HK1234830A - Pattern forming device and substrate support device - Google Patents

Description

Pattern forming apparatus and substrate supporting apparatus

The present application is a divisional application of an invention patent application having PCT international application No. PCT/JP2013/057062, application date of 2013, 3/13/2013, an invention name of "substrate supporting apparatus and exposure apparatus", and a national application No. 201380043800.5.

Technical Field

The present invention relates to a substrate supporting apparatus for supporting a portion of a flexible substrate processed by a processing apparatus in a curved state or a flat state, and an exposure apparatus for the flexible substrate supported by the supporting apparatus.

The present application claims priority based on Japanese preferred application No. 2012-188116, filed on 8/28/2012, and the contents of which are incorporated herein by reference.

Background

In recent years, as flat panel displays, an organic EL system has been attracting attention in addition to a liquid crystal system and a plasma system. In the case of an active matrix organic EL (amoled) display, an upper plate including a pixel light emitting layer and a transparent electrode layer formed of organic EL is laminated on a backplane including Thin Film Transistors (TFTs) for driving pixels, a driver circuit, various signal lines, and the like.

As one of the methods for manufacturing a display formed of an organic EL at a lower cost and with high productivity, the following method is proposed: flexible resin materials, plastics, or metal foils are formed into long sheets (films) having a thickness of 200 μm or less, and the back plate and the upper plate of the display are directly manufactured thereon in a Roll-to-Roll (patent document 1).

Patent document 1 discloses a production method including: a display is manufactured at low cost by continuously forming an electrode layer, a semiconductor layer, an insulating film, and the like constituting each pixel TFT, and a fluid material for forming a pixel light emitting layer and a wiring layer on a flexible long sheet (a PET (Poly-Ethylene Terephthalate) film or the like) by a printer of an ink jet method or the like.

Further, patent document 1 proposes the following: in order to precisely form the relative positional relationship between the gate electrode layer and the drain/source electrode layer of the TFT stacked vertically with the insulating layer interposed therebetween, the shape of each electrode, and the like, a self-assembled monolayer (SAM) capable of modifying the hydrophilicity and hydrophobicity of the surface by irradiation of ultraviolet rays is formed, and the shape of each electrode layer is more precisely formed using a pattern exposure apparatus using ultraviolet rays.

[ Prior art documents ]

[ patent document 1 ] International publication No. 2010/001537

Disclosure of Invention

The exposure apparatus of patent document 1 projects and exposes the pattern of the flat mask onto a flexible long substrate sheet which is supported flatly via a projection optical system.

On the other hand, when the pattern of the mask is repeatedly exposed on the continuously transported flexible substrate sheet by the roll-to-roll method, a dramatic improvement in productivity can be expected by using a scanning exposure apparatus that uses a rotary mask in which the transportation direction of the substrate sheet is set to the scanning direction and the mask is cylindrical.

The continuously conveyed flexible substrate sheet is a thin substrate and is supported by a flat or curved pad surface of an air bearing or the like. Alternatively, the substrate sheet is wound around a part of the cylindrical outer peripheral surface of a rotating drum (a large-diameter roller) and supported in a curved state.

When a highly transparent PET film, PEN (Poly-Ethylene Naphthalate) film, or extra thin glass film, in which a transparent layer such as ITO is formed, is patterned by an exposure apparatus, pattern exposure light projected onto a photosensitive layer (e.g., photoresist, photosensitive silane coupling agent, or the like) applied to the surface of the substrate reaches a pad surface under the substrate or an outer peripheral surface of the rotary drum.

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

However, in order to perform alignment of the exposure apparatus and alignment of the substrate, a reference mark or a reference pattern is provided on a flat pad surface or a part of the outer peripheral surface of the rotary drum, and when the reference mark or the reference pattern is detected by an optical alignment microscope or the like, since the reflectance of the pad surface or the outer peripheral surface of the rotary drum is low, there is a problem that it is difficult to detect the reference mark or the reference pattern with good contrast.

An object of an embodiment of the present invention is to provide a substrate supporting apparatus capable of reducing an influence of reflected light (return light) from a member supporting a substrate.

Another object of an embodiment of the present invention is to provide a substrate supporting apparatus capable of satisfactorily detecting a reference mark and a reference pattern formed on a part of a supporting surface of an apparatus for supporting a substrate, or reflected light (return light) from the mark and the pattern formed on the substrate, by an optical observation apparatus formed by an alignment microscope or the like.

It is another object of an embodiment of the present invention to provide an exposure apparatus that performs a high-precision optical pattern on a substrate supported by the substrate support apparatus.

According to the 1 st aspect of the present invention, there is provided a substrate supporting apparatus comprising: a base material having a surface for supporting a flexible substrate having transparency to which optical processing (for example, exposure processing and measurement processing at the time of alignment) is applied, in a curved state or a flat state; and a film body formed on the surface of the base material, and having a reflectance of 50% or less with respect to light used in optical processing.

According to the 2 nd aspect of the present invention, there is provided a substrate supporting apparatus comprising: a base material having a surface for supporting a flexible substrate having transparency to which optical processing (for example, exposure processing and measurement processing at the time of alignment) is applied, in a curved state or a flat state; a film body formed on a surface of the base material and having a reflectance of 50% or less with respect to light used in optical processing; and a reference pattern formed by a minute step on the surface of the film body.

According to the 3 rd aspect of the present invention, there is provided an exposure apparatus for performing pattern exposure by using the substrate supporting apparatus of the 1 st or 2 nd aspect.

Effects of the invention

According to the first and second aspects of the present invention, it is possible to provide a supporting device that can reduce unnecessary exposure (reflection of unnecessary patterns, etc.) that becomes noise when exposing a pattern on a thin substrate having transparency.

According to the 3 rd aspect of the present invention, an exposure apparatus capable of performing precise pattern exposure can be provided.

Drawings

Fig. 1 is a diagram showing a schematic configuration of an exposure apparatus according to embodiment 1.

Fig. 2 is a perspective view showing the arrangement of the main part of the exposure apparatus of fig. 1.

Fig. 3 is a diagram showing a configuration of a projection optical system of the exposure apparatus shown in fig. 1 and 2.

Fig. 4 is a schematic diagram showing a configuration relationship of the illumination area and the projection area.

Fig. 5 is a diagram showing the arrangement of the rotary drum supporting the substrate and the encoder head.

Fig. 6 is a diagram showing a configuration relationship of an alignment system and a projection area on a substrate.

Fig. 7 is a diagram schematically showing the configuration of a substrate supported on a rotating drum.

Fig. 8 is a sectional view showing the surface structure of the rotary drum of embodiment 1.

Fig. 9 is a graph showing reflectance characteristics based on the thickness of the surface material of the rotating drum.

Fig. 10 is a perspective view showing the surface structure of the rotary drum of embodiment 2.

Fig. 11 is a sectional view showing the surface structure of the rotary drum of embodiment 2.

Fig. 12 is a diagram showing the configuration of the pattern drawing apparatus according to embodiment 3.

Fig. 13 is a diagram illustrating a substrate drawing method implemented by the apparatus of fig. 12.

Fig. 14 is a perspective view showing the surface structure of the rotary drum of embodiment 4.

Fig. 15 is a cross-sectional view showing the surface structure of the rotary drum according to embodiment 5.

Fig. 16 is a diagram showing the configuration of a pattern exposure apparatus according to embodiment 6.

Detailed Description

[ embodiment 1 ]

Fig. 1 is a diagram showing the overall configuration of a projection exposure apparatus EX for a flexible substrate according to the present embodiment. The exposure apparatus EX irradiates a photosensitive layer of a flexible sheet-like substrate P carried by a processing apparatus in a previous step with ultraviolet pattern light corresponding to a circuit pattern and a wiring pattern for a display.

The ultraviolet light includes, for example, g-line (436Nm), h-line (405Nm), and I-line (365Nm) which are glows such as mercury discharge, excimer laser light (each having a wavelength of 248Nm, 308Nm, and 193Nm) such as KrF, XECl, and ArF, and light having a wavelength of 400Nm or less from a semiconductor laser light source, an LED light source, a high-frequency laser light source, and the like.

The exposure apparatus EX of fig. 1 is provided in the temperature adjustment chamber EVC. The exposure apparatus EX is installed on the floor of the manufacturing shop via passive or active vibration isolation units SU1 and SU 2. The exposure apparatus EX is provided with a transport mechanism for transporting the substrate P transported from the previous step to the next step at a predetermined speed.

The conveyance mechanism is constituted by an edge position controller EPC for controlling the center of the substrate P in the Y direction (width direction orthogonal to the longitudinal direction) at a constant position, a drive roller DR4, a rotary drum DR, tension adjustment rollers RT1, RT2, 2 sets of drive rollers DR6, DR7, and the like; the drive roller DR4 is nipped; the rotary drum DR rotates around a rotation center line AX2 to convey the substrate P while supporting the pattern-exposed portion of the substrate P in a cylindrical surface; tension adjusting rollers RT1, RT2 for giving a prescribed tension to the substrate P wound on the rotary drum DR; the 2 sets of driving rollers DR6 and DR7 are used to impart a predetermined slack amount (margin) DL to the substrate P.

Further, the exposure apparatus EX includes: a cylindrical mask DM of a cylindrical shape which rotates around a rotation center line AX 1; a plurality of projection optical systems PL1, PL2, … project an image of a part of a transmission-type mask pattern formed on the outer peripheral surface of a cylindrical mask DM onto a part of a substrate P supported by a rotary drum DR; an alignment system AM for aligning the shadowgraph image of a part of the mask pattern relative to the substrate P.

The alignment system AM includes an alignment microscope for detecting an alignment mark or the like formed in advance on the substrate P.

In the above configuration, the XY plane of the orthogonal coordinate system XYZ specified in fig. 1 is set to be parallel to the floor of the vehicle, and the width direction (also referred to as TD direction) of the surface of the substrate P is set to coincide with the Y direction. 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 disposed apart from each other in the Z axis direction.

The projection optical systems PL1, PL2, and … according to the present embodiment are configured as a multi-lens system in which a plurality of projection views (projection images) are arranged alternately, and the projection magnification is set to equal magnification (x 1), which will be described later in detail.

The diameter (radius from the center AX 1) 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 may be substantially equal. For example, the diameter of the cylindrical mask DM may be 30cm, and the diameter of the rotary drum DR may be 30 cm.

The diameter (radius from the center AX 1) 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 do not necessarily have to be equal to each other, but may be different from each other. For example, the diameter of the cylindrical mask DM may be set to 30cm, and the diameter of the rotary drum DR may be set to about 40 to 50 cm.

The above numerical values are examples, and the present invention is not limited to these.

In addition, when the diameter of the rotary drum DR is equal to the diameter of the cylindrical mask DM (pattern surface), the thickness of the substrate P wound around the outer peripheral surface of the rotary drum DR is strictly taken into consideration. For example, if the thickness of the substrate P is 100 μm (0.1mm), the radius of the outer peripheral surface of the rotary drum DR is smaller than the radius of the cylindrical mask DM (pattern surface) by 0.1 mm.

