JP2017083855A - Substrate supporting device and pattern forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate supporting device in which influence by reflection light (return light) from a member supporting a substrate is reduced.SOLUTION: Provided is a substrate supporting device provided at an exposure device exposing a pattern by the first light at a substrate having light permeability, and supporting the substrate during the exposure. The device includes a cylindrical base material having an outer circumferential face curved into a cylindrical face shape at a certain radius from a prescribed central line and supporting the substrate along the outer circumferential face, a film body formed on the outer circumferential face of the cylindrical base material at a prescribed thickness and forming a supporting face in contact with the reverse face of the substrate and a standard pattern formed on the film body at a level difference, and the reflectance at the supporting face to the second light with a wavelength different from the first light detecting the standard pattern is made higher than the reflectance at the supporting face to the first light.SELECTED DRAWING: Figure 10

Description

The present invention relates to a substrate support device that supports a part of a flexible substrate processed by a processing apparatus in a curved state or a flat state, and pattern formation of the flexible substrate supported by the support device. Relates to the device.
This application claims priority based on Japanese Patent Application No. 2012-188116 for which it applied on August 28, 2012, and uses the content here.

In recent years, organic EL systems have attracted attention as flat panel displays in addition to liquid crystal systems and plasma systems. In the case of an active matrix type organic EL (AMOLED) display, an organic EL pixel light emitting layer, a transparent electrode layer, etc. on a back plate including a thin film transistor (TFT), a driving circuit, various signal lines and the like for driving each pixel. A top plate containing is laminated.
As one of the cheaper and more mass-productive methods for display manufacturing using organic EL, flexible resin material, plastic, or metal foil is used as a long sheet (film) with a thickness of 200 μm or less. It has been proposed that a back plate and a top plate of a display are directly formed thereon by a roll-to-roll method (Patent Document 1).

In Patent Document 1, fluid materials for forming an electrode layer, a semiconductor layer, an insulating film, and the like, and a pixel light emitting layer and a wiring layer constituting a TFT for each pixel can be used with a printer such as an ink jet method. A method of manufacturing a display at low cost by continuously forming on a flexible long sheet (such as a PET (Poly-Ethylene Terephthalate) film) has been disclosed.
Further, in Patent Document 1, in order to precisely finish the relative positional relationship between the gate electrode layer and the drain / source electrode layer and the shape of each electrode of the TFT stacked vertically with the insulating layer interposed therebetween, irradiation with ultraviolet rays is performed. A device has been proposed that forms a self-assembled monolayer (SAM) that modifies the lyophilicity of the surface by using a pattern exposure device with ultraviolet rays, and finishes the shape of each electrode layer more precisely. .

International Publication 2010/001537

The exposure apparatus disclosed in Patent Document 1 projects and exposes a pattern of a planar mask onto a flexible long sheet substrate that is flatly supported via a projection optical system.
In contrast, when a mask pattern is repeatedly exposed to a flexible sheet substrate that is continuously conveyed by a roll-to-roll method, the sheet substrate conveyance direction is the scanning direction, and the mask is cylindrical. A dramatic improvement in productivity can be expected by using a scanning exposure apparatus having a cylindrical rotating mask.

The flexible sheet substrate that is continuously conveyed is a thin substrate and is supported by an air-bearing flat or curved pad surface. Alternatively, the sheet substrate is wound around a part of a cylindrical outer peripheral surface of a rotating drum (roller having a large diameter) and supported in a curved state.
In the case of patterning on a highly transparent PET film, PEN (Poly-Ethylene Naphthalate) film, ultra-thin glass, etc. formed with a transparent layer such as ITO using an exposure apparatus, the photosensitive layer applied on the surface of the substrate Pattern exposure light projected on (for example, a photoresist, a photosensitive silane coupling material, etc.) reaches the pad surface under the substrate and the outer peripheral surface of the rotating drum.

  Therefore, the light component (return light) reflected from the pad surface and the outer peripheral surface of the rotating drum returns from the back surface side of the substrate to the front surface side (projection optical system), and the pattern formed on the photosensitive layer The image quality may be deteriorated. If the reflectance of the pad surface located on the back side of the substrate or the outer peripheral surface of the rotating drum can be kept low, the influence of the return light can be ignored.

  However, for calibration of the exposure apparatus and alignment of the substrate, a reference mark or a reference pattern is provided on a part of the outer peripheral surface of the flat pad surface or the rotating drum, and the reference mark or reference pattern is provided via an optical alignment microscope or the like. When detecting, since the reflectance of the pad surface and the outer peripheral surface of the rotating drum is low, there arises a problem that it becomes difficult to detect the reference mark and the reference pattern with good contrast.

An object of an aspect of the present invention is to provide a substrate support device in which the influence of reflected light (returned light) from a member that supports the substrate is reduced.
In addition, the aspect of the present invention aligns the reference mark or reference pattern formed on a part of the support surface of the apparatus that supports the substrate, or the reflected light (return light) from the mark or pattern formed on the substrate. It is an object of the present invention to provide a substrate support device that can be satisfactorily detected by an optical observation device such as a microscope.
Another object of the present invention is to provide a pattern forming apparatus that performs high-precision optical patterning on a substrate supported by such a substrate support apparatus.

  According to a first aspect of the present invention, there is provided a substrate support apparatus that is provided in an exposure apparatus that exposes a pattern with a first light onto a light-transmitting substrate, and that supports the substrate being exposed. A cylindrical base material having an outer peripheral surface curved into a cylindrical surface with a constant radius from a center line, and a cylindrical base material for supporting the substrate along the outer peripheral surface; and on the outer peripheral surface of the cylindrical base material A first body for detecting the reference pattern, comprising: a film body that has a predetermined thickness and that forms a support surface that contacts the back surface of the substrate; and a reference pattern that is formed in a step on the film body. There is provided a substrate support device in which the reflectance on the support surface for the second light having a wavelength different from that of the first light is larger than the reflectance on the support surface for the first light.

  According to a second aspect of the present invention, there is provided a pattern forming apparatus for optically processing a flexible sheet substrate conveyed in the longitudinal direction to form a pattern, wherein the sheet substrate is curved. Or a substrate support member having a base material for supporting in a flat state, a film body formed on the surface of the base material for supporting the sheet substrate, and a reference pattern formed by a step on the film body; In order to optically detect the reference pattern, a pattern exposure unit that projects the first light for optically processing the sheet substrate supported by the substrate support member, and exposes the pattern. An optical detection unit that detects the reflected light from the reference pattern by projecting the second light having a wavelength different from that of the first light, and reflects the reflectance of the film body by the first light, The reflectance of the film body by the second light Also small, the pattern forming apparatus is provided.

  According to a third aspect of the present invention, there is provided a pattern forming apparatus for forming a pattern on a light sensitive layer of a flexible sheet substrate having light permeability that is conveyed in the longitudinal direction, and having a constant radius from the center line. A rotating drum that supports the sheet substrate with a part of the outer peripheral surface curved in a cylindrical shape and rotates around the center line to convey the sheet substrate in the longitudinal direction, and light of the sheet substrate A pattern exposure unit that exposes a pattern by projecting light for exposure including a wavelength for exposing the sensitive layer onto the light sensitive layer of the sheet substrate supported by the rotating drum; and a light having a wavelength different from that of the light for exposure. An alignment system configured to detect alignment marks formed on the sheet substrate supported by the rotating drum by irradiating light for alignment, and the rotating drum includes A film body whose thickness is adjusted so that the reflectance with respect to the exposure light is larger than the reflectance with respect to the exposure light, and a reference pattern formed by steps on the film body so as to be detectable by the alignment system A forming apparatus is provided.

According to the aspect of the present invention, it is possible to provide a substrate support device that can reduce unnecessary exposure (such as reflection of an unnecessary pattern) that becomes noise when a pattern is exposed on a thin transparent substrate.
According to the aspect of the present invention, it is possible to provide a pattern forming apparatus capable of precise pattern exposure.

It is a figure which shows schematic structure of the exposure apparatus by 1st Embodiment. It is a perspective view which shows arrangement | positioning of the principal part of the exposure apparatus of FIG. It is a figure which shows the structure of the projection optical system of the exposure apparatus of FIG. 1, FIG. It is a schematic diagram which shows the arrangement | positioning relationship between an illumination area | region and a projection area | region. It is a figure which shows arrangement | positioning of the rotating drum and encoder head which support a board | substrate. It is a figure which shows the arrangement | positioning relationship between the alignment system on a board | substrate, and a projection area | region. It is a figure which shows typically the structure of the board | substrate supported on a rotating drum. It is sectional drawing which shows the surface structure of the rotating drum by 1st Embodiment. It is a figure which shows the reflectance characteristic by the thickness of the surface material of a rotating drum. It is a perspective view which shows the surface structure of the rotating drum by 2nd Embodiment. It is sectional drawing which shows the surface structure of the rotating drum by 2nd Embodiment. It is a figure which shows the structure of the pattern drawing apparatus by 3rd Embodiment. It is a figure explaining the drawing form of the board | substrate by the apparatus of FIG. It is a perspective view which shows the surface structure of the rotating drum by 4th Embodiment. It is a figure which shows the cross section of the surface structure of the rotating drum by 5th Embodiment. It is a figure which shows the structure of the pattern exposure apparatus by 6th Embodiment.

[First Embodiment]
FIG. 1 is a diagram showing an overall configuration of a projection exposure apparatus EX for a flexible substrate according to the present embodiment. The exposure apparatus EX irradiates the photosensitive layer of the flexible sheet-like substrate P conveyed from the process apparatus of the previous process with ultraviolet patterning light corresponding to the circuit pattern or wiring pattern for display. .
Ultraviolet rays are, for example, g-line (436 nm), h-line (405 nm), i-line (365 nm) that are bright lines such as mercury discharge, or excimer lasers such as KrF, XeCl, ArF (wavelengths 248 nm, 308 nm, 193 nm, respectively) Alternatively, light having a wavelength of 400 nm or less from a semiconductor laser light source, an LED light source, a harmonic laser light source, or the like is included.

The exposure apparatus EX of FIG. 1 is provided in the temperature control chamber EVC. The exposure apparatus EX is installed on the floor of a manufacturing plant via passive or active image stabilization units SU1, SU2. In the exposure apparatus EX, a transport mechanism for sending the substrate P sent from the previous process to the subsequent process at a predetermined speed is provided.
The transport mechanism is a cylindrical position that is subjected to pattern exposure on the edge position controller EPC that controls the center of the substrate P in the Y direction (width direction perpendicular to the longitudinal direction) to a fixed position, the nipped drive roller DR4, and the substrate P. A rotating drum DR that rotates around a rotation center line AX2 and supports the substrate P while supporting it in a planar shape, tension adjusting rollers RT1 and RT2 that apply a predetermined tension to the substrate P wound around the rotating drum DR, and a substrate It is composed of two sets of drive rollers DR6, DR7 and the like for giving a predetermined slack (play) DL to P.

Further, in the exposure apparatus EX, a cylindrical cylindrical mask DM rotating around the rotation center line AX1, and an image of a part of a transmissive mask pattern formed on the outer peripheral surface of the cylindrical mask DM are transferred to the rotary drum DR. , A plurality of projection optical systems PL1, PL2,... Projected onto a portion of the substrate P supported by the substrate P, and an alignment system for relatively aligning the projection image of a portion of the mask pattern with the substrate P. AM is provided.
The alignment system AM includes an alignment microscope that detects an alignment mark or the like previously formed on the substrate P.

