direction (Y-axis direction) and at the same time with respect to the exposure area (illumination light IL). By moving the wafer W relative to the scanning direction (Y-axis direction), scanning exposure of one shot area (partition area) on the wafer W is performed, and a reticle pattern is transferred to the shot area. That is, in this embodiment, a pattern is generated on the wafer W by the illumination system 10, the reticle R, and the projection optical system PL, and the pattern is formed on the wafer W by exposure of the sensitive layer (resist layer) on the wafer W by the illumination light IL. Is formed.

  The wafer stage apparatus 12 includes a stage base 71 that is supported substantially horizontally by a plurality of (for example, three) second vibration isolation mechanisms (not shown) on the base plate BS, and a wafer disposed above the stage base 71. A stage WST, a wafer stage drive system 27 for driving the wafer stage WST, and the like are provided.

  Stage base 71 is made of a plate-like member also called a surface plate, and the upper surface thereof is finished with a very high flatness, and serves as a guide surface when wafer stage WST moves.

  Wafer stage WST is driven by a wafer stage drive system 27 including, for example, a linear motor, a voice coil motor, and the like, in six degrees of freedom in the X axis direction, Y axis direction, Z axis direction, θx direction, θy direction, and θz direction. The

  As wafer stage WST, for example, a wafer stage main body driven in at least the X-axis direction, the Y-axis direction, and the θz direction by a linear motor or the like, and at least the Z-axis direction by the voice coil motor on the wafer stage main body, θx A structure including a wafer table that is finely driven in the direction and θy direction may be employed.

  Wafer W is placed on wafer stage WST via a wafer holder (not shown), and wafer W is fixed by, for example, vacuum chucking (or electrostatic chucking).

  The position information of wafer stage WST in the XY plane (moving plane) includes an encoder system including head units 46B, 46C, 46D and moving scales 44B, 44C, 44D, etc., as shown in FIG. 1, and a wafer laser interferometer system. (Hereinafter referred to as “wafer interferometer system”) 18 and so on. Hereinafter, the configuration and the like of the encoder system for wafer stage WST and wafer interferometer system 18 will be described in detail.

  On the upper surface of wafer stage WST, four moving scales 44A to 44D are fixed so as to surround wafer W as shown in FIG. More specifically, the moving scales 44 </ b> A to 44 </ b> D are made of the same material (for example, ceramics or low thermal expansion glass), and a reflective diffraction grating having a longitudinal direction as a periodic direction is formed on the surface thereof. . The diffraction grating is formed at a pitch of, for example, 4 μm to 138 nm, and in this embodiment, 1 μm pitch. In FIG. 2, for the sake of convenience of illustration, the pitch of the lattice is shown much wider than the actual pitch.

  The moving scales 44A and 44C are symmetrical with respect to a center line parallel to the Y-axis direction, the longitudinal direction of which coincides with the Y-axis direction in FIG. 2 and passes through the center of wafer stage WST (considered except for moving mirrors 17X and 17Y). The diffraction gratings arranged and formed on the moving scales 44A and 44C are also symmetrically arranged with respect to the center line. These moving scales 44A and 44C are used for measuring the position of wafer stage WST in the Y-axis direction because the diffraction gratings are periodically arranged in the Y-axis direction.

  Further, the moving scales 44B and 44D have a longitudinal direction that coincides with the X-axis direction in FIG. 2 and that passes through the center of wafer stage WST (considered by moving mirrors 17X and 17Y) and is parallel to the X-axis direction. The diffraction gratings arranged symmetrically and formed on the moving scales 44B and 44D are also symmetrically arranged with respect to the center line. These moving scales 44B and 44D are used for measuring the position of wafer stage WST in the X-axis direction because the diffraction gratings are periodically arranged in the X-axis direction.

  FIG. 1 shows a state in which the wafer W is exposed above the moving scale 44C, but this is for convenience, and the upper surfaces of the moving scales 44A to 44D are actually the wafers. It is substantially the same height as the upper surface of W or located above.

  On the other hand, as can be seen from FIGS. 1 and 2, four encoder head units (hereinafter abbreviated as “head units”) 46 </ b> A to 46 </ b> D in a state of surrounding the bottom end of the projection unit PU from four directions, Each is arranged so as to intersect with the corresponding moving scales 44A to 44D. The head units 46 </ b> A to 46 </ b> D are not shown in FIG. 1 from the viewpoint of avoiding complication of the drawing, but are actually fixed to the lens barrel surface plate 38 in a suspended state via a support member.

  The head units 46A and 46C have the X-axis direction orthogonal to the longitudinal direction (Y-axis direction in FIG. 2) of the corresponding moving scales 44A and 44C on the −X side and + X side of the projection unit PU, respectively, and They are arranged symmetrically with respect to the optical axis AX of the projection optical system PL. Further, the head units 46B and 46D have the Y-axis direction orthogonal to the longitudinal direction (X-axis direction in FIG. 2) of the corresponding moving scales 44B and 44D on the + Y side and −Y side of the projection unit PU, respectively. And symmetrically arranged with respect to the optical axis AX of the projection optical system PL.

  Each of the head units 46A to 46D has the same configuration and operation. Therefore, the head unit 46A will be described representatively.

  As shown in FIGS. 3A and 3B as an example, the head unit 46A has a plurality of light sources 48 (for example, a pitch with almost no gap) arranged along the longitudinal direction thereof. A light source unit 47 having a light source group), a light receiving element PD, and three fixed-side diffraction gratings, that is, first to third index scales 49a to 49c.

  Each light source 48 emits laser light having a wavelength of 850 nm, for example, substantially vertically downward (−Z direction). Therefore, in this embodiment, as shown in FIG. 4A and FIG. 4B as an example, the light beam Bm that extends substantially in the X-axis direction from the light source unit 47 is substantially vertically downward. It is injected towards. For example, a laser diode (semiconductor laser) or the like is used as the light source 48.

  The first index scale 49a is arranged below the light source unit 47 (on the −Z side), and has a pitch between 4 μm and 138 nm, for example, with the Y-axis direction as a periodic direction, for example, 0.98 μm (1 μm is slightly A diffraction grating having a different pitch is a transmission type phase grating composed of a plate formed in almost the entire range in the longitudinal direction (X-axis direction). For this reason, when the light beam Bm emitted from the light source unit 47 is irradiated onto the index scale 49a, a plurality of diffracted lights of the light beam Bm are generated. FIG. 5A shows the + 1st order diffracted light Ba1 and the −1st order diffracted light Ba2 generated by the first index scale 49a among the diffracted lights.