Further, when the circumferential total length (circumferential length) of the outer circumferential surface of the rotary drum DR is a proper length, for example, 100.0cm, the diameter of the outer circumferential surface of the rotary drum DR is 100/pi cm depending on the circumferential ratio pi, and therefore, it is necessary to process the diameter with an accuracy of several μm to submicron (submicron).

In the present embodiment, since the transmission-type cylindrical mask DM is used, the illumination system IU is provided in the inner space of the cylindrical mask DM, and the illumination system IU irradiates the pattern surface (outer peripheral surface) of the cylindrical mask DM with exposure illumination light (ultraviolet rays) corresponding to each of the visual field regions of the projection optical systems PL1, PL2, and ….

In addition, when the cylindrical mask DM is a reflective type, an epi-illumination optical system is provided, which irradiates illumination light for exposure toward the outer peripheral surface (a pattern surface of the reflective type) of the cylindrical mask DM via some optical elements of the projection optical systems PL1, PL2, ….

In the above configuration, by rotating the cylindrical mask DM and the rotary drum DR at a predetermined rotation speed ratio in synchronization with each other, the surface (surface curved along the cylindrical surface) of the substrate P wound around a part of the outer peripheral surface of the rotary drum DR can be continuously and repeatedly scanned and exposed with the image of the mask pattern formed on the outer peripheral surface of the cylindrical mask DM.

The substrate P used in the present embodiment is, for example, a resin film, a foil (film) made of a metal such as stainless steel or an alloy, or the like.

The material of the resin film includes, for example, 1 or 2 or more of polyethylene resin, polypropylene resin, polyester resin, ethylene-vinyl alcohol copolymer resin, polyvinyl chloride resin, cellulose resin, polyamide resin, polyimide resin, polycarbonate resin, polystyrene resin, and vinyl acetate resin.

The substrate P may be selected from a material having a thermal expansion coefficient not significantly increased so that the amount of deformation due to heat applied in various processing steps can be substantially ignored. For example, the coefficient of thermal expansion can be reduced by mixing an inorganic filler into the resin film. Examples of the inorganic filler include titanium oxide, zinc oxide, aluminum oxide, and silicon oxide.

The substrate P may be a single layer of extra thin glass having a thickness of, for example, about 100 μm manufactured by a float process or the like, or may be a laminate in which the above-described resin film, foil, or the like is laminated on the extra thin glass.

The above numerical values are examples, and the present invention is not limited to these.

Fig. 2 is a perspective view showing the arrangement of the cylindrical mask DM, the plurality of projection optical systems PL1, PL2, …, and the rotary drum DR in the exposure apparatus EX shown in fig. 1.

In fig. 2, projection optical systems PL1, PL2, PL3, PL4, and … (4 projection optical systems are illustrated here) provided between a cylindrical mask DM and a rotary drum DR are, for example, 2 catadioptric type equal power imaging lenses using half of a circular projection field of view (half field of view) are connected in series in the Z direction as disclosed in japanese patent application laid-open No. 7-57986, respectively, and a mask pattern is projected as an erect non-inverted image on the substrate side at an equal power.

The projection optical systems PL1, PL2, PL3, and PL4 … are all of the same configuration, and details will be described later.

The projection optical systems PL1, PL2, PL3, PL4, and … are 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 against temperature change, and can suppress positional variation among the projection optical systems PL1, PL2, PL3, PL4, and … due to temperature change to a small extent.

As shown in fig. 2, on the outer peripheral surface of the rotary drum DR, scale portions GPa and GPb for an encoder system for measuring the rotation angle position (or the position in the circumferential direction) of the rotary drum DR are provided in a ring shape over the entire circumferential range at both ends in the direction (Y direction) in which the rotation center line AX2 extends.

The scale portions GPa and GPb are diffraction grids in which concave or convex grid lines are drawn at a constant pitch (for example, 20 μm) in the circumferential direction of the outer peripheral surface of the rotary drum DR, and are formed as incremental scales.

The above numerical values are examples, and the present invention is not limited to these.

The substrate P is wound inside the rotary drum DR while avoiding the scale portions GPa and GPb at both ends. When a strict arrangement relationship is required, the outer circumferential surfaces of the scale portions GPa and GPb are set to be flush with the partial outer circumferential surface of the substrate P wound around the rotary drum DR (the radii from the center line AX2 are the same). Therefore, the outer peripheral surfaces of the scale portions GPa and GPb may be radially raised by the thickness of the substrate P with respect to the outer peripheral surface of the rotary drum DR for winding the substrate.

In order to rotate the rotary drum DR about the rotation center line AX2, shaft portions Sf2 coaxial with the center line AX2 are provided on both sides of the rotary drum DR. The shaft Sf2 is provided with a rotational torque from a drive source (a motor, a reduction gear mechanism, and the like) not shown.

In the present embodiment, encoder heads EN1 and EN2 are provided, and encoder heads EN1 and EN2 are fixed to posts PLM that fix projection optical systems PL1, PL2, PL3, PL4, and …, respectively, so as to face scale portions GPa and GPb at both ends of rotary drum DR. In fig. 2, only 2 encoder heads EN1, EN2 are shown facing scale section GPa, but similar encoder heads EN1, EN2 are arranged facing scale section GPb.

By mounting the encoder heads EN1 and EN2 on the column PLM in this manner, relative positional variations between the projection optical systems and the encoder heads EN1 and EN2 due to the influence of temperature changes and the like can be suppressed to a small extent.

Each of the encoder heads EN1 and EN2 projects a measuring light beam onto the scale portions GPa and GPb, and photoelectrically detects the reflected light beam (diffracted light), thereby generating a detection signal (for example, a 2-phase signal having a phase difference of 90 degrees) corresponding to a change in the circumferential position of the scale portions GPa and GPb.

By performing digital processing by internally interpolating the detection signal by a not-shown counting circuit, the angular change of the rotary drum DR, that is, the change in the circumferential position of the outer circumferential surface thereof can be measured with a submicron resolution.

As shown in fig. 2, encoder heads EN1 and EN2 are disposed on installation direction lines Le1 and Le2, respectively. The set orientation lines Le1 and Le2 are virtual lines that pass through the projection region of the measuring beam on the scale gpa (gpb), are set in a plane parallel to the XZ plane in fig. 2, and have their extended lines intersecting the rotation center line AX2 of the rotating drum DR.

The set orientation line Le1 is determined to be parallel to the principal ray of the imaging light beam projected from the odd-numbered projection optical systems PL1, PL3 toward the substrate P as viewed in the XZ plane, which will be described later in detail. Further, the set azimuth line Le2 is determined to be parallel to the principal rays of the imaging light beams projected from the even number of projection optical systems PL2, PL4 toward the substrate P as viewed in the XZ plane.

On the other hand, shaft portions Sf1 are provided on both end sides of the cylindrical mask DM coaxially with the rotation center line AX1, and rotation torque from a drive source (a motor or the like), not shown, is applied to the cylindrical mask DM via the shaft portions Sf 1. The scale sections GPM measured by the encoder are annularly provided over the entire circumferential range around the rotation center line AX1, as in the case of the rotary drum DR, at the edges of both ends of the cylindrical mask DM in the direction of the rotation center line AX 1.

The transmissive mask pattern formed on the outer peripheral surface of the cylindrical mask DM is disposed inside the scale sections GPM avoiding both end sections. When a strict arrangement relationship is required, the outer peripheral surface of the scale GPM and the outer peripheral surface of the pattern surface (cylindrical surface) of the cylindrical mask DM are set to be flush with each other (the radii from the center line AX1 are the same).

Further, the encoder head EN11 is disposed at a position facing each scale portion GPM of the cylindrical mask DM in the direction of each field of view of the odd-numbered projection optical systems PL1, PL3, … viewed from the rotation center line AX1, and the encoder head EN12 is disposed in the direction of each field of view of the even-numbered projection optical systems PL2, PL4, … viewed from the rotation center line AX 1.

These encoder heads EN11, EN12 are also attached to holding posts PLM that fix projection optical systems PL1, PL2, PL3, PL4, ….

Encoder heads EN11 and EN12 are disposed on installation direction lines Le11 and Le12 in the same manner as the arrangement states of encoder heads EN1 and EN2 on the rotary drum DR side.

The azimuth lines Le11 and Le12 are provided in a plane parallel to the XZ plane in fig. 2, and their extensions are set to intersect the rotation center line AX1 of the cylindrical mask DM, passing through the region where the measuring light beam of the encoder head is projected onto the scale GPM of the cylindrical mask DM.

In the case of the cylindrical mask DM, the scale marks and the mesh pattern drawn on the scale mark portions GPM can be formed on the outer peripheral surface of the cylindrical mask DM together with the mask pattern of the device (the circuit of the display panel, etc.), and therefore the relative positional relationship between the mask pattern and the scale mark portions GPM can be precisely set.

In the present embodiment, the cylindrical mask DM is exemplified by a transmissive type, but similarly, in a reflective type cylindrical mask, a scale part GPM (scale, grid, origin pattern, etc.) can be formed together with a mask pattern of a device.

In general, when manufacturing a reflective cylindrical mask, since a metal cylindrical material having the shaft portion Sf1 is machined by a high-precision lathe or grinder, roundness of the outer peripheral surface and axial misalignment (eccentricity) can be suppressed to a minimum. Therefore, by forming the scale section GPM on the outer peripheral surface in the same step as the formation of the mask pattern, highly accurate encoder measurement can be realized.

As described above, in the present embodiment, the outer peripheral surface of the scale sections GPM formed on the cylindrical mask DM is set to have substantially the same radius as the mask pattern surface, and the outer peripheral surfaces of the scale sections GPa and GPb formed on the rotary drum DR are set to have substantially the same radius as the outer peripheral surface of the substrate P.

Therefore, encoder heads EN11 and EN12 can detect し scale sections GPM at the same radial position as the mask pattern (illumination area of illumination system IU) on cylindrical mask DM, and encoder heads EN1 and EN2 can detect GPa and GPb at the same radial position as the projection area (projection image imaging surface) of substrate P wound around rotary drum DR.

Therefore, the abbe error caused by the difference between the measurement position and the processing position in the radial direction of the rotation system can be suppressed to be small.

Next, a specific configuration of the projection optical systems PL1 to PL4 and … according to the present embodiment will be described with reference to fig. 3. Since the respective projection optical systems have the same configuration, only the configuration of the projection optical system PL1 will be representatively described. The projection optical system PL1 shown in fig. 3 includes telecentric 1 st imaging optical system 51 and 2 nd imaging optical system 58 of the catadioptric type.

