JP6690695B2 - Scanning exposure device - Google Patents

Description

The present invention projects a pattern of a mask onto a substrate, relates to a scanning exposure equipment that exposes the pattern on the substrate.

  There is a device manufacturing system for manufacturing various devices such as display devices such as liquid crystal displays and semiconductors. The device manufacturing system includes a substrate processing apparatus such as an exposure apparatus. The substrate processing apparatus projects an image of a pattern formed on a mask (or reticle) arranged in the illumination area onto a substrate or the like arranged in the projection area, and exposes the pattern on the substrate. The mask used in the substrate processing apparatus is generally a planar mask, but a cylindrical mask is also known for continuously scanning and exposing a plurality of device patterns on the substrate (Patent Document 1). 1).

  Further, as a substrate processing apparatus, there is a projection exposure apparatus described in Patent Document 2. The projection exposure apparatus described in Patent Document 2 uses a photosensitive substrate as a substrate so that the surface of the photosensitive substrate and the best image plane of the pattern image projected by the projection optical system are relatively inclined with respect to the one-dimensional moving direction. The substrate holder held on the stage and the photosensitive substrate move along the tilted direction during the scanning exposure so that the substrate holder moves in the one-dimensional direction of the substrate stage in the direction of the optical axis of the projection optical system. And holder drive means for moving in the direction. With the above configuration, the projection exposure apparatus can change the focus state of the light beam projected on the exposure surface of the photosensitive substrate depending on the position of the scanning exposure in the one-dimensional direction.

International Publication No. 2008/029917 Japanese Patent No. 2830492

  As described in Patent Document 2, by performing exposure while changing the focus state, the light flux projected by the projection optical system and the exposure surface due to the shift of the relative relationship between the mask and the substrate or the shift of the optical system. Even when a change occurs in the relationship with, exposure can be performed in a focus state including the best focus position. As a result, it is possible to suppress a change in image contrast exposed on the photosensitive substrate (photoresist layer).

  However, the projection exposure apparatus described in Patent Document 2 uses the substrate holder to tilt the substrate with respect to the projection optical device (projection optical system). Therefore, the adjustment (control) of the relative position becomes complicated. Particularly, in the step-and-scan method in which the mask and the substrate are relatively scanned for each of a plurality of exposure regions (shots) on the substrate to move the substrate stepwise, the substrate holder is provided for each scanning exposure of each exposure region on the substrate. It is necessary to repeatedly control the inclination of and the movement in the focus direction at high speed, which complicates the control and causes vibration.

  Further, in the scanning exposure type substrate processing apparatus, when the width of the exposure region on the substrate in the scanning exposure direction is small, the exposure amount given to the photosensitive substrate becomes small. For this reason, it is necessary to increase the illuminance per unit area of the exposure light projected onto the exposure area on the substrate or to slow down the scanning exposure speed. Conversely, if the width of the exposure region on the substrate in the scanning exposure direction is increased, the quality of the formed pattern (transfer fidelity) may decrease.

Aspect of the present invention has an object to provide a scanning exposure equipment capable of producing a high quality substrate with high productivity.

  According to the first aspect of the present invention, while rotating the cylindrical mask having the mask pattern held along the circumferential surface curved at the first radius from the first axis about the first axis, A scanning exposure apparatus which moves a flexible long sheet-shaped substrate in a scanning exposure direction along a longitudinal direction to expose the mask pattern on the surface of the substrate, wherein the mask pattern is formed on the mask pattern. Illumination light directed toward an illumination area that is set to have a slender rectangular shape or a rectangle in the direction of the first axis and has a predetermined width in the circumferential direction of the circumferential surface corresponding to the scanning exposure direction. And a light flux from the mask pattern appearing in the illumination area toward the projection area on the substrate side corresponding to the illumination area to project an image of the mask pattern. Depending on the radius of 1 A projection optical system for forming an image along a projection image plane curved in the scanning exposure direction, and an outer peripheral surface curved in a cylindrical surface with a second radius from a second axis arranged parallel to the first axis. A curved drum that supports the substrate by bending it in the lengthwise direction, and rotates around the second axis to move the substrate in the circumferential direction of the outer peripheral surface corresponding to the scanning exposure direction; The cylindrical mask, the rotating drum, and the projection optical system are arranged so that the projected image plane and the curved surface of the substrate intersect at each of two positions separated in the scanning exposure direction in the projection area. A set scanning exposure apparatus is provided.