  In the second index scale 49b, for example, a diffraction grating having a pitch direction of the Y-axis direction, for example, 0.49 μm pitch (half pitch of the index scale 49a) is formed in almost the entire range in the longitudinal direction (X-axis direction). It is a transmission type phase grating composed of a plate. The index scale 49b is disposed at a position where the + first-order diffracted light Ba1 generated by the index scale 49a can enter. The third index scale 49c is a transmissive phase grating composed of a plate on which a diffraction grating similar to the index scale 49b is formed. The third index scale 49c is at a position where the −1st-order diffracted light Ba2 generated by the index scale 49a can enter. Has been placed.

  The index scale 49b diffracts the + 1st order diffracted light Ba1 generated by the index scale 49a to generate a −1st order diffracted light Bb, and the −1st order diffracted light Bb travels toward the moving scale 44A. The index scale 49c diffracts the −1st order diffracted light Ba2 generated by the index scale 49a to generate + 1st order diffracted light, and the + 1st order diffracted light travels toward the moving scale 44A.

  Here, the −1st order diffracted light generated by the index scale 49b and the + 1st order diffracted light generated by the index scale 49c are incident on the same position (region) on the moving scale 44A. FIG. 5B shows a side view of FIG. 5A viewed from the + Y side.

  As described above, the reflective diffraction grating having the Y-axis direction as the periodic direction is formed on the surface of the moving scale 44A. The moving scale 44A diffracts the −1st order diffracted light generated by the index scale 49b to generate + 1st order diffracted light, and diffracts the + 1st order diffracted light generated by the third index scale 49c to generate a −1st order diffracted light. . These diffracted lights are received by the light receiving element PD positioned above the moving scale 44A (below the index scale 49a) while interfering with each other.

  In this case, as described above, the grating pitch of the index scale 49a and the grating pitch of the moving scale 44A are slightly different from each other. As an example, as shown in FIG. 5C, vernier fringes are generated on the light receiving element surface. Can be made. In this case, as shown in FIG. 5D as an example, the light receiving element PD is a two-part light receiving element made up of two partial light receiving elements (PDa, PDb). Is output, and a cosine wave signal is output from the partial light receiving element PDb. That is, a two-phase sine wave can be obtained. As a method for obtaining a two-phase sine wave, for example, Yanao, Watanabe: “Recent Photoelectric Encoder Technology and Applications”, Optical Technology Contact, Vol19. There are various methods as described in No. 5 (hereinafter referred to as “Yanao Literature” for the sake of convenience), and either method may be used.

  Note that the grating pitch of the index scale 49a and the moving scale 44A is not necessarily slightly different. For example, the grating pitch of the index scale 49a and the moving scale 44A may be the same (for example, 1 μm). In this case, the grating pitch of the index scales 49b and 49c may be set to 0.5 μm, for example. In any case, the photoelectric conversion signal of the interference light received by the light receiving element PD (not necessarily the two-divided light receiving element) is supplied to the main controller 20 as an output signal of the encoder head 46A.

  The main controller 20 uses, for example, a method described in the above-mentioned Yanagio literature, or other known methods, and is obtained based on an output signal from the light receiving element PD. Periodic signals (for example, sine waves and cosine waves) are detected, and the relative positional relationship between the encoder head 46A and the moving scale 44A and the relative motion direction of both are calculated from the relationship between the amplitude and phase of the two signals. To do. That is, main controller 20 calculates position information regarding the Y-axis direction of moving scale 44A (wafer stage WST) based on the output signal of light receiving element PD. Thus, in the present embodiment, a Y linear encoder (hereinafter referred to as “encoder” as appropriate) that measures positional information (movement amount and movement direction) of wafer stage WST in the Y-axis direction using head unit 46A and movement scale 44A. 50A (refer to FIG. 2 and FIG. 6) is configured.

  Similarly, the head unit 46B, together with the movement scale 44B, is an X linear encoder (hereinafter abbreviated as “encoder” as appropriate) 50B that measures position information (movement amount and movement direction) of the wafer stage WST in the X-axis direction. (See FIGS. 2 and 6). The head unit 46C, together with the movement scale 44C, constitutes a Y linear encoder 50C (see FIGS. 2 and 6) that measures the Y-axis direction (movement amount and movement direction) of the wafer stage WST. The head unit 46D, together with the movement scale 44D, constitutes an X linear encoder 50D (see FIGS. 2 and 6) that measures the X-axis direction (movement amount and movement direction) of the wafer stage WST. Output signals of these encoders 50B to 50D are supplied to the main controller 20. Main controller 20 adds position information relating to the Y-axis direction and / or X-axis direction of wafer stage WST based on the output signals of at least one of Y linear encoders 50A and 50C and X linear encoders 50B and 50D. , Position information regarding the θz direction, that is, rotation information about the Z axis (yawing) is also calculated. In the present embodiment, the four head units 46A to 46D are suspended and supported on the lens barrel surface plate 38, but the exposure apparatus 100 in FIG. 1 projects onto the main frame member or the reticle base 36 as described above. When the unit PU is suspended and supported, for example, the head units 46A to 46D may be suspended and supported integrally with the projection unit PU, or from the main frame member or the reticle base 36 independently of the projection unit PU. You may provide four head units 46A-46D in the measurement frame supported by suspension. In the latter case, the projection unit PU need not be suspended and supported.

  As shown in FIG. 1, the position information of wafer stage WST in the XY plane is obtained by a wafer laser interferometer system (hereinafter referred to as “wafer interferometer”) that irradiates a moving mirror 17 fixed to wafer stage WST with a measurement beam. System) 18) is always detected with a resolution of, for example, about 0.5 to 1 nm. At least a part of the wafer interferometer system 18 (for example, an optical unit excluding the light source) is fixed to the lens barrel surface plate 38 in a suspended state. Note that at least a part of the wafer interferometer system 18 may be suspended and supported integrally with the projection unit PU, or may be provided on the above-described measurement frame.

  Here, on wafer stage WST, actually, as shown in FIG. 2, Y movable mirror 17Y having a reflecting surface perpendicular to the Y-axis direction that is the scanning direction and X-axis direction that is the non-scanning direction An X moving mirror 17X having a reflecting surface orthogonal to is provided, but these are typically shown as the moving mirror 17 in FIG.