The 1 st imaging optical system 51 includes a plurality of lens elements, a focal length correction optical member 44, an image shift correction optical member 45, a1 st deflecting member 50, a1 st concave mirror 52 disposed on a pupil plane, and the like.

The 1 st imaging optical system 51 images an image of a mask pattern, which is developed in the illumination area IR1 formed on the pattern surface (outer peripheral surface) of the cylindrical mask DM by the illumination light D1 (whose principal ray is EL1) from the illumination system IU, on an intermediate image surface on which the field stop 43 is arranged.

The 2 nd imaging optical system 58 is composed of a plurality of lens elements, a2 nd deflecting member 57, a2 nd concave mirror 59 disposed on a pupil plane, a magnification correcting optical member 47, and the like.

The 2 nd imaging optical system 58 re-images an image, which is limited by the opening shape (e.g., trapezoid) of the field stop 43, of the intermediate image formed by the 1 st imaging optical system 51, in the projection area PA1 of the substrate P.

In the above configuration of the projection optical system PL1, the focal length correction optical member 44 finely adjusts the focal length state of a mask pattern image (hereinafter referred to as a projection image) formed on the substrate P, the image shift correction optical member 45 finely shifts the projection image laterally within the image plane, and the magnification correction optical member 47 finely corrects the magnification of the projection image within a range of about ± several tens ppm.

Further, the projection optical system PL1 is provided with a rotation correction mechanism 46, and the rotation correction mechanism 46 minutely rotates the 1 st deflection member 50 around an axis parallel to the Z axis in fig. 3, thereby minutely rotating the projection image formed on the substrate P in the image plane.

The image light beam EL2 from the pattern in the illumination region IR1 on the cylindrical mask DM is emitted from the illumination region IR1 in the normal direction, passes through the focal length correction optical element 44 and the image shift correction optical element 45, is reflected on the 1 st reflecting surface (flat mirror) P4 of the 1 st deflecting unit 50, is reflected on the 1 st concave mirror 52 by the plurality of lens elements, and is reflected on the 2 nd reflecting surface (flat mirror) P5 of the 1 st deflecting unit 50 again by the plurality of lens elements, thereby reaching 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 rotary drum DR shown in fig. 2 (or fig. 1) is defined as the center plane p3 (parallel to the YZ plane). In this case, the optical axis AX3 of the 1 st imaging optical system 51 and the optical axis AX4 of the 2 nd imaging optical system 58 are both arranged so as to be orthogonal to the central plane p 3.

In the present embodiment, since the illumination area IR1 is offset by a predetermined amount in the-X direction with respect to the center plane p3 when viewed in the XZ plane, the extension line of the main ray EL1 of the illumination light D1 passing through the center in the illumination area IR1 is set to intersect the rotation center line AX1 of the cylindrical mask DM.

Thereby, the principal ray EL3 of the imaging light beam EL2 from the pattern located at the center point within the illumination area IR1 also proceeds in a state of being inclined in the XZ plane with respect to the center plane P3, and reaches the 1 st reflection plane P4 of the 1 st deflecting member 50.

The 1 st deflecting member 50 is a triangular prism extending in the Y-axis direction. In the present embodiment, the 1 st reflection surface P4 and the 2 nd reflection surface P5 each include a mirror surface (surface of a reflection film) formed on the surface of a triangular prism.

The 1 st deflecting means 50 deflects the imaging light beam EL2 such that a principal ray EL3 from the illumination area IR1 to the 1 st reflecting surface p4 is inclined with respect to the central surface p3 in the XZ plane, and such that a principal ray EL3 from the 2 nd reflecting surface p5 to the field stop 43 is parallel to the central surface p 3.

In order to form such an optical path, in the present embodiment, the 1 st deflecting member 50 is arranged such that a ridge line intersecting the 1 st reflecting surface p4 and the 2 nd reflecting surface p5 is located on the optical axis AX 3. When a plane parallel to the XY plane including the ridge line and the optical axis AX3 is defined as p6, the 1 st reflecting surface p4 and the 2 nd reflecting surface p5 are disposed at asymmetric angles with respect to the plane p 6.

Specifically, if the angle of the 1 st reflecting surface P4 with respect to the plane P6 is θ 1 and the angle of the 2 nd reflecting surface P5 with respect to the plane P6 is θ 2, the angle (θ 1+ θ 2) is set to less than 90 °, the angle θ 1 is set to less than 45 °, and the angle θ 2 is set to substantially 45 ° in the present embodiment.

Since the principal ray EL3 reflected by the 1 st reflection surface P4 and incident on the plurality of lens elements is set to be parallel to the optical axis AX3, the principal ray EL3 can pass through the center of the 1 st concave mirror 52, that is, the intersection of the pupil plane and the optical axis AX3, and a telecentric imaging state can be ensured.

Therefore, in fig. 3, assuming that the inclination angle of the principal ray EL3 between the illumination region IR1 and the 1 st reflection surface p4 with respect to the XZ plane of the central surface p3 is θ d, the angle θ 1 of the 1 st reflection surface p4 may be set as the following expression (1).

θ1＝45°-(θd/2)···(1)

The imaging light beam EL2 that has passed through the 1 st imaging optical system 51 and the field stop 43 is reflected by the 3 rd reflecting surface (plane mirror) p8 of the 2 nd deflecting unit 57 that is an element of the 2 nd imaging optical system 58, and passes through a plurality of lens elements to reach the 2 nd concave mirror 59 disposed at the pupil plane.

The image light beam EL2 reflected by the 2 nd concave mirror 59 passes through the plurality of lens elements again, is reflected by the 4 th reflecting surface (flat mirror) P9 of the 2 nd deflecting unit 57, passes through the magnification correction optical unit 47, and reaches the projection area PA1 on the substrate P.

This makes it possible to project the image of the pattern appearing in the illumination area IR1 into the projection area PA1 at an equal magnification (x 1).

The 2 nd deflecting member 57 is also a triangular prism extending in the Y-axis direction. In the present embodiment, each of the 3 rd reflection surface p8 and the 4 th reflection surface p9 includes a mirror surface (surface of a reflection film) formed on the surface of a triangular prism.

The 2 nd deflecting section 57 deflects the imaging light beam EL2 such that the principal ray EL3 between the field stop 43 and the 3 rd reflection surface p8 is parallel to the central surface p3 in the XZ plane, and such that the principal ray EL3 between the 4 th reflection surface p9 and the projection area PA1 is inclined in the XZ plane with respect to the central surface p 3.

In the present embodiment, since the projection area PA1 is also shifted by a predetermined amount in the-X direction with respect to the center plane p3 when viewed in the XZ plane, the extension line of the principal ray EL3 of the imaging light flux reaching the projection area PA1 is set so as to intersect the rotation center line AX2 of the rotary drum DR. Thus, since the image plane formed in the projection area PA1 is a contact plane with the surface (curved surface) of the substrate P supported by the outer peripheral surface of the rotary drum DR, it is possible to perform a faithful projection exposure with a secured resolution.

In order to form such an optical path, in the present embodiment, a ridge line of the 2 nd deflecting member 57, which intersects the 3 rd reflecting surface p8 and the 2 nd reflecting surface p9, is disposed on the optical axis AX4, and when a plane including the ridge line and the optical axis AX4 and parallel to the XY plane is defined as p7, the 3 rd reflecting surface p8 and the 4 th reflecting surface p9 are disposed at asymmetric angles with respect to the plane p 7.

Specifically, if the angle of the 3 rd reflecting surface p8 with respect to the plane p7 is θ 3 and the angle of the 4 th reflecting surface p9 with respect to the plane p7 is θ 4, the angle (θ 3+ θ 4) is set to less than 90 °, the angle θ 4 is set to less than 45 °, and the angle θ 3 is set to substantially 45 °.

By setting the principal ray EL3 reflected by the 2 nd concave mirror 59, emitted from the plurality of lens elements, and reaching the 4 th reflection surface p9 to be parallel to the optical axis AX4, a telecentric imaging state can be ensured.

Therefore, in fig. 3, when the inclination angle of the principal ray EL3 in the XZ plane with respect to the central plane p3 between the 4 th reflection surface p9 and the projection area PA1 is θ s, the angle θ 4 of the 4 th reflection surface p9 may be set as the following expression (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 and … are configured similarly to fig. 3, and the even-numbered projection optical systems PL2 and PL4 are configured by symmetrically inverting the arrangement of fig. 3 with respect to the center plane p 3.

Further, as the imaging characteristic adjustment mechanism, a focal length correction optical member 44, an image shift correction optical member 45, a rotation correction mechanism 46, and a magnification correction optical member 47 are provided for each of the odd-numbered and even-numbered projection optical systems PL1 to PL4 ….

Thereby, the projection conditions of the projection image on the substrate P can be adjusted for each projection optical system. The projection conditions include 1 or more items of translational position and rotational position, magnification, and focal length of the projection region on the substrate P. The projection conditions can be determined according to the position of the projection area with respect to the substrate P at the time of the synchronous scanning. By adjusting the projection conditions of the projected image, the distortion of the projected image when compared with the mask pattern can be corrected.

The focal length correcting optical member 44 is formed by superimposing 2 wedge prisms so that they are transparent as a whole, in opposite directions (opposite directions with respect to the X direction in fig. 3). By sliding the pair of prisms 1 in the direction of the inclined plane with the interval between the facing surfaces unchanged, and by changing the thickness of the parallel plate, the effective optical path length can be finely adjusted, and the in-focus state of the pattern image formed in the projection area PA1 can be finely adjusted.

The image shift correction optical member 45 is composed of a transparent parallel plate glass tiltable in the XZ plane in fig. 3 and a transparent parallel plate glass tiltable in a direction orthogonal thereto. By adjusting the respective inclination amounts of these 2 pieces of parallel plate glass, the pattern image formed in the projection area PA1 can be slightly shifted in the X direction and the Y direction.

The magnification correction optical member 47 is configured such that 3 concave lenses, a convex lens, and a concave lens are coaxially arranged at a predetermined interval, the front and rear concave lenses are fixed, and the convex lens therebetween is moved in the optical axis direction (principal ray EL 3). Thus, the pattern image formed in the projection area PA1 can be expanded or reduced by a small amount in an equal direction while maintaining a telecentric imaging state.

The rotation correcting mechanism 46 slightly rotates the 1 st deflecting member 50 about 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 on 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, 3 odd-numbered projection optical systems PL1, PL3, and PL5 and 3 even-numbered projection optical systems PL2, PL4, and PL6 are arranged in parallel in the Y direction.

The left diagram in fig. 4 is a plan view of 6 illumination regions IR1 to IR6 set on the cylindrical mask DM for the 6 projection optical systems PL1 to PL6, as viewed from the-Z side. The right drawing in fig. 4 is a plan view of the 6 projection areas PA1 to PA6 on the substrate P supported by the rotary drum DR for the 6 projection optical systems PL1 to PL6, as viewed from the + Z side. Reference symbol Xs in fig. 4 denotes a moving direction (rotating direction) of the cylindrical mask DM or the rotating drum DR.

