JP2009258391A - Stage device, exposure method and device, and device manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stage device that suppresses an increase in size of a mask. <P>SOLUTION: The stage device which holds the mask includes a first mask stage MST1 which holds a mask MA1 and moves in a scanning direction, a second mask stage MST2 which holds a mask MA2 and is mounted movably on the first mask stage MST1, alignment systems 31A and 31B which detect relative arrangement information on the mask MA1 and mask MA2, and a control unit which adjusts stage arrangement of the mask stages MST1 and MST2 on the basis of detection results of the alignment systems 31A and 31B and controls relative arrangement of the masks MA1 and MA2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a stage apparatus for holding a plurality of masks, an exposure method and apparatus using the stage apparatus, and a device manufacturing method.

  For example, when manufacturing a device such as a semiconductor element or a liquid crystal display element (electronic device, microdevice), a plate (glass plate or glass) on which a pattern of a mask (reticle, photomask, etc.) is applied via a projection optical system A projection exposure apparatus for projecting onto a semiconductor wafer or the like) is used. In recent years, plates for manufacturing liquid crystal display elements have become increasingly larger, and plates exceeding 2 m square have been used. In addition, the mask tends to increase in size as the plate increases in size. On the other hand, maintaining the flatness of the mask (surface accuracy of the pattern surface) becomes more difficult as the size increases. Furthermore, the cost of the mask increases because the manufacturing process becomes more complex as the size increases.

Therefore, for example, an enlargement composed of a plurality of partial projection optical systems that are arranged in two rows in the scanning direction and have an enlargement magnification that is arranged adjacent to a direction orthogonal to the scanning direction (hereinafter referred to as a non-scanning direction). There has been proposed a scanning projection exposure apparatus (scanning exposure apparatus) in which a mask pattern is made smaller than that of a plate by using a system multilens (see, for example, Patent Document 1). In this conventional scanning exposure apparatus equipped with a magnifying system multi-lens, the mask pattern is divided into strips (strips) into a plurality of pattern areas corresponding to each partial projection optical system, The projected image of the pattern is transferred onto the plate in a non-scanning direction by one scanning exposure.
JP-A-11-265848

However, in the scanning exposure apparatus provided with the magnifying system multi-lens as described above, although the entire pattern area formed on the mask (the sum of the pattern areas formed in a strip shape) is smaller than the conventional one, Since each strip-shaped pattern area is arranged in the non-scanning direction at equal intervals to the partial projection optical system, the width of the mask in the non-scanning direction is the width of a series of pattern transfer areas transferred on the plate. The size of the mask in the non-measurement direction has not been eliminated.
In view of such circumstances, it is an object of the present invention to provide a stage apparatus, an exposure method and apparatus, and a device manufacturing method that can suppress an increase in the size of a mask.

  A stage apparatus according to the present invention holds a first mask that moves in the scanning direction while holding a first mask, and a second stage that holds a second mask and is movably mounted on the first stage. Stage, a placement detection device for detecting relative placement information between the first mask and the second mask, and the second stage relative to the first stage based on a detection result of the placement detection device. And a control device that adjusts the stage arrangement and controls the relative arrangement of the first mask and the second mask.

  An exposure apparatus according to the present invention projects onto the photosensitive substrate a stage device of the present invention, a substrate stage that holds and moves the photosensitive substrate, and a pattern image formed on the first and second masks. A projection optical system, and an exposure control system for moving the substrate stage in a synchronous scanning direction corresponding to the scanning direction via the projection optical system in synchronization with the movement of the first stage in the scanning direction. It is to be prepared.

In the exposure method according to the present invention, the relative arrangement of the first and second masks held by the stage apparatus of the present invention is controlled, and the image of the pattern formed on the first and second masks is displayed on the substrate stage. While projecting onto the photosensitive substrate to be held, the substrate stage is moved in a direction corresponding to the scanning direction in synchronization with the movement of the first stage in the scanning direction.
The device manufacturing method according to the present invention includes a step of transferring a pattern image formed on the first and second masks to a photosensitive substrate using the exposure apparatus or exposure method of the present invention, and an image of the pattern. Developing the photosensitive substrate to which is transferred, forming a transfer pattern layer having a shape corresponding to the image of the pattern on the photosensitive substrate, and processing the photosensitive substrate through the transfer pattern layer; Is included.

According to the present invention, since the first and second masks can be held and the relative arrangement of the first and second masks can be controlled, the pattern provided on the conventional large mask can be changed to the first and second patterns. By providing the mask in a divided manner, the mask can be prevented from being enlarged, and the entire pattern can be subjected to an exposure process or the like as in the case of using a large mask.
In addition, since the increase in size of the mask can be suppressed, the influence of manufacturing error, deflection, and the like can be reduced and the flatness of the mask can be improved as compared with the case where a large mask is used. Furthermore, since each mask can be manufactured using an existing small-sized mask manufacturing facility, it is possible to suppress an increase in cost for mask manufacturing.

[First Embodiment]
A preferred first embodiment of the present invention will be described below with reference to FIGS.
FIG. 2 is a perspective view showing a schematic configuration of an exposure apparatus 100 including the step-and-scan type scanning projection exposure apparatus of the present embodiment, and FIG. 1 shows an illumination device IU and a mask stage system 20 of the exposure apparatus 100. It is a perspective view which shows schematic structure of these. 1 and 2, the exposure apparatus 100 includes an illuminator IU that illuminates a pattern of masks MA1 and MA2 with illumination light from a light source, a mask stage system 20 that drives the masks MA1 and MA2, and masks MA1 and MA2. A projection optical device PL that projects an enlarged image of the formed pattern onto a plate PT as a photosensitive substrate, and a plate stage PST that holds and moves the plate PT are provided. The mask stage system 20 includes a first mask stage MST1 that holds and moves the mask MA1, a second mask stage MST2 that is movably mounted on the first mask stage MST1 and holds the mask MA2, and a mask MA1. And mask alignment systems 31A and 31B for detecting relative arrangement information including information on the relative position and relative rotation angle between the mask MA2 and a drive mechanism (not shown) for driving the first mask stage MST1. Yes.

  Further, the exposure apparatus 100 includes a drive mechanism (not shown) including a linear motor that drives the plate stage PST, a main control system 23 that includes a computer that comprehensively controls the operation of the exposure apparatus 100, and the like. . The illumination device IU, the base members (not shown) of the first mask stage MST1 and the plate stage PST, the projection optical device PL, and the like are supported by a frame mechanism (not shown).

  As an example, the plate PT of the present embodiment has a 1.9 × 2.2 m square, a 2.2 × 2.4 m square, a 2.4 × 2 .2 square coated with a photoresist (photosensitive material) for manufacturing a liquid crystal display element. It is a rectangular flat glass plate of about 8 m square or 2.8 × 3.2 m square. Further, as an example, the surface of the plate PT is recognized by the main control system 23 by being divided into two pattern transfer regions EP1 and EP2 to which the patterns of the masks MA1 and MA2 are transferred, respectively.

  Hereinafter, in FIGS. 1 and 2, the Z-axis is taken perpendicular to a plane parallel to the upper surface (holding surface) of the first mask stage MST1 on which the mask MA1 is held, and the masks MA1 and MA2 at the time of scanning exposure in that plane. In the following description, the X axis is taken along the scanning direction, and the Y axis is taken along the non-scanning direction orthogonal to the X axis. In the present embodiment, the upper surface (holding surface) of the second mask stage MST2 on which the mask MA2 is held is on the same plane as the holding surface of the mask MA1. Further, the surface of the plate stage PST on which the plate PT is held is parallel to the holding surface of the mask MA1, and the scanning direction of the plate PT during scanning exposure is parallel to the X axis. Hereinafter, the rotational direction around an axis parallel to the Z axis is also referred to as a θz direction.

  In the illumination device IU of FIG. 1, the illumination light (exposure light) IL emitted from the four light transmitting units 10a, 10b, 10c, and 10d of the light source unit 10 is partially illuminated optical systems ILS1, ILS2 having the same configuration. , ILS3 and ILS4, respectively. Partial illumination optical systems ILS1 and ILS2 illuminate illumination areas (illumination field areas) IF1 and IF2 on the pattern surface (lower surface) of mask MA1, and partial illumination optical systems ILS3 and ILS4 illuminate the pattern surface (lower surface) of mask MA2. (Teruno region) Illuminate IF3 and IF4. As the illumination light for exposure, the third harmonic (wavelength 355 nm) of YAG laser is used.

  The illumination light that has entered the partial illumination optical systems ILS1 to ILS4 is made into a parallel light beam by the collimator lens 4 and enters the fly-eye lens 6 that is an optical integrator. Illumination light from a large number of secondary light sources formed on the rear focal plane of the fly-eye lens 6 of the partial illumination optical systems ILS1 to ILS4 illuminates the variable field stop 8 via the condenser lens 7, respectively. Illumination light that has passed through the variable field stop 8 passes through the relay optical system 9 and has a trapezoidal shape having two sides parallel to the Y direction on the masks MA1 and MA2 (the two sides aligned in the Y direction are parallel or inclined with respect to the X direction). The trapezoidal illumination areas IF1, IF2, IF3, and IF4 are illuminated almost uniformly. The illumination areas IF1 to IF4 are arranged at equal intervals in a line along the Y direction.