In the above configuration, the XY plane of the Cartesian coordinate system XYZ defined in FIG. 1 is set parallel to the factory floor, and the width direction (also referred to as the TD direction) of the surface of the substrate P coincides with the Y direction. Is set. In this case, the rotation center line AX1 of the cylindrical mask DM and the rotation center line AX2 of the rotary drum DR are both set parallel to the Y axis and are spaced apart in the Z axis direction.
The projection optical systems PL1, PL2,... Of this embodiment are configured as a multi-lens system in which a plurality of projection fields (projected images) are arranged in a staggered manner, as will be described in detail later. Set to 1 × (× 1).

The diameter (radius from the center AX1) of the outer peripheral surface (pattern surface) of the cylindrical mask DM and the diameter (radius from the center AX2) of the outer peripheral surface (support surface) of the rotary drum DR can be made substantially equal. it can. For example, the diameter of the cylindrical mask DM can be 30 cm, and the diameter of the rotary drum DR can be 30 cm.
Note that the diameter (radius from the center AX1) of the outer peripheral surface (pattern surface) of the cylindrical mask DM and the diameter (radius from the center AX2) of the outer peripheral surface (support surface) of the rotary drum DR need to be the same. No, it can be very different. For example, the diameter of the cylindrical mask DM may be set to 30 cm, and the diameter of the rotary drum DR may be set to about 40 to 50 cm.
In addition, the said numerical value is an example and this invention is not limited to this.
When the diameter of the rotating drum DR is made equal to the diameter of the cylindrical mask DM (pattern surface), strictly speaking, the thickness of the substrate P wound around the outer peripheral surface of the rotating drum DR is taken into consideration. For example, if the thickness of the substrate P is 100 μm (0.1 mm), the radius of the outer peripheral surface of the rotary drum DR is 0.1 mm smaller than the radius of the cylindrical mask DM (pattern surface).
Furthermore, when the overall length (circumferential length) in the circumferential direction of the outer peripheral surface of the rotating drum DR is set to an appropriate length, for example, 100.0 cm, the diameter of the outer peripheral surface of the rotating drum DR is 100 / π cm depending on the circumferential ratio π. Therefore, it is necessary to process the diameter with an accuracy of several μm to submicron.

In this embodiment, since a transmissive cylindrical mask DM is used, illumination light (ultraviolet light) for exposure corresponding to each visual field region of the projection optical systems PL1, PL2,. An illumination system IU that irradiates the pattern surface (outer peripheral surface) of the cylindrical mask DM is provided.
When the cylindrical mask DM is a reflection type, the outer peripheral surface (reflection pattern surface) of the cylindrical mask DM is irradiated with exposure illumination light through some optical elements of the projection optical systems PL1, PL2,. A down-tilt illumination optical system for irradiating the light is provided.

  In the above configuration, by rotating the cylindrical mask DM and the rotating drum DR synchronously at a predetermined rotation speed ratio, a mask pattern image formed on the outer peripheral surface of the cylindrical mask DM becomes a part of the outer peripheral surface of the rotating drum DR. The surface of the substrate P wound around (surface curved along the cylindrical surface) is continuously and repeatedly scanned and exposed.

The board | substrate P used by this embodiment is foil (foil) etc. which consist of metals or alloys, such as a resin film and stainless steel, for example.
The material of the resin film is, for example, one of polyethylene resin, polypropylene resin, polyester resin, ethylene vinyl copolymer resin, polyvinyl chloride resin, cellulose resin, polyamide resin, polyimide resin, polycarbonate resin, polystyrene resin, and vinyl acetate resin. Or two or more.

The substrate P can be selected so that its thermal expansion coefficient is not significantly large so that the amount of deformation caused by heat in various processing steps can be substantially ignored. A thermal expansion coefficient can be made small by mixing an inorganic filler with a resin film, for example. As the inorganic filler, for example, titanium oxide, zinc oxide, alumina, silicon oxide and the like are used.
Further, the substrate P may be a single layer of ultrathin glass having a thickness of, for example, about 100 μm manufactured by a float process or the like, and the above resin film, foil, or the like is bonded to the ultrathin glass. A laminated body may be sufficient.
In addition, the said numerical value is an example and this invention is not limited to this.

FIG. 2 is a perspective view showing the arrangement relationship of the cylindrical mask DM, the plurality of projection optical systems PL1, PL2,..., And the rotating drum DR in the exposure apparatus EX shown in FIG.
In FIG. 2, each of the projection optical systems PL1, PL2, PL3, PL4,... (Here, four projection optical systems are shown) provided between the cylindrical mask DM and the rotary drum DR is disclosed in, for example, As disclosed in Japanese Patent Laid-Open No. 7-57986, two catadioptric imaging lenses that use half of the circular projection field of view (half field) are connected in tandem in the Z direction to erect the mask pattern. Is projected to the substrate side at the same magnification as a non-inverted image of
The projection optical systems PL1, PL2, PL3, PL4... Have the same configuration, and details will be described later.

  The projection optical systems PL1, PL2, PL3, PL4,... Are respectively attached to and integrated with a strong holding column PLM. The holding column PLM is made of a metal such as Invar having a small thermal expansion coefficient with respect to a temperature change, and can suppress a positional variation between the projection optical systems PL1, PL2, PL3, PL4,. it can.

As shown in FIG. 2, the rotation angle position (or position in the circumferential length direction) of the rotating drum DR is measured at both ends in the direction (Y direction) in which the rotation center line AX2 extends on the outer peripheral surface of the rotating drum DR. Scale portions GPa and GPb for the encoder system are respectively provided in an annular shape over the entire circumferential direction.
The scale portions GPa and GPb are diffraction gratings in which concave or convex lattice lines are formed at a constant pitch (for example, 20 μm) in the circumferential direction of the outer peripheral surface of the rotary drum DR, and are configured as incremental scales.
In addition, the said numerical value is an example and this invention is not limited to this.

The substrate P is configured to be wound inside avoiding the scale portions GPa and GPb at both ends of the rotary drum DR. When a strict arrangement relationship is required, the outer peripheral surfaces of the scale portions GPa and GPb and the outer peripheral surface of the portion of the substrate P wound around the rotary drum DR are set to be the same surface (same radius from the center line AX2). To do. For this purpose, the outer peripheral surfaces of the scale parts GPa and GPb may be made higher by the thickness of the substrate P in the radial direction than the outer peripheral surface for winding the substrate of the rotary drum DR.
In order to rotate the rotating drum DR around the rotation center line AX2, shafts Sf2 coaxial with the center line AX2 are provided on both sides of the rotation drum DR. Rotational torque from a drive source (not shown) (motor, deceleration gear mechanism, etc.) is given to the shaft portion Sf2.

Further, in the present embodiment, each of the scale parts GPa and GPb at both ends of the rotary drum DR is opposed to each other and fixed to a column PLM for fixing the projection optical systems PL1, PL2, PL3, PL4,. Encoder heads EN1 and EN2 are provided. In FIG. 2, only two encoder heads EN1 and EN2 facing the scale part GPa are shown, but similar encoder heads EN1 and EN2 are also arranged facing the scale part GPb.
Thus, by attaching the encoder heads EN1 and EN2 to the column PLM, the relative positional fluctuation between each projection optical system and each encoder head EN1 and EN2 caused by the influence of a temperature change or the like can be suppressed small.

Each encoder head EN1, EN2 projects a measurement light beam toward the scale portions GPa, GPb, and photoelectrically detects the reflected light beam (diffracted light), thereby changing the position of the scale portions GPa, GPb in the circumferential direction. Detection signals (for example, a two-phase signal having a phase difference of 90 degrees) are generated.
The detected signal is interpolated and digitally processed by a counter circuit (not shown), whereby the angular change of the rotating drum DR, that is, the circumferential position change of the outer peripheral surface can be measured with submicron resolution. .

Further, as shown in FIG. 2, the encoder heads EN1 and EN2 are arranged on installation orientation lines Le1 and Le2. The installation azimuth lines Le1 and Le2 are set in a plane parallel to the XZ plane in FIG. 2 through the projection region of the measurement light beam on the scale part GPa (GPb), and the extension line is the rotation of the rotary drum DR. This is a virtual line determined to intersect the center line AX2.
As will be described in detail later, when viewed in the XZ plane, the installation azimuth line Le1 is determined to be parallel to the principal ray of the imaging light beam projected onto the substrate P from the odd-numbered projection optical systems PL1 and PL3. Further, when viewed in the XZ plane, the installation orientation line Le2 is determined to be parallel to the principal ray of the imaging light beam projected onto the substrate P from the even-numbered projection optical systems PL2 and PL4.

On the other hand, a shaft portion Sf1 is provided on both ends of the cylindrical mask DM so as to be coaxial with the rotation center line AX1, and the rotational torque from a drive source (not shown) (not shown) is transmitted through the shaft portion Sf1 to the cylindrical mask DM. Given to. At both ends of the cylindrical mask DM in the direction of the rotation center line AX1, similarly to the rotary drum DR, the encoder measurement scale part GPM is provided annularly over the entire circumferential direction centered on the rotation center line AX1. It has been.
The transmission type mask pattern formed on the outer peripheral surface of the cylindrical mask DM is arranged inside avoiding the scale portions GPM at both ends. When a strict arrangement relationship is required, the outer peripheral surface of the scale portion GPM and the outer peripheral surface of the pattern surface (cylindrical surface) of the cylindrical mask DM are set to be the same surface (same radius from the center line AX1). .

Further, in the direction of each field of view of the odd-numbered projection optical systems PL1, PL3,... At a position facing each of the scale portions GPM of the cylindrical mask DM and viewed from the rotation center line AX1, the encoder head EN11 , And the encoder head EN12 is arranged in the direction of each field of the even-numbered projection optical systems PL2, PL4,... As viewed from the rotation center line AX1.
These encoder heads EN11 and EN12 are also attached to a holding column PLM for fixing the projection optical systems PL1, PL2, PL3, PL4,.

Furthermore, the encoder heads EN11 and EN12 are arranged on the installation azimuth lines Le11 and Le12 as in the arrangement state of the encoder heads EN1 and EN2 on the rotary drum DR side.
The installation azimuth lines Le11 and Le12 are set in a plane parallel to the XZ plane in FIG. 2 through an area on which the measurement light beam of the encoder head is projected on the scale part GPM of the cylindrical mask DM. Is defined so as to intersect the rotation center line AX1 of the cylindrical mask DM.

  In the case of the cylindrical mask DM, it is possible to draw and form a scale or a lattice pattern to be engraved on the scale portion GPM on the outer peripheral surface of the cylindrical mask DM together with a mask pattern of a device (display panel circuit, etc.) The relative positional relationship between the mask pattern and the scale part GPM can be set strictly.

In this embodiment, the cylindrical mask DM is exemplified as a transmission type. However, in the reflection type cylindrical mask, the scale portion GPM (scale, grid, origin pattern, etc.) can be formed together with the mask pattern of the device. Is possible.
In general, when a reflective cylindrical mask is manufactured, the metal columnar material having the shaft portion Sf1 is processed with a high-precision lathe and polishing machine, so that the roundness and axial blurring (eccentricity) of the outer peripheral surface are extremely low. It can be kept small. Therefore, if the scale part GPM is also formed on the outer peripheral surface by the same process as that for forming the mask pattern, highly accurate encoder measurement can be performed.