Wafer interferometer system 18, as shown in FIG. 2, includes a wafer Y interferometer 18Y, two three interferometers with wafer X interferometer 18X ₁ and 18X _2. Among these, as a wafer Y interferometer (hereinafter abbreviated as “Y interferometer”) 18Y, as shown in FIG. A multi-axis interferometer having a plurality of measurement axes including two measurement axes that are symmetrical with respect to an axis (center axis) parallel to the Y axis passing through the detection center of the illustrated alignment system is used. As shown in FIG. 2, the Y interferometer 18Y is separated from the straight line parallel to the Y axis passing through the projection center (optical axis AX, see FIG. 1) of the projection optical system PL to the same distance −X side and + X side. Position information in the Y-axis direction of wafer stage WST at the measurement beam irradiation point by projecting two measurement beams along movable axis 17Y along the Y-axis direction and receiving the respective reflected lights. Is detected with reference to the reflection surface of the Y fixed mirror fixed to the side surface of the lens barrel of the projection optical system PL. The Y interferometer also measures rotation information (pitching) in the θx direction and rotation information (yawing) in the θz direction of wafer stage WST.

Wafer X interferometer 18X ₁ irradiates movable mirror 17X with a measurement beam along two length measurement axes that are symmetrical with respect to an axis (center axis) parallel to the X axis passing through optical axis AX of projection optical system PL. . This wafer X interferometer 18X ₁ measures the position information of the reflecting surface of the movable mirror 17X with reference to the reflecting surface of the X fixed mirror fixed to the side surface of the barrel 40 of the projection unit PU as the X position of the wafer stage WST. To do. Further, the X interferometer 18X _1, the rotation information of the θy directions of the wafer stage WST (rolling) also measured.

Wafer X interferometer 18X ₂ irradiates measurement beam to movable mirror 17X along a measurement axis parallel to the X axis that passes through the detection center of an alignment system (not shown), and is fixed to the side surface of the alignment system. Position information of the reflecting surface of the movable mirror 17X with respect to the reflecting surface of the fixed mirror is measured as the X position of the wafer stage WST.

In FIG. 1, the X interferometers 18X ₁ and 18X ₂ and the Y interferometer 18Y are typically shown as a wafer interferometer system 18, and a fixed mirror for measuring the X-axis direction position and a fixed for measuring the Y-axis direction position are shown. A mirror is typically shown as a fixed mirror 57. Further, the alignment system and the fixed mirror fixed thereto are not shown.

In this embodiment, the wafer X interferometer 18X ₁ and wafer Y interferometer 18Y, together used for calibration of the encoder system used during an exposure operation of the wafer, the wafer X interferometer 18X ₂ and wafer Y interferometer 18Y and Is used when a mark is detected by the alignment system. Wafer X interferometer 18X ₂ is constituted by a multi-axis interferometer as in wafer X interferometer 18X ₁ so that rotation information (yawing and rolling) can be measured in addition to the X position of wafer stage WST. good. Further, for example, instead of the moving mirrors 17X and 17Y, the end surface of the wafer stage WST may be mirror-finished to form a reflecting surface (corresponding to the reflecting surfaces of the moving mirrors 17X and 17Y). Further, wafer interferometer system 18 does not necessarily have to measure the position information of wafer stage WST using the projection unit PU and a fixed mirror provided in the alignment system.

Wafer Y interferometer 18Y, the measurement result of the wafer X interferometer 18X ₁ and wafer X interferometer 18X ₂ are supplied to main controller 20.

  FIG. 6 is a block diagram with a part of a control system related to wafer stage control of the exposure apparatus 100 of the present embodiment omitted. The control system of FIG. 6 includes a so-called microcomputer (or workstation) including a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc. The main control device 20 is centrally controlled and is mainly configured.

  In the exposure apparatus 100 configured as described above, for example, EGA (Enhanced Global Alignment) disclosed in Japanese Patent Laid-Open No. 61-44429 and the corresponding US Pat. No. 4,780,617. At the time of the wafer alignment operation performed by the method, as described above, the position of the wafer stage WST is managed by the main controller 20 based on the measurement value of the wafer interferometer system 18, and other than during the wafer alignment operation, for example, during the exposure operation For example, the position of wafer stage WST is managed by main controller 20 based on the measurement results of encoders 50A to 50D. Note that the position of wafer stage WST may also be managed based on the measurement values of encoders 50A to 50D during the wafer alignment operation. Further, when managing the position of wafer stage WST based on the measurement values of encoders 50A to 50D, at least one measurement value (for example, position information in the Z axis, θx, and θy directions) of wafer interferometer system 18 is used in combination. May be.

Therefore, in this embodiment, the position measurement system used for position measurement in the XY plane of the wafer stage after the end of the wafer alignment operation and before the start of exposure is the wafer interferometer system 18 (that is, the wafer Y interferometer 18Y). The position measurement system switching operation for switching from the wafer X interferometer 18X ₂ ) to the encoders 50A to 50D is performed by the main controller 20 in a predetermined procedure.

In exposure apparatus 100 of the present embodiment, reticle alignment (reticle coordinate system) is performed using a reticle alignment system, a reference mark plate on wafer stage WST, an alignment system (both not shown), and the like, as in a normal scanning stepper. And a wafer coordinate system) and a series of operations such as baseline measurement of the alignment system. These series of reticle stage RST in the working position control of wafer stage WST, interferometers 16y and 16x, and is performed based on the interferometer 18X _1, 18X _2, measurement value of 18Y. In reticle alignment, baseline measurement, or the like, position control of reticle stage RST and wafer stage WST may be performed based on only the above-described encoder measurement values or both interferometer and encoder measurement values.

  Next, main controller 20 performs wafer exchange on wafer stage WST (if there is no wafer on wafer stage WST) using a wafer loader (conveyor) (not shown), and aligns the wafer. For example, EGA wafer alignment is performed using the system. By this wafer alignment, arrangement coordinates (that is, position information in the X-axis and Y-axis directions) of a plurality of shot areas on the wafer on the alignment coordinate system are obtained.

  Thereafter, the position measurement system is switched, and the main controller 20 determines the position information of each shot area on the wafer obtained by the EGA method, the baseline measured earlier, and the measured values of the encoders 50A to 50D. Step-and-scan exposure is performed in the same procedure as a normal scanning stepper while managing the position of wafer stage WST and managing the position of reticle stage RST based on the measurement values of interferometers 16y and 16x. The pattern of the reticle R is transferred to a plurality of shot areas on the wafer.