According to the second aspect of the present invention, the long substrate having flexibility and the mask pattern are moved in the scanning exposure direction with respect to the projection optical system to expose the mask pattern on the surface of the substrate. A scanning exposure method, wherein a cylindrical mask holding the mask pattern is rotated around the first axis along a first circumferential surface curved in the scanning exposure direction with a predetermined radius from the first axis. And a part of the substrate in the longitudinal direction is curved in the scanning exposure direction along a second circumferential surface that is curved in a cylindrical shape with a predetermined radius from a second axis that is set parallel to the first axis. Rotating the supporting and rotating drum about the second axis to move the substrate in the longitudinal direction;
On the mask pattern, it is set to be an elongated rectangular shape or a rectangle in the direction of the first axis, and is set to have a predetermined width in the circumferential direction corresponding to the scanning exposure direction of the first circumferential surface. Illuminating the illumination area toward the illumination area, and projecting the projection light flux from the mask pattern appearing in the illumination area toward the projection area on the substrate side corresponding to the illumination area by the projection optical system. By doing so, the image of the mask pattern is imaged along the projection image plane curved in the scanning exposure direction according to the radius of the first circumferential surface, and is curved with the curved projection image plane. Setting the positional relationship in the focus direction between the projection image plane and the surface of the substrate such that the surface of the substrate intersects with each other at two positions apart in the scanning exposure direction in the projection area. Including査露 light method is provided.

  According to a third aspect of the present invention, there is provided a device manufacturing method for forming a pattern of an electronic device on a sheet-shaped flexible long substrate, wherein a photosensitive functional layer is formed on the surface of the substrate. By the first step and the scanning exposure method of the second aspect, the photosensitive functional layer formed on the surface of the curved substrate is scanned and exposed with a projected image of a mask pattern corresponding to the pattern of the electronic device. There is provided a device manufacturing method including a second step, and a third step of performing a wet process on the exposed photosensitive functional layer to form a pattern of the electronic device.

  According to the aspect of the present invention, in the scanning exposure direction of the exposure surface of the substrate, by projecting the light flux including the two best focus positions onto the projection area, it is possible to produce a high quality substrate with high productivity. .

FIG. 1 is a diagram showing the configuration of the device manufacturing system of the first embodiment. FIG. 2 is a diagram showing the overall configuration of the exposure apparatus (substrate processing apparatus) of the first embodiment. FIG. 3 is a diagram showing an arrangement of illumination areas and projection areas of the exposure apparatus shown in FIG. FIG. 4 is a diagram showing a configuration of an illumination optical system and a projection optical system of the exposure apparatus shown in FIG. FIG. 5 is a diagram exaggerating the behavior of the illumination light beam and the projection light beam in the mask. FIG. 6A is an explanatory diagram showing the relationship between the projected image plane of the mask pattern and the exposure plane of the substrate. FIG. 6B is a graph showing how the defocus amount changes within the exposure width. FIG. 7 is a diagram showing the overall configuration of an exposure apparatus (substrate processing apparatus) according to the second embodiment. FIG. 8 is an explanatory diagram showing the relationship between the projected image plane of the mask pattern and the exposure plane of the substrate. FIG. 9 is a graph showing an example of the relationship between exposure coordinates and defocus. FIG. 10 is a graph showing an example of the relationship between defocus and point image intensity. FIG. 11 is a graph showing an example of the relationship between the change in defocus amount and the intensity difference. FIG. 12 is a graph showing an example of the relationship between the defocus amount and the L / S contrast change. FIG. 13 is a graph showing an example of the relationship between the defocus amount and the change in the L / S contrast ratio. FIG. 14 is a graph showing an example of the relationship between the defocus amount and the L / S CD and slice level. FIG. 15 is a graph showing an example of the relationship between the defocus amount and the contrast change of an isolated line. FIG. 16 is a graph showing an example of the relationship between the defocus amount and the change in the contrast ratio of an isolated line. FIG. 17 is a graph showing an example of the relationship between the defocus amount and the CD and slice level of an isolated line. FIG. 18 is a diagram showing the overall configuration of an exposure apparatus (substrate processing apparatus) according to the third embodiment. FIG. 19 is a diagram showing the overall configuration of an exposure apparatus (substrate processing apparatus) according to the fourth embodiment. FIG. 20 is an explanatory diagram showing the relationship between the projected image surface of the mask pattern and the exposure surface of the substrate. FIG. 21 is a flowchart showing the exposure method. FIG. 22 is a flowchart showing the device manufacturing method.