As described above, in the present embodiment, the outer peripheral surface of the scale portion GPM formed on the cylindrical mask DM is set to have substantially the same radius as the mask pattern surface, and the outer periphery of the scale portions GPa and GPb formed on the rotary drum DR. The surface was set to have substantially the same radius as the outer peripheral surface of the substrate P.
Therefore, the encoder heads EN11 and EN12 detect the scale portion GPM at the same radial position as the mask pattern surface (illumination area by the illumination system IU) on the cylindrical mask DM, and the encoder heads EN1 and EN2 are wound around the rotary drum DR. In addition, the scale portions GPa and GPb can be detected at the same radial position as the projection region (imaging plane of the projection image) on the substrate P.
Therefore, Abbe error caused by the difference between the measurement position and the processing position in the radial direction of the rotating system can be reduced.

  Next, a specific configuration of the projection optical systems PL1 to PL4,... According to the present embodiment will be described with reference to FIG. Since each projection optical system has the same configuration, only the configuration of the projection optical system PL1 will be described as a representative. The projection optical system PL1 shown in FIG. 3 includes a catadioptric-type telecentric first imaging optical system 51 and a second imaging optical system 58.

The first imaging optical system 51 includes a plurality of lens elements, a focus correction optical member 44, an image shift correction optical member 45, a first deflection member 50, a first concave mirror 52 disposed on the pupil plane, and the like. The
The first imaging optical system 51 has a mask pattern that appears in the illumination area IR1 formed on the pattern surface (outer peripheral surface) of the cylindrical mask DM by the illumination light D1 (its principal ray is EL1) from the illumination system IU. The image is formed on an intermediate image plane on which the field stop 43 is disposed.

The second imaging optical system 58 includes a plurality of lens elements, a second deflecting member 57, a second concave mirror 59 disposed on the pupil plane, a magnification correcting optical member 47, and the like.
The second imaging optical system 58 converts an image limited by the aperture shape (for example, trapezoid) of the field stop 43 out of the intermediate image formed by the first imaging optical system 51 into the projection area PA1 of the substrate P. Re-image inside.

In the above-described configuration of the projection optical system PL1, the focus correction optical member 44 finely adjusts the focus state of a mask pattern image (hereinafter referred to as a projection image) formed on the substrate P, and the image shift correction optical member 45 projects. The image is slightly laterally shifted in the image plane, and the magnification correcting optical member 47 slightly corrects the magnification of the projected image within a range of about ± tens of ppm.
Further, in the projection optical system PL1, the first deflecting member 50 is slightly rotated around an axis parallel to the Z axis in FIG. 3, so that the projected image formed on the substrate P is slightly rotated in the image plane. A rotation correction mechanism 46 is provided.

  The imaging light beam EL2 from the pattern in the illumination area IR1 on the cylindrical mask DM is emitted from the illumination area IR1 in the normal direction, passes through the focus correction optical member 44 and the image shift correction optical member 45, and is subjected to the first deflection. Reflected by the first reflecting surface (plane mirror) p4 of the member 50, reflected by the first concave mirror 52 through the plurality of lens elements, and again through the plurality of lens elements, the second reflecting surface of the first deflecting member 50. (Plane mirror) Reflected by p5 and reaches the field stop 43.

  In the present embodiment, a plane including both the rotation center line AX1 of the cylindrical mask DM and the rotation center line AX2 of the rotating drum DR shown in FIG. 2 (or FIG. 1) is defined as a center plane p3 (parallel to the YZ plane). In this case, the optical axis AX3 of the first imaging optical system 51 and the optical axis AX4 of the second imaging optical system 58 are both arranged so as to be orthogonal to the center plane p3.

In the present embodiment, when viewed in the XZ plane, the illumination area IR1 is biased by a predetermined amount in the −X direction with respect to the center plane p3, so that the principal ray EL1 of the illumination light D1 passing through the center in the illumination area IR1 is extended. The line is set so as to intersect the rotation center line AX1 of the cylindrical mask DM.
As a result, the principal ray EL3 of the imaging light beam EL2 from the pattern located at the center point in the illumination area IR1 also advances in a state inclined in the XZ plane with respect to the center plane p3, and the first deflection member 50 1 reflection surface p4 is reached.

The first deflection member 50 is a triangular prism that extends in the Y-axis direction. In the present embodiment, each of the first reflecting surface p4 and the second reflecting surface p5 includes a mirror surface (the surface of the reflecting film) formed on the surface of the triangular prism.
The first deflecting member 50 is configured so that the principal ray EL3 from the illumination region IR1 to the first reflecting surface p4 is inclined with respect to the center plane p3 in the XZ plane and from the second reflecting surface p5 to the field stop 43. The imaging light beam EL2 is deflected so that the light beam EL3 is parallel to the center plane p3.

In order to form such an optical path, in the present embodiment, a ridge line where the first reflecting surface p4 and the second reflecting surface p5 of the first deflecting member 50 intersect is disposed on the optical axis AX3. When a plane including the ridge line and the optical axis AX3 and parallel to the XY plane is p6, the first reflection surface p4 and the second reflection surface p5 are arranged at an asymmetric angle with respect to the plane p6.
Specifically, when the angle of the first reflecting surface p4 with respect to the plane p6 is θ1, and the angle of the second reflecting surface p5 with respect to the plane p6 is θ2, in this embodiment, the angle (θ1 + θ2) is set to be less than 90 °. The angle θ1 is set to less than 45 °, and the angle θ2 is set to substantially 45 °.

By setting the principal ray EL3 reflected by the first reflecting surface p4 and entering the plurality of lens elements in parallel with the optical axis AX3, the principal ray EL3 is the center of the first concave mirror 52, that is, the optical axis of the pupil plane. It can pass through the intersection with AX3, and a telecentric imaging state can be secured.
For this purpose, in FIG. 3, the inclination angle in the XZ plane with respect to the center plane p3 of the principal ray EL3 between the illumination region IR1 and the first reflection plane p4 is θd, and the angle θ1 of the first reflection plane p4 is What is necessary is just to set like Formula (1).
θ1 = 45 ° − (θd / 2) (1)

The imaging light beam EL2 passing through the first imaging optical system 51 and passing through the field stop 43 is a third reflecting surface (plane mirror) p8 of the second deflecting member 57 that is an element of the second imaging optical system 58. And passes through the plurality of lens elements to reach the second concave mirror 59 disposed on the pupil plane.
The imaging light beam EL2 reflected by the second concave mirror 59 is again reflected by the fourth reflecting surface (planar mirror) p9 of the second deflecting member 57 through the plurality of lens elements, and passes through the magnification correcting optical member 47. It passes through and reaches the projection area PA1 on the substrate P.
As a result, an image of the pattern appearing in the illumination area IR1 is projected at the same magnification (× 1) in the projection area PA1.

The second deflection member 57 is also a triangular prism that extends in the Y-axis direction. In the present embodiment, each of the third reflecting surface p8 and the fourth reflecting surface p9 includes a mirror surface (the surface of the reflecting film) formed on the surface of the triangular prism.
The second deflecting member 57 is arranged so that the principal ray EL3 between the field stop 43 and the third reflecting surface p8 is parallel to the central plane p3 in the XZ plane and between the fourth reflecting surface p9 and the projection area PA1. The image forming light beam EL2 is deflected so that the principal ray EL3 of the light beam tilts in the XZ plane with respect to the center plane p3.

In the present embodiment, when viewed in the XZ plane, the projection area PA1 is also shifted by a predetermined amount in the −X direction with respect to the center plane p3, so that the extended line of the principal ray EL3 of the imaging light beam reaching the projection area PA1. Is set so as to intersect the rotation center line AX2 of the rotary drum DR. As a result, the image plane formed in the projection area PA1 becomes a tangential plane of the surface (curved surface) of the substrate P supported by the outer peripheral surface of the rotary drum DR, and faithful projection exposure while maintaining resolution is possible.
In order to form such an optical path, in the present embodiment, a ridge line where the third reflection surface p8 and the second reflection surface p9 of the second deflection member 57 intersect is arranged on the optical axis AX4, and the ridge line and the light When a plane including the axis AX4 and parallel to the XY plane is p7, the third reflection surface p8 and the fourth reflection surface p9 are arranged at an asymmetric angle with respect to the plane p7.
Specifically, if the angle of the third reflecting surface p8 with respect to the plane p7 is θ3, and the angle of the fourth reflecting surface p9 with respect to the plane p7 is θ4, the angle (θ3 + θ4) is set to be less than 90 °, and the angle θ4 is 45 °. The angle θ3 is set to substantially 45 °.

By setting the principal ray EL3 reflected by the second concave mirror 59 and emitted from a plurality of lens elements to reach the fourth reflecting surface p9 in parallel with the optical axis AX4, a telecentric imaging state can be ensured.
For that purpose, in FIG. 3, when the inclination angle in the XZ plane with respect to the center plane p3 of the principal ray EL3 between the fourth reflection surface p9 and the projection area PA1 is θs, the angle θ4 of the fourth reflection surface p9 is What is necessary is just to set like the following formula | equation (2).
θ4 = 45 ° − (θs / 2) (2)

Although the configuration of the projection optical system PL1 has been described above, the odd-numbered projection optical systems PL3,... Are configured in the same manner as in FIG. 3, and the even-numbered projection optical systems PL2, PL4,. Are arranged symmetrically with respect to the center plane p3.
Further, the focus correction optical member 44, the image shift correction optical member 45, the rotation correction mechanism 46, and the magnification correction optical member 47 are formed on any of the odd-numbered and even-numbered projection optical systems PL1 to PL4. It is provided as a characteristic adjustment mechanism.

  Thereby, the projection condition of the projected image on the substrate P can be adjusted for each projection optical system. The projection conditions here include one or more items of the translation position, rotation position, magnification, and focus of the projection area on the substrate P. The projection condition can be determined for each position of the projection area with respect to the substrate P at the time of synchronous scanning. By adjusting the projection condition of the projection image, it is possible to correct the distortion of the projection image when compared with the mask pattern.

  The focus correcting optical member 44 is formed by superposing two wedge-shaped prisms in opposite directions (in the opposite direction in the X direction in FIG. 3) so as to form a transparent parallel plate as a whole. This pair of prisms is slid in the direction of the slope without changing the distance between the opposing surfaces, and the thickness of the parallel plate is changed, so that the effective optical path length is finely adjusted and formed in the projection area PA1. The focus state of the pattern image is finely adjusted.

  The image shift correction optical member 45 includes a transparent parallel flat glass that can be tilted in the XZ plane in FIG. 3 and a transparent parallel flat glass that can be tilted in a direction perpendicular thereto. By adjusting the respective tilt amounts of the two parallel flat glass plates, the pattern image formed in the projection area PA1 can be slightly shifted in the X direction or the Y direction.

  The magnification correcting optical member 47 has a concave lens, a convex lens, and a concave lens arranged coaxially at predetermined intervals, the front and rear concave lenses are fixed, and the convex lens between them is moved in the direction of the optical axis (principal ray EL3). It is composed. As a result, the pattern image formed in the projection area PA1 is isotropically enlarged or reduced by a minute amount while maintaining a telecentric imaging state.

  The rotation correction mechanism 46 slightly rotates the first deflection member 50 around an axis parallel to the Z axis by an actuator (not shown). The rotation correction mechanism 46 can slightly rotate the pattern image formed in the projection area PA1 within the image plane.