  As described above, according to this embodiment, the head units 46A to 46D of the encoders 50A to 50D irradiate the moving scales 44A to 44D on the wafer stage WST from directly above, so that the optical path of the light beam The length can be made much shorter than the optical path length of the measuring beam of the laser interferometer. Further, since the head unit irradiates the moving scale with the light beam from directly above, it is possible to employ an arrangement in which the moving scales 44A to 44D surround the wafer W in the vicinity of the wafer W. Therefore, the wafer stage WST can be downsized, and unlike the laser interferometer, the position information (θz direction) of the wafer stage WST in the XY plane is not substantially affected by fluctuation (refractive index change). Can be obtained with high accuracy.

  Even if wafer stage WST moves in a direction intersecting the Y axis, for example, in the X axis direction, a light beam that extends substantially in the X axis direction from the irradiation system of head units 46A and 46C is on wafer stage WST. Since the moving scales 44A and 44C are respectively irradiated, the main controller 20 determines the position information of the wafer stage WST in the Y-axis direction (and the θz direction) based on the output signals of the head units 46A and 46C (encoders 50A and 50C). Rotation information). Similarly, even if wafer stage WST moves in a direction intersecting the X axis, for example, in the Y axis direction, a light beam extending substantially elongated in the Y axis direction from the irradiation system of head units 46B and 46D is formed on wafer stage WST. The main controller 20 irradiates the moving scales 44B and 44D of the respective positions, so that the main controller 20 determines positional information (and θz rotation) of the wafer stage WST in the X-axis direction based on output signals of the head units 46B and 46D (encoders 50B and 50D). Information).

  In the present embodiment, an index scale 49a and moving scales 44A to 44D having a diffraction grating with a pitch of approximately 1 μm using a light source having a wavelength of 850 nm, and index scales 49b and 49c having a pitch of ½ of these. Is used to constitute the reflection-type three-grating encoder (diffraction interference method) as described above, so that the position information of the wafer stage WST in the XY plane can be obtained with the same or higher resolution as the laser interferometer. (Including rotation information in the θz direction) can be accurately measured. As described above, by appropriately determining the period (grating pitch) of the moving scales 44A to 44D (grating) in consideration of the wavelength of the light beam, measurement with the same resolution as that of the laser interferometer can be performed.

  Further, according to the present embodiment, at least during exposure, position information of wafer stage WST in the XY plane can be obtained with high accuracy using encoders 50A to 50D as described above. Therefore, main controller 20 can accurately drive wafer stage WST in the XY plane via wafer stage drive system 27 based on the measurement result.

  Further, according to the present embodiment, the pattern is generated on the wafer W by the illumination system 10, the reticle R, and the projection optical system PL by synchronously moving the reticle stage RST and the wafer stage WST in the Y-axis direction. The sensitive layer (resist layer) on the wafer W is exposed with the pattern. This makes it possible to form a pattern on the wafer W with high accuracy.

  In the present embodiment, the case where each of the head units forms a light beam Bm that extends substantially in the X-axis direction or the Y-axis direction by a plurality of light sources 48 (light source group) of the light source unit 47 will be described. However, the present invention is not limited to this. For example, an optical element such as a cylindrical lens (beam expander) is used to shape the laser light emitted from a single light source, thereby forming a light beam that extends substantially in the X-axis direction or the Y-axis direction. The laser light emitted from a plurality of light sources may be shaped by one or a plurality of cylindrical lenses, and the plurality of shaped laser lights may be connected to substantially form the X-axis direction or the Y-axis. A light beam elongated in the direction may be formed. In the former, only one light source of the light source unit 47 is required, and in the latter, a plurality of light sources are discretely arranged in the longitudinal direction of the light source unit 47, and the number of light sources can be reduced as compared with FIG. .

  Alternatively, instead of the head unit 46A, as shown in FIG. 7 as an example, a light source 48 and a light beam (laser light) emitted from the light source 48 are converted into an XZ plane (including the Z axis and the X axis). A head unit having a deflection optical element 50 (for example, a galvanomirror) for scanning the light beam in the X-axis direction in the XY plane by deflecting the light within the predetermined angle range within the plane) and the light receiving element PD. May be used. In other words, a light beam extending substantially in the X-axis direction may be formed by the scanned light beam. In this case, as shown in FIG. 8A as an example, the signal output from the light receiving element PD is intermittent, but if the scanning frequency of the light beam is sufficiently faster than the movement of the wafer stage WST, The encoder signal Se can be restored by a technique such as peak hold (see FIG. 8B).

  For the other head units 46B to 46D, the same configuration as in FIG. 8A is adopted, and a light beam that extends substantially in the X-axis direction or the Y-axis direction is formed by the scanned light beam. It is also good. In the case of forming a light beam that extends substantially in the Y-axis direction, the light beam (laser light) emitted from the light source 48 is allowed to fall within a predetermined angular range within the YZ plane (a plane that includes the Z-axis and the Y-axis). Of course, by deflecting, the light beam is scanned in the Y-axis direction in the XY plane. When a head unit that scans a light beam in the X-axis or Y-axis direction in the XY plane is used, the cross-sectional shape of the light beam in the XY plane is, for example, a spot shape or a line extending in the scanning direction. It may be a shape.

  In short, a light beam that extends substantially in a direction orthogonal to the measurement direction in the head units 46A to 46D may be emitted from each head unit.

  In the above embodiment, the case where the light receiving element PD of the head unit is a single light receiving element has been described. However, the present invention is not limited to this, and a plurality of light receiving elements may be arranged in the longitudinal direction of each head unit. In this case, a plurality of light receiving elements may be connected in parallel. Further, a plurality of light receiving elements may be used by switching according to the position of wafer stage WST.

  In the above-described embodiment, the case where a three-grating diffraction interference type encoder is used as the encoders 50A to 50D has been described. However, the present invention is not limited to this. For example, instead of the index scales 49b and 49c in the encoder of the above-described embodiment. In addition, an encoder provided with two reflecting mirrors, or an encoder that branches light from a light source by an optical element such as a beam splitter instead of the index scale 49a may be used. Or you may use the encoder etc. which were provided with the light reflection block etc. which are disclosed by Unexamined-Japanese-Patent No. 2005-114406 etc., for example.