  Modes (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the embodiments below. Further, the constituent elements described below include those that can be easily conceived by those skilled in the art and those that are substantially the same. Furthermore, the components described below can be combined as appropriate. Further, various omissions, substitutions or changes of the constituent elements can be made without departing from the scope of the present invention. For example, in the following embodiments, a case of manufacturing a flexible display as a device will be described, but the present invention is not limited to this. As the device, a wiring board, a semiconductor substrate, or the like can be manufactured.

[First Embodiment]
In the first embodiment, the substrate processing apparatus that performs the exposure processing on the substrate is the exposure apparatus. In addition, the exposure apparatus is incorporated in a device manufacturing system that manufactures a device by performing various types of processing on a substrate after exposure. First, the device manufacturing system will be described.

<Device manufacturing system>
FIG. 1 is a diagram showing the configuration of the device manufacturing system of the first embodiment. A device manufacturing system 1 shown in FIG. 1 is a line for manufacturing a flexible display as a device (flexible display manufacturing line). An example of the flexible display is an organic EL display. The device manufacturing system 1 sends out the substrate P from a supply roll FR1 in which a flexible substrate P is wound in a roll shape, continuously performs various processes on the sent-out substrate P, and then This is a so-called roll-to-roll system in which the processed substrate P is wound around a recovery roll FR2 as a flexible device. In the device manufacturing system 1 of the first embodiment, the substrate P, which is a film-like sheet, is sent out from the supply roll FR1, and the substrates P sent out from the supply roll FR1 are sequentially processed into n processing units U1 and U2. , U3, U4, U5, ... Un before being wound around the recovery roll FR2. First, the substrate P to be processed by the device manufacturing system 1 will be described.

  As the substrate P, for example, a resin film, a foil made of metal or alloy such as stainless steel, or the like is used. Examples of the material of the resin film include polyethylene resin, polypropylene resin, polyester resin, ethylene vinyl copolymer resin, polyvinyl chloride resin, cellulose resin, polyamide resin, polyimide resin, polycarbonate resin, polystyrene resin, and vinyl acetate resin. It contains 1 or 2 or more.

  It is desirable to select a substrate P having a coefficient of thermal expansion that is not remarkably large so that the amount of deformation due to heat received in various processes performed on the substrate P can be substantially ignored. The coefficient of thermal expansion may be set smaller than a threshold value according to the process temperature or the like by mixing an inorganic filler with the resin film, for example. The inorganic filler may be, for example, titanium oxide, zinc oxide, alumina, silicon oxide or the like. The substrate P may be a single-layer body of ultra-thin glass having a thickness of about 100 μm manufactured by a float method or the like, or a laminate obtained by laminating the above-mentioned resin film, foil, etc. on the ultra-thin glass. May be

  The substrate P configured in this way becomes a supply roll FR1 by being wound in a roll shape, and the supply roll FR1 is mounted in the device manufacturing system 1. The device manufacturing system 1 in which the supply roll FR1 is mounted repeatedly performs various kinds of processing for manufacturing one device on the substrate P sent from the supply roll FR1. Therefore, the processed substrate P is in a state in which a plurality of devices are connected. That is, the substrate P sent from the supply roll FR1 is a substrate for multiple cutting. The substrate P is obtained by modifying and activating the surface of the substrate P in advance by a predetermined pretreatment, or an imprinting method (micro stamper) having a fine partition structure (concavo-convex structure) for precise patterning on the surface. It is also possible to use those formed by the above.

  The processed substrate P is wound as a roll to be collected as a collecting roll FR2. The recovery roll FR2 is mounted on a dicing device (not shown). The dicing machine equipped with the recovery roll FR2 divides (dices) the processed substrate P into devices to form a plurality of devices. The size of the substrate P is, for example, about 10 cm to 2 m in the width direction (shorter direction) and 10 m or more in the length direction (longer direction). The size of the substrate P is not limited to the above size.

  Next, the device manufacturing system 1 will be described with reference to FIG. In FIG. 1, an orthogonal coordinate system in which the X direction, the Y direction, and the Z direction are orthogonal to each other. The X direction is a direction connecting the supply roll FR1 and the recovery roll FR2 in the horizontal plane, and is the left-right direction in FIG. The Y direction is a direction orthogonal to the X direction in the horizontal plane, and is the front-back direction in FIG. The Y direction is the axial direction of the supply roll FR1 and the recovery roll FR2. The Z direction is the vertical direction and is the vertical direction in FIG.

  The device manufacturing system 1 includes a substrate supply device 2 that supplies a substrate P, processing devices U1 to Un that perform various processes on the substrate P that is supplied by the substrate supply device 2, and processing devices U1 to Un. A substrate recovery device 4 for recovering the processed substrate P and a host controller 5 for controlling each device of the device manufacturing system 1 are provided.