FIG. 4 is a diagram showing the arrangement of the illumination area IR and the projection area PA in the present embodiment. In FIG. 4, as the projection optical system PL, three odd-numbered projection optical systems PL1, PL3, PL5 and three even-numbered projection optical systems PL2, PL4, PL6 are arranged in the Y direction. To do.
The left figure in FIG. 4 is a plan view of the six illumination regions IR1 to IR6 set on the cylindrical mask DM for each of the six projection optical systems PL1 to PL6 as viewed from the −Z side. The right view in FIG. 4 is a plan view of six projection areas PA1 to PA6 on the substrate P supported by the rotary drum DR for each of the six projection optical systems PL1 to PL6, as viewed from the + Z side. A symbol Xs in FIG. 4 indicates the moving direction (rotating direction) of the cylindrical mask DM or the rotating drum DR.

The illumination system IU individually illuminates the six illumination areas IR1 to IR6 on the cylindrical mask DM. In FIG. 4, each of the illumination areas IR1 to IR6 will be described as a trapezoidal area elongated in the Y direction. As described with reference to FIG. 3, when the aperture shape of the field stop 43 is a trapezoid, each of the illumination areas IR1 to IR6 may be a rectangular area including the trapezoid area.
The odd-numbered illumination areas IR1, IR3, and IR5 have the same shape (trapezoid or rectangle), and are arranged at regular intervals in the Y-axis direction. Even-numbered illumination areas IR2, IR4, and IR6 are also arranged at regular intervals in the Y-axis direction. The even-numbered illumination areas IR2, IR4, IR6 have a trapezoidal (or rectangular) shape symmetrical to the odd-numbered illumination areas IR1, IR3, IR5 with respect to the center plane p3.
Further, as shown in FIG. 4, each of the six illumination areas IR1 to IR6 is arranged so that the peripheral portions of adjacent illumination areas partially overlap in the Y direction.

In the present embodiment, the outer peripheral surface of the cylindrical mask DM has a pattern formation region A3 where a pattern is formed and a pattern non-formation region A4 where a pattern is not formed.
The pattern non-formation region A4 is arranged so as to surround the pattern formation region A3 in a frame shape, and particularly has a characteristic of shielding the illumination light beam that irradiates each illumination region IR1 to IR6.
The pattern formation region A3 moves in the direction Xs with the rotation of the cylindrical mask DM, and each partial region in the Y-axis direction of the pattern formation region A3 passes through one of the six illumination regions IR1 to IR6. In other words, the six illumination regions IR1 to IR6 are arranged so as to cover the entire width in the Y-axis direction of the pattern formation region A3.

  In FIG. 4, six projection optical systems PL1 to PL6 are provided corresponding to each of the six illumination regions IR1 to IR6. Therefore, each of the projection optical systems PL1 to PL6 displays a partial pattern image of the mask pattern appearing in the corresponding illumination areas IR1 to IR6 in six projections on the substrate P as shown in the right diagram in FIG. Projecting into areas PA1 to PA6.

As shown in the right diagram in FIG. 4, the pattern images in the odd-numbered illumination areas IR1, IR3, and IR5 are respectively projected onto the odd-numbered projection areas PA1, PA3, and PA5 arranged in a line in the Y-axis direction. . The pattern images in the even-numbered illumination areas IR2, IR4, and IR6 are also projected onto the even-numbered projection areas PA2, PA4, and PA6 arranged in a line in the Y-axis direction.
The odd-numbered projection areas PA1, PA3, PA5 and the even-numbered projection areas PA2, PA4, PA6 are arranged symmetrically with respect to the center plane p3.

  Each of the six projection areas PA1 to PA6 is arranged such that ends (trapezoidal triangular portions) of adjacent projection areas overlap each other in a direction (Y direction) parallel to the rotation center line AX2. From this, the exposure area A7 of the substrate P exposed in the six projection areas PA1 to PA6 with the rotation of the rotary drum DR has substantially the same exposure amount everywhere.

  As shown in FIG. 1, the exposure apparatus EX according to the present embodiment detects an alignment mark formed on the substrate P or a reference mark or reference pattern formed on the rotary drum DR. An alignment system AM is provided for aligning the substrate P and the mask pattern and calibrating the base line and the projection optical system. The alignment system AM will be described below with reference to FIGS.

  FIG. 5 is a view of the arrangement of the rotary drum DR, the encoder heads EN1 and EN2, and the alignment system AM1 as seen in the XZ plane. FIG. 6 is a view of the arrangement of the rotary drum DR, the six projection areas PA1 to PA6 set on the substrate P, and the five alignment systems AM1 to AM5 in the XY plane.

In FIG. 5, as described above, the installation azimuth lines Le1 and Le2 in which the encoder heads EN1 and EN2 are arranged are symmetrically inclined with respect to the center plane p3 including the rotation center line AX2 and parallel to the YZ plane. Is set.
The inclination angles of the installation orientation lines Le1 and Le2 with respect to the center plane p3 are the projection areas PA1 described in FIG. 3 (or the odd-numbered projection areas PA1, PA3, PA5 and the even-numbered projection areas PA2, PA4, PA6) is set to be equal to the inclination angle θs from the central plane p3 of the principal ray EL3 reaching the center of PA6).

In FIG. 5, an alignment system AM1 includes an illumination unit GC1 for irradiating a mark or pattern on the substrate P or the rotary drum DR with alignment illumination light, and a beam splitter GB1 for guiding the illumination light to the substrate P or the rotary drum DR. The image of the mark or pattern received through the objective lens system GA1, the objective lens system GA1 and the beam splitter GB1 that projects the illumination light onto the substrate P or the rotating drum DR and receives the light generated by the mark or pattern ( A bright field image, a dark field image, a fluorescent image, and the like) are configured by an imaging system GD1 that captures a two-dimensional CCD, CMOS or the like.
Note that the illumination light for alignment from the illumination unit GC1 is light in a wavelength region that has little sensitivity to the photosensitive layer on the substrate P, for example, light having a wavelength of about 500 to 800 nm.

The observation area (imaging area) of the mark or pattern by the alignment system AM1 is set to a range of about 200 μm square on the substrate P and the rotating drum DR, for example.
The optical axis of the alignment system AM1, that is, the optical axis of the objective lens system GA1, is set in the same direction as the installation orientation line La1 extending from the rotation center line AX1 in the radial direction of the rotary drum DR. The installation orientation line La1 is inclined by an angle θj from the center plane p3, and is set so that θj> θs with respect to the inclination angle θs of the principal ray EL3 of the odd-numbered projection optical systems PL1, PL3, and PL5. The

Further, in the present embodiment, an encoder head EN3 similar to the encoder heads EN1 and EN2 is provided on the installation direction line La1 at a position facing each of the scale portions GPa and GPb of the rotary drum DR. Thus, the rotational angle position (or circumferential position) of the rotating drum DR at the moment when the alignment system AM1 samples a mark or pattern image within the observation area (imaging area) can be accurately measured.
When viewed in the XZ plane, an encoder head EN4 that faces each of the scale portions GPa and GPb of the rotary drum DR is also provided in the X-axis direction orthogonal to the center plane p3.

As shown in FIG. 6, five alignment systems AM having the same configuration as the alignment system AM1 in FIG. 5 are provided. In FIG. 6, only the objective lens systems GA1 to GA5 of the five alignment systems AM1 to AM5 are shown for easy understanding.
The observation area (imaging area) Vw on the substrate P (or the outer peripheral surface of the rotating drum DR) by the objective lens systems GA1 to GA5 is parallel to the Y axis (rotation center line AX2) as shown in FIG. Arranged at predetermined intervals. The optical axes of the objective lens systems GA1 to GA5 passing through the center of each observation area (imaging area) Vw are all arranged in parallel to the XZ plane.

As shown in FIG. 2, the scale parts GPa and GPb are provided on both ends of the rotary drum DR, and a narrow band regulation band CLa by a concave groove or a convex rim is provided on the inside thereof. , CLb is engraved over the entire circumference.
The width in the Y direction of the substrate P is set to be smaller than the interval in the Y direction between the two regulation bands CLa and CLb. The substrate P is supported in close contact with the inner region sandwiched between the regulation bands CLa and CLb on the outer peripheral surface of the rotary drum DR.

On the substrate P, as shown in the right figure of FIG. 4, the exposure area A7 exposed by each of the six projection areas PA1 to PA6 is arranged at a predetermined interval in the X direction. .
A pattern may already be formed in each exposure area A7 of the substrate P, and a new pattern may be superimposed and exposed on the pattern. In this case, around the exposure area A7 on the substrate P, a plurality of marks (alignment marks) Ks1 to Ks5 for alignment are formed in a cross shape, for example.

  In FIG. 6, marks Ks1 are provided in the peripheral area on the −Y side of the exposure area A7 at regular intervals in the X direction, and marks Ks5 are constant in the peripheral area on the + Y side of the exposure area A7 in the X direction. Provided at intervals. The marks Ks2, Ks3, and Ks4 are provided in a blank area between two adjacent exposure areas A7 in the X direction and in a line at intervals in the Y direction.

Among these alignment marks, the mark Ks1 is set so as to be sequentially captured while the substrate P is being sent within the imaging region Vw of the objective lens system GA1 (alignment system AM1). The mark Ks5 is set so as to be sequentially captured while the substrate P is being sent within the imaging region Vw of the objective lens system GA5 (alignment system AM5).
The marks Ks2, Ks3, and Ks4 are captured in the imaging regions Vw of the objective lens system GA2 (alignment system AM2), the objective lens system GA3 (alignment system AM3), and the objective lens system GA4 (alignment system AM4), respectively. In addition, the position in the Y direction is determined.

In the configuration as described above, when exposure is performed by relatively aligning the exposure area A7 on the substrate P and the mask pattern on the cylindrical mask DM, the exposure is performed within the imaging areas Vw of the alignment systems AM1 to AM5. The imaging data is sampled at the timing when the marks Ks1 to Ks5 to enter, and the angular position (circumferential position) of the rotating drum DR at that time is read from the encoder head EN3 and stored.
By analyzing each imaging data, the amount of deviation in the XY direction of each of the marks Ks1 to Ks5 with respect to each imaging region Vw is obtained.

When the relative positional relationship between the imaging regions Vw of the alignment systems AM1 to AM5 and the projection regions PA1 to PA6, that is, a so-called baseline is accurately obtained in advance by calibration or the like, each obtained mark Ks1 Based on the amount of deviation in the XY directions of Ks5 and the angular position (circumferential position) of the rotary drum DR read and stored by the encoder head EN3, the exposure area A7 on the substrate P and the projection areas PA1 to PA6 Can be accurately estimated from the measured values of the two encoder heads EN1 and EN2 arranged at the exposure position.
Therefore, by sequentially comparing the measured values of the two encoder heads EN1 and EN2 with the measured values of the encoder heads EN11 and EN12 on the cylindrical mask DM side and performing synchronous control, the mask pattern is exposed to the exposure area of the substrate P. Accurate overlay exposure can be performed on A7.