  As shown in FIG. 2, the illumination light from the illumination areas IF1 to IF4 of the masks MA1 and MA2 passes through the corresponding projection optical systems PL1, PL2, PL3, and PL4, and the exposure areas (image field areas) on the plate PT. (Or image field) EF1, EF2, EF3, and EF4 are exposed. The projection optical systems PL1 to PL4 are telecentric on the masks MA1 and MA2 side and the plate PT side, respectively, and have an enlargement magnification from the masks MA1 and MA2 side to the plate PT side. The shapes of the exposure regions EF1 to EF4 are shapes obtained by enlarging the shapes of the illumination regions IF1 to IF4 with the projection magnification of the projection optical systems PL1 to PL4. The projection optical systems PL1 to PL4 and the exposure areas EF1 to EF4 are arranged at regular intervals in a line in the Y direction. The arrangement period (arrangement pitch) of the illumination areas IF1 to IF4 in the Y direction is equal to the arrangement period of the exposure areas EF1 to EF4. The shapes of the exposure areas EF1 to EF4 are set when the variable field stop 8 blocks part of the illumination light.

  In the present embodiment, the projection optical device PL is configured including the four projection optical systems (partial projection optical systems) PL1 to PL4, and the projection optical systems PL1 to PL4 are respectively illumination areas IF1 to IF4 of the masks MA1 and MA2. A projection image obtained by enlarging the pattern at a common magnification M (absolute value) is formed in the exposure areas EF1 to EF4 on the surface of the plate PT. The projection optical systems PL1 to PL4 form images on the plate PT that are upright in the X direction (scanning direction) and inverted in the Y direction (non-scanning direction) of the patterns of the masks MA1 and MA2. The enlargement magnification M is preferably 2 times or more, and is 2.5 times as an example in the present embodiment.

  In the mask stage system 20 of FIG. 1, the mask MA1 is adsorbed and held on the first mask stage MST1 via a mask holder (not shown) by vacuum adsorption (or electrostatic adsorption). The first mask stage MST1 is placed on a base member (not shown) in a state where it can move in the X and Y directions and rotate in the θz direction within a predetermined range via a gas bearing mechanism (air bearing). Has been. X-axis and Y-axis moving mirrors 50X and 50Y are fixed on the first mask stage MST1, and X-axis laser interferometers 22XA and 22XB that irradiate the measuring mirror parallel to the X-axis on the moving mirror 50X and the moving mirrors A mask-side laser interferometer composed of a Y-axis laser interferometer 22Y that irradiates a measurement beam parallel to the Y-axis is arranged at 50Y. When the amount of movement of the first mask stage MST1 in the Y direction is small, two retro reflectors (trihedral reflection mirrors) arranged at a predetermined interval in the Y direction may be used instead of the moving mirror 50X. Good.

The mask side laser interferometer measures the position of the first mask stage MST1 in the X direction and the Y direction, and the rotation angle in the θz direction, and supplies the measurement result to the main control system 23. The main control system 23 controls the position and speed in the X direction, the Y direction, and the rotation angle in the θz direction of the first mask stage MST1 via a stage drive mechanism (not shown) such as a linear motor based on the measured value. .
Further, on the upper surface of the first mask stage MST1, a stepped portion CA having a low Z position is formed on almost half of the −Y direction, and the first mask stage MST1 is movable on the stepped portion CA in the X, Y, and θz directions. A two-mask stage MST2 is placed, for example, via a gas bearing mechanism. The mask MA2 is sucked and held on the second mask stage MST2 by vacuum suction (or electrostatic suction or the like) via a mask holder (not shown). The pattern surface of the mask MA2 is on the same plane as the pattern surface of the mask MA1.

  Then, on the pattern surfaces (lower surfaces) of the masks MA1 and MA2, four partial pattern regions A1, B1, A2, and B2 having the same rectangular shape (strip shape) elongated in the X direction, each having a transfer pattern, are formed. , And partial pattern areas A3, B3, A4, and B4 are formed in the Y direction with an arrangement period that is 1/2 of the arrangement period of the illumination areas IF1 to IF4. In the partial pattern areas A1, B1 to A4, B4, a pattern obtained by dividing an original pattern obtained by reducing a device pattern transferred onto the plate PT is formed. Further, the interval in the Y direction between the partial pattern region B2 at the end of the mask MA1 and the partial pattern region A3 at the end of the mask MA2 adjacent to the mask MA1 is set, for example, between the partial pattern regions A1 and B2 by mask alignment described later. The interval is set to be substantially the same as the interval in the Y direction.

  In the present embodiment, as will be described later, the patterns of the masks MA1 and MA2 are exposed to the pattern transfer regions EP1 and EP2 on the plate PT by two scanning exposures, so that the portions on the two masks MA1 and MA2 are exposed. The total number of pattern areas A1 to B4 is set to twice the number of projection optical systems PL1 to PL4. As described above, in the present embodiment, the pattern transferred to the pattern transfer regions EP1 and EP2 on the plate PT is divided into two masks MA1 and MA2.

  FIG. 4A is a plan view showing the mask stages MST1 and MST2 of FIG. 1 and the masks MA1 and MA2 placed thereon. 4A, at both ends in the X direction of the partial pattern areas A1 to B2 of the mask MA1, first mask alignment marks (hereinafter referred to as first MA marks) 15A for alignment with the plate PT, respectively. 15B, 15C, and 15D are formed, and first MA marks 16A, 16B, 16C, and 16D are formed at both ends in the X direction of the partial pattern areas A3 to B4 of the mask MA2. Further, second mask alignment marks (hereinafter referred to as second MA marks) 17A and 18A for mutual alignment of the masks MA1 and MA2 are formed at the ends in the −Y direction of the pattern surface of the mask MA1, respectively. Second MA marks 17B and 18B are formed at both ends in the X direction of the + Y direction end of the pattern surface of MA2. In the present embodiment, as an example, the second MA marks 17A and 18A are cross-shaped light shielding marks, and the second MA marks 17B and 18B are square frame-shaped light shielding marks.

  The second mask stage MST2 is formed with openings through which illumination light or detection light passes through the partial pattern regions A3 to B4 of the mask MA2 and the first MA marks 16A to 16D and the second MA marks 17B and 18B. Similarly, on the first mask stage MST1, the partial pattern areas A3 to B4, the first MA marks 16A to 16D, the second MA marks 17B and 18B of the mask MA2, and the partial pattern areas A1 to B2 of the mask MA1 and the first MA mark Openings for allowing illumination light or detection light to pass through 15A to 15D and the second MA marks 17A and 18A are formed.

  Further, the first mask stage MST1 includes a pair of mask alignments for measuring the positional relationship between the second MA marks 17A and 18A of the mask MA1 and the second MA marks 17B and 18B of the mask MA2 in the X direction and the Y direction. Systems 31A and 31B (details will be described later) are fixed by support members 32A and 32B. Therefore, alignment systems 31A and 31B move on a base member (not shown) integrally with first mask stage MST1.

  In FIG. 1, detection information of alignment systems 31 </ b> A and 31 </ b> B indicated by two-dot chain lines is supplied to an actuator control system 24 under the control of the main control system 23. The first mask stage MST1 includes an X-axis actuator 25X and two Y-axis actuators for driving the second mask stage MST2 in the X direction, the Y direction, and the θz direction with respect to the first mask stage MST1. 25Y1 and 25Y2 are provided. As the actuators 25X, 25Y1, and 25Y2, for example, a voice coil motor (VCM), a direct-acting piezo motor using a large number of piezo elements (piezoelectric elements) as drive elements, an ultrasonic motor, or the like can be used. Further, a coil spring, a leaf spring, or the like that biases the second mask stage MST2 toward the actuators 25X, 25Y1, and 25Y2 is provided between the side surface of the second mask stage MST2 and the side wall portion of the stepped portion CA that faces the second mask stage MST2. A force member may be provided.

  The drive control unit in the actuator control system 24 controls information from the main control system 23 (for example, information according to the position of the first mask stage MST1 in the X direction measured by the laser interferometers 22XA and 22XB), and alignment. Based on the detection information of the systems 31A, 31B, etc., via the actuators 25X, 25Y1, 25Y2, the second mask stage MST2 with respect to the first mask stage MST1, that is, the position of the mask MA2 with respect to the mask MA1 in the X direction and Y direction, and The rotation angle in the θz direction is controlled.

  In FIG. 2, the plate PT is sucked and held on the plate stage PST via a plate holder (not shown). X-axis and Y-axis movable mirrors 51X and 51Y are fixed to the plate stage PST. Also, X-axis laser interferometers 21XA and 21XB that are arranged at predetermined intervals in the Y direction and irradiate the measurement beam parallel to the X axis on the movable mirror 51X, and the measurement beam parallel to the Y axis on the movable mirror 51Y. A plate-side laser interferometer including a Y-axis laser interferometer 21YA to be irradiated is disposed. The plate-side laser interferometer measures the position of the plate stage PST in the X and Y directions and the rotation angle in the θz direction.