The illumination system IU illuminates 6 illumination areas IR1 to IR6 on the cylindrical mask DM, respectively. In fig. 4, the illumination regions IR1 to IR6 are described as trapezoidal regions elongated in the Y direction. As described with reference to fig. 3, when the aperture shape of the field stop 43 is a trapezoid, the illumination regions IR1 to IR6 may be rectangular regions including a trapezoid region.

The odd-numbered illumination regions IR1, IR3, and IR5 have the same shape (trapezoidal or rectangular shape) and are arranged at regular intervals in the Y-axis direction. The even-numbered illumination regions 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 central plane p 3.

As shown in fig. 4, the 6 illumination regions IR1 to IR6 are arranged such that the peripheral portions of adjacent illumination regions overlap with each other in the Y direction.

In the present embodiment, the outer peripheral surface of the cylindrical mask DM has a patterned region A3 where a pattern is formed and a non-patterned region a4 where no pattern is formed.

The non-pattern-formed region a4 is disposed so as to surround the pattern region A3 in a frame shape, and has a characteristic of shielding the illumination light beams that illuminate the illumination regions IR1 to IR 6.

The patterned region A3 moves in the direction Xs with the rotation of the cylindrical mask DM, and each partial region in the Y-axis direction in the patterned region A3 passes through any one of the 6 illumination regions IR1 to IR 6. In other words, the 6 illumination regions IR1 to IR6 are arranged so as to cover the entire width of the layout region A3 in the Y axis direction.

In fig. 4, 6 projection optical systems PL1 to PL6 are provided corresponding to 6 illumination regions IR1 to IR6, respectively. Therefore, as shown in the right drawing of fig. 4, the projection optical systems PL1 to PL6 project partial pattern images of the mask patterns appearing in the corresponding illumination areas IR1 to IR6 into the 6 projection areas PA1 to PA6 on the substrate P.

As shown in the right drawing of fig. 4, images of patterns in the odd-numbered illumination regions IR1, IR3, IR5 are projected in the odd-numbered projection regions PA1, PA3, PA5 aligned in a row in the Y-axis direction, respectively. Images of the patterns in the even-numbered illumination regions IR2, IR4, IR6 are also projected in the even-numbered projection regions PA2, PA4, PA6 aligned in a line in the Y-axis direction, respectively.

The odd-numbered projection regions PA1, PA3, PA5 and the even-numbered projection regions PA2, PA4, PA6 are arranged symmetrically with respect to the central plane p 3.

The 6 projection areas PA1 to PA6 are respectively arranged such that ends (triangular portions of a trapezoid) of the projection areas adjacent in a direction (Y direction) parallel to the rotation center line AX2 coincide with each other. Thus, the exposure area a7 of the substrate P exposed in the 6 projection areas PA1 to PA6 with the rotation of the rotary drum DR is substantially the same exposure amount anywhere.

As shown in fig. 1, the exposure apparatus EX of the present embodiment is provided with an alignment system AM for detecting an alignment mark formed on the substrate P, a reference mark and a reference pattern formed on the rotary drum DR so as to align the substrate P with the mask pattern, or for aligning the reference mark and the projection optical system. This alignment system AM is explained below with reference to fig. 5 and 6.

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

In fig. 5, as described above, the setting direction lines Le1 and Le2 of the encoder heads EN1 and EN2 are set to be inclined symmetrically with respect to the center plane p3 including the rotation center line AX2 and parallel to the YZ plane.

The inclination angles of the setting direction lines Le1, Le2 with respect to the center plane p3 are set to be equal to the inclination angle θ s of the principal ray EL3 with respect to the center plane p3, which reaches the center of the projection area PA1 illustrated in fig. 3 (or the odd-numbered projection areas PA1, PA3, PA5 and the even-numbered projection areas PA2, PA4, PA6 shown in fig. 4).

In fig. 5, the alignment system AM1 is composed of, among others: an illumination unit GC1 for irradiating illumination light for alignment to the mark and the pattern on the substrate P or the rotary drum DR; a beam splitter GB1 for directing the illumination light to the substrate P or the rotating drum DR; an objective lens system GA1 for projecting the illumination light toward the substrate P or the rotary drum DR and allowing the light generated in the marks and patterns to enter; the imaging system GD1 captures images (bright-field image, dark-field image, fluorescence image, etc.) of the marker and the pattern received through the objective lens system GA1 and the spectrometer GB1 by a two-dimensional CCD, a CMOS, or the like.

The illumination light for alignment from illumination unit GC1 is a light in a wavelength band having almost no sensitivity to the photosensitive layer on substrate P, for example, a light having a wavelength of about 500 to 800 nm.

The observation area (imaging area) of the mark and the pattern realized by the alignment system AM1 is set in a range of an angle of about 200 μm, for example, on the substrate P and the rotating drum DR.

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 set 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 at an angle θ j from the center plane p3, and the inclination angle θ s with respect to the principal ray EL3 of the odd-numbered projection optical systems PL1, PL3, PL5 is set to θ j > θ s.

In the present embodiment, encoder head EN3 similar to encoder heads EN1 and EN2 is provided on installation orientation line La1 at a position facing each scale GPa and GPb of rotary drum DR. Thus, the alignment system AM1 can precisely measure the rotational angle position (or circumferential position) of the rotating drum DR at the moment of sampling the image of the mark or pattern in the observation region (imaging region).

Further, when viewed in the XZ plane, encoder head EN4 facing each scale section GPa, GPb of rotary drum DR is also provided in the X-axis direction perpendicular to center plane p 3.

As shown in fig. 6, the alignment system AM is provided with 5 components similar to the alignment system AM1 of fig. 5. In fig. 6, for easy understanding, only the arrangement of the respective objective lens systems GA1 to GA5 of the 5 alignment systems AM1 to AM5 is shown.

As shown in fig. 6, observation regions (imaging regions) Vw on the substrate P (or the outer circumferential surface of the rotary drum DR) realized by the objective lens systems GA1 to GA5 are arranged at predetermined intervals in a direction parallel to the Y axis (rotation center line AX 2). The optical axes of the objective lens systems GA1 to GA5 passing through the center of each observation region (imaging region) Vw are all arranged parallel to the XZ plane.

As shown in fig. 2, the rotary drum DR is provided with scale portions GPa and GPb at both end sides thereof, and narrow regulation bands CLa and CLb formed by concave grooves or convex edges are formed around the entire circumference of the inside of the scale portions GPa and GPb.

The width of the substrate P in the Y direction is set smaller than the interval between the 2 confinement strips CLa, CLb in the Y direction. The substrate P is supported in close contact with an inner region of the outer peripheral surface of the rotary drum DR, the inner region being sandwiched between the regulation belts CLa and CLb.

As shown in the right view of fig. 4, exposure regions a7 exposed to 6 projection regions PA1 to PA6 are disposed on the substrate P at predetermined intervals in the X direction.

There are cases where a pattern has already been formed in each exposure region a7 of substrate P and a new pattern is superimposed thereon and exposed. In this case, a plurality of marks (alignment marks) Ks1 to Ks5 for alignment are formed in a cross shape, for example, around the exposure region a7 on the substrate P.

In fig. 6, the mark Ks1 is provided at constant intervals in the X direction in the peripheral region on the-Y side of the exposure region a7, and the mark Ks5 is provided at constant intervals in the X direction in the peripheral region on the + Y side of the exposure region a 7. The marks Ks2, Ks3, Ks4 are arranged in a row with spaces in the Y direction in the blank regions between 2 exposure regions a7 adjacent in the X direction.

Of these alignment marks, the mark Ks1 is set to be sequentially captured while the substrate P is being transported within the imaging region Vw of the objective lens system GA1 (alignment system AM 1). The mark Ks5 is set to be sequentially captured while the substrate P is being conveyed, within the imaging region Vw of the objective lens system GA5 (alignment system AM 5).

The marks Ks2, Ks3, and Ks4 determine the positions in the Y direction so as to be captured in the respective 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 the above configuration, when the exposure area a7 on the substrate P and the mask pattern on the cylindrical mask DM are aligned and exposed with respect to each other, in the imaging region Vw of each alignment system AM1 to AM5, imaging data is sampled at the timing when the corresponding marks Ks1 to Ks5 enter, and the angular position (circumferential position) of the rotary drum DR at that time is read and stored from the encoder head EN 3.

The shift amounts in the XY direction of the markers Ks1 to Ks5 with respect to the imaging regions Vw are obtained by performing image analysis on the imaging data.

When the relative positional relationship between the imaging region Vw of each of the alignment systems AM1 to AM5 and each of the projection regions PA1 to PA6, that is, the so-called reference line, is accurately obtained in advance by calibration or the like, the positional relationship (dynamically changing positional relationship) between the exposure region a7 on the substrate P and each of the projection regions PA1 to PA6 can be accurately estimated from the respective measured values of the 2 encoder heads EN1 and EN2 arranged at the exposure position, based on the shift amounts of the marks Ks1 to Ks5 in the XY direction obtained and the angular position (circumferential position) of the rotary drum DR read and stored by the encoder head EN 3.

Therefore, by successively comparing the measured values of the 2 encoder heads EN1 and EN2 with the measured values of the encoder heads EN11 and EN12 on the side of the cylindrical mask DM and performing synchronization control, the mask pattern can be precisely superimposed on the exposure region a7 of the substrate P and exposed.

In the above exposure, the substrate P may be as thin as about 100 μm, and a transparent film such as ITO may be formed as an underlayer.

In the case of using such a substrate P, if the reflectance of the outer peripheral surface of the rotating drum DR supporting the substrate P is relatively high or if there are many fine scratches on the surface thereof, which are several micrometers wide, the exposure illumination light is reflected, radiated, and diffracted on the outer peripheral surface of the rotating drum DR, and returns from the back side to the front side of the substrate P, and exposure which is not contained in the original mask pattern and becomes noise is applied to the photosensitive layer.

Therefore, at least the portion of the outer peripheral surface of the rotating drum DR which is in contact with the exposure area a7 on the substrate P can have the surface locally flattened to the submicron level, and the reflectance is uniformly reduced. The reflectance is, for example, 50, 45, 40, 35, 30, 25, 20, 15, 10, or 5% or less, preferably 20% or less, with respect to the exposure illumination light.

The above numerical values are examples, and the present invention is not limited to these.

The structure of the outer peripheral surface of the rotary drum DR will be described below with reference to fig. 7 and 8. Fig. 7 is a diagram showing a configuration of the substrate P supported in close contact with the outer peripheral surface of the rotary drum DR, and reflection conditions with respect to the exposure imaging light beam EL2 (illumination light IE0) and the alignment illumination light ILa, respectively. Fig. 8 is a view showing a cross-sectional structure of the outer peripheral surface of the rotary drum DR.