In the exposure as described above, the substrate P may be as thin as about 100 μm, and a transparent film such as ITO may be formed as a base layer.
When such a substrate P is used, if the reflectance of the outer peripheral surface of the rotary drum DR that supports the substrate P is relatively high, or if there are many small scratches on the surface of several microns, exposure light for exposure is used. Is reflected, scattered, or diffracted by the outer peripheral surface of the rotating drum DR, and returns from the back surface side to the front side of the substrate P, giving the photosensitive layer exposure that causes noise that is not in the original mask pattern. .
Therefore, at least a portion of the outer peripheral surface of the rotating drum DR that is in contact with the exposure area A7 on the substrate P has a locally flat surface with a submicron flatness, and the reflectance is uniformly low. Can be. The reflectance can be, for example, 50, 45, 40, 35, 30, 25, 20, 15, 10, or 5% or less, preferably 20% or less, with respect to the illumination light for exposure.
In addition, the said numerical value is an example and this invention is not limited to this.

  Hereinafter, the structure of the outer peripheral surface of the rotating drum DR will be described with reference to FIGS. FIG. 7 shows the configuration of the substrate P supported in close contact with the outer peripheral surface of the rotary drum DR, the reflection of the imaging light beam EL2 for exposure (illumination light IE0), and the alignment illumination light ILa. FIG. FIG. 8 is a diagram showing a cross-sectional structure of the outer peripheral surface of the rotary drum DR.

  In FIG. 7, the imaging light beam EL2 (illumination light IE0) traveling along the principal ray EL3 is projected onto the photosensitive layer Pb3 formed on the surface of the substrate P having a thickness Tp. When the base layer Pb2 of the light sensitive layer Pb3 is made of a material having high light transmission properties such as ITO, the illumination light IE1 transmitted through the base layer Pb2 is hardly attenuated with respect to the original illumination light IE0. Toward the base material Pb1 of the substrate P.

When the base material Pb1 of the substrate P is a transparent resin film such as PET or PEN and the thickness is as thin as 100 μm or less, when the wavelength range of the illumination light IE0 (IE1) is 350 nm or more, the base material Pb1 is The illumination light IE1 has a relatively large transmittance (80% or more).
Therefore, the illumination light IE1 that has passed through the base material Pb1 reaches the outer peripheral surface DRs of the rotary drum DR. If the reflectance of the outer peripheral surface DRs is not zero, the illumination light IE1 transmitted through the base material Pb1 generates reflected light (including scattered light and diffracted light) IE2 from the outer peripheral surface DRs, and the base material Pb1 and the underlayer It returns to the photosensitive layer Pb3 in the order of Pb2. Since the reflected light IE2 is not the original patterning light beam EL2 for patterning, it becomes noise and gives unnecessary exposure to the photosensitive layer Pb3.

One of the noises is, for example, a defocused image of a pattern image created by the imaging light beam EL2.
In the case of the projection optical system PL1 (to PL6) as shown in FIG. 3, the resolution (R) and the depth of focus (DOF) are generally determined by the wavelength λ of the illumination light for exposure and the numerical aperture NA. For example, in a projection optical system that uses illumination light having a wavelength of 365 nm (i-line) and can image a line width of 3 μm as resolution (R), when the k factor is about 0.35, the depth of focus (DOF) is It becomes about 70 μm.

If the thickness of the base material Pb1 of the substrate P is 100 μm, the imaging light beam EL2 is projected in a slightly defocused state on the outer peripheral surface DRs of the rotary drum DR, and the reflected light IE2 reflected by the outer peripheral surface DRs is On the surface of the photosensitive layer Pb3, the image light beam is further defocused.
Therefore, a blurred image of the pattern image itself is projected on the photosensitive layer Pb3 together with the pattern image by the focused light beam EL2 in focus. That is, there may be a problem that an undesirable unnecessary pattern image (such as a blurred image) is reflected in the photosensitive layer Pb3.

  On the other hand, for the mark detection by the alignment systems AM1 to AM5, for example, as a material of the alignment marks Ks1 to Ks5 formed on the base material Pb1 of the substrate P, a highly reflective material such as aluminum (Al) is used. When it can be used, since the intensity of the reflected light ILb by the illumination light ILa applied to the marks Ks1 to Ks5 is relatively large, good mark observation and detection are possible.

  However, when the reflectance of the marks Ks1 to Ks5 is not so high, the illumination light ILa that has passed through the transparent region around the marks Ks1 to Ks5 reaches the outer peripheral surface DRs of the rotary drum DR, and the light reflected here is the mark Ks1. The image contrast of the marks Ks1 to Ks5 may be reduced because the image pickup device picks up the image with the reflected light ILb from .about.Ks5.

From the above, the outer peripheral surface DRs of the rotary drum DR in the present embodiment is about 50, 45, 40, 35, 30, 25, 20, 15, 10, or 5% or less with respect to the illumination light IE0 for exposure. It is formed so as to have a reflectance.
Therefore, in the rotating drum DR of the present embodiment, a base layer DR2 (thickness) made of chromium (Cr) or copper (Cu) is formed on the surface of a cylindrical base material DR1 made of iron (SUS) or aluminum (Al). Plating Td2). The surface of the underlying layer DR2 is optically polished to reduce the local surface roughness sufficiently, and then a top layer DR3 (thickness Td3) made of chromium oxide (Cr2O3) or diamond-like carbon (DLC) is formed thereon. Form.

The thickness Td2 of the base layer DR2 can be arbitrarily set in the range of several hundred nm to several μm, but the thickness Td3 of the top layer DR3 has a certain range of conditions in order to adjust the reflectance of the outer peripheral surface DRs. Exists.
Therefore, when the base layer DR2 is made of chromium (Cr) and the top layer DR3 is made of chromium oxide (Cr2O3), the wavelength characteristic (spectral reflectance) of the reflectance of the outer peripheral surface DRs using the thickness Td3 of the top layer DR3 as a parameter. Will be described with reference to FIG.

  FIG. 9 is a graph of simulation results when the refractive index n of chromium oxide is 2.2 and the absorption coefficient k is 0. The vertical axis is the reflectance (%) of the outer peripheral surface DRs, and the horizontal axis is the wavelength (nm). ). FIG. 9 shows six spectral reflectance characteristics in which the thickness Td3 of the top layer DR3 made of chromium oxide is changed by 30 nm between 0 and 150 nm.

For example, when the thickness Td3 of the chromium oxide top layer DR3 is about 30 nm, the reflectance can be 20% or less (15% or less in the simulation) over the entire wavelength band of 350 nm to 500 nm. In this case, when the wavelength of the illumination light ILa for alignment is about 500 nm with a reflectance of about 7% with respect to the wavelength of 436 nm (g-line exposure light), the reflectance is also about 12%.
Further, assuming that the wavelength of the exposure light (illumination light IE0) is 405 nm (such as a semiconductor laser for Blu-ray near the h line), the thickness Td3 of the top layer DR3 of chromium oxide is set to about 120 nm. A reflectance of about 40% can be achieved for the illumination light ILa for alignment near 500 nm while having a minimum value.

Conversely, when the thickness Td3 of the chromium oxide top layer DR3 is about 60 nm or 150 nm, the reflectance with respect to exposure light (illumination light IE0) having a wavelength band of 350 to 436 nm increases to about 50%, and the wavelength of 500 nm The reflectance with respect to the alignment illumination light ILa is 40% or less.
Further, when the thickness Td3 of the top layer DR3 of chromium oxide is set to about 90 nm, the reflectance of the outer peripheral surface DRs can be reduced to 30% or less for ultraviolet light in a wavelength band shorter than the wavelength of 350 nm, and the wavelength of 500 nm. The reflectance of the outer peripheral surface DRs with respect to the alignment illumination light ILa can be increased to about 60%.

As can be seen from the simulation results of FIG. 9, by controlling the thickness Td3 of the top layer DR3 by chromium oxide, the reflectance of the outer peripheral surface DRs with respect to the alignment illumination light and the exposure illumination light is about several to 50%. The top layer DR3 made of chromium oxide is not provided (Td3 = 0 nm), and can be set lower than the reflectance in the case of only the base layer DR2 made of pure chromium.
As described above with reference to FIG. 7, when the reflectance of the outer peripheral surface DRs with respect to the exposure illumination light (IE0) and the alignment illumination light (ILa) is to be kept as low as possible as a whole, for example, the top layer DR3 made of chromium oxide is used. By setting the thickness Td3 to 30 nm, a reflectance of approximately 15% or less can be obtained over the entire wavelength range of 350 nm to 500 nm.

The simulation of FIG. 9 is an example in which a chromium layer is formed on the base material DR1 of the rotating drum DR, and a chromium oxide layer is formed on the substrate DR1 with a controlled thickness to adjust the reflectance. It is not limited.
For example, the material of the base layer DR2 may be aluminum (Al), copper (Cu), silver (Ag), gold (Au), etc. in addition to chromium (Cr).
As the material of the top layer DR3 on the base layer DR2, the above-mentioned chromium oxide, a dielectric having a high refractive index capable of relatively controlling reflectance, titanium oxide (TiO), zircon, hafnium oxide, diamond-like carbon (DLC) And metal compounds such as oxides and nitrides can be used in the same manner.

In general, the illumination light for exposure (IE0) is ultraviolet light having a wavelength of 436 nm (g-line) or less, and the illumination light for alignment (ILa) is in a visible range where the photosensitive layer (Pb3) is not exposed. Use light in the infrared wavelength band.
Therefore, the base layer DR2 is formed of a metal material such as copper (Cu) that has a low reflectance with respect to light in the ultraviolet region and a high reflectance with respect to light in the red wavelength region. It is also possible to make a difference in the reflectance with respect to each of the illumination light for alignment (ILa) and the illumination light for exposure (IE0).

  After depositing copper (Cu) thick as a base layer DR2, diamond-like carbon (DLC) is formed as a top layer DR3 with a thickness of 0.5 μm and 2 μm, and ultraviolet light (exposure light) with a wavelength of 355 nm. The reflectance Re and the reflectance Rv for light in the visible range (alignment light) with a wavelength of 450 nm to 650 nm were measured. The results are shown in Table 1.

  In this way, at least the reflectance of the outer peripheral surface DRs of the rotary drum DR with respect to the illumination light for exposure (IE0) is suppressed, thereby eliminating the problem that an unnecessary pattern image (blurred image) appears during exposure. It becomes possible.

[Second Embodiment]
Since the exposure apparatus according to the first embodiment is a so-called multi-lens system, the mask pattern image formed in each of the projection areas PA1 to PA6 of the plurality of projection optical systems PL1 to PL6 results in the Y direction (or as a result). It is necessary to be well spliced in the (X direction) and to be well aligned (superposed) with the underlying pattern on the substrate P.
For this purpose, calibration is required to keep the joint accuracy by the plurality of projection optical systems PL1 to PL6 within an allowable range. In addition, the relative positional relationship of the projection optical systems PL1 to PL6 with respect to the projection areas PA1 to PA6 and the observation (imaging) area Vw of the alignment systems AM1 to AM5 needs to be precisely determined by baseline management. . Calibration is also required for the baseline management.

  At least a part of the outer peripheral surface of the rotary drum DR that supports the substrate P is used for calibration for confirming splicing accuracy by the plurality of projection optical systems PL1 to PL6 and calibration for baseline management of the alignment systems AM1 to AM5. In addition, it is necessary to provide a reference mark or a reference pattern.

  In a conventional exposure apparatus in which a flat glass plate is placed on a flat substrate holder and the substrate holder is moved two-dimensionally to perform projection exposure, the outer periphery of the substrate holder is not covered by the glass plate. A calibration reference mark or reference pattern is provided, and the reference mark or reference pattern is moved under the objective lens of the projection optical system or alignment system during calibration.