  The measurement value of the plate-side laser interferometer is supplied to the main control system 23. The main control system 23, based on the measurement value, passes through the stage drive system (not shown) such as a linear motor in the X direction and Y direction of the plate stage PST. The direction position and speed, and the rotation angle in the θz direction are controlled. As an example, the plate stage PST is driven so that the rotation angle in the θz direction becomes a constant value. During the scanning exposure, the plate stage PST is driven at the speed V in the X direction in synchronization with the first mask stage MST1 being driven at the speed V / M (M is an enlargement magnification) in the X direction. Since the images of the projection optical systems PL1 to PL4 are erect images in the X direction, the scanning direction of the first mask stage MST1 and the scanning direction of the plate stage PST are in the same direction along the X axis.

  In FIG. 2, in the vicinity of the projection optical systems PL1 to PL4, for example, an image processing type off-axis plate alignment system ALG for aligning the plate PT, and the masks MA1 and MA2 and the plate PT in the Z direction are arranged. An autofocus system (not shown) for measuring the position (focus position) is arranged. Therefore, a plurality of alignment marks AM1 and AM2 are formed in the vicinity of the pattern transfer regions EP1 and EP2 on the plate PT. Further, based on the measurement result of the autofocus system, for example, the position of the first mask stage MST1 in the Z direction is controlled using a Z drive mechanism (not shown), and / or projection optical systems PL1 to PL4 described later are used. By driving individual focus mechanisms, the image planes of the projection optical systems PL1 to PL4 and the surface of the plate PT are focused.

  The plate stage PST has an aerial image measurement as an alignment system for measuring the positions of the images of the first MA marks 15A to 15D and 16A to 16D on the masks MA1 and MA2 projected via the projection optical systems PL1 to PL4. A system 53 is installed. Detection signals of the plate alignment system ALG and the aerial image measurement system 53 are processed by an alignment signal processing system (not shown), and the position information of the test mark obtained by this processing is supplied to the main control system 23.

Next, the configuration of the partial illumination optical systems ILS1 to ILS4 and the projection optical systems PL1 to PL4 constituting the projection optical apparatus PL of this embodiment will be described. A configuration of the partial illumination optical system ILS1 and the projection optical system PL1 will be described typically with reference to FIG.
FIG. 3 shows a configuration of a part of the light source unit 10 of FIG. 1, the partial illumination optical system ILS1, and the projection optical system PL1. In FIG. 3, a laser light source 1 for generating laser light, a lens system 2 for condensing the laser light, and a light guide 3 for transmitting the condensed laser light are accommodated in the light source unit 10 of FIG. Has been. The illumination light composed of the laser light emitted from the light guide 3 passes through the collimator lens 4 in the partial illumination optical system ILS1, the mirror 5, and the optical member from the fly-eye lens 6 to the relay optical system 9 through the mask MA1. Illuminate. 3 is omitted in FIG.

The laser light from the laser light source 1 may be branched and supplied to the four partial illumination optical systems ILS1 to ILS4, or the laser light may be transmitted through the mirror system without using the light guide 3. .
In FIG. 3, a relay optical system 9 includes, as an example, a prism-type mirror member 9a that bends an optical path, a condensing lens 9b that condenses the bent illumination light, and a concave mirror that reflects and collects the condensed illumination light. 9c. The relay optical system 9 forms an image (illumination area) inverted in the scanning direction of the opening of the variable field stop 8 on the mask MA1.

  The projection optical system PL1 is disposed in the optical path between the mask MA1 and the concave reflector CCMc and parallel to the Z axis, and is disposed in the optical path between the mask MA1 and the concave reflector CCMc. A first lens group G1c having an optical axis AX21, a second lens group G2c disposed in an optical path between the first lens group G1c and the concave reflecting mirror CCMc, and the second lens group G2c and the plate PT. A first deflection member FM1c disposed in the optical path between the second lens group G2c and deflecting along the optical axis AX22 in the + X direction so as to cross the optical axis AX21 in the + Z direction, and the first deflection A second deflection member FM2c disposed in the optical path between the member FM1c and the plate PT and deflecting light traveling in the + X direction from the first deflection member FM1c in the −Z direction; a second deflection member FM2c and the plate It is disposed in the optical path between the T, the and a third lens group G3c having an optical axis AX23 parallel to the optical axis AX21 of the first lens group G1c.

Further, a magnification correction mechanism AD11 including a plurality of lenses whose mutual distance can be changed is disposed between the first lens group G1c and the mask MA1, and two tilt angles are provided between the third lens group G3c and the plate PT. An X-direction and Y-direction image shift correction mechanism AD12 including a variable parallel plate and a focus correction mechanism AD13 including, for example, two wedge-shaped prisms are disposed.
The other projection optical systems PL2 to PL4 are configured in the same manner, and the magnification correction mechanism AD11, the image shift correction mechanism AD12, and the focus correction mechanism AD13 (imaging characteristic correction mechanism) of the projection optical systems PL1 to PL4 are each a drive unit (not configured). Can be controlled independently of each other. In addition, the structure of projection optical system PL1-PL4 is not limited to FIG.

  Next, since the configurations of the mask alignment systems 31A and 31B in FIG. 4A are the same, the configuration of the alignment system 31A passes through the center of the second MA marks 17A and 17B in FIG. 4A below. This will be described with reference to FIG. 4B which is a cross-sectional view along a straight line. 4B, condenser lenses 40A and 40B are fixed in the first mask stage MST1 on the bottom side of the second MA marks 17A and 17B of the masks MA1 and MA2 by an attachment member (not shown) made of, for example, low expansion ceramics. Has been. Further, a flat glass substrate 33 made of quartz is fixed to the bottom surface of the first mask stage MST1 on the bottom surface side of the condenser lenses 40A and 40B by an attachment member (not shown) made of, for example, low expansion ceramics. Two-dimensional index marks 34A and 34B are formed by vapor deposition of a metal film such as chromium, for example, at a position substantially opposite to the second MA marks 17A and 17B. Images 34AP and 34BP of the index marks 34A and 34B by the alignment system 31A are shown in FIGS. 5 (A) and 5 (B). As described above, the index marks 34A and 34B include two line patterns each parallel to the X axis and the Y axis, and images 17AP and 17BP of the second MA marks 17A and 17B are formed between these line pattern images. The

  Further, illumination systems 35A and 35B for illuminating the indicator marks 34A and 34B with detection light from the −Z direction via a support member (not shown) are fixed to the bottom surface of the first mask stage MST1 in FIG. . The illumination system 35A includes, for example, a light source 37A composed of a high-intensity light emitting diode (LED) that generates detection light in a wavelength region such as i-line, and a collector lens 38A that Koehler-illuminates the index mark 34A with detection light from the light source 37A. And a mirror 39A that bends the optical path of the detection light toward the index mark 34A. In contrast to the illumination system 35A, the illumination system 35B includes a light source 37B, a collector lens 38B, and a mirror 39B.

The detection light transmitted around the index marks 34A and 34B illuminates the second MA marks 17A and 17B via the condenser lenses 40A and 40B. By the condenser lenses 40A and 40B, the formation surface of the index marks 34A and 34B and the formation surface of the second MA marks 17A and 17B are set in a conjugate positional relationship.
Further, on the upper surface of the first mask stage MST1, an image of the index marks 34A and 34B and the second MA marks 17A and 17B is picked up by the detection light transmitted through the second MA marks 17A and 17B via the support member 32A. Systems 36A and 36B are fixed. The imaging system 36A includes a first objective lens 41A, a second objective lens 42A, and a two-dimensional imaging element 43A of, for example, a CCD type (or may be a MOS type).

  Similar to the imaging system 36A, the imaging system 36B includes a first objective lens 41B, a second objective lens 42B, and an imaging element 43B. The objective lenses 41A and 41B are infinity correction optical systems that emit detection lights emitted from the second MA marks 17A and 17B as parallel light beams, respectively. In the image sensors 43A and 43B, as shown in FIGS. 5A and 5B, the images 34AP and 34BP of the index marks 34A and 34B and the images 17AP and 17BP of the second MA marks 17A and 17B are captured in an overlapping manner. Imaging signals of the imaging elements 43A and 43B are supplied to the actuator control system 24. The signal processing unit in the actuator control system 24 processes the image pickup signal to determine the amount of displacement in the X and Y directions of the second MA mark images 17AP and 17BP with respect to the index mark images 34AP and 34BP. For example, the amount of positional deviation (ΔMX1, ΔMY1) from the target value of the distance in the X direction and the Y direction of the second MA mark 17B with respect to the second MA mark 17A is obtained from the information of the amount and the known interval of the index marks 34A, 34B. An alignment system 31A is configured including a glass substrate 33 on which index marks 34A and 34B are formed, illumination systems 35A and 35B, condenser lenses 40A and 40B, and imaging systems 36A and 36B.