In fig. 7, an imaging light beam EL2 (illumination light IE0) traveling along a principal ray EL3 is projected on a photosensitive layer Pb3 formed on the surface of a substrate P of thickness Tp. When the base layer Pb2 of the photosensitive layer Pb3 is made of a material having high light transmittance such as ITO, the illumination light IE1 transmitted through the base layer Pb2 is emitted toward the base material Pb1 of the substrate P therebelow without being attenuated substantially from the original illumination light IE 0.

Since the base material Pb1 of the substrate P is a transparent resin film such as PET or PEN and is as thin as 100 μm or less, when the wavelength band of the illumination light IE0(IE1) is 350nm or more, the base material Pb1 has a relatively large transmittance (80% or more) with respect to the illumination light IE 1.

Therefore, the illumination light IE1 transmitted 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, reflected light (including scattered light and diffracted light) IE2 is generated from the outer peripheral surface DRs by the illumination light IE1 transmitted through the base material Pb1, and returns to the photosensitive layer Pb3 in the order of the base material Pb1 and the undercoat layer Pb 2. The reflected light IE2 is not the imaging light beam EL2 for original layout, and therefore becomes noise and applies unnecessary exposure to the photosensitive layer Pb 3.

One of the noises is, for example, an out-of-focus image of a pattern image formed by the imaging light beam EL 2.

In the case of the projection optical system PL1 (PL 6) as shown in fig. 3, the resolution (R) and the depth of focus (DOF) are roughly determined in accordance with the wavelength λ of the exposure illumination light and the aperture number NA. For example, in a projection optical system that uses illumination light having a wavelength of 365nm (I-line) and can form an image with a resolution (R) having a line width of 3 μm, when the K coefficient is set to about 0.35, the depth of focus (DOF) is about 70 μm.

When the base material Pb1 of the substrate P has a thickness of 100 μm, the image beam EL2 is projected in a slightly defocused state toward the outer peripheral surface DRs of the rotary drum DR, and the reflected light IE2 reflected by the outer peripheral surface DRs becomes an image beam further defocused on the surface of the photosensitive layer Pb 3.

Therefore, on the photosensitive layer Pb3, a blurred image of the pattern image itself is also superimposed and projected along with the pattern image formed by the focused imaging light beam EL 2. That is, there is a problem that an undesired unnecessary pattern image (such as a blurred image) is reflected in the photosensitive layer Pb 3.

On the other hand, in the mark detection performed by the alignment systems AM1 to AM5, for example, when a highly reflective material such as aluminum (Al) is used as the material of the alignment marks Ks1 to Ks5 formed on the base material Pb1 of the substrate P, the intensity of the reflected light ILb of the illumination light ILa irradiated to the marks Ks1 to Ks5 is relatively high, and therefore, favorable mark observation and detection can be performed.

However, when the reflectance of the marks Ks1 to Ks5 is not so high, the illumination light ILa passing through the transparent regions around the marks Ks1 to Ks5 reaches the outer peripheral surface DRs of the rotating drum DR, and the reflected light is captured by the imaging element together with the reflected light ILb from the marks Ks1 to Ks5, so that the image contrast of the marks Ks1 to Ks5 may be low.

Due to the above, the outer peripheral surface DRs of the rotary drum DR in the present embodiment is formed to have a reflectance of about 50, 45, 40, 35, 30, 25, 20, 15, 10, or 5% or less with respect to the exposure illumination light IE 0.

Therefore, in the rotary drum DR of the present embodiment, the surface of the cylindrical base DR1 made of iron (SUS) or aluminum (Al) is plated with the underlying layer DR2 (thickness Td2) of chromium (Cr) or copper (Cu). After the surface of the base layer DR2 was optically polished to make the local surface roughness sufficiently small, chromium oxide (Cr) was formed thereon₂O₃) Or a top layer DR3 (thickness Td3) of diamond-like carbon (DLC).

The thickness Td2 of the base layer DR2 can be arbitrarily set in a range of about several hundreds nm to several μm, and the thickness Td3 of the top layer DR3 has a certain range of conditions for adjusting the reflectance of the outer peripheral surface DRs.

Thus, the base layer DR2 is chromium (Cr) and the top layer DR3 is chromium oxide (Cr)₂O₃) In the case of (2), the wavelength characteristics (spectral reflectance) of the reflectance of the outer peripheral surface DRs with the thickness Td3 of the top layer DR3 as a parameter will be described with reference to fig. 9.

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 ordinate represents the reflectance (%) of the outer peripheral surface DRs, and the abscissa represents the wavelength (nm). In fig. 9, the characteristics of 6 spectral reflectances of the top layer DR3 formed of chromium oxide in which the thickness Td3 was changed every 30nm between 0 and 150Nnm are shown.

For example, if the thickness Td3 of the top layer DR3 of chromium oxide is about 30nm, the reflectance can be set to 20% or less (15% or less in the simulated figure) over the entire wavelength range of 350nm to 500 nm. In this case, the reflectance is about 7% with respect to the wavelength 436nm (g-line exposure light), and if the wavelength of the illumination light ILa for alignment is about 500nm, the reflectance is about 12% with respect to the wavelength.

When the wavelength of the exposure light (illumination light IE0) is 405nm (e.g., a semiconductor laser for blue light near the h-line), the reflectance can be minimized at the wavelength of the exposure light by setting the thickness Td3 of the top layer DR3 of chromium oxide to about 120nm, and the reflectance can be about 40% with respect to the alignment illumination light ILa near 500 nm.

On the other hand, when the thickness Td3 of the top layer DR3 of chromium oxide is about 60nm or 150nm, the reflectance with respect to the exposure light (illumination light IE0) having a wavelength band of 350 to 436nm is increased to about 50%, and the reflectance with respect to the alignment illumination light ILa having a wavelength of 500nm is 40% or less.

When the thickness Td3 of the chrome oxide top layer DR3 is about 90nm, the reflectance of the outer peripheral surface DRs with respect to ultraviolet light in a wavelength band shorter than the wavelength of 350nm can be reduced to 30% or less, and the reflectance of the outer peripheral surface DRs with respect to the alignment illumination light ILa having the wavelength of 500nm can be increased to about 60%.

As is clear from the simulation results of fig. 9, by controlling the thickness Td3 of the top layer DR3 formed of chromium oxide, the reflectance of the outer peripheral surface DRs with respect to the alignment illumination light and the exposure illumination light can be arbitrarily set to approximately several% to 50%, and can be set to be lower than the reflectance in the case where the top layer DR3 formed of chromium oxide is not provided (Td3 is 0nm) but only the base layer DR2 formed of simple chromium is provided.

As described above with reference to fig. 7, when the reflectance with respect to the outer peripheral surface DRs of the exposure illumination light (IE0) and the alignment illumination light (ILa) is suppressed as low as possible in general, the reflectance of approximately 15% or less can be obtained over the entire wavelength range of 350nm to 500nm by setting the thickness Td3 of the chrome oxide top layer DR3 to 30nm, for example.

The simulation of fig. 9 is an example of adjusting the reflectance by forming a chrome layer on the base DR1 of the rotating drum DR and forming a chrome oxide layer thereon at a controlled thickness, but is not limited to this combination.

For example, the base layer DR2 may be made of aluminum (Al), copper (Cu), silver (Ag), gold (Au), or the like, in addition to chromium (Cr).

As the material of the top layer DR3 on the underlayer DR2, the above-described chromium oxide, an electrolyte having a relatively high refractive index and capable of controlling the reflectance, and metal-based compounds such as oxides and nitrides, e.g., titanium oxide (TIO), zirconium, hafnium oxide, and diamond-like carbon (DLC), can be used in the same manner.

In addition, the illumination light (IE0) for exposure is ultraviolet light having a wavelength of 436nm (g line) or less, and light in a visible wavelength band to an infrared wavelength band in which the photosensitive layer (Pb3) is not sensitized is used as the illumination light (ILa) for alignment.

Therefore, by forming the base layer DR2 with a metal material such as copper (Cu) that has a low reflectance with respect to ultraviolet light and a high reflectance with respect to infrared light, the reflectance with respect to the alignment illumination light (ILa) and the exposure illumination light (IE0) can be made different from each other.

After copper (Cu) was thickly deposited by electroplating as the base layer DR2, diamond-like carbon (DLC) was formed as the top layer DR3 at a thickness of 0.5 μm and 2 μm, and the reflectance Re with respect to ultraviolet light (exposure light) having a wavelength of 355nm and the reflectance Rv with respect to light (alignment light) having a visible wavelength band of 450nm to 650nm were measured. The results are shown in Table 1.

[ TABLE 1 ]

Thickness of DLC	0.5μm	2μm
			Reflectance Re	About 15 percent	About 20 percent
Reflectance ratio Rv	About 15 percent	About 15 percent

By suppressing at least the reflectance of the exposure illumination light (IE0) with respect to the outer peripheral surface DRs of the rotary drum DR in this manner, it is possible to solve the problem that an unnecessary pattern image (blurred image) is reflected at the time of exposure.

[ 2 nd embodiment ]

Since the exposure apparatus according to embodiment 1 is a so-called multi-lens system, it is necessary to connect the mask pattern images formed in the projection areas PA1 to PA6 of the projection optical systems PL1 to PL6 in the Y direction (or X direction) as a result, and to align (overlap) the mask pattern images with the base pattern on the substrate P in a good manner.

Therefore, calibration is required to keep the connection accuracy of the plurality of projection optical systems PL1 to PL6 within an allowable range. The relative positional relationships between the projection areas PA1 to PA6 of the projection optical systems PL1 to PL6 and the observation (imaging) area Vw of the alignment systems AM1 to AM5 need to be precisely determined by reference line management. For this baseline management, calibration is required.

In the calibration for confirming the connection accuracy by the plurality of projection optical systems PL1 to PL6 and the calibration for reference line management by the alignment systems AM1 to AM5, it is necessary to provide a reference mark or a reference pattern on at least a part of the outer peripheral surface of the rotating drum DR supporting the substrate P.

In a conventional exposure apparatus in which a flat glass plate is mounted on a flat substrate holder, the substrate holder is moved two-dimensionally, and projection exposure is performed, a reference mark or a reference pattern for calibration is provided in a portion not covered with the glass plate on the outer peripheral portion of the substrate holder, and the reference mark or the reference pattern is moved to a position below an objective lens of a projection optical system or an alignment system during calibration.

However, as in the exposure apparatus according to embodiment 1, such reference marks and reference patterns have to be provided on the outer peripheral surface of the rotary drum DR at the portion that is in contact with the substrate P in a state where the substrate P is wrapped around a part of the outer peripheral surface of the rotary drum DR (the positions of the projection areas PA1 to PA6) during almost the entire operation time.

Therefore, in the present embodiment, as shown in fig. 10, a case of using a rotary drum DR having a reference mark and a reference pattern provided on an outer peripheral surface thereof will be described.