However, as in the exposure apparatus of the first embodiment, in the state where the substrate P is wound around a part of the outer peripheral surface of the rotary drum DR (positions of the projection areas PA1 to PA6) during most of the operation time. A reference mark or a reference pattern must be provided on the outer peripheral surface of the rotary drum DR in a portion that contacts the substrate P.
Therefore, in this embodiment, as shown in FIG. 10, a case where a rotating drum DR having a reference mark or a reference pattern on the outer peripheral surface is used will be described.

FIG. 10 is a perspective view of the rotary drum DR that is integrally turned with the shaft portion Sf2 coaxial with the rotation center line AX2, and similarly to the configuration shown in FIGS. 2 and 6, the scale for encoder measurement is shown. Portions GPa and GPb and regulation bands CLa and CLb are provided.
Further, in the present embodiment, a plurality of line patterns RL1 inclined at +45 degrees with respect to the Y axis and −45 with respect to the Y axis are provided on the entire circumference sandwiched between the regulation bands CLa and CLb on the outer peripheral surface of the rotary drum DR. A mesh-like reference pattern (which can also be used as a reference mark) RMP is provided in which a plurality of line patterns RL2 inclined at degrees are repeatedly engraved at a constant pitch (period) Pf1, Pf2.

Since the outer peripheral surface of the rotating drum DR, that is, the entire periphery sandwiched between the regulation bands CLa and CLb, always comes into contact with the substrate P, the reference pattern RMP is the outer peripheral surface of the substrate P and the rotating drum DR. In order to prevent changes in the frictional force, the tension of the substrate P, and the like due to the place where the contacted with the substrate, a uniform oblique pattern (oblique lattice pattern) was used.
By making the line patterns RL1 and RL2 oblique to each of the transport direction (X direction) of the substrate P and the width direction (Y direction) of the substrate P, the directionality such as frictional force and tension is alleviated. .
However, the line patterns RL1 and RL2 do not necessarily need to be inclined at 45 degrees, and may be a vertical and horizontal mesh pattern in which the line pattern RL1 is parallel to the Y axis and the line pattern RL2 is parallel to the X axis.
Furthermore, the line patterns RL1 and RL2 do not need to intersect at 90 degrees, and the rectangular area surrounded by the two adjacent line patterns RL1 and the two adjacent line patterns RL2 is other than a square (or a rectangle). The line patterns RL1 and RL2 may be crossed at such an angle as to form a rhombus.

Further, the pitches Pf1 and Pf2 of the line patterns RL1 and RL2 shown in FIG. 10 are the expected fluctuation amounts of the baseline of the alignment system (relative positional relationship between the projection area PA and the imaging area Vw of the projection optical system PL), Alternatively, in consideration of an expected fluctuation amount between the plurality of projection optical systems PL1 to PL6 of the multi-lens method, it is sufficient that the expected fluctuation amount is at least twice or more.
For example, when the maximum value of the expected fluctuation amount is 10 μm, the pitches Pf1 and Pf2 differ depending on the line width LW (5 to 20 μm) of the line patterns RL1 and RL2, but if it is about 30 to 50 μm, Accurate calibration is possible.

The line width LW of each of the line patterns RL1 and RL2 is determined by the precision (resolution) of the drawing apparatus that engraves each of the line patterns RL1 and RL2, the limit that can be reduced, and the like. It is better to make it as thin as possible within the range that can be analyzed.
When the reference pattern RMP is detected in the imaging (observation) regions Vw of the alignment systems AM1 to AM5 and the baseline measurement is performed, the pitches Pf1 and Pf2 of the line patterns RL1 and RL2 are set to about 50 μm. Then, the intersections of the line patterns RL1 and RL2 appear at a pitch of about 70 μm in the Y direction and the X direction, and if the imaging (observation) region Vw is in the range of 200 μm square, a specific one intersection is improved. Capturing and image analysis of misalignment can be performed.

FIG. 11 is a cross-sectional view in which a part of the reference pattern RMP by the line patterns RL1 and RL2 is broken along the X axis shown in the circle in FIG.
Also in this embodiment, as in FIG. 8 of the previous first embodiment, a chromium or copper underlayer DR2 is deposited thickly by plating on the surface of a cylindrical base material DR1 of iron or aluminum. Thereafter, the surface of the underlayer DR2 is optically polished to improve the flatness, and then a photoresist is applied to the entire periphery of the underlayer DR2, and a reference pattern RMP based on the line patterns RL1 and RL2 is applied to the underlayer DR2 by a drawing apparatus. To expose.
At this time, the relative positional relationship (especially the positional relationship in the circumferential direction) between the reference pattern RMP and the scale portions GPa and GPb can be made constant by drawing the grid lines of the scale portions GPa and GPb together. .

Thereafter, by developing the photoresist, the resist corresponding to the line patterns RL1 and RL2 is removed, and the exposed underlayer DR2 (chrome or copper) is etched to a predetermined depth, and then the top layer DR3 is formed on the surface. (Chromium oxide or DLC) is deposited with a predetermined thickness.
In the case of chromium oxide, the thickness of the top layer DR3 is set based on the characteristics shown in FIG. The step amount ΔDP of the line patterns RL1 and RL2 (concave portions) by the finally formed top layer DR3 is compared with the design value by measurement, and is confirmed to be within a predetermined allowable range.

The reference pattern RMP based on such line patterns RL1 and RL2 can suppress the reflectance of the surface to the illumination light for exposure to 20% or less as in the first embodiment. For this reason, even if the illumination light for exposure is reflected by the reference pattern RMP, the energy is not high enough to be exposed as an unnecessary pattern on the photosensitive layer Pb3, so that there is substantially no problem.
Although the line patterns RL1 and RL2 are formed as concave portions by etching as shown in FIG. 11, the line patterns RL1 and RL2 may be formed as convex portions using a negative photoresist.

By the way, since the reference pattern RMP by the line patterns RL1 and RL2 is formed as unevenness on the outer peripheral surface DRs of the rotary drum DR, if the step amount of the unevenness is set to a specific condition, the entire reference pattern RMP is used for exposure. It is possible to obtain a phase pattern that suppresses the reflection intensity for both the illumination light and the alignment illumination light.
For this purpose, the step amount ΔDP shown in FIG. 11 may be set under the following conditions.

Here, suppose that the center wavelength of the illumination light IE0 for exposure is λ1, the center wavelength of the illumination light ILa for alignment is λ2, and m is an arbitrary integer including zero (m = 0, 1, 2,...). As for the central wavelength λ1 of the illumination light IE0 for exposure,
λ1 · (m + 1/8) / 2 ≦ ΔDP ≦ λ1 · (m + 7/8) / 2 (3)
In this range, the step amount ΔDP may be set. further,
λ1 · (m + 1/4) / 2 ≦ ΔDP ≦ λ1 · (m + 3/4) / 2 (4)
In this range, the step amount ΔDP can be set.

On the other hand, regarding the center wavelength λ2 of the illumination light ILa for alignment, the range of the step amount ΔDP can be determined by replacing the wavelength λ1 in the above formulas (3) and (4) with λ2.
At that time, the range of the step amount ΔDP required for the wavelength λ1 of the illumination light for exposure is compared with the range of the step amount ΔDP required for the wavelength λ2 of the illumination light for alignment, and the two ranges overlap or are close to each other. However, if the optimum step amount ΔDP is set, the intensity of the reflected light generated from the reference pattern RMP can be reduced for both the illumination light for exposure and the illumination light for alignment.
That is, a step amount ΔDP that satisfies or approximates the above equations (3) and (4) is set for both the center wavelength λ1 of the exposure illumination light and the center wavelength λ2 of the alignment illumination light. It ’s fine.

As described above, in the first embodiment and the second embodiment, the reflectance is adjusted by laminating the relatively thick base layer DR2 and the top layer DR3 on the outer peripheral surface of the cylindrical base material DR1 serving as the rotary drum DR. However, a stacked structure having a larger number of layers may be used.
For example, in order to reduce the weight of the rotary drum DR, the base material DR1 is cut out from an Al (aluminum) block, and the outer peripheral surface of the base material DR1 is compared for flatness (roundness and surface roughness) processing. After plating hard chromium (Cr) thickly, it is further plated with copper (Cu) as the underlying layer DR2 shown in FIGS. 8 and 11, and the top layer DR3 is further formed thereon. As an alternative, the DLC may be laminated with a predetermined thickness.
In this case, the reference pattern RMP (line patterns RL1, RL2) and the lattice lines of the scale portions GPa, GPb are engraved on the hard chromium layer or the copper base layer DR2 thereon.

[Third Embodiment]
Although the exposure apparatus of the previous embodiment scans and exposes the mask pattern onto the substrate P using the cylindrical mask DM, even an exposure apparatus such as a so-called pattern generator, which does not use a mask, Pattern exposure can be performed while the substrate P is supported using the rotating drum DR. An example of such an exposure apparatus will be described with reference to FIGS.

FIG. 12 is a front view of the main part of the exposure apparatus (pattern drawing apparatus) according to the present embodiment as viewed in the XZ plane, and FIG. 13 is a top view of the configuration of FIG. 12 as viewed in the XY plane. .
In the present embodiment, as shown in FIG. 13, a laser that scans the exposure area A7 on the substrate P that is in close contact with and supported by the outer peripheral surface of the rotary drum DR in the Y direction (direction in which the rotation center line AX2 extends). Pattern drawing is performed by linear scanning lines LL1, LL2, LL3, and LL4 of spot light (for example, 4 μm diameter). Since each of the scanning lines LL1 to LL4 has a relatively short scanning length in the Y direction, the scanning lines LL1 to LL4 are staggered symmetrically with respect to the center plane p3.

Among the scanning lines LL1 to LL4, the odd-numbered scanning lines LL1 and LL3 are arranged on the −X side with respect to the central plane p3, and the even-numbered scanning lines LL2 and LL4 are arranged with respect to the central plane p3. Arranged on the + X side.
As shown in FIG. 12, this is because the odd-numbered drawing modules UW1 and UW3 that scan the spot light along the scanning lines LL1 to LL4 and the even-numbered drawing modules UW2 and UW4 avoid spatial interference. This is because they are arranged symmetrically with respect to the center plane p3.

In the present embodiment, a scale disk SD for encoder measurement is individually attached to the shaft portion Sf2 of the rotary drum DR. The scale part GPa (and GPb) engraved on the outer peripheral surface of the scale disk SD is measured by the encoder head EN1 arranged on the installation direction line Le1 and the encoder head EN2 arranged on the installation direction line Le2. The
In addition, an encoder head EN3 that reads the scale portion GPa (and GPb) is also disposed at the position of the installation orientation line La1 where the alignment systems AM1 to AM5 are disposed as shown in FIGS.

As shown in FIG. 12, since the four drawing modules UW1 to UW4 all have the same configuration, the detailed configuration of the drawing module UW1 will be described as a representative.
The drawing module UW1 receives a beam LB from an external ultraviolet laser light source (continuous or pulsed), and switches AOM (Acousto-Optic Modulator) 80 and AOM 80 to switch projection / non-projection of the beam LB onto the substrate P at high speed. A rotating polygon mirror 82, a bending mirror 84, an f-θ lens system 86, a photoelectric element 88, and the like for scanning the beam LB from the laser beam LB along the scanning line LL1 on the substrate P.