  Similarly, from the imaging signal from the imaging system of the alignment system 31B in the + X direction in FIG. 4A, the signal processing unit in the actuator control system 24 uses the second MA mark 18B of the mask MA2 with respect to the second MA mark 18A of the mask MA1. The amount of positional deviation (ΔMX2, ΔMY2) from the target value of the distance in the X direction and Y direction is obtained. From these two sets of positional shift amounts, the signal processing unit shifts the mask MA2 pattern from the target values of the X- and Y-direction positional shift amounts and the θz-direction rotation angle (relative arrangement) with respect to the mask MA1 pattern. The amount can be determined.

  Next, FIG. 6A shows mask stages MST1 and MST2 holding the masks MA1 and MA2, and FIG. 6B shows a plate PT onto which an enlarged image of the pattern of the masks MA1 and MA2 is transferred. In FIG. 6B, the surface of the plate PT is divided into two pattern transfer regions EP1 and EP2 in the Y direction. In the first pattern transfer area EP1, the enlarged images of the patterns of the partial pattern areas A1, B1 to A4, B4 of the masks MA1, MA2 in FIG. It is divided into partial transfer areas 54A to 54H that are joined together and inverted in the Y direction for exposure. Similarly, the second pattern transfer region EP2 is divided into eight partial transfer regions in the Y direction. Further, the same pattern is overlapped on the end portions in the Y direction of the partial pattern areas A1, B1 to A4, B4 of the masks MA1, MA2 corresponding to the joints in the pattern transfer areas EP1, EP2. .

Hereinafter, an example of the exposure operation of the exposure apparatus 100 of the present embodiment will be described. The following exposure operation is controlled by the main control system 23.
First, masks MA1 and MA2 are transferred onto mask stages MST1 and MST2 by a mask transfer system (not shown). Next, in order to align the masks MA1 and MA2, for example, the light receiving surface of the aerial image measurement system 53 on the plate stage PST is moved to the exposure area EF1 of the projection optical system PL1. The actual position of the light receiving surface in the Z direction is the same height as the surface of the plate PT. Then, the first mask stage MST1 is moved in the X and Y directions, and in FIG. 6A, the illumination area IF1 is moved to the first MA marks 15A, 15B and 15C, 15D at both ends of the partial pattern area A1 of the mask MA1. Move sequentially to the area containing. Then, the position of the image of these marks by the projection optical system PL 1 is measured by the aerial image measurement system 53.

  Furthermore, the light receiving surface of the aerial image measurement system 53 is moved to the exposure area EF3 of the projection optical system PL3, and the illumination area IF3 includes first MA marks 16A, 16B and 16C, 16D at both ends of the partial pattern area A3 of the mask MA2. Move sequentially to the area. Then, the position of the image of these marks by the projection optical system PL3 is measured by the aerial image measurement system 53. For example, when measuring drawing errors of patterns in the partial pattern areas A1, B1 to A4, B4, the first MA marks 15A to 15D, 16A at the ends of the other partial pattern areas B1 to B2, B3 to B4 are used. The position of the image of ~ 16D is also measured. The drawing error may be measured separately and stored in the storage device of the main control system 23.

  Based on the measurement results of the positions of the images of the first MA marks 15A to 15D of the mask MA1 and the first MA marks 16A to 16D of the mask MA2, the main control system 23 performs the X direction of the pattern of the mask MA2 with respect to the pattern of the mask MA1. The amount of displacement in the Y direction and the amount of displacement from the target value of the rotation angle in the θz direction (relative arrangement information) can be obtained. The information on the shift amount is supplied to the actuator control system 24, and the actuator control system 24 corrects the shift amount by using the actuators 25X, 25Y1, and 25Y2 to determine the second mask stage MST2 relative to the first mask stage MST1. Correct the position and rotation angle. Further, when the drawing errors of the patterns of the masks MA1 and MA2 are measured, information on the drawing errors is supplied to the main control system 23. This completes the mask alignment. This mask alignment only needs to be performed once when the masks MA1 and MA2 are replaced.

  When the mask alignment is completed, the second MA marks 17A, 17B and 18A, 18BA are arranged in the imaging field of the alignment systems 31A and 31B. Therefore, the alignment systems 31A and 31B measure the amount of positional deviation between the second MA marks 17A and 18A of the mask MA1 and the second MA marks 17B and 18B of the mask MA2, and the signal processing unit of the actuator control system 24 uses these measured values. An initial value <ΔM12X, ΔM12Y> of the positional deviation amount in the X direction and the Y direction of the pattern of the mask MA2 with respect to the pattern of the mask MA1 and an initial value <ΔM12θ> of the rotation angle in the θz direction are obtained. This initial value becomes the initial value of the target value of the relative arrangement of the pattern of the mask MA2 with respect to the pattern of the mask MA1.

  Next, the plate PT to be exposed is placed on the plate stage PST in FIG. Then, while driving the plate stage PST and moving the plate PT in the X and Y directions, the positions of a plurality of (for example, four) alignment marks AM1 and AM2 in the pattern transfer regions EP1 and EP2 are moved by the plate alignment system ALG. measure. From this measurement result, the main control system 23 recognizes the positional relationship between the pattern images of the partial pattern areas A1 to B4 of the masks MA1 and MA2 and the partial transfer areas 54A to 54H of the pattern transfer areas EP1 and EP2 of the plate PT. . For example, when exposure is performed on the second and subsequent layers of the plate PT, scaling of the patterns formed in the previous processes in the pattern transfer regions EP1 and EP2 (linear) is performed based on the measurement results of the positions of the alignment marks AM1 and AM2. It is also possible to measure non-linear distortion such as expansion and contraction and trapezoidal distortion.

Thereafter, scanning exposure is performed so that the pattern images of the partial pattern areas A1 to B4 of the masks MA1 and MA2 are accurately exposed to the partial transfer areas 54A to 54H of the pattern transfer area EP1 (EP2) of the plate PT. Is called.
For example, when scaling in the Y direction occurs in the pattern transfer regions EP1 and EP2 of the plate PT, the spacing in the Y direction of the masks MA1 and MA2 may be adjusted accordingly. In this case, the Y component of the initial value <ΔM12X, ΔM12Y, ΔM12θ> of the target value of the relative arrangement is corrected by the adjustment amount of the interval so that the relative arrangement becomes the initial value after the correction. The actuators 25Y1 and 25Y2 may be driven.

  In the main control system 23, the result of the mask alignment (mask MA1) so that the pattern images of the masks MA1 and MA2 are accurately exposed to the partial transfer regions 54A to 54H of the pattern transfer region EP1 (EP2) of the plate PT. , MA2 including the drawing error) and the alignment result of the plate PT, the position of the first mask stage MST1 in the scanning direction (X direction), that is, the X direction between the illumination areas IF1 to IF4 and the masks MA1 and MA2 X, Y, θz components <ΔM12X (X, Y), ΔM12Y (X, Y), ΔM12θ (X, Y) >> of the target values of the relative arrangement of the mask MA1 and the mask MA2 are obtained with respect to the relative position. The initial value of the target value is <ΔM12X, ΔM12Y, ΔM12θ> described above. Information on the target value of the relative arrangement is supplied from the main control system 23 to the actuator control system 24 at predetermined time intervals.

  Then, as shown in FIGS. 2 and 6A, the masks MA1 and MA2 are moved in the −X direction at a speed V / M (M is a projection magnification) via the first mask stage MST1, and the illumination light is transmitted. The illumination areas IF1 to IF4 to be irradiated are scanned in the + X direction relative to the odd-numbered partial pattern areas A1 to A4 of the masks MA1 and MA2. In synchronization with this, as shown in FIGS. 2 and 6B, the plate PT is moved in the −X direction at the speed V via the plate stage PST, and the exposure areas EF1 to EF4 are moved to the pattern transfer area EP1. Relative scanning is performed in the + X direction with respect to the odd-numbered partial transfer regions 54A, 54C, 54E, and 54G. As a result, the pattern images of the partial pattern areas A1 to A4 (images inverted in the Y direction) are scanned and exposed in the partial transfer areas 54A, 54C, 54E, and 54G of the pattern transfer area EP1, respectively.

  During this scanning exposure, in the actuator control system 24, the relative arrangement of the masks MA1 and MA2 measured by the alignment systems 31A and 31B is such that the target value <ΔM12X (X, Y), Actuators 25X, 25Y1, and 25Y2 are driven by dynamic control so that ΔM12Y (X, Y), ΔM12θ (X, Y)>. Thereby, the patterns of the partial pattern areas A1 to A4 of the masks MA1 and MA2 are transferred with high accuracy to the partial transfer areas 54A to 54G of the pattern transfer area EP1. At this time, by performing magnification correction and image shift by the magnification correction mechanism AD11 and the image shift correction mechanism AD12 of the projection optical systems PL1 to PL4, the patterns of the masks MA1 and MA2 are transferred onto the plate PT with higher accuracy. .