  In the above embodiment, a pair of moving scales 44A and 44C used for measuring the position in the Y-axis direction and a pair of moving scales 44B and 44D used for measuring the position in the X-axis direction are provided on wafer stage WST. Correspondingly, the pair of head units 46A and 46C are arranged on one side and the other side of the projection optical system PL in the X-axis direction, and the pair of head units 46B and 46D are arranged in the Y-axis direction of the projection optical system PL. The case where it arrange | positions to one side and the other side of was illustrated. However, the present invention is not limited to this, and at least one of the moving scales 44A and 44C for measuring the position in the Y-axis direction and the moving scales 44B and 44D for measuring the position in the X-axis direction is not a pair, but only one wafer stage WST. Alternatively, at least one of the pair of head units 46A and 46C and the pair of head units 46B and 46D may be provided instead of the pair. Further, the extending direction of the moving scale and the extending direction of the head unit are not limited to orthogonal directions such as the X-axis direction and the Y-axis direction of the above embodiment.

  In the above-described embodiment, the moving scales 44A to 44D have a reflection type diffraction grating formed on the surface of a plate-like member made of, for example, ceramics or low thermal expansion glass. A reflective diffraction grating may be formed directly. Further, the reflective diffraction grating may be covered with a protective member (for example, a thin film or a glass plate) that can transmit the light beam Bm from the head units 46A to 46D to prevent the diffraction grating from being damaged. In the above embodiment, the reflective diffraction grating is provided on the upper surface of wafer stage WST substantially parallel to the XY plane. However, for example, a reflective diffraction grating may be provided on the lower surface of wafer stage WST. In this case, the head units 46A to 46D are disposed on the stage base 71, for example, which faces the lower surface of the wafer stage WST. Furthermore, in the above embodiment, wafer stage WST is moved in the horizontal plane, but it may be moved in a plane (for example, ZX plane) intersecting the horizontal plane. When the reticle stage RST moves two-dimensionally, an encoder system having the same configuration as that of the encoder system described above may be provided to measure the position information of the reticle stage RST.

  In the above-described embodiment, the wafer interferometer system 18 can measure the position information of the wafer stage WST with respect to directions with five degrees of freedom (X-axis, Y-axis, θx, θy, and θz directions). The position information of the direction may be measurable. In this case, at least during the exposure operation, the position control of wafer stage WST may be performed using the measurement value of the encoder system and the measurement value of wafer interferometer system 18 (including at least position information in the Z-axis direction). . This wafer interferometer system 18 is disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-323404 (corresponding US Pat. No. 7,116,401), Japanese Patent Application Publication No. 2001-513267 (corresponding US Pat. No. 6,208,407). As shown in the document, etc., a reflecting surface inclined at a predetermined angle (for example, 45 degrees) with respect to the XY plane is provided on the side surface of the wafer stage WST, and the measurement beam is passed through the reflecting surface, for example, a lens barrel. By irradiating the reflecting surface provided on the board 38 or the above-described measurement frame, the position information of the wafer stage WST in the Z-axis direction is measured. In the wafer interferometer system 18, by using a plurality of measurement beams, position information in the θx direction and / or the θy direction can be measured in addition to the Z-axis direction. In this case, a measurement beam for measuring position information in the θx direction and / or θy direction irradiated on the movable mirror 17 of wafer stage WST may not be used.

  Further, for example, in Japanese Patent Application Laid-Open No. 10-214783 and corresponding US Pat. No. 6,341,007, International Publication No. 98/40791 pamphlet and corresponding US Pat. No. 6,262,796, etc. As disclosed, even in a twin wafer stage type exposure apparatus that can execute an exposure operation and a measurement operation (for example, mark detection by an alignment system) substantially in parallel using two wafer stages, the encoder described above is used. It is possible to control the position of each wafer stage using the system (FIG. 2). Here, not only during the exposure operation but also during the measurement operation, by appropriately setting the arrangement and length of each head unit, the position control of each wafer stage can be performed using the encoder system (FIG. 2) as it is. Although possible, a head unit that can be used during the measurement operation may be provided separately from the head units (46A to 46D) described above. For example, four head units arranged in a cross shape with the alignment system as the center are provided, and the position information of each wafer stage WST is measured by these head units and the corresponding movement scales (46A to 46D) during the measurement operation. Anyway. In the exposure apparatus of the twin wafer stage system, two or four moving scales (FIG. 2) are provided on the two wafer stages, respectively, and when the exposure operation of the wafer placed on one of the wafer stages is finished, By exchanging with the wafer stage, the other wafer stage on which the next wafer on which the mark detection or the like has been performed at the measurement position is placed is placed at the exposure position. Further, the measurement operation performed in parallel with the exposure operation is not limited to the detection of a mark such as a wafer by the alignment system, but instead of or in combination with it, for example, wafer surface information (step information, etc.) Detection or the like may be performed.

  In the above embodiment, as disclosed in, for example, International Publication No. 2005/074014, International Publication No. 1999/23692, US Pat. No. 6,897,963, etc. Separately, a measurement stage having measurement members (reference marks, sensors, etc.) is provided, and the measurement stage is disposed immediately below the projection optical system PL by exchanging with the wafer stage during the exchange operation of the wafer, and the characteristics of the exposure apparatus (for example, The imaging characteristics (wavefront aberration, etc.) of the projection optical system, the polarization characteristics of the illumination light IL, etc.) may be measured. In this case, a moving scale may be arranged on the measurement stage, and the position of the measurement stage may be controlled using the encoder system described above. Further, during the exposure operation of the wafer placed on the wafer stage, the measurement stage is retracted to a predetermined position that does not interfere with the wafer stage, and is moved between the retracted position and the exposure position. Therefore, even at the retracted position or during the movement from one of the retracted position and the exposure position to the other, the position measurement by the encoder system is performed in consideration of the moving range of the measurement stage in the same manner as the wafer stage. It is preferable to set the arrangement, length, etc. of each head unit so that the position control of the measurement stage is not interrupted due to this, or to provide a head unit different from these head units. Alternatively, when the position control of the measurement stage by the encoder system is cut off at the retracted position or during the movement, the position control of the measurement stage is performed using a measurement device (for example, an interferometer, an encoder, etc.) different from the encoder system. Preferably it is done.