The beam BS1 projected onto the substrate P through the f-θ lens system 86 is modulated by the AOM 80 that is turned on / off based on the CAD information of the pattern to be drawn during the scan in the Y direction, and the light sensitivity of the substrate P is detected. Draw a pattern on the layer. By synchronizing the scanning in the Y direction of the beam BS1 along the scanning line LL1 and the movement of the substrate P in the X direction by the rotation of the rotating drum DR, a pattern is exposed at a portion corresponding to the scanning line LL1 in the exposure area A7. Is done.
Because of such a drawing method, as shown in FIG. 12, the axis of the beam BS1 reaching the substrate P is in a direction coinciding with the installation orientation line Le1 when viewed in the XZ plane. The same applies to the beam BS2 projected from the even-numbered drawing module UW2, and the axis of the beam BS2 reaching the substrate P is in a direction that coincides with the installation orientation line Le2.

Thus, when a pattern is drawn in the exposure area A7 by the four scanning lines LL1 to LL4, the accuracy of the joint between the scanning lines LL1 to LL4 is important. In the case of FIG. 13, in the exposure area A7, first, exposure of the areas corresponding to the odd-numbered scanning lines LL1 and LL3 is started, and from the position where the substrate P has advanced in the circumferential direction by the distance ΔXu, Exposure of an area corresponding to the even-numbered scanning lines LL2 and LL4 is started.
Therefore, by accurately setting the drawing start point and the drawing end point by the spot light of each scanning line LL1 to LL4, the pattern formed in the entire exposure area A7 can be satisfactorily pinched.

  Also in the pattern drawing apparatus as described above, the rotary drum DR having the structure shown in FIG. 8 of the first embodiment or the rotary drum DR having the structure shown in FIGS. 10 and 11 of the second embodiment is used. By using it, the reflection of an unnecessary pattern which becomes noise is reduced, and highly accurate patterning is achieved.

  As described above, each of the embodiments has been described. As a support device for the substrate P, in addition to the cylindrical rotary drum DR, the substrate P has a flat support surface, and is curved in a cylindrical shape with a large curvature in the transport direction of the substrate P. It may have a support surface. Alternatively, the invention can be similarly applied even to a support device in which a gas layer is formed by an air bearing on the support surface of these support devices and the substrate is supported by floating a small amount of the substrate by the gas layer. .

In each of the previous embodiments, Cu (copper), Cr (chromium), and Cr ₂ O ₃ (trivalent chromium oxide) were cited as the metal-based thin films of the base layer DR2 and the top layer DR3. It is not limited, and may be CrO (divalent chromium oxide). For example, the base layer DR2 to be formed on the base material DR1 (SUS, Al, etc.) may be Cu, and CrO may be formed by plating, vapor deposition, or sputtering as the top layer DR3 to be deposited on the base layer DR2. good.
In addition, the diamond-like carbon (DLC) formed as the top layer DR3 of each of the previous embodiments is composed of carbon atoms, and has an amorphous structure and / or an amorphous structure containing a crystalline material. In this structure, the sp2 bond of graphite and the sp3 bond of diamond are mixed.
DLC is formed as a hard film, but its properties are distinguished depending on the amount of hydrogen content and whether the crystalline electron orbit contained is closer to diamond or graphite.

[Fourth Embodiment]
By the way, the form of the reference pattern RMP formed on the outer peripheral surface DRs of the rotary drum DR shown in FIG. 10 is strong stray light (unnecessary reflected light) from the reference pattern RMP when irradiated with the exposure light transmitted through the substrate P. Any shape may be used as long as it does not occur.
FIG. 14 is a perspective view showing a modified example of the reference pattern RMP formed on the outer peripheral surface DRs of the rotating drum DR as a fourth embodiment. The same members as those of the rotating drum DR in FIG. Is attached.

  In FIG. 14, a scale disk SD for encoder measurement is fastened by a plurality of screws FB on both end faces in the direction (Y-axis direction) in which the shaft portion Sf2 of the rotary drum DR extends, as in FIGS. Has been. In the present embodiment, the diameters (or the radius from the center line AX2) of the scale portions GPa and GPb formed on the outer peripheral surface of the scale disk SD are the diameters of the outer peripheral surface DRs (or the radius from the center line AX2) of the rotary drum DR. ).

The outer peripheral surface DRs of the rotary drum DR has a line pattern RLa extending linearly along a direction (Y-axis direction) parallel to the rotation center line AX2 and linearly extending along the circumferential direction (parallel to the XZ plane). Two line patterns RLb and RLc that circulate in the plane are formed as the reference pattern RMP.
In the case of FIG. 14, the line patterns RLa are arranged at 45 ° intervals in the circumferential direction. The two line patterns RLb and RLc are arranged at a certain interval in a direction parallel to the rotation center line AX2 (Y-axis direction). The angular interval η in the circumferential direction of the line pattern RLa is not limited to 45 °, and may be any number of times.

  The fixed interval corresponds to the interval in the Y-axis direction of each imaging region Vw of the alignment systems AM1 to AM5 shown in FIG. That is, the line patterns RLa and the two line patterns RLb and RLc intersect each other so that the intersection ALA appears one after another in each imaging region Vw of the alignment systems AM1 to AM5 as the rotary drum DR rotates. RLa, RLb, and RLc are arranged, and the line pattern portion of the intersection ALA is detected as the reference pattern RMP.

As shown in FIG. 6, since the marks Ks1 to Ks5 are formed on the substrate P, at least one of the two line patterns RLb and RLc does not overlap the position of the marks Ks1 to Ks5 in the Y-axis direction. Are arranged so as to be shifted.
As an example, the line width LW of the two line patterns RLb and RLc is set to 15 μm, the distance in the Y-axis direction is set to 150 μm, and each of the marks Ks1 to Ks5 is between the two line patterns RLb and RLc. When set so as to be positioned at, each of the alignment systems AM1 to AM5 can detect the line patterns RLb and RLc together with the marks Ks1 to Ks5 within the imaging region Vw.

  Furthermore, the margin (the transparent area where the marks Ks2 to Ks4 are arranged) between the two exposure areas A7 arranged adjacent to each other in the feeding direction on the substrate P shown in FIG. And the crossing part ALA by line pattern RLa, RLb, RLc formed in the outer peripheral surface DRs of rotary drum DR can also be reliably arrange | positioned under the margin part.

For example, if the diameter of the outer peripheral surface DRs of the rotary drum DR is Rdd, the circumferential distance LK of the line pattern RLa along the outer peripheral surface DRs uses the angular interval η in the circumferential direction of the line pattern RLa described above. When,
LK = π · Rdd · (η / 360) (5)
It is represented by
Assuming that the size of the blank portion between the two exposure areas A7 in the longitudinal direction (feed direction) of the substrate P is LU, if it is set so as to satisfy the condition LU> LK, at least one line is formed in the blank portion of the substrate P. A pattern RLa can be arranged.

  As described above, in the present embodiment, the reference pattern RMP is configured by the line patterns RLa, RLb, and RLc that linearly extend in the longitudinal direction (feed direction) and the short direction (Y-axis direction) of the substrate P. The two-dimensional position of the intersection ALA appearing in each imaging region Vw of the alignment systems AM1 to AM5 can be directly measured in the direction along the horizontal scanning line or the vertical scanning line of the imaging device, and the computation time of the image processing There is an advantage of being shortened.

[Fifth Embodiment]
By the way, when line patterns RLa, RLb, and RLc as shown in FIG. 14 are formed on the outer peripheral surface DRs of the rotary drum DR, they are aligned with the arrangement direction of the wiring patterns and pixel patterns formed in the exposure region A7 on the substrate P.
For this reason, for example, even if the reflectivity of the outer peripheral surface DRs with respect to the exposure light is reduced by the base layer DR2 and the top layer DR3 (see FIG. 8 above), a slight amount occurs at the step edge portions of the line patterns RLa, RLb, RLc. Scattered light or the like is distributed in the direction of the line patterns RLa, RLb, and RLc, and may be a problem when aligned with the arrangement direction of the wiring patterns and pixel patterns formed in the exposure region A7 on the substrate P.

  Therefore, in the present embodiment, as shown in FIG. 15, in order to reduce slight scattered light and the like that may occur at the step edge portions of the line patterns RLa, RLb, and RLc, it is formed on the outer peripheral surface DRs of the rotary drum DR. The line patterns RLa, RLb, RLc are formed as recesses having a line width LW, and the recesses are filled with a material PI that absorbs ultraviolet rays (exposure light).

  The material PI is a paint containing an ultraviolet absorber (cured after drying), absorbs scattered light and diffracted light generated at the step edge, and determines the amount of scattered light and diffracted light reaching the front side of the substrate P. Reduce. As an example, the ultraviolet absorber is commercially available from BASF-SE under the trade name Uvinul (registered trademark) or TINUVIN (registered trademark), and absorbs exposure light in the ultraviolet wavelength region, but for alignment in the visible wavelength region. The illumination light has a characteristic of hardly absorbing.

As described above, in the present embodiment, the line pattern constituting the reference pattern RMP is formed by the concave portion, and the concave portion is filled with the ultraviolet absorbing material. Therefore, the outer peripheral surface DRs of the rotary drum DR is irradiated by exposure light. Stray light reflected from the light can be further reduced.
Note that the method of filling the concave portion of the outer peripheral surface DRs with the ultraviolet absorbing material can be similarly applied to the line patterns RL1 and RL2 shown in FIGS. Moreover, the coating material containing such an ultraviolet absorber can also be used for repairing irregular portions such as scratches and dents on the outer peripheral surface DRs in contact with the substrate P.

[Sixth Embodiment]
Next, the configuration in the case where the substrate support apparatus described in FIGS. 2, 7, 10, and 14 is applied to the maskless pattern exposure apparatus will be described with reference to FIG.
In FIG. 16, the substrate supporting apparatus is supported by the tension adjusting rollers TR1, TR2 and the shaft portion Sf2, and the rotating drum DR, the scale disk SD, the encoder heads EN1, EN3, which wind the substrate P, as in the previous embodiments. Etc. Similarly, the alignment system AM1 (and AM2 to AM5) includes an objective lens system GA1, a beam splitter GB1, an illumination unit GC1, and an imaging system GD1.

  The exposure unit is an illumination that uniformly illuminates a light source 100 that generates exposure illumination light (exposure light) and a DMD (Digital Micromirror Device (registered trademark)) 104 in which a large number of movable micromirrors are arranged two-dimensionally with uniform illuminance. A system 101, a mirror 103, a lens system 105 for condensing the exposure light reflected by each micromirror of the DMD 104, an MLA (Micro-Lens Array) 106 in which a large number of microlenses are two-dimensionally arranged, and a rotating drum DR Projection optical system composed of lens systems 108 and 109 for projecting the light spot formed in the aperture of the field stop 107 by the microlenses of the field stop 107 and the MLA 106 conjugate with the surface of the substrate P onto the substrate P PL.

Further, the pupil plane in the projection optical system PL of the present embodiment is provided with a beam splitter 110 that can be inserted and removed in a direction (Y-axis direction) orthogonal to the paper surface of FIG.
When this beam splitter 110 is inserted, the exposure light from the MLA 106 passes through the lens system 108, the beam splitter 110, and the lens system 109 of the projection optical system PL, or the outer peripheral surface DRs of the rotating drum DR. A part of the reflected light reflected and returned by the surface of the substrate P or the outer peripheral surface DRs when projected onto the substrate P can be guided to the monitor system 112 including a condensing lens, a photoelectric element, and the like.