Further, since the boundary portions in the Y direction of the partial transfer regions 54A to 54G on the plate PT are overlapped and exposed at the oblique sides of the trapezoidal exposure regions EF1 to EF4 at the next second scanning exposure, there is a joint error. Reduced.
After that, as shown in FIG. 7A, the masks MA1 and MA2 are placed in the + Y direction with respect to the projection optical apparatus PL via the first mask stage MST1, and only the width in the Y direction at the center of the partial pattern areas A1 and B1. Moving. At substantially the same time, as shown in FIG. 7B, the plate PT is placed in the + Y direction with respect to the projection optical device PL via the plate stage PST, and the width in the Y direction at the center of the partial transfer regions 54A and 54B (this In the embodiment, it is moved by the width in the Y direction at the center of the partial pattern areas A1 and B1). In FIGS. 7A, 7B, and 2, the patterns of the masks MA1 and MA2 exposed in the first scanning exposure and the transfer region on the plate PT are hatched.

  Next, as shown in FIG. 7A, the masks MA1 and MA2 are moved in the + X direction at a speed V / M via the first mask stage MST1, and illumination areas IF1 to IF4 irradiated with illumination light are moved. Relative scanning is performed in the −X direction indicated by the locus TM1 with respect to the even-numbered partial pattern areas B1 to B4 of the masks MA1 and MA2. In synchronization with this, as shown in FIG. 7B, the plate PT is moved at the speed V in the + X direction via the plate stage PST, and the exposure areas EF1 to EF4 are moved to even-numbered portions of the pattern transfer area EP1. The transfer areas 54B, 54D, 54F, and 54H are relatively scanned in the −X direction indicated by the locus TP1. As a result, the pattern images of the partial pattern areas B1 to B4 of the masks MA1 and MA2 are transferred to the partial transfer areas 54B, 54D, 54F, and 54H of the pattern transfer area EP1, respectively.

  Even during this scanning exposure, in the actuator control system 24, the relative arrangement of the masks MA1 and MA2 measured by the alignment systems 31A and 31B is such that the target values supplied from the main control system 23 <ΔM12X (X, Y), ΔM12Y. Actuators 25X, 25Y1, and 25Y2 are driven by dynamic control so that (X, Y), ΔM12θ (X, Y)>. As a result, the patterns of the partial pattern areas B1 to B4 are transferred with high accuracy to the partial transfer areas 54B, 54D, 54F, and 54H of the pattern transfer area EP1.

  Thereafter, for example, the front of the partial pattern areas A1 to A4 of the masks MA1 and MA2 is aligned with the illumination areas IF1 to IF4 via the first mask stage MST1, and then the exposure areas EF1 to EF1 to the pattern transfer area EP2 on the plate PT. As indicated by the relative trajectory TP2 of EF4, the first scanning exposure, the movement of the first mask stage MST1 and the plate stage PST in the Y direction, and the second scanning exposure are performed. As a result, the pattern images of the masks MA1 and MA2 are also transferred to the pattern transfer region EP2. Thereafter, the plate on the plate stage PST is exchanged and the exposure is repeated.

Effects and the like of this embodiment are as follows.
(1) The mask stage device of the present embodiment holds the mask MA1 and moves in the X direction (scanning direction), and holds the mask MA2 and can move to the first mask stage MST1. Second mask stage MST2 placed on the substrate, and an alignment system for detecting relative arrangement information including information on the relative positions of the mask MA1 and the mask MA2 in the X direction, the Y direction, and the θz direction. 31A, 31B (placement detection device). Furthermore, a control mechanism including an actuator control system 24 and actuators 25X, 25Y1, and 25Y2 (position adjustment mechanisms) is provided. By this control mechanism, a second mask for the first mask stage MST1 based on the detection results of the alignment systems 31A and 31B. The relative positions of the mask MA1 and the mask MA2 are controlled by adjusting the relative positions of the stage MST2 in the X and Y directions and the relative rotation angle (stage arrangement) in the θz direction.

Therefore, by dividing the pattern provided on the conventional large mask into the masks MA1 and MA2, it is possible to suppress an increase in the size of the mask, and to expose the entire pattern in the same manner as in the case of using the large mask ( Scanning exposure) and the like.
In addition, since the increase in size of the mask can be suppressed, the influence of manufacturing error, self-weight deflection, and the like can be reduced and the flatness of the mask can be improved as compared with the case where a large mask is used. Furthermore, since each mask MA1, MA2 can be manufactured using the existing small mask manufacturing equipment, it is possible to suppress an increase in the mask manufacturing cost.

The control mechanism uses at least one piece of information (relative arrangement information) among the relative positions in the X and Y directions and the relative rotation angle in the θz direction of the patterns of the masks MA1 and MA2, and the mask stage for the mask stage MST1. At least one of the relative positions of the MST2 in the X direction and the Y direction and the relative rotation angle in the θz direction (stage arrangement) may be adjusted.
(2) Further, the control mechanism adjusts the stage arrangement during the scanning exposure based on the position (moving position) of the first mask stage MST1 in the scanning direction and the detection results of the alignment systems 31A and 31B. Yes.

In this way, by dynamically controlling the relative arrangement of the masks MA1 and MA2 during the scanning of the first mask stage MST1 (that is, during scanning exposure), the drawing error between the masks MA1 and MA2 (the pattern between the masks and / or the masks). Alternatively, it is possible to correct (suppress) the influence of the difference in mark dimensional error.
For example, when the mask is divided into two as in the present embodiment, if the allowable drawing error in each of the masks MA1 and MA2 is Er, the maximum relative error between the masks is 2Er. Therefore, dynamic control is effective in order to eliminate the influence of relative drawing errors caused by such mask division. Note that when the projection optical systems PL1 to PL4 are magnifying systems as in the present embodiment, the drawing error on the mask is magnified (M times) on the plate PT, so that the exposure accuracy (line width accuracy, etc.) is improved. If it is equal to or higher than before, it is necessary to suppress the mask drawing error more than before, and dynamic control is also effective in this respect.

Further, the relative arrangement of the masks MA1 and MA2 is dynamically controlled in accordance with the linear and nonlinear errors of the pattern of the previous layer (for example, the first layer) on the plate PT measured by the plate alignment system ALG. Thus, the influence of a non-linear error or the like on the plate PT can be corrected (suppressed), and the overlay accuracy can be improved.
(3) The alignment system 31A in FIG. 4B includes first objective lenses 41A and 41B (optical members) provided on the first mask stage MST1, and detection is performed via the first objective lenses 41A and 41B. The relative arrangement of the masks MA1 and MA2 is detected using light.

Thereby, when the first mask stage MST1 is moved during the scanning exposure, the relative arrangement can always be detected.
(4) The alignment systems 31A and 31B detect the relative positions of the second MA marks 17A and 18A (first mark) of the mask MA1 and the second MA marks 17B and 18B (second mark) of the mask MA2. . However, the relative position may be detected with respect to a plurality of combinations using a plurality of at least one of the mark of the mask MA1 and the mark of the mask MA2 by an alignment system equivalent to the alignment systems 31A and 31B.

  In this case, for example, relative arrangement (relative position and relative angle) between the masks MA1 and MA2 is detected by detecting relative position information of one mark of the mask MA1 with respect to the two marks of the mask MA2. Thus, when detecting one mark of the mask MA1 and two marks of the mask MA2, (a) two-dimensional measurement of at least one mark of the mask MA2 and (b) three marks are detected. It is necessary that they are not aligned on the same straight line.

  (5) The alignment system 31A includes a glass substrate 33 (index member) on which index marks 34A and 34B are formed, and the alignment system 31A has relative positions of the second MA marks 17A and 17B with respect to the index marks 34A and 34B. And the relative arrangement of the masks MA1 and MA2 is obtained based on the detection result. Therefore, for example, even when the positions of the imaging elements 43A and 43B of the alignment system 31A slightly change, the relative arrangement of the masks MA1 and MA2 can be obtained with high accuracy.

Instead of providing the index marks 34A and 34B corresponding to the second MA marks 17A and 17B in this way, for example, only one index mark is formed on the glass substrate 33, and an image of the index mark is obtained. You may project on the 2nd MA marks 17A and 17B via a predetermined branch optical system.
(6) In addition, the alignment system 31A includes first objective lenses (objective lens systems) 41A and 41B provided on the first mask stage MST1 and arranged to face the second MA marks 17A and 17B, respectively, and the first objective lens 41A. , 41B and second objective lenses (condensing lens systems) 42A and 42B that form observation images of the second MA marks 17A and 17B by condensing the detection light, and image sensors 43A and 43B that capture the observation images. Including. The second objective lenses 42A and 42B and the image sensors 43A and 43B are supported by the first mask stage MST1, and the first objective lenses 41A and 41B are an infinite correction optical system.

As in the present embodiment, when the mark images are individually detected by the imaging elements 43A and 43B supported by the first mask stage MST1 by the light beams from the first objective lenses 41A and 41B, the first objective lens is used. 41A and 41B are not necessarily limited to the infinity correction optical system.
(7) Although the illumination systems 35A and 35B of the alignment system 31A are transmitted illumination, the illumination systems 35A and 35B (or at least one of them) are the epi-illumination systems, and the imaging systems 36A and 36B are the first mask stage MST1. You may arrange | position on the bottom face side.