Fig. 10 is a perspective view of the rotary drum DR which is integrally machined with the shaft portion SF2 coaxial with the rotation center line AX2, and the scale portions GPa and GPb for encoder measurement and the restricting bands CLa and CLb are provided in the same manner as in the above-described configurations shown in fig. 2 and 6.

In the present embodiment, a grid-like reference pattern RMP is provided on the entire circumference sandwiched between the restricted bands CLa, CLb on the outer circumferential surface of the rotary drum DR (which can also be used as a reference mark), and the grid-like reference pattern RMP is formed by repeatedly drawing a plurality of line patterns RL1 inclined at +45 degrees with respect to the Y axis and a plurality of line patterns RL2 inclined at-45 degrees with respect to the Y axis at constant pitches (periods) Pf1, Pf 2.

Since the outer peripheral surface of the rotary drum DR, that is, the entire periphery sandwiched by the regulation belts CLa and CLb, is always in contact with the substrate P by the rotation of the rotary drum DR, the reference pattern RMP has a tilted pattern (a diagonal lattice pattern) uniform over the entire surface so that the frictional force at the portion where the substrate P is in contact with the outer peripheral surface of the rotary drum DR, the tension of the substrate P, and the like do not change.

The line patterns RL1 and RL2 are inclined with respect to the conveyance direction (X direction) of the substrate P and the width direction (Y direction) of the substrate P, respectively, so that the directionality of friction, tension, and the like can be reduced.

However, the line patterns RL1 and RL2 do not necessarily have to be inclined at 45 degrees, and a longitudinal and transverse grid pattern in which the line pattern RL1 is parallel to the Y axis and the line pattern RL2 is parallel to the X axis may be used.

The line patterns RL1 and RL2 do not necessarily intersect at 90 degrees, and the line patterns RL1 and RL2 may intersect at such an angle that a rectangular region surrounded by the adjacent 2 line patterns RL1 and the adjacent 2 line patterns RL2 is a rhombus other than a square (or rectangle).

Note that, regarding the pitches Pf1, Pf2 of the line patterns RL1, RL2 shown in fig. 10, when an expected amount of fluctuation of the reference line of the alignment system (the relative positional relationship between the projection area PA of the projection optical system PL and the imaging area Vw) or an expected amount of fluctuation between the plural projection optical systems PL1 to PL6 of the multi-lens system is considered, the expected amount of fluctuation may be at least 2 times or more the expected amount of fluctuation.

For example, when the maximum value of the fluctuation amount is expected to be 10 μm, the pitches Pf1 and Pf2 are different depending on the line widths LW (5 to 20 μm) of the line patterns RL1 and RL2, but accurate calibration can be performed only at about 30 to 50 μm.

The line width LW of each line pattern RL1, RL2 can be determined to be as narrow as possible in accordance with the accuracy (resolution) of a drawing device that draws each line pattern RL1, RL2, etching conditions, and the like, and is preferably as narrow as possible within a range in which image analysis can be stably performed by the alignment systems AM1 to AM 5.

When the reference pattern RMP is detected and measured in the imaging (observation) area Vw of each of the alignment systems AM1 to AM5, the pitch Pf1 and Pf2 of the line patterns RL1 and RL2 are set to about 50 μm. Then, the intersection portions 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 within a range of 200 μm, it is possible to favorably capture 1 specific intersection portion and perform image analysis of positional deviation.

Fig. 11 is a sectional view partially cut out of the reference pattern RMP formed by the line patterns RL1 and RL2 along the X-axis shown in the circle in fig. 10.

In the present embodiment, as in fig. 8 of embodiment 1 described above, a base layer DR2 of chromium or copper is thickly deposited by electroplating on the surface of a cylindrical base DR1 of iron or aluminum. Then, after the surface of the base layer DR2 is polished optically to improve flatness, a photoresist is applied to the entire periphery of the base layer DR2, and the reference pattern RMP formed by the line patterns RL1 and RL2 is exposed to light on the base layer DR2 by a drawing device.

At this time, since the grid lines of the scale portions GPa and GPb are also drawn together, the relative positional relationship between the reference pattern RMP and the scale portions GPa and GPb (particularly, the positional relationship in the circumferential direction) can be made constant.

Then, the resist of the portions corresponding to the line patterns RL1, RL2 is removed by development of the photoresist, and the exposed base layer DR2 (chromium or copper) is etched to a prescribed depth, and then the top layer DR3 (chromium oxide or DLC) is deposited on the surface thereof in a prescribed thickness.

The thickness of the top layer DR3 is set according to the characteristics of fig. 9 described above in the case of chromium oxide. The step amount Δ DP of the line patterns RL1 and RL2 (recesses) of the top layer DR3 finally formed was measured and compared with the design value, and it was confirmed that the step amount Δ DP was within the predetermined allowable range.

The reference pattern RMP formed by the line patterns RL1 and RL2 can suppress the reflectance of the surface with respect to the exposure illumination light to 20% or less as in the above-described embodiment 1. Therefore, even if the exposure illumination light is reflected by the reference pattern RMP, the exposure illumination light is not energy to such an extent that the exposure illumination light can be exposed as an unnecessary pattern in the photosensitive layer Pb3, and thus does not substantially become a problem.

In addition, the line patterns RL1, RL2 are formed as recesses by etching as shown in fig. 11, but the line patterns RL1, RL2 may be formed as projections using negative photoresist.

Further, since the reference pattern RMP formed by the line patterns RL1 and RL2 is formed as irregularities on the outer peripheral surface DRs of the rotary drum DR, if the layer difference of the irregularities is a specific condition in advance, the entire reference pattern RMP can be a phase pattern that suppresses the reflection intensity of both the illumination light for exposure and the illumination light for alignment.

Therefore, the level difference Δ DP shown in fig. 11 is preferably set under the following conditions.

Here, when the center wavelength of the exposure illumination light IE0 is λ 1, the center wavelength of the alignment illumination light ILa is λ 2, and m is an arbitrary integer including 0 (m ═ 0, 1, 2, · · s.), the center wavelength λ 1 of the exposure illumination light IE0 is set at λ 1

λ1·(m+1/8)/2≦ΔDP≦λ1·(m+7/8)/2···(3)

In the range of (3), the layer difference Δ DP is preferably set. Further, can be at

λ1·(m+1/4)/2≦ΔDP≦λ1·(m+3/4)/2···(4)

Within the range of (d), the step difference Δ DP is set.

On the other hand, the range of the step amount Δ DP can be determined by replacing the wavelength λ 1 in the above equations (3) and (4) with λ 2 with respect to the center wavelength λ 2 of the illumination light ILa for alignment.

In this case, by comparing the range of the layer difference Δ DP obtained with respect to the wavelength λ 1 of the exposure illumination light and the range of the layer difference Δ DP obtained with respect to the wavelength λ 2 of the alignment illumination light and setting the optimum layer difference Δ DP at or near the place where both the ranges overlap, the intensity of the reflected light by the reference pattern RMP can be reduced for both the exposure illumination light and the alignment illumination light.

That is, the step difference Δ DP satisfying or approximating the above-described equations (3) and (4) may be set for both the center wavelength λ 1 of the exposure illumination light and the center wavelength λ 2 of the alignment illumination light.

As described above, in embodiment 1 and embodiment 2, the base layer DR2 and the top layer DR3 are laminated on the outer peripheral surface of the cylindrical base material DR1 as the rotary drum DR to be relatively thick, and the reflectance is adjusted.

For example, in order to make the rotary drum DR lighter, the base DR1 may be cut out from an Al (aluminum) block, relatively hard chromium (Cr) for flatness (roundness and surface roughness) processing may be thickly plated on the outer peripheral surface of the base DR1, and then copper (Cu) plating as the base layer DR2 shown in fig. 8 and 11 described above may be further performed thereon, and DLC as the top layer DR3 may be laminated thereon in a predetermined thickness.

In this case, the reference pattern RMP (line patterns RL1, RL2) and the grid lines of the scale sections GPa, GPb are drawn with respect to the hard chromium layer or the copper base layer DR2 thereon.

[ embodiment 3 ]

The exposure apparatus of the above-described embodiment is an exposure apparatus in which an exposure mask pattern is scanned over a substrate P using a cylindrical mask DM, and even an exposure apparatus not using a mask, that is, an exposure apparatus such as so-called pattern generation, can perform pattern exposure while supporting the substrate P using a rotary drum DR. An example of such an exposure apparatus will be described with reference to fig. 12 and 13.

Fig. 12 is a plan view of a main part of the exposure apparatus (pattern writing apparatus) according to the present embodiment, as viewed in the XZ plane, and fig. 13 is a top view of the structure of fig. 12, as viewed in the XY plane.

In the present embodiment, as shown in fig. 13, pattern drawing is performed on an exposure area a7 on a substrate P supported in close contact with the outer peripheral surface of a rotary drum DR by linear scanning lines LL1, LL2, LL3, and LL4 of laser spot light (for example, having a diameter of 4 μm) scanned at high speed in the Y direction (the direction in which a rotation center line AX2 extends). The scanning lines LL1 to LL4 are arranged symmetrically with respect to the center plane p3 in a staggered manner because the scanning length in the Y direction is relatively short.

Among the scanning lines LL1 to LL4, odd-numbered scanning lines LL1 and LL3 are disposed on the-X side with respect to the central plane p3, and even-numbered scanning lines LL2 and LL4 are disposed on the + X side with respect to the central plane p 3.

This is because, as shown in fig. 12, the odd-numbered rendering modules UW1 and UW3 and the even-numbered rendering modules UW2 and UW4 that scan the spot light along the respective scan lines LL1 to LL4 are arranged symmetrically with respect to the center plane P3, avoiding spatial interference.

In the present embodiment, the shaft portions SF2 of the rotary drum DR are each independently provided with a scale disk SD for encoder measurement. The scale portions GPa (and GPb) engraved on the outer peripheral surface of the scale disk SD are measured by the encoder head EN1 disposed at the installation orientation line Le1 and the encoder head EN2 disposed at the installation orientation line Le 2.

Further, an encoder head EN3 that reads the scale portions 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 fig. 5 and 6.

As shown in fig. 12, since the 4 drawing modules UW1 to UW4 have the same configuration, a detailed configuration will be representatively described with respect to the drawing module UW 1.

The drawing module UW1 includes: an AOM (Acousto-optical Modulator) 80 that receives a light beam LB from an external ultraviolet laser light source (continuous or pulsed) and switches the projection/non-projection of the light beam LB onto the substrate P at a high speed; a rotating polygon mirror 82 for scanning beam LB from AOM80 along scan line LL1 on substrate P; a bending mirror 84; an f-theta lens system 86; and a photoelectric element 88.

The light beam BS1 projected toward the substrate P via the f- θ lens system 86 is modulated by the AOM80 that is ON/OFF in accordance with CAD information of a pattern to be drawn in scanning in the Y direction, and a pattern is drawn ON a photosensitive layer of the substrate P. By synchronizing the scanning of the Y direction of the light 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 partial exposure pattern corresponding to the scanning line LL1 in the exposure region a7 can be obtained.