  In the above embodiment, the case where the present invention is applied to the scanning stepper has been described. However, the present invention is not limited to this, and the present invention is applied to a stationary exposure apparatus such as a step-and-repeat projection exposure apparatus (stepper). May be applied. Even if it is a stepper, etc., the position of the stage on which the object to be exposed is mounted is measured by an encoder, which is different from measuring the position of the stage using an interferometer. The generation of errors can be made almost zero. The present invention can also be applied to a step-and-stitch type exposure apparatus, a proximity type exposure apparatus, or a mirror projection aligner that synthesizes a shot area and a shot area.

  In addition, the projection optical system PL in the exposure apparatus of the above embodiment may be not only a reduction system but also any of the same magnification and enlargement system, not only a refraction system, but also any of a reflection system and a catadioptric system, The projected image may be an inverted image or an erect image. Further, the exposure area irradiated with the illumination light IL via the projection optical system PL is an on-axis area including the optical axis AX within the field of the projection optical system PL. For example, in the pamphlet of International Publication No. 2004/107011 As disclosed, an optical system (a reflective system or a catadioptric system) having a plurality of reflecting surfaces and forming an intermediate image at least once is provided in a part thereof, and has a single optical axis. Similar to the in-line catadioptric system, the exposure area may be an off-axis area that does not include the optical axis AX. In addition, the illumination area and the exposure area described above are rectangular in shape, but the shape is not limited to this, and may be, for example, an arc, a trapezoid, or a parallelogram.

The illumination light IL is not limited to ArF excimer laser light (wavelength 193 nm), but is far ultraviolet light such as KrF excimer laser light (wavelength 248 nm) or vacuum ultraviolet light such as F ₂ laser light (wavelength 157 nm). Also good. As the vacuum ultraviolet light, for example, as disclosed in WO 1999/46835 (corresponding to US Pat. No. 7,023,610), an infrared region oscillated from a DFB semiconductor laser or a fiber laser, or visible For example, a single-wavelength laser light having a wavelength in the range may be amplified by a fiber amplifier doped with erbium (or both erbium and ytterbium) and converted into ultraviolet light using a nonlinear optical crystal.

  Needless to say, the illumination light IL of the exposure apparatus is not limited to light having a wavelength of 100 nm or more, and light having a wavelength of less than 100 nm may be used. For example, in recent years, in order to expose a pattern of 70 nm or less, EUV (Extreme Ultraviolet) light in a soft X-ray region (for example, a wavelength region of 5 to 15 nm) is generated using an SOR or a plasma laser as a light source, and its exposure wavelength Development of an EUV exposure apparatus using an all-reflection reduction optical system designed under (for example, 13.5 nm) and a reflective mask is underway. In this apparatus, since a configuration in which scanning exposure is performed by synchronously scanning the mask and the wafer using arc illumination is conceivable, the present invention can also be suitably applied to such an apparatus. In addition, the present invention can be applied to an exposure apparatus using a charged particle beam such as an electron beam or an ion beam.

  Further, for example, WO99 / 49504 pamphlet, WO2004 / 053955 pamphlet (corresponding US Patent Application Publication No. 2005/0252506), US Pat. No. 6,952,253, European Patent Application. In the publication No. 1420298 specification, the international publication No. 2004/055803 pamphlet, the international publication No. 2004/057590 pamphlet, the US patent application publication No. 2006/0231206, the US patent application publication No. 2005/0280791 etc. The present invention can also be applied to a disclosed immersion exposure apparatus in which a liquid (for example, pure water) is filled between the projection optical system PL and the wafer. In such a case, for example, as shown in FIG. 9, a liquid repellent plate WRP provided on the upper surface of wafer stage WST (or wafer table WTB) is made of, for example, a glass having a low thermal expansion coefficient, and a scale pattern (diffraction) is formed on the glass. (Lattice) may be formed directly. Alternatively, the diffraction grating may be formed using glass as the wafer table. In the immersion exposure apparatus including the wafer stage (or measurement stage) having the moving scale (FIG. 2) of the above embodiment, it is preferable to form a liquid repellent film on the surface of the moving scale.

  In the above-described embodiment, a light transmission mask (reticle) in which a predetermined light-shielding pattern (or phase pattern / dimming pattern) is formed on a light-transmitting substrate is used. Instead of this reticle, For example, as disclosed in US Pat. No. 6,778,257, an electronic mask (variable shaping mask, which forms a transmission pattern, a reflection pattern, or a light emission pattern based on electronic data of a pattern to be exposed, as disclosed in US Pat. No. 6,778,257. For example, a non-light emitting image display element (spatial light modulator) including a DMD (Digital Micro-mirror Device) may be used. When such a variable molding mask is used, the stage on which the wafer or glass plate is mounted is scanned with respect to the variable molding mask, and the position of the stage may be measured using an encoder.

  Further, as disclosed in, for example, International Publication No. 2001/035168 pamphlet, an exposure apparatus (lithography system) that forms line and space patterns on the wafer W by forming interference fringes on the wafer W. The present invention can also be applied to. Further, as disclosed in, for example, Japanese translations of PCT publication No. 2004-51850 (corresponding US Pat. No. 6,611,316), two reticle patterns are synthesized on a wafer via a projection optical system. The present invention can also be applied to an exposure apparatus that double exposes one shot area on a wafer almost simultaneously by multiple scanning exposures.

  Note that the object on which the pattern is to be formed (the object to be exposed to which the energy beam is irradiated) in the above embodiment and the modification is not limited to the wafer, but may be a glass plate, a ceramic substrate, a mask blank, or a film member. It may be an object. Further, the shape of the object is not limited to a circle but may be other shapes such as a rectangle.

  The use of the exposure apparatus is not limited to the exposure apparatus for semiconductor manufacturing. For example, an exposure apparatus for liquid crystal that transfers a liquid crystal display element pattern onto a square glass plate, an organic EL, a thin film magnetic head, an image sensor ( CCDs, etc.), micromachines, DNA chips and the like can also be widely applied to exposure apparatuses. Further, in order to manufacture reticles or masks used in not only microdevices such as semiconductor elements but also light exposure apparatuses, EUV exposure apparatuses, X-ray exposure apparatuses, and electron beam exposure apparatuses, glass substrates, silicon wafers, etc. The present invention can also be applied to an exposure apparatus that transfers a circuit pattern.