  (8) Further, the mask stages MST1 and MST2 are parallel to the scanning direction (X direction) in the longitudinal direction of the strip-shaped partial pattern areas A1 to B4 provided on the masks MA1 and MA2 (including the case of being substantially parallel). The masks MA1 and MA2 are held. Accordingly, by moving the mask stages MST1 and MST2 only in the X direction in each scanning exposure, the patterns of the partial pattern areas A1 to B4 can be transferred onto the plate PT, and exposure control can be easily performed.

The number of partial pattern areas A1 to B4 formed in each mask MA1 and MA2 is arbitrary, and the number of partial pattern areas formed in masks MA1 and MA2 may be different from each other. Further, only one partial pattern region may be formed on each of the masks MA1 and MA2.
(9) In the present embodiment, the pattern transferred to the pattern transfer regions EP1 and EP2 of the plate PT is divided into two masks MA1 and MA2, but the pattern is formed into three or more masks. You may divide and form. In this case, a first mask is held by the first mask stage MST1, and a plurality of second mask stages each holding a mask (second mask, etc.) are movable on the first mask stage MST1. An alignment system similar to the alignment systems 31A and 31B and an adjustment mechanism similar to the actuators 25X, 25Y2 and 25Y2 are provided for each second mask stage. Thereby, each mask can be further miniaturized.

[Second Embodiment]
A second embodiment of the present invention will be described with reference to FIGS. The exposure apparatus of this embodiment is different from the exposure apparatus 100 of FIG. 1 in that alignment systems 31C and 31D are used instead of the alignment systems 31A and 31B. Hereinafter, in FIGS. 8A, 8B, and 9A, portions corresponding to FIGS. 4A, 4B, 5A, and 5B are not included. The same reference numerals are assigned and detailed description thereof is omitted.

  8A is a plan view showing the masks MA1 and MA2 on the mask stages MST1 and MST2 of the present embodiment, and FIG. 8B passes through the centers of the second MA marks 19A and 17B in FIG. 8A. It is sectional drawing which follows a straight line. In the present embodiment, second MA marks 19A and 19B are formed instead of the second MA marks 17A and 18A at the end in the −Y direction of the mask MA1. The second MA marks 19A and 19B are square frame-shaped marks that are smaller than the second MA marks 17B and 18B and have a wider line width.

The same alignment systems 31C and 31D that measure the relative positions of the second MA marks 19A and 19B and the second MA marks 17B and 18B are provided to the first mask stage MST1 via support members 32A and 32B. Yes.
In FIG. 8B, the alignment system 31C projects images of the glass substrate 33 on which the index marks 34A and 34B are formed, the illumination systems 35A and 35B, and the index marks 34A and 34B onto the second MA marks 19A and 17B. Condenser lenses 40A and 40B, and an imaging system 36C that superimposes and forms the images of the index marks 34A and 34B and the second MA marks 19A and 17B from the detection light from the second MA marks 19A and 17B. The imaging system 36C includes first objective lenses 41A and 41B that convert the detection light from the second MA marks 19A and 17B into a parallel beam, a mirror 39C that folds the parallel beam from the first objective lens 41A in the −Y direction, and a mirror 39C. The half mirror 44 for combining the light flux from the first objective lens 41B and the light flux from the first objective lens 41B, the images 34AP and 34BP of the index marks 34A and 34B shown in FIG. 9 and the second MA marks 19A and 17B shown in FIG. A second objective lens 42B is formed by overlapping the images 19AP and 17BP, and a two-dimensional image sensor 43A that captures the image. Since the first objective lenses 41A and 41B are infinity correction optical systems, even if the optical path lengths from the second MA marks 19A and 17B to the image sensor 43A are different, the index marks 34A and 34A are formed on the image pickup surface of the image sensor 43A. Images of 34B and second MA marks 19A and 17B are simultaneously formed with high resolution. The imaging signal of the imaging element 43A is supplied to the actuator control system 24.

  The actuator control system 24 detects the amount of displacement between the images of the two index marks 34A and 34B and the two second MA marks 19A and 17B, and the positions of the second MA marks 19A and 17B. A relationship can be sought. Similarly, since the positional relationship between the second MA marks 19B and 18B can be obtained from the imaging signals of the alignment system 31D, the actuator control system 24 can obtain the relative positions and relative rotation angles of the masks MA1 and MA2. Other configurations and operations are the same as those in the first embodiment.

According to this embodiment, since only one image sensor 43A of the alignment system 31C is required, the configuration of the alignment system 31C can be simplified.
In the present embodiment, as shown in FIG. 9A, since the images 19AP and 17BP of the second MA marks 19A and 17B are simultaneously formed on the imaging surface, the index marks 34A and 34B can be omitted. It is. In this case, for example, immediately after the mask alignment performed based on the detection results of the images of the first MA marks 15A to 15D and 16A to 16D of the masks MA1 and MA2 of FIG. The relative positions of 19AP and 17BP in the X direction and Y direction are stored as initial values, and thereafter, the relative positions of the masks MA1 and MA2 are controlled so as to obtain a correction value obtained by adding a mask drawing error or the like to the initial values. May be.

  Further, in the present embodiment, for example, as shown in the imaging system 36E of the alignment system 31C of the first modification of FIG. 10B, a mirror 39D is provided for bending the light beam synthesized by the half mirror 44 in the −X direction. Also good. In this case, as shown in the plan view of FIG. 10A, the parallel light beam reflected in the −X direction from the mirror 39D is supported by a frame mechanism (not shown) different from the first mask stage MST1. The light is received by the two objective lens 42B and the image sensor 43A. The same applies to the alignment system 31D. The second objective lens 42B has an effective diameter corresponding to the amount of movement of the first mask stage MST1 in the Y direction. According to this modification, the first mask stage MST1 can be reduced in weight.

  Further, as a second modification of the embodiment of FIG. 8B, as shown by the imaging system 36G of the alignment system 31C of FIG. One set of light beams is received by a one-dimensional line sensor 43XA having a plurality of pixels arranged in a direction corresponding to the X direction, and a plurality of pixels arranged in a direction corresponding to the Y direction is received by a second set of light beams. The light may be received by a one-dimensional line sensor 43YA having the same. In this case, the line sensor 43XA converts the image of the region 43Xf that is elongated in the X direction in the image of FIG. 11B into an imaging signal, and the line sensor 43YA is elongated in the Y direction of the image of FIG. 11B. The image of the region 43Yf is converted into an imaging signal, and these imaging signals are supplied to the actuator control system 24. The actuator control system 24 can process these imaging signals to determine the relative positions of the second MA marks 19A and 17B.

According to this modification, since the line sensors 43XA and 43YA can perform high-speed processing, the relative position and the relative rotation angle between the masks MA1 and MA2 can be controlled at high speed.
[Third Embodiment]
A third embodiment of the present invention will be described with reference to FIG. In this embodiment, a laser interferometer is used to measure the relative position and the relative rotation angle between the masks MA1 and MA2. Hereinafter, in FIG. 12, portions corresponding to those in FIGS. 1 and 4A are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 12 is a plan view showing the masks MA1 and MA2 on the mask stages MST1 and MST2 of the present embodiment. In FIG. 12, a Y-axis movable mirror 50Y and an X-axis movable mirror 50X are fixed in the vicinity of the + Y direction and the −X direction of the mask MA1 on the first mask stage MST1. A Y-axis laser interferometer 22Y that irradiates the measurement beam parallel to the Y axis on the movable mirror 50Y and a Y-axis that irradiates the measurement beam parallel to the X axis on the movable mirror 50X are arranged at predetermined intervals. Two X-axis laser interferometers 22XA and 22XB are arranged in a frame mechanism (not shown). When the amount of movement of the first mask stage MST1 in the Y direction (direction orthogonal to the scanning direction) is small, retroreflectors (three-surface reflection mirrors) 60A and 60B are used instead of the moving mirror 50X in the first mask stage MST1. You may install in.

  The laser interferometers 22XA, 22XB, and 22Y are, for example, positions in the X direction of the movable mirror 50X with reference to reference mirrors 61XA, 61XB, and 61Y provided on members (not shown) that support the projection optical systems PL1 to PL4, respectively. The position of the movable mirror 50Y in the Y direction is measured. Information on the position of the first mask stage MST1 in the X and Y directions and the rotation angle in the θz direction obtained from these measured values is a main control system (not shown) and an actuator for controlling the operation of the first mask stage MST1. It is supplied to the control system 24A.

  Also, a small Y-axis moving mirror 64Y and an X-axis moving mirror 64X having a reflecting surface substantially parallel to the XZ plane are fixed in the vicinity of the −Y direction and the −X direction of the mask MA2 on the second mask stage MST2. Has been. Further, two X-axis laser interferometers 55XA and 55XB that are arranged at predetermined intervals in the Y direction and irradiate the measuring mirror parallel to the X axis on the movable mirror 64X are arranged in a frame mechanism (not shown). The laser interferometers 55XA and 55XB measure the position of the movable mirror 64X in the X direction based on reference mirrors 62XA and 62XB provided on members (not shown) that support the projection optical systems PL1 to PL4, for example. These measured values are supplied to the actuator control system 24. From these measured values, the position of the second mask stage MST2 in the X direction and the rotation angle in the θz direction can be obtained. If the amount of movement in the Y direction of the first mask stage MST1 (and thus the second mask stage MST2) is small, retroreflectors 60C and 60D may be installed on the second mask stage MST2 instead of the movable mirror 64X. .