  The monitor system 112 measures the amount of reflected light (exposure light) from the surface of the substrate P or the outer peripheral surface DRs, and determines whether or not an appropriate exposure amount (illuminance) is given to the substrate P. Alignment that collects light information (optical image, diffracted light, etc.) relating to the marks Ks1 to Ks5 on the substrate P and the reference pattern RMP on the outer peripheral surface DRs based on the light amount monitor for performing or the reflected light (exposure light) Configured as a monitor.

In the maskless type pattern exposure apparatus as shown in FIG. 16, the pattern drawing data (CAD data), the information on the feed position of the substrate P based on the measurement signal from the encoder head EN1 (or EN3), or the alignment system AM1 (AM2 to AM2). Based on the position information of the marks Ks1 to Ks5 of the substrate P measured by AM5), the angle of each micromirror of the DMD 104 is switched at high speed.
As a result, the exposure light reflected by each micromirror is switched between a state where it is incident on the microlens corresponding to the MLA 106 and a state where it is not incident, so that a pattern according to the drawing data is exposed (drawn) on the substrate P. The

  The pattern exposure apparatus of this embodiment shown in FIG. 16 is also provided with a plurality of exposure units in the direction parallel to the rotation center line AX2 (Y-axis direction) under the conditions shown in FIGS. Thus, it is possible to cope with exposure processing of the substrate P having a large width in the Y-axis direction. In that case, the aperture shape of the field stop 107 in FIG. 16 is a trapezoidal shape similar to the shape of each of the exposure areas PA1 to PA6 in FIG. 4, and a large number of light spots created by the MLA 106 in the trapezoidal aperture. Should be arranged at a constant pitch.

  Further, for example, the MLA 106 shown in FIG. 16 is formed so that the focus surface defined by the condensing points of a large number of light spots formed on the emission side of the MLA 107 is curved in a cylindrical shape like the outer peripheral surface DRs of the rotary drum DR. In this case, among the microlenses, the focal lengths may be slightly different between the microlenses arranged in the X direction.

  DM: cylindrical mask, DR: rotating drum, DRs: outer peripheral surface of rotating drum, DR1: base material of rotating drum, DR2: foundation layer of rotating drum, DR3: rotating drum Top layer, P ... flexible substrate, PL1, PL2, PL3, PL4 ... projection optical system, AM1-AM5 ... alignment system, RMP ... reference pattern, RL1, RL2, RLa, RLb, RLc... Line pattern, UW1 to UW4.

Claims (28)

A substrate support device that is provided in an exposure apparatus that exposes a pattern to a substrate having optical transparency with a first light, and supports the substrate under exposure,
A cylindrical base material for supporting the substrate along the outer peripheral surface, having an outer peripheral surface curved into a cylindrical surface with a constant radius from a predetermined center line;
A film body that is formed with a predetermined thickness on the outer peripheral surface of the cylindrical base material and forms a support surface that contacts the back surface of the substrate;
A reference pattern formed in steps on the film body,
The reflectance at the support surface for the second light having a wavelength different from that of the first light for detecting the reference pattern is made larger than the reflectance at the support surface for the first light,
Substrate support device. The substrate support apparatus according to claim 1,
The cylindrical substrate is made of a metal material mainly composed of iron or aluminum,
The film body is formed of two or more layers on the outer peripheral surface of the cylindrical base material, and the film thickness is set so that the reflectance on the support surface with respect to the first light is 50% or less. A multilayer film,
Substrate support device. The substrate support apparatus according to claim 2,
The multilayer film has a two-layer structure of a base layer formed on the outer peripheral surface of the cylindrical base material and a top layer formed on the base layer and serving as the support surface,
The thickness of the foundation layer is larger than the thickness of the top layer,
Substrate support device. The substrate support apparatus according to claim 3,
The underlayer is any one of chromium (Cr), copper (Cu), aluminum (Al), silver (Ag), or gold (Au),
The top layer is any one of chromium oxide (Cr2O3, CrO), titanium oxide (TiO), zircon, hafnium oxide, or diamond-like carbon (DLC).
Substrate support device. The substrate support apparatus according to claim 4,
The underlayer is made of chromium (Cr),
The top layer is made of chromium oxide (Cr2O3, CrO) having a thickness of 30 nm to 150 nm.
Substrate support device. The substrate support apparatus according to claim 4,
The underlayer is made of copper (Cu),
The top layer is made of diamond-like carbon (DLC) having a thickness of 0.5 μm or more.
Substrate support device. The substrate support apparatus according to any one of claims 3 to 6,
The reference pattern is formed in steps on the underlayer.
Substrate support device. A substrate support apparatus according to any one of claims 1 to 4,
When the center wavelength of the first light is λ1, m is an arbitrary integer including zero, and the step amount of the reference pattern is ΔDP,
λ1 · (m + 1/8) / 2 ≦ ΔDP ≦ λ1 · (m + 7/8) / 2, or
λ1 · (m + 1/4) / 2 ≦ ΔDP ≦ λ1 · (m + 3/4) / 2 is set.
Substrate support device. A substrate support apparatus according to any one of claims 1 to 8,
The first light is ultraviolet light;
The second light is light in a wavelength band from a visible range to an infrared range,
Substrate support device. A pattern forming apparatus for optically processing a flexible sheet substrate conveyed in a longitudinal direction to form a pattern,
A base material for supporting the sheet substrate in a curved state or a flat state, a film body formed on the surface of the base material for supporting the sheet substrate, and a reference formed by a step in the film body A substrate support member having a pattern;
A pattern exposure unit that exposes the pattern by projecting a first light for optically processing the sheet substrate supported by the substrate support member;
An optical detection unit for detecting the reflected light from the reference pattern by projecting a second light having a wavelength different from that of the first light in order to optically detect the reference pattern;
The reflectance of the film body by the first light is smaller than the reflectance of the film body by the second light.
Pattern forming device. It is a pattern formation apparatus of Claim 10, Comprising:
The substrate is made of a metal material mainly composed of iron or aluminum,
The film body is formed as a multilayer film of two or more layers on the surface of the base material, and the reflectance with respect to the first light is 20% or less,
Pattern forming device. It is a pattern formation apparatus of Claim 11, Comprising:
The multilayer film has a two-layer structure of a base layer formed on the surface of the base material and a top layer formed on the base layer, and the thickness of the base layer is made larger than the thickness of the top layer. Also increased,
Pattern forming device. It is a pattern formation apparatus of Claim 12, Comprising:
The underlayer is made of chromium (Cr), copper (Cu), aluminum (Al), silver (Ag), or gold (Au), and the top layer is made of chromium oxide (Cr2O3, CrO), oxidized Either titanium (TiO), zircon, hafnium oxide, or diamond-like carbon (DLC),
Pattern forming device. It is a pattern formation apparatus of Claim 13, Comprising:
The underlayer is made of chromium (Cr), and the top layer is made of chromium oxide (Cr2O3, CrO) having a thickness of 30 nm to 150 nm.
Pattern forming device. It is a pattern formation apparatus of Claim 13, Comprising:
The underlayer is made of copper (Cu), and the top layer is made of diamond-like carbon (DLC) having a thickness of 0.5 μm or more.
Pattern forming device. It is a pattern formation apparatus of Claim 12, Comprising:
The reference pattern is formed in a step on the underlayer, and the top layer is stacked along the step of the underlayer.
Pattern forming device. It is a pattern formation apparatus as described in any one of Claims 10-16,
When the center wavelength of the first light is λ1, m is an arbitrary integer including zero, and the step amount of the reference pattern is ΔDP,
λ1 · (m + 1/8) / 2 ≦ ΔDP ≦ λ1 · (m + 7/8) / 2, or
λ1 · (m + 1/4) / 2 ≦ ΔDP ≦ λ1 · (m + 3/4) / 2 is set.
Pattern forming device. It is a pattern formation apparatus as described in any one of Claims 10-17,
The first light is ultraviolet light;
The second light is light in a wavelength band from a visible range to an infrared range,
Pattern forming device. A pattern forming apparatus for forming a pattern on a light sensitive layer of a flexible sheet substrate having light permeability conveyed in a longitudinal direction,
A rotating drum that supports the sheet substrate with a part of the outer peripheral surface curved into a cylindrical surface with a constant radius from the center line, and rotates around the center line to convey the sheet substrate in the longitudinal direction;
A pattern exposure unit that exposes a pattern by projecting light for exposure including a wavelength for exposing the photosensitive layer of the sheet substrate onto the photosensitive layer of the sheet substrate supported by the rotating drum;
An alignment system that detects alignment marks formed on the sheet substrate supported by the rotating drum by irradiating alignment light having a wavelength different from that of the exposure light; and
The rotating drum includes a film body whose thickness is adjusted so that the reflectance with respect to the alignment light is larger than the reflectance with respect to the exposure light, and a step on the film body so as to be detectable by the alignment system Having a reference pattern to be formed,
Pattern forming device. The pattern forming apparatus according to claim 19,
The rotating drum is made of a base material having a cylindrical outer peripheral surface made of a metal material mainly composed of iron or aluminum,
The film body is a multilayer film formed of two or more layers on the outer peripheral surface of the substrate, and the reflectance with respect to the exposure light is 50% or less.
Pattern forming device. The pattern forming apparatus according to claim 20, wherein
The multilayer film has a two-layer structure of a base layer formed on the outer peripheral surface of the base material and a top layer formed on the base layer, and the thickness of the base layer is set to the top layer. Larger than the thickness of the
Pattern forming device. The pattern forming apparatus according to claim 21,
The underlayer is made of chromium (Cr), copper (Cu), aluminum (Al), silver (Ag), or gold (Au), and the top layer is made of chromium oxide (Cr2O3, CrO), oxidized Either titanium (TiO), zircon, hafnium oxide, or diamond-like carbon (DLC),
Pattern forming device. The pattern forming apparatus according to claim 22, wherein
The underlayer is made of chromium (Cr), and the top layer is made of chromium oxide (Cr2O3, CrO) having a thickness of 30 nm to 150 nm.
Pattern forming device. The pattern forming apparatus according to claim 22, wherein
The underlayer is made of copper (Cu), and the top layer is made of diamond-like carbon (DLC) having a thickness of 0.5 μm or more.
Pattern forming device. The pattern forming apparatus according to any one of claims 21 to 24,
The reference pattern is formed with a small step in the underlayer.
Pattern forming device. The pattern forming apparatus according to any one of claims 19 to 22,
The alignment system is
An illumination unit that irradiates the alignment light to the mark formed on the sheet substrate or the reference pattern formed on the film body of the rotating drum;
An objective lens for entering light generated by the mark or the reference pattern;
An imaging system that captures an image of the mark or the reference pattern received through the objective lens,
Pattern forming device. The pattern forming apparatus according to any one of claims 19 to 22,
When the center wavelength of the light for exposure is λ1, m is an arbitrary integer including zero, and the step amount of the reference pattern is ΔDP,
λ1 · (m + 1/8) / 2 ≦ ΔDP ≦ λ1 · (m + 7/8) / 2, or
λ1 · (m + 1/4) / 2 ≦ ΔDP ≦ λ1 · (m + 3/4) / 2 is set.
Pattern forming device. It is a pattern formation apparatus as described in any one of Claims 19-27,
The light for exposure is light in the ultraviolet wavelength region,
The alignment light is light in the visible to infrared wavelength band,
Pattern forming device.

Images