Due to such a drawing, as shown in fig. 12, the direction of the axis of light flux BS1 reaching substrate P coincides with installation orientation line Le1 when viewed in the XZ plane. In this case, the direction of the axis of the light beam BS2 reaching the substrate P coincides with the installation orientation line Le2, similarly to the light beam BS2 projected from the even-numbered drawing modules UW 2.

In this way, when a pattern is drawn on exposure area a7 by 4 scan lines LL1 to LL4, the accuracy of the connection between scan lines LL1 to LL4 is important. In the case of fig. 13, the exposure region a7 first starts exposure of the regions corresponding to the odd-numbered scan lines LL1, LL3, and starts exposure of the regions corresponding to the even-numbered scan lines LL2, LL4 at the position where the substrate P has traveled the distance Δ Xu in the circumferential direction from this position.

Therefore, by accurately setting the writing start point and the writing end point formed by the spot lights of the scanning lines LL1 to LL4, the patterns formed in the entire exposure region a7 can be connected well.

In the pattern drawing apparatus as described above, by using the rotary drum DR having the structure shown in fig. 8 of embodiment 1 or the rotary drum DR having the structure shown in fig. 10 and 11 of embodiment 2, reflection of an unnecessary pattern as noise is reduced, and a high-precision layout is achieved.

In the above description of the respective embodiments, the substrate P may be supported by a flat support surface or a support surface curved in a cylindrical shape with a large curvature in the conveyance direction of the substrate P, in addition to the cylindrical rotary drum DR. Alternatively, the present invention can be similarly applied to a supporting device in which a gas layer formed by an air bearing is formed on a supporting surface of the supporting device, and the substrate is supported by floating a small amount of the substrate by the gas layer.

In each of the above embodiments, examples of the metal thin films of the underlayer DR2 and the overlayer DR3 include Cu (copper), Cr (chromium), and Cr₂O₃(trivalent chromium oxide), but not limited thereto, CrO (divalent chromium oxide) may be used. For example, Cu may be used as the base layer DR2 formed on the base DR1(SUS, Al, or the like), and CrO may be formed by plating, evaporation, or sputtering as the top layer DR3 deposited on the base layer DR 2.

Further, the diamond-like carbon (DLC) formed as the top layer DR3 in each of the above embodiments is composed of carbon atoms, and has an amorphous structure and/or an amorphous structure including a crystal, and the bonds between the carbon atoms are structures in which SP2 bonds of graphite and SP3 bonds of diamond are mixed.

DLC is formed as a hard film, but its properties differ depending on the amount of hydrogen contained, whether the electron orbitals of the crystal contained are close to diamond or graphite.

[ 4 th embodiment ]

The reference pattern RMP formed on the outer peripheral surface DRs of the rotary drum DR shown in fig. 10 may have any shape as long as strong stray light (unnecessary reflected light) is not generated from the reference pattern RMP by irradiation of the exposure light transmitted through the substrate P.

Fig. 14 is a perspective view showing a modification example of the reference pattern RMP formed on the outer peripheral surface DRs of the rotary drum DR as the 4 th embodiment, and the same reference numerals are given to the same components as those of the rotary drum DR in fig. 10.

In fig. 14, the scale disk SD for encoder measurement is fastened to both end surfaces in the direction (Y-axis direction) in which the shaft portion SF2 of the rotary drum DR extends, by a plurality of screws FB, as in fig. 12 and 13 described above. In the present embodiment, the diameters (or the radii from the center line AX2) of the scale portions GPa and GPb formed on the outer peripheral surface of the scale disc SD are set to be the same as the diameter (or the radius from the center line AX2) of the outer peripheral surface DRs of the rotary drum DR.

On the outer peripheral surface DRs of the rotary drum DR, a line pattern RLa linearly extending in a direction (Y axis direction) parallel to the rotation center line AX2, and 2 line patterns RLb, RLc linearly extending in the circumferential direction (circling in a plane parallel to the XZ plane) are formed as reference patterns RMP.

In the case of fig. 14, the line patterns RLa are arranged at 45 ° intervals in the circumferential direction. The 2 line patterns RLb, RLc are arranged at a constant interval in a direction (Y-axis direction) parallel to the rotation center line AX 2. The angular interval η in the circumferential direction of the line pattern RLa is not limited to 45 °, and may be any degree.

The constant intervals correspond to the intervals in the Y axis direction of the respective imaging regions Vw of the alignment systems AM1 to AM5 shown in fig. 6 described above. That is, the respective line patterns RLa, RLb, RLc are arranged such that the line pattern portions ALA of the line patterns RLa and the 2-line patterns RLb, RLc appear in the respective imaging regions Vw of the alignment systems AM1 to AM5 at a time as the rotary drum DR rotates, and the line pattern portions ALA of the intersection portions ALA are detected as the reference patterns RMP.

As shown in fig. 6, since the marks Ks1 to Ks5 are formed on the substrate P, at least one of the 2 line patterns RLb, RLc is arranged so as not to overlap the positions of the marks Ks1 to Ks5 in the Y-axis direction.

For example, when the line widths LW of the 2 line patterns RLb, RLc are set to 15 μm, the spacing distance in the Y axis direction is set to 150 μm, and the markers Ks1 to Ks5 are set to be located between the 2 line patterns RLb, RLc, the alignment systems AM1 to AM5 can detect both the markers Ks1 to Ks5 and the line patterns RLb, RLc in the imaging region Vw.

Further, when the blank portions (transparent regions where the marks Ks1 to Ks5 are arranged) between the 2 exposure regions a7 arranged adjacent to each other in the feeding direction on the substrate P shown in fig. 6 are set to be equal to or larger than a predetermined size, the intersection portion ALA formed by the line patterns RLa, RLb, RLc formed on the outer peripheral surface DRs of the rotary drum DR can be reliably arranged below the blank portions.

For example, if the diameter of the outer peripheral surface DRs of the rotary drum DR is Rdd, the spacing distance LK in the circumferential direction of the line pattern RLa along the outer peripheral surface DRs can be used when the previously described angular interval η in the circumferential direction of the line pattern RLa is employed

LK＝π·Rdd·(η/360)···(5)

And (4) showing.

If the dimension of the margin between the 2 exposure areas a7 with respect to the longitudinal direction (running direction) of the substrate P is LU, at least 1 line pattern RLa can be arranged in the margin of the substrate P once the condition LU > LK is satisfied.

As described above, in the present embodiment, since the reference pattern RMP is formed of the line patterns RLa, RLb, and RLc linearly extending in each of the longitudinal direction (the feeding direction) and the short direction (the Y-axis direction) of the substrate P, the two-dimensional positions of the intersections ALA appearing in the respective imaging regions Vw of the alignment systems AM1 to AM5 can be directly measured in the directions along the horizontal scanning lines and the vertical scanning lines of the imaging device, and the calculation time of the image processing can be advantageously shortened.

[ 5 th embodiment ]

When the line patterns RLa, RLb, and RLc shown in fig. 14 are formed on the outer peripheral surface DRs of the rotary drum DR, the arrangement directions of the line patterns and the pixel patterns formed in the exposure area a7 on the substrate P are aligned.

Therefore, even if the reflectance 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 described above), for example, the slight scattered light or the like generated at the step edge portions of the line patterns RLa, RLb, RLc is distributed in the direction of the line patterns RLa, RLb, RLc, and coincides with the arrangement direction of the wiring pattern and the pixel pattern formed in the exposure region a7 on the substrate P, which may be problematic.

Therefore, in the present embodiment, as shown in fig. 15, in order to reduce the minute scattered light and the like that may be generated at the step edge portions of the line patterns RLa, RLb, RLc, the line patterns RLa, RLb, RLc formed on the outer peripheral surface DRs of the rotary drum DR are recessed portions having a line width Lw, and the recessed portions are filled with the material PI that absorbs ultraviolet rays (exposure light).

The material PI is a paint containing an ultraviolet absorbing agent (hardened after drying), and can absorb scattered light and diffracted light generated at the edge of the layer difference and reduce the amount of scattered light and diffracted light reaching the front side of the substrate P. As an example of the ultraviolet absorber, BASF-SE is sold under the trade name Ubinul (registered trademark) or TINUVIN (registered trademark), and has a characteristic of absorbing exposure light in the ultraviolet band but hardly absorbing alignment illumination light in the visible band.

As described above, in the present embodiment, since the line pattern constituting the reference pattern RMP is formed by the concave portion and the ultraviolet absorbing material is filled in the concave portion, it is possible to further reduce the stray light reflected from the outer peripheral surface DRs of the rotary drum DR by the irradiation of the exposure light.

The method of filling the recesses of the outer peripheral surface DRs with the ultraviolet absorbing substance can be similarly applied to the line patterns RL1 and RL2 shown in fig. 10 and 11 described above. The coating material containing such an ultraviolet absorber can also be used for repairing uneven portions such as scratches and pits formed on the outer peripheral surface DRs in contact with the substrate P.

[ 6 th embodiment ]

Next, the structure of the substrate support apparatus described in fig. 2, 7, 10, and 14 above is applied to a maskless pattern exposure apparatus according to fig. 16.

In fig. 16, the substrate supporting apparatus is constituted by tension adjusting rollers TR1 and TR2, a rotary drum DR which is axially supported by a shaft portion SF2 and around which the substrate P is wound, a scale disk SD, encoder heads EN1 and EN3, and the like, as in the previous embodiments. The alignment system AM1 (and AM2 to AM5) is also constituted by an objective lens system GA1, a beam splitter GB1, an illumination unit GC1, and an imaging system GD 1.

The exposure unit includes: a light source 100 that generates exposure illumination light (exposure light); an illumination system 101 for uniformly illuminating a two-dimensionally arranged DMD (Digital Micromirror device, registered trademark) 104 with uniform illuminance by a plurality of movable micromirrors; 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 plurality of microlenses are two-dimensionally arranged; a field stop 107 conjugate to the surface of the substrate P wound on the rotary drum DR; and a projection optical system PL including lens systems 108 and 109 for projecting a light spot formed in the opening of the field stop 107 by each microlens of the MLA106 onto the substrate P.

Further, a beam splitter 110 that can be inserted into and removed from a direction (Y-axis direction) perpendicular to the paper surface of fig. 16 is provided on a pupil plane in the projection optical system PL of the present embodiment.

When the beam splitter 110 is inserted, when the exposure light from the MLA106 is projected onto the surface of the substrate P or the outer peripheral surface DRs of the rotary drum DR via the lens system 108, the beam splitter 110, and the lens system 109 of the projection optical system PL, a part of the reflected light reflected and returned by the surface or the outer peripheral surface DRs of the substrate P can be guided to the monitor system 112 including the condensing lens, the photoelectric element, and the like.