  Also, a frame mechanism (not shown) includes a laser interferometer 55Y that irradiates a laser beam obtained by combining a measurement beam and a reference beam having different polarization states along the X axis on the side surface in the −Y direction of the second mask stage MST2. It is supported by. Further, a reference mirror 64YR having a reflecting surface substantially parallel to the YZ plane is fixed on the stepped portion CA of the first mask stage MST1 in the vicinity of the movable mirror 64Y. Then, on the attachment member 56 fixed on the stepped portion CA, the laser beam from the laser interferometer 55Y is directed to the reference mirror 64YR parallel to the Y axis and to the reference mirror 64YR parallel to the X axis. A polarization beam splitter 57 that separates the laser beam and a mirror 58 that reflects the laser beam toward the polarization beam splitter 57 are fixed. In this case, the measurement beam reflected by the movable mirror 64Y and the reference beam reflected by the reference mirror 64YR are combined by the polarization beam splitter 57 and returned to the laser interferometer 55Y. The laser interferometer 55Y measures the relative position ΔLBY in the Y direction of the movable mirror 64Y on the second mask stage MST2 with reference to the reference mirror 64YR on the first mask stage MST1, and the measurement result is sent to the actuator control system 24A. Supply.

  When the first mask stage MST1 is moved in the + Y direction to expose the patterns of the partial pattern areas B1 to B4 of the masks MA1 and MA2, the laser beam from the laser interferometer 55Y is reflected by the mirror 58. The light enters the polarization beam splitter 57. The beams from the movable mirror 64Y and the reference mirror 64YR are returned to the laser interferometer 55Y via the polarization beam splitter 57 and the mirror 58.

  Further, the actuator control system 24A determines the relative position ΔLBX in the X direction of the second mask stage MST2 with respect to the first mask stage MST1, based on the difference between the measured values of the laser interferometers 22XA and 22XB and the measured values of the laser interferometers 55XA and 55XB. And the relative rotation angle ΔLBθ in the θz direction is calculated. These relative positions (ΔLBX, ΔLBY) and the relative rotation angle ΔLBθ can be regarded as the relative position and the relative rotation angle (relative arrangement) between the mask MA1 and the mask MA2.

  As described above, in this embodiment, the relative arrangement of the masks MA1 and MA2 is achieved by the laser interferometer system (arrangement detection device) including the moving mirror and the reference mirror corresponding to the laser interferometers 22XA, 22XB, 55XA, 55XB, and 55Y. Information is being measured. Therefore, the relative arrangement of the masks MA1 and MA2 can be controlled by driving the actuators 25X, 25Y1 and 25Y2 using this relative arrangement information.

Effects and the like of this embodiment are as follows.
(1) The laser interferometers 22XA, 22XB, 55XA, 55XB, and 55Y pass through the movable mirrors 50X and 64X (or retroreflectors 60A to 60D) and the movable mirror 64Y (optical members) provided on the mask stages MST1 and MST2. The relative arrangement information is detected using a measurement beam (detection light). Therefore, the relative arrangement information can always be detected during scanning exposure.

  (2) In addition, in order to measure the information on the relative arrangement, the alignment system 31A, 31B or the like that captures the mark image on the mask of the first embodiment is used in combination with the laser interferometer system. Also good. Further, when a predetermined mark (for example, any of the first MA marks 15A to 15D, 16A to 16D, etc.) on the masks MA1 and MA2 is detected together with or separately from the alignment systems 31A and 31B, the laser interferometer 22XA. , 22XB, 55XA, 55XB, 55Y, an alignment microscope (reference position detection device) that generates an origin signal for resetting (or presetting) the measurement values may be provided in a frame mechanism (not shown).

  (3) The Y-axis laser interferometer 55Y supplies a reference beam in the X direction to the reference mirror 64YR on the first mask stage MST1, and performs measurement in the Y direction on the movable mirror 64Y on the second mask stage MST2. A beam is supplied, a measurement beam and a reference beam are received from these beams, and a relative position between the reference mirror 64YR and the movable mirror 64Y is measured. Therefore, the laser interferometer 55Y can directly measure the relative position in the Y direction of the second mask stage MST2 with respect to the first mask stage MST1.

  Instead of the laser interferometer 55Y, a measuring beam is irradiated parallel to the Y axis onto a moving mirror that is long on the X direction and is set on the second mask stage MST2, and is applied to the support members of the projection optical systems PL1 to PL4. A Y-axis laser interferometer that measures the position of the movable mirror in the Y direction with a fixed reference mirror as a reference may be used. The relative position ΔLBY can be measured from the difference between the measured value of the laser interferometer and the measured value of the laser interferometer 22Y.

  In the X-axis laser interferometers 55XA and 55XB, the reference mirror is fixed on the first mask stage MST1, and the position of the movable mirror 64X on the second mask stage MST2 in the X direction is measured using the reference mirror as a reference. May be. Thereby, the relative position and relative rotation angle in the X direction of the second mask stage MST2 with respect to the first mask stage MST1 can be directly measured.

  In this embodiment, the relative position information of the mask stages MST1 and MST2 is measured using a laser interferometer. However, instead of this, for example, gap sensors (for example, electrostatic capacitance type sensors) are installed at three positions not on the same straight line on the first mask stage MST1, and the mask stages MST1, MST2 are used by using these gap sensors. Relative position information in the X direction, Y direction, and θz direction may be measured. Alternatively, for example, sensors (for example, small linear encoders) that measure the amount of movement of the mover are arranged in the actuators 25X, 25Y1, and 25Y2, and using these sensors, the movement amount of the corresponding mover, and thus the mask, are used. The relative position information of the stages MST1 and MST2 may be measured.

In addition, a liquid crystal display element as a micro device can be obtained by forming a predetermined pattern (circuit pattern, electrode pattern, etc.) on a substrate (glass plate) using the exposure apparatus 100 of the above embodiment. . Hereinafter, an example of this manufacturing method will be described with reference to FIG.
In step S401 (pattern formation process) in FIG. 13, first, a mask pattern for a liquid crystal display element is formed using the above-described exposure apparatus, which is a coating process in which a photoresist is applied to a substrate to be exposed to prepare a photosensitive substrate. An exposure process for transferring and exposing the photosensitive substrate and a developing process for developing the photosensitive substrate are performed. A predetermined resist pattern (transfer pattern layer) is formed on the substrate by a lithography process including the coating process, the exposure process, and the development process. Subsequent to this lithography process, a predetermined pattern including a large number of electrodes and the like is formed on the substrate through an etching process using the resist pattern as a mask and a resist stripping process (processing process). The lithography process or the like is executed a plurality of times according to the number of layers on the substrate.

  In the next step S402 (color filter forming step), a large number of groups of three fine filters corresponding to red R, green G, and blue B are arranged in a matrix, or red R, green G, and blue B are arranged. A color filter is formed by arranging a set of three stripe-shaped filters in the horizontal scanning line direction. In the next step S403 (cell assembly process), for example, liquid crystal is injected between the substrate having the predetermined pattern obtained in step S401 and the color filter obtained in step S402, and a liquid crystal panel (liquid crystal cell) is obtained. ).

  In subsequent step S404 (module assembly process), the liquid crystal panel (liquid crystal cell) thus assembled is attached with an electric circuit for performing a display operation and components such as a backlight to complete a liquid crystal display element. Let According to the above-described method for manufacturing a liquid crystal display element, the manufacturing cost of the masks MA1, MA2, etc. used in the exposure process can be reduced. Furthermore, since the exposure accuracy is improved by driving the second mask stage MST2 and the like during the exposure, the liquid crystal display element can be manufactured with high accuracy at low cost.

  The present invention is not limited to application to a manufacturing process of a liquid crystal display element. For example, a manufacturing process of a display device such as a plasma display, an imaging element (CCD or the like), a micromachine, a MEMS (Microelectromechanical Systems: It can be widely applied to manufacturing processes of various devices such as micro electromechanical systems), thin film magnetic heads using ceramic wafers or the like as substrates, and semiconductor elements.

  In the above embodiment, the third harmonic of the YAG laser is used as the illumination light for exposure. In addition, the illumination light for exposure is selected from a wavelength range including g-line (wavelength 436 nm), h-line (wavelength 405 nm) and i-line (wavelength 365 nm) emitted from an ultra-high pressure mercury lamp, for example. It is also possible to use wavelength light, excimer laser light such as KrF (wavelength 248 nm) or ArF (wavelength 193 nm), or harmonics of a semiconductor laser. 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.