  The pattern forming apparatus of the present invention is not limited to an exposure apparatus that forms a pattern on an object by exposure with an energy beam, and generates the pattern on the object by the moving body driving system of the present invention in which the object is placed on the moving body. What is necessary is just to provide a pattern generation apparatus. For example, the present invention is also applied to a pattern forming apparatus provided with a pattern generating apparatus similar to an element manufacturing apparatus provided with an ink jet type functional liquid applying apparatus similar to the ink jet head group disclosed in Japanese Patent Application Laid-Open No. 2004-130312. The invention is applicable. The inkjet head group disclosed in the above publication discloses a predetermined functional liquid (for example, a metal-containing liquid, a photosensitive material, etc.) discharged from a nozzle (discharge port) onto a substrate (for example, PET, glass, silicon, paper, etc.). A plurality of inkjet heads to be applied are provided. Therefore, the pattern generation device described above is formed on the object placed on the moving body while accurately controlling the position of the moving body based on the position information measured by the position measuring device constituting the moving body drive system. By generating a pattern by the above, it becomes possible to form a pattern on the object with high accuracy.

  The present invention is not limited to an exposure apparatus, and other substrate processing apparatuses (for example, a laser repair apparatus, a substrate inspection apparatus, etc.), or a moving stage such as a sample positioning apparatus or a wire bonding apparatus in other precision machines. It can be widely applied to devices equipped.

  As long as the national laws of the designated country (or selected selected country) designated in this international application allow, the disclosures in the above-mentioned various publications, international publication pamphlets, US patent application publication specifications and US patent specifications are incorporated. As a part of the description of this specification.

  The semiconductor device was formed on the reticle by the step of designing the function / performance of the device, the step of manufacturing a reticle based on this design step, the step of manufacturing a wafer from a silicon material, and the exposure apparatus 100 of the above embodiment. Sography step, device that exposes an object (wafer, etc.) with an image of the pattern projection optical system PL or a pattern generated by a pattern generation device including, for example, an electronic mask (variable molding mask), and develops the exposed object It is manufactured through an assembly step (including a dicing process, a bonding process, and a packaging process), an inspection step, and the like. In this case, since the exposure apparatus of the above embodiment is used in the lithography step, a highly integrated device can be manufactured with a high yield.

  Further, the exposure apparatus (pattern forming apparatus) of the above embodiment maintains various mechanical subsystems including the constituent elements recited in the claims of the present application so as to maintain predetermined mechanical accuracy, electrical accuracy, and optical accuracy. Manufactured by assembling. In order to ensure these various accuracies, before and after assembly, various optical systems are adjusted to achieve optical accuracy, various mechanical systems are adjusted to achieve mechanical accuracy, and various electrical systems are Adjustments are made to achieve electrical accuracy. The assembly process from the various subsystems to the exposure apparatus includes mechanical connection, electrical circuit wiring connection, pneumatic circuit piping connection and the like between the various subsystems. Needless to say, there is an assembly process for each subsystem before the assembly process from the various subsystems to the exposure apparatus. When the assembly process of the various subsystems to the exposure apparatus is completed, comprehensive adjustment is performed to ensure various accuracies as the entire exposure apparatus. The exposure apparatus is preferably manufactured in a clean room where the temperature, cleanliness, etc. are controlled.

  As described above, the position measuring device and the position measuring method of the present invention are suitable for measuring the position of a moving body. Moreover, the moving body drive system and the moving body drive method of the present invention are suitable for driving a moving body in a two-dimensional plane. The pattern forming apparatus and the pattern forming method of the present invention are suitable for forming a pattern on an object. The device manufacturing method of the present invention is suitable for manufacturing a micro device (electronic device).

Claims (43)