The monitor system 112 is configured as a light quantity monitor for measuring the light quantity of reflected light (exposure light) from the front surface or the outer peripheral surface DRs of the substrate P to determine whether or not a proper exposure amount (illuminance) is applied to the substrate P, or as an alignment monitor for collecting light information (optical images, diffracted light, and the like) on the marks Ks1 to Ks5 on the substrate P and the reference pattern RMP on the outer peripheral surface DRs from the reflected light (exposure light).

In the maskless pattern exposure apparatus shown in fig. 16, the angles of the micromirrors of the DMD104 are switched at high speed based on pattern drawing data (CAD data), feed position information of the substrate P based on a measurement signal from the encoder head EN1 (or EN3), or position information of marks Ks1 to Ks5 of the substrate P measured by the alignment system AM1(AM2 to AM 5).

This allows switching between a state in which the exposure light reflected by each micromirror is incident on the corresponding microlens of the MLA106 and a state in which the exposure light is not incident, and thus allows exposure (drawing) of a pattern formed in accordance with the drawing data on the substrate P.

The pattern exposure apparatus of the present embodiment shown in fig. 16 can cope with exposure processing of a substrate P having a large width in the Y-axis direction by providing a plurality of exposure units in the direction (Y-axis direction) parallel to the rotation center line AX2 under the conditions shown in fig. 2 and 4 described above. In this 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 it is preferable that many spots formed by the MLA106 are arranged at constant intervals in the trapezoidal shaped aperture.

In addition, in the case of the MLA106 in fig. 16, for example, in order to curve a focal length plane defined by a convergence point of a plurality of light spots formed on the emission side of the MLA107 into a cylindrical shape similarly to the outer peripheral surface DRs of the rotating drum DR, the focal distance may be slightly different between the microlenses arranged in the X direction among the respective microlenses.

Description of reference numerals

DM & gtcylinder mask, DR & gtrotation roller, DRs & gtrotation roller peripheral surface, DR1 & gtrotation roller base material, DR2 & gtrotation roller base layer, DR3 & gtrotation roller top layer, P & gtflexible substrate, PL1, PL2, PL3, PL4 & gtrotation roller projection optical system, AM 1-AM 5 & gtalignment system, RMP & gtreference pattern, RL1, RL2, RLa, RLb, RLc & gtline pattern, UW 1-UW 4 & gtdrawing module.

Claims (28)

1. A pattern forming apparatus for forming a pattern by optically processing a flexible sheet-like substrate conveyed in a longitudinal direction, comprising:

a substrate support member having: a base material for supporting the sheet-like substrate in a curved state or a flat state; a film body formed on a surface of the base material supporting the sheet-like substrate; a reference pattern formed on the film body by a layer difference;

a pattern exposure section that projects a first light for optically processing the sheet-like substrate supported by the substrate support member to expose the pattern; and

an optical detection unit for projecting a second light having a different wavelength from the first light to detect the reflected light from the reference pattern, in order to optically detect the reference pattern,

the thickness of the film body is adjusted to set the reflectance of the film body with respect to the first light to be smaller than the reflectance with respect to the second light.

2. The patterning device of claim 1,

the base material is made of a metal material containing iron or aluminum as a main component,

the film body is formed on the surface of the base material as a multilayer film having 2 or more layers, and the film body has a reflectance with respect to the first light of 20% or less.

3. The patterning device of claim 2,

the multilayer film is a two-layer construction of a base layer formed on a surface of the substrate and a top layer formed on top of the base layer, the base layer having a thickness greater than a thickness of the top layer.

4. The patterning device of claim 3,

the base layer is any one of chromium (Cr), copper (Cu), aluminum (Al), silver (Ag) or gold (Au), and the top layer is chromium oxide (Cr)₂O₃CrO), titanium oxide (TiO), zircon, hafnium oxide, and diamond-like carbon (DLC).

5. The patterning device of claim 4,

the base layer is made of chromium (Cr), and the top layer is made of chromium oxide (Cr) with the thickness of 30-150 nm₂O₃CrO).

6. The patterning device of claim 4,

the base layer is made of copper (Cu), and the top layer is made of diamond-like carbon (DLC) having a thickness of 0.5 [ mu ] m or more.

7. The patterning device of claim 3,

the reference pattern is formed on the base layer by a minute step, and the top layer is laminated along the minute step of the base layer.

8. The pattern forming apparatus according to any one of claims 1 to 7,

when the center wavelength of the first light is λ 1, m is an arbitrary integer including zero, and the step difference amount of the reference pattern is Δ DP, the following ranges are set:

λ1·(m+1/8)/2≦ΔDP≦λ1·(m+7/8)/2，

or λ 1 · (m +1/4)/2 ≦ Δ DP ≦ λ 1 · (m + 3/4)/2.

9. The pattern forming apparatus according to any one of claims 1 to 7,

the first light is light in the ultraviolet band,

the second light is light in a wavelength region from a visible waveband to an infrared waveband.

10. A pattern forming apparatus for forming a pattern on a photosensitive layer of a flexible sheet-like substrate having light transmissivity and being conveyed in a longitudinal direction, comprising:

a rotating drum that supports the sheet-like substrate at a part of an outer peripheral surface thereof, the outer peripheral surface being bent in a cylindrical surface shape at a constant radius from a center line, and the rotating drum being rotated about the center line to convey the sheet-like substrate in a longitudinal direction;

a pattern exposure section that exposes a pattern by projecting exposure light including a wavelength at which the photosensitive layer of the sheet-like substrate is exposed onto the photosensitive layer of the sheet-like substrate supported by the rotary drum;

an alignment system for irradiating alignment light having a wavelength different from that of the exposure light to detect an alignment mark formed on the sheet-like substrate supported by the rotating drum,

the rotating drum has a film body adjusted in thickness so that the reflectance with respect to the alignment light is greater than the reflectance with respect to the exposure light, and a reference pattern formed on the film body by a layer difference so as to be detectable by the alignment system.

11. The patterning device of claim 10,

the rotary drum is formed of a base material having a cylindrical outer peripheral surface, the base material being made of a metal material containing iron or aluminum as a main component,

the film body is a multilayer film formed on the outer peripheral surface of the base material in 2 or more layers, and the film body has a reflectance of 20% or less with respect to the exposure light.

12. The patterning device of claim 11,

the multilayer film is 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 larger than that of the top layer.

13. The patterning device of claim 12,

the base layer is any one of chromium (Cr), copper (Cu), aluminum (Al), silver (Ag) or gold (Au), and the top layer is chromium oxide (Cr)₂O₃CrO), titanium oxide (TiO), zircon, hafnium oxide, and diamond-like carbon (DLC).

14. The patterning device of claim 13,

the base layer is made of chromium (Cr), and the top layer is made of chromium oxide (Cr) with the thickness of 30-150 nm₂O₃CrO).

15. The patterning device of claim 13,

the base layer is made of copper (Cu), and the top layer is made of diamond-like carbon (DLC) having a thickness of 0.5 [ mu ] m or more.

16. The pattern forming apparatus according to any one of claims 12 to 15,

the reference pattern is formed on a surface of the base layer by a minute step.

17. The pattern forming apparatus according to any one of claims 10 to 13,

the alignment system includes:

an illumination unit that irradiates the alignment light to the mark formed on the sheet-like substrate or the reference pattern formed on the film body of the rotating drum;

an objective lens that enters light generated by the mark or the reference pattern;

and an imaging system that images the mark or the reference pattern received through the objective lens.

18. The pattern forming apparatus according to any one of claims 10 to 13,

when the center wavelength of the exposure light is λ 1, m is an arbitrary integer including zero, and the step difference amount of the reference pattern is Δ DP, the following ranges are set:

λ1·(m+1/8)/2≦ΔDP≦λ1·(m+7/8)/2，

or λ 1 · (m +1/4)/2 ≦ Δ DP ≦ λ 1 · (m + 3/4)/2.

19. The pattern forming apparatus according to any one of claims 10 to 13,

the exposure light is light in an ultraviolet band,

the alignment light is light in a wavelength region from a visible band to an infrared band.

20. A substrate supporting device, provided in an exposure device for exposing a sheet-like substrate having optical transparency to a first light, to a pattern, for supporting the sheet-like substrate under exposure, comprising:

a cylindrical base member having an outer peripheral surface and a shaft portion for supporting the sheet-like substrate along the outer peripheral surface, the outer peripheral surface being bent into a cylindrical surface shape at a constant radius from a predetermined center line, the shaft portion being provided coaxially with the center line and being axially supported in the exposure apparatus;

a film body formed on the outer peripheral surface of the cylindrical base material with a predetermined thickness, and having a support surface in contact with the back surface of the sheet-like substrate;

a reference pattern formed on a portion of the film body by a minute step,

the supporting surface has a reflectance with respect to the first light that is smaller than a reflectance of the supporting surface with respect to second light that is light of a different wavelength from the first light for detecting the reference pattern.

21. The substrate support apparatus of claim 20,

the cylindrical base material is made of a metal material containing iron or aluminum as a main component,

the film body is a multilayer film as follows: the film is formed on the outer peripheral surface of the cylindrical base material in 2 or more layers, and the film thickness is set so that the reflectance of the support surface with respect to the first light is 20% or less.

22. The substrate support apparatus of claim 21,

the multilayer film has a double-layer structure including a base layer formed on the outer peripheral surface of the cylindrical base material and a top layer formed on the base layer and constituting the support surface, and the base layer has a thickness larger than that of the top layer.

23. The substrate support apparatus of claim 22,

the base layer is any one of chromium (Cr), copper (Cu), aluminum (Al), silver (Ag) or gold (Au), and the top layer is chromium oxide (Cr)₂O₃CrO), titanium oxide (TiO), zircon, hafnium oxide, and diamond-like carbon (DLC).

24. The substrate support apparatus of claim 23,

the base layer is made of chromium (Cr), and the top layer is made of chromium oxide (Cr) with the thickness of 30-150 nm₂O₃CrO).

25. The substrate support apparatus of claim 23,

the base layer is made of copper (Cu), and the top layer is made of diamond-like carbon (DLC) having a thickness of 0.5 [ mu ] m or more.

26. The substrate support apparatus of any of claims 22 to 25,

the reference pattern is formed on the base layer by a minute step.

27. The substrate support apparatus of any of claims 20 to 23,

when the center wavelength of the first light is λ 1, m is an arbitrary integer including zero, and the difference in the minute layer of the reference pattern is Δ DP, the following ranges are set:

λ1·(m+1/8)/2≦ΔDP≦λ1·(m+7/8)/2，

or λ 1 · (m +1/4)/2 ≦ Δ DP ≦ λ 1 · (m + 3/4)/2.

28. The substrate support apparatus of any of claims 20 to 23,

the first light is light in the ultraviolet band,

the second light is light in a wavelength region from a visible waveband to an infrared waveband.