  A supply roll FR1 is rotatably mounted on the substrate supply device 2. The substrate supply device 2 has a drive roller R1 that sends out the substrate P from the mounted supply roll FR1 and an edge position controller EPC1 that adjusts the position of the substrate P in the width direction (Y direction). The drive roller R1 rotates while sandwiching both front and back surfaces of the substrate P, and supplies the substrate P to the processing devices U1 to Un by feeding the substrate P in the transport direction from the supply roll FR1 toward the recovery roll FR2. At this time, the edge position controller EPC1 moves the board P in the width direction so that the position at the end portion (edge) in the width direction of the board P falls within a range of ± 10 μm to several tens μm with respect to the target position. Then, the position of the substrate P in the width direction is corrected.

  A recovery roll FR2 is rotatably mounted on the substrate recovery device 4. The substrate recovery device 4 includes a drive roller R2 that draws the processed substrate P toward the recovery roll FR2 side, and an edge position controller EPC2 that adjusts the position of the substrate P in the width direction (Y direction). The substrate collecting device 4 rotates while holding both front and back surfaces of the substrate P by the driving roller R2, pulls the substrate P in the transport direction, and rotates the collecting roll FR2 to wind up the substrate P. At this time, the edge position controller EPC2 is configured similarly to the edge position controller EPC1 and corrects the position of the substrate P in the width direction so that the end (edge) in the width direction of the substrate P does not vary in the width direction. ..

  The processing device U1 is a coating device that coats the photosensitive functional liquid on the surface of the substrate P supplied from the substrate supply device 2. As the photosensitive functional liquid, for example, a photoresist, a photosensitive silane coupling material (liquid-repellency modifying material), a photosensitive plating reducing material, a UV curable resin liquid, or the like is used. The processing unit U1 is provided with a coating mechanism Gp1 and a drying mechanism Gp2 in order from the upstream side in the transport direction of the substrate P. The coating mechanism Gp1 includes an impression roller DR1 around which the substrate P is wound, and an application roller DR2 that faces the impression roller DR1. The coating mechanism Gp1 sandwiches the substrate P between the impression cylinder roller DR1 and the application roller DR2 while the supplied substrate P is wound around the impression cylinder roller DR1. Then, the application mechanism Gp1 applies the photosensitive functional liquid by the application roller DR2 while moving the substrate P in the transport direction by rotating the impression cylinder roller DR1 and the application roller DR2. The drying mechanism Gp2 blows drying air such as hot air or dry air to remove the solute (solvent or water) contained in the photosensitive functional liquid, and dries the substrate P coated with the photosensitive functional liquid. A photosensitive functional layer is formed on the substrate P.

  The processing device U2 heats the substrate P transported from the processing device U1 to a predetermined temperature (for example, several tens to 120 ° C.) in order to stabilize the photosensitive functional layer formed on the surface of the substrate P. Is. The processing apparatus U2 is provided with a heating chamber HA1 and a cooling chamber HA2 in order from the upstream side in the transport direction of the substrate P. The heating chamber HA1 is provided therein with a plurality of rollers and a plurality of air turnbars, and the plurality of rollers and the plurality of air turnbars form a transfer path for the substrate P. The plurality of rollers are provided in rolling contact with the back surface of the substrate P, and the plurality of air turn bars are provided on the front surface side of the substrate P in a non-contact state. The plurality of rollers and the plurality of air turn bars are arranged in a meandering conveyance path in order to lengthen the conveyance path of the substrate P. The substrate P passing through the heating chamber HA1 is heated to a predetermined temperature while being transported along a meandering transport path. The cooling chamber HA2 cools the substrate P to the environmental temperature so that the temperature of the substrate P heated in the heating chamber HA1 becomes equal to the environmental temperature of the subsequent process (processing device U3). The cooling chamber HA2 is provided with a plurality of rollers therein, and the plurality of rollers are arranged in a meandering transfer path in order to lengthen the transfer path of the substrate P, similarly to the heating chamber HA1. The substrate P passing through the cooling chamber HA2 is cooled while being transported along a meandering transport path. A drive roller R3 is provided on the downstream side in the transport direction of the cooling chamber HA2, and the drive roller R3 rotates while nipping the substrate P that has passed through the cooling chamber HA2, so that the substrate P is directed toward the processing apparatus U3. Supply. When the substrate P is a resin film such as PET (polyethylene terephthalate) or PEN (polyethylene naphthalate), the heating of the substrate P by the heating chamber HA1 is preferably set so as not to exceed its glass transition temperature.