A position measuring device that measures position information of a movable body movable within a predetermined plane,
A first grating disposed on the movable body and having a direction parallel to the first axis in the plane as a periodic direction;
A first irradiation system for irradiating the first grating with a light beam extending substantially elongated in a direction perpendicular to the first axis in the plane; and receiving light from the first grating; And a first axis encoder head including a first light receiving element that outputs a signal including position information relating to a direction parallel to the first axis. The position measuring device according to claim 1,
A second grating disposed on the movable body and having a periodic direction in a direction parallel to a second axis intersecting the first axis in the plane;
A second irradiation system for irradiating the second grating with a light beam extending substantially elongated in a direction perpendicular to the second axis in the plane; and receiving light from the second grating; And a second axis encoder head including a second light receiving element that outputs a signal including position information relating to a direction parallel to the second axis. The position measuring device according to claim 2,
The light beam applied to the second grating from the second irradiation system has a predetermined angular range within a plane including a third axis orthogonal to the plane and an axis orthogonal to the second axis in the plane. Position measuring device that is light deflected by the. In the position measuring device according to any one of claims 1 to 3,
The light beam applied to the first grating from the first irradiation system has a predetermined angular range within a plane including a third axis orthogonal to the plane and an axis orthogonal to the first axis in the plane. Position measuring device that is light deflected by the. In the position measuring device according to any one of claims 1 to 4,
A pair of at least one of the first grating and the second grating is disposed on the movable body at a predetermined interval,
A position measuring device in which at least one of the first and second axis encoder heads is provided as a pair corresponding to the at least one grating. In the position measuring device according to any one of claims 1 to 5,
A position measurement device further comprising an arithmetic device that calculates rotation information in the plane of the movable body based on outputs of a pair of encoder heads of the first and second axis encoder heads. A position measuring device that measures position information of a movable body that is movable in a direction parallel to the first and second axes within a predetermined plane,
A first grating periodically disposed in a direction parallel to the first axis on the movable body;
A first encoder head that irradiates the first grating with a light beam that intersects the first axis in the plane and extends in a direction that is at least as long as the first grating in a direction parallel to the second axis; A position measuring device. In the position measuring device according to claim 7,
The first encoder head includes a light receiving unit that detects light from the first grating at different positions according to movement of the movable body in a direction parallel to the second axis. In the position measuring device according to claim 7 or 8,
The first encoder head is a position measurement device that moves the light beam in a direction parallel to the second axis. In the position measuring device according to any one of claims 7 to 9,
The first grating is provided on one surface of the moving body substantially parallel to the plane, and the first encoder head is provided so as to face one surface of the moving body. In the position measuring device according to any one of claims 7 to 10,
A pair of the first gratings are provided apart from each other in a direction parallel to the second axis on the movable body, and a pair of the first encoder heads are provided corresponding to the pair of first gratings. In the position measuring device according to any one of claims 7 to 11,
A second grating periodically disposed in a direction parallel to the second axis on the moving body;
A second encoder head that irradiates the second grating with a light beam that intersects the second axis in the plane and extends in a direction that is at least as long as the second grating in a direction parallel to the first axis; And a position measuring device. In the position measuring device according to claim 12,
The second encoder head includes a light receiving unit that detects light from the second grating at different positions according to movement of the movable body in a direction parallel to the first axis. In the position measuring device according to claim 12 or 13,
The second encoder head is a position measurement device that moves the light beam in a direction parallel to the first axis. In the position measuring device according to any one of claims 12 to 14,
The second grating is provided on one surface of the moving body substantially parallel to the plane, and the second encoder head is provided so as to face one surface of the moving body. In the position measuring device according to any one of claims 12 to 15,
A pair of the second gratings are provided apart from each other in a direction parallel to the first axis on the moving body, and a pair of the second encoder heads are provided corresponding to the pair of first gratings. A position measuring device according to any one of claims 1 to 16;
And a driving device that drives the moving body in the plane based on a measurement result of the position measuring device. The moving body drive system according to claim 17, wherein an object is placed on the moving body;
A pattern generating device for generating a pattern on the object. A moving body that holds the object;
The position measuring device according to any one of claims 1 to 16, which measures position information of the moving body;
A pattern generation device for generating a pattern on the object,
The pattern formation apparatus which moves the said mobile body using the said position measuring device. The pattern forming apparatus according to claim 18 or 19,
The pattern generation apparatus generates the pattern by exposing the object with an energy beam. Forming a pattern on an object using the pattern forming apparatus according to claim 18;
And a step of processing the object on which the pattern is formed. An exposure apparatus that exposes an object,
A moving body that holds the object;
An exposure apparatus comprising: the position measuring device according to claim 1 that measures position information of the moving body. A position measurement method for measuring position information of a movable body movable within a predetermined plane,
Irradiating the first grating disposed on the movable body with a direction parallel to the first axis in the plane as a periodic direction is substantially elongated in a direction perpendicular to the first axis in the plane. A position measuring method including a step of receiving light from the first grating and measuring position information related to a direction parallel to the first axis of the moving body. The position measurement method according to claim 23, wherein
A second grating disposed on the movable body with a direction parallel to the second axis intersecting the first axis in the plane as a periodic direction is substantially in a direction perpendicular to the second axis in the plane. A position measuring method further comprising: irradiating a light beam extending in an elongated manner, receiving light from the second grating, and measuring position information relating to a direction parallel to the second axis of the movable body. The position measurement method according to claim 24, wherein
The light beam applied to the second grating is light that is deflected in a predetermined angle range within a plane including a third axis orthogonal to the plane and an axis orthogonal to the second axis in the plane. A position measurement method. In the position measuring method according to any one of claims 23 to 25,
The light beam applied to the first grating is light that is deflected within a predetermined angle range in a plane including a third axis orthogonal to the plane and an axis orthogonal to the first axis in the plane. A position measurement method. In the position measurement method according to any one of claims 23 to 26,
A pair of at least one of the first grating and the second grating is disposed on the movable body at a predetermined interval,
The at least one grating disposed in the pair is irradiated with the light beam, and the light from the at least one grating disposed in the pair is received, and rotation information in the plane of the movable body is calculated. A position measurement method further including a step of performing. A position measurement method for measuring position information of a movable body movable in a direction parallel to the first and second axes within a predetermined plane,
A light beam that intersects with the first axis in the plane and extends with a length equal to or greater than the first grating in a direction parallel to the second axis is parallel to the first axis on the movable body. Irradiating a first grating periodically arranged in a certain direction, receiving light from the first grating, and measuring position information related to a direction parallel to the first axis of the movable body. Position measurement method. The position measurement method according to claim 28, wherein
A position measurement method for detecting light from the first grating at different positions in accordance with movement of the moving body in a direction parallel to the second axis. The position measurement method according to claim 28 or 29,
A position measurement method for moving the light beam in a direction parallel to the second axis. In the position measuring method according to any one of claims 28 to 30,
The position measurement method in which the first grating is provided on one surface of the moving body substantially parallel to the plane, and the light beam is irradiated from a direction facing the one surface of the moving body. The position measurement method according to any one of claims 28 to 31,
A pair of the first gratings are provided apart from each other in a direction parallel to the second axis on the movable body, and the pair of first gratings are respectively irradiated with the light beam, and light from the pair of first gratings is provided. Position measurement method for receiving light respectively. The position measurement method according to any one of claims 28 to 32,
A light beam that intersects with the second axis in the plane and extends with a length equal to or greater than that of the second grating in a direction parallel to the first axis is parallel to the second axis on the movable body. Irradiating a second grating periodically arranged in a certain direction, receiving light from the second grating, and measuring positional information in a direction parallel to the second axis of the movable body Including position measurement method. The position measurement method according to claim 33,
A position measurement method for detecting light from the second grating at different positions in accordance with movement of the moving body in a direction parallel to the first axis. The position measurement method according to claim 33 or 34,
A position measuring method in which a light beam extending at a length equal to or greater than that of the second grating in a direction parallel to the first axis is moved in a direction parallel to the first axis. In the position measurement method according to any one of claims 33 to 35,
The second grating is provided on one surface of the moving body substantially parallel to the plane, and the second encoder head is irradiated from a direction facing the one surface of the moving body. In the position measuring method according to any one of claims 33 to 36,
A pair of the second gratings are provided apart from each other in a direction parallel to the first axis on the movable body, and the light beams are emitted from the pair of second gratings by irradiating the pair of second gratings with the light beam, respectively. Position measurement method for receiving light respectively. A step of measuring position information of the moving body using the position measurement method according to any one of claims 23 to 37;
And a step of driving the moving body in the plane based on the measured position information. A step of driving a moving body on which an object is placed using the moving body driving method according to claim 38;
Generating a pattern on the object. A pattern forming method for forming a pattern on an object,
38. A pattern forming method including a step of measuring position information of a moving body that holds the object using the position measuring method according to any one of claims 23 to 37 when generating a pattern on the object. . The pattern forming method according to claim 39 or 40,
The pattern is generated by exposing the object with an energy beam. Forming a pattern on the object using the pattern forming method according to claim 41;
And a step of processing the object on which the pattern is formed. An exposure method for exposing an object,
An exposure method including a step of measuring position information of a moving body that holds the object using the position measurement method according to any one of claims 23 to 37.

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