1 is a perspective view showing a partial configuration of an exposure apparatus according to a first embodiment. 1 is a perspective view showing an overall schematic configuration of an exposure apparatus according to a first embodiment. It is a figure which shows the structure of the partial illumination optical system of FIG. 1, and the projection optical system of FIG. 4A is a plan view showing the mask stage and the mask of FIG. 1, and FIG. 4B is a cross-sectional view showing the mask alignment system of FIG. 4A. 5A is an enlarged view showing an image picked up by the image pickup device 43A of FIG. 4B, and FIG. 5B is an enlarged view showing an image picked up by the image pickup device 43B of FIG. 4B. is there. FIG. 6A is a plan view showing a mask stage and a mask during scanning exposure, and FIG. 6B is a plan view showing a plate during scanning exposure. FIG. 7A is a plan view showing the mask stage and the mask during the second scanning exposure, and FIG. 7B is a plan view showing the plate during the second scanning exposure. FIG. 8A is a plan view showing the mask stage of the second embodiment, and FIG. 8B is a cross-sectional view showing the mask alignment system of FIG. 8A. It is an enlarged view which shows the image imaged in 2nd Embodiment. FIG. 10A is a plan view showing a mask stage of a first modification of the second embodiment, and FIG. 10B is a cross-sectional view showing the mask alignment system of FIG. 10A. FIG. 11A is a cross-sectional view showing a mask alignment system of a second modification of the second embodiment, and FIG. 11B is an enlarged view showing an image formed in the second modification. . It is a top view which shows the mask stage which concerns on 3rd Embodiment. It is a flowchart which shows an example of the device manufacturing method which concerns on this invention.

Explanation of symbols

  MA1, MA2 ... mask, MST1 ... first mask stage, MST2 ... second mask stage, PL1-PL4 ... projection optical system, PT ... plate, PST ... plate stage, 15A-15D, 16A-16D ... first mask alignment mark (First MA mark), 17A, 17B, 18A, 18B, 19A, 19B ... second mask alignment mark (second MA mark), 31A, 31B ... alignment system, 41A, 41B ... first objective lens, 43A, 43B ... imaging Element, 55XA, 55XB, 55Y ... Laser interferometer

Claims (24)

A first stage that holds the first mask and moves in the scanning direction;
A second stage that holds the second mask and is movably mounted on the first stage;
An arrangement detection device for detecting relative arrangement information between the first mask and the second mask;
A control device for adjusting a stage arrangement of the second stage with respect to the first stage based on a detection result of the arrangement detection apparatus, and controlling a relative arrangement of the first mask and the second mask;
A stage apparatus comprising:   The stage apparatus according to claim 1, wherein the control apparatus adjusts the stage arrangement based on movement position information of the first stage in the scanning direction and a detection result of the arrangement detection apparatus.   The said arrangement | positioning detection apparatus contains the optical member provided in the said 1st stage, and detects the said relative arrangement | positioning information using the detection light which passed through this optical member. Stage equipment.   The arrangement detection device includes a mark detection system that detects relative position information between a first mark formed on the first mask and a second mark formed on the second mask, the mark detection system The stage apparatus according to claim 3, wherein the relative arrangement information is detected based on a detection result of the system. A plurality of at least one of the first and second marks are formed,
The stage apparatus according to claim 4, wherein the mark detection system detects the relative position information for a plurality of combinations of the first mark and the second mark. The arrangement detection device includes an index member on which an index mark is formed,
The mark detection system detects relative position information of the first and second marks with respect to the index mark, and based on the relative position information, the relative position between the first mark and the second mark 6. The stage apparatus according to claim 4, wherein information is detected. The mark detection system is
A plurality of objective lens systems provided on the first stage and arranged to face the first and second marks, respectively;
An imaging device that captures an observation image of at least one of the first and second marks formed by the detection light via the objective lens system;
The stage apparatus according to any one of claims 4 to 6, comprising: The mark detection system includes a condensing lens system that condenses the detection light via the objective lens system to form the observation image;
8. The infinity correction optical system according to claim 7, wherein the objective lens system is an infinite correction optical system that emits the detection light emitted from the first or second mark opposed to the objective lens system as a parallel light beam. The stage apparatus as described.   The stage apparatus according to claim 8, wherein the condenser lens system and the imaging apparatus are supported by a member different from the first and second stages.   The arrangement detection device includes a laser interferometer system that detects relative position information between a first reflecting member provided on the first stage and a second reflecting member provided on the second stage, The stage apparatus according to claim 3, wherein the relative arrangement information is detected based on a detection result of the laser interferometer system. The laser interferometer system includes:
A reference reflecting member provided on a member different from the first and second stages;
A first laser interferometer that makes the detection light incident on the first reflecting member in the scanning direction and measures position information of the first reflecting member with respect to the reference reflecting member;
A second laser interferometer that makes the detection light incident on the second reflecting member in the scanning direction and measures positional information of the second reflecting member with respect to the reference reflecting member,
The stage according to claim 10, wherein relative position information between the first reflecting member and the second reflecting member is detected based on measurement results of the first and second laser interferometers. apparatus.   The laser interferometer system causes the detection light to be incident on the second reflecting member in a scanning orthogonal direction orthogonal to the scanning direction, and the detection light in the scanning direction relative to the first reflecting member. And a third laser interferometer that measures positional information of the second reflecting member with respect to the first reflecting member, and the first reflecting member based on the measurement result of the third laser interferometer The stage apparatus according to claim 11, wherein relative position information between the first reflecting member and the second reflecting member is detected. A reference position detecting device for detecting a reference position of the first and second masks;
The stage apparatus according to claim 1, wherein the control apparatus adjusts the stage arrangement based on a detection result of the arrangement detection apparatus at the reference position.   The first and second stages hold the first mask or the second mask with the longitudinal direction of the strip-shaped pattern region provided in the first and second masks parallel to the scanning direction. The stage apparatus according to claim 1, wherein the stage apparatus is a stage apparatus. The stage apparatus according to any one of claims 1 to 14,
A substrate stage that holds and moves the photosensitive substrate;
A projection optical system that projects an image of a pattern formed on the first and second masks onto the photosensitive substrate;
An exposure control system for moving the substrate stage in a synchronous scanning direction corresponding to the scanning direction via the projection optical system in synchronization with the movement of the first stage in the scanning direction;
An exposure apparatus comprising: The first and second masks are provided with a plurality of strip-shaped pattern regions in parallel,
The first and second stages hold the first and second masks with the longitudinal direction of the pattern region parallel to the scanning direction, respectively.
There are a plurality of the projection optical systems, and the projection optical systems are arranged to face each other with respect to the plurality of pattern regions,
The exposure control system moves the first stage in the scanning direction in a state in which a part of the pattern image in the pattern area facing the plurality of projection optical systems is projected onto the photosensitive substrate. And at least one scanning exposure for moving the substrate stage in the synchronous scanning direction.
The exposure apparatus according to claim 15, wherein:   The exposure control system moves the first stage in a direction orthogonal to the scanning direction, and faces the pattern area that is different between the first scanning exposure and the second scanning exposure to the projection optical system. The exposure apparatus according to claim 16, wherein A projection image detecting device for detecting a projection image of the mark provided on the first and second masks by the projection optical system;
The exposure according to claim 15, wherein the control device adjusts the stage arrangement based on a detection result of the projection image detection device and a detection result of the arrangement detection device. apparatus. Using the exposure apparatus according to any one of claims 15 to 18, a step of transferring an image of a pattern formed on the first and second masks to a photosensitive substrate;
Developing the photosensitive substrate to which the pattern image has been transferred, and forming a transfer pattern layer having a shape corresponding to the pattern image on the photosensitive substrate;
Processing the photosensitive substrate through the transfer pattern layer;
A device manufacturing method comprising:   15. The relative arrangement of the first and second masks held by the stage apparatus according to claim 1 is controlled, and an image of a pattern formed on the first and second masks is a substrate. An exposure method, wherein the substrate stage is moved in a direction corresponding to the scanning direction in synchronization with the movement of the first stage in the scanning direction while projecting onto a photosensitive substrate held by the stage. The first and second masks are provided with a plurality of strip-shaped pattern regions in parallel,
The first and second stages of the stage apparatus hold the first and second masks with the longitudinal direction of the pattern region parallel to the scanning direction, respectively.
The first stage is scanned in a state in which an image of a part of the pattern in the pattern region is projected onto the photosensitive substrate via the plurality of projection optical systems arranged to face the plurality of pattern regions. Scanning exposure is performed at least once to move the substrate stage in a direction corresponding to the scanning direction.
21. The exposure method according to claim 20, wherein:   The first stage is moved in a direction orthogonal to the scanning direction, and the pattern area that is different between the first scanning exposure and the second scanning exposure is made to face the projection optical system. The exposure method according to claim 21. Detecting projected images of marks provided on the first and second masks;
The exposure according to any one of claims 20 to 22, wherein the control device adjusts the stage arrangement based on a detection result of the projected image of the mark and a detection result of the arrangement detection apparatus. Method. Using the exposure method according to any one of claims 20 to 23, transferring a pattern image formed on the first and second masks to a photosensitive substrate;
Developing the photosensitive substrate to which the pattern image has been transferred, and forming a transfer pattern layer having a shape corresponding to the pattern image on the photosensitive substrate;
Processing the photosensitive substrate through the transfer pattern layer;
A device manufacturing method comprising:

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