  The processing device (substrate processing device) U3 projects and exposes a pattern such as a display circuit or wiring on a substrate (photosensitive substrate) P, which is supplied from the processing device U2 and has a photosensitive functional layer formed on the surface thereof. It is an exposure device that does. As will be described later in detail, the processing apparatus U3 illuminates the reflection type mask M with the illumination light flux, and projects and exposes the projection light flux obtained by the illumination light flux being reflected by the mask M onto the substrate P. The processing device U3 includes a drive roller R4 that sends the substrate P supplied from the processing device U2 to the downstream side in the transport direction, and an edge position controller EPC3 that adjusts the position of the substrate P in the width direction (Y direction). The drive roller R4 rotates while sandwiching both front and back surfaces of the substrate P, and sends the substrate P to the downstream side in the transport direction to support the substrate P at the exposure position (also referred to as a rotating drum). Supply for.

  The edge position controller EPC3 is configured similarly to the edge position controller EPC1, and corrects the position of the substrate P in the width direction so that the width direction of the substrate P at the exposure position (substrate supporting drum) becomes the target position. Further, the processing apparatus U3 has two sets of drive rollers R5 and R6 that send the substrate P to the downstream side in the transport direction in a state where the exposed substrate P is slackened. The drive roller R5 cooperates with the drive roller R4 described above to apply a predetermined tension in the transport direction of the substrate P. The two sets of drive rollers R5 and R6 are arranged at a predetermined interval in the transport direction of the substrate P. The drive roller R5 holds and rotates the upstream side of the conveyed substrate P, and the drive roller R6 holds and rotates the downstream side of the conveyed substrate P to direct the substrate P to the processing apparatus U4. Supply. At this time, since the substrate P is provided with the slack, it is possible to absorb the fluctuation of the transport speed that occurs on the downstream side of the driving roller R6 in the transport direction, and the influence of the exposure process on the substrate P due to the fluctuation of the transport speed is cut off. can do. Further, in the processing unit U3, an alignment microscope for detecting alignment marks or the like formed in advance on the substrate P in order to relatively align (align) the image of a part of the mask pattern of the mask M and the substrate P. AM1 and AM2 are provided.

  The processing apparatus U4 is a wet processing apparatus that performs wet development processing, electroless plating processing, and the like on the exposed substrate P transported from the processing apparatus U3. The processing unit U4 has therein three processing baths BT1, BT2, BT3 hierarchically arranged in the vertical direction (Z direction), and a plurality of rollers for transporting the substrate P. The plurality of rollers are arranged so as to serve as a transport path through which the substrate P sequentially passes inside the three processing tanks BT1, BT2, and BT3. A drive roller R7 is provided on the downstream side in the transport direction of the processing tank BT3, and the drive roller R7 rotates while sandwiching the substrate P that has passed through the processing tank BT3, so that the substrate P is directed toward the processing device U5. Supply.

  Although illustration is omitted, the processing device U5 is a drying device that dries the substrate P transported from the processing device U4. The processing unit U5 removes droplets and mist adhering to the substrate P that has been wet-processed in the processing unit U4, and adjusts the water content of the substrate P to a predetermined water content. The substrate P dried by the processing device U5 is transported to the processing device Un via some processing devices. After being processed by the processing device Un, the substrate P is wound up on the recovery roll FR2 of the substrate recovery device 4.

  The host controller 5 centrally controls the substrate supply device 2, the substrate recovery device 4, and the plurality of processing devices U1 to Un. The host controller 5 controls the substrate supply device 2 and the substrate recovery device 4 to convey the substrate P from the substrate supply device 2 toward the substrate recovery device 4. Further, the host controller 5 controls the plurality of processing devices U1 to Un in synchronization with the transport of the substrate P to execute various processes on the substrate P.

<Exposure device (substrate processing device)>
Next, the configuration of the exposure apparatus (substrate processing apparatus) as the processing apparatus U3 of the first embodiment will be described with reference to FIGS. 2 to 4. FIG. 2 is a diagram showing the overall configuration of the exposure apparatus (substrate processing apparatus) of the first embodiment. FIG. 3 is a diagram showing an arrangement of illumination areas and projection areas of the exposure apparatus shown in FIG. FIG. 4 is a diagram showing a configuration of an illumination optical system and a projection optical system of the exposure apparatus shown in FIG. Hereinafter, the processing device U3 is referred to as an exposure device U3.

  The exposure apparatus U3 shown in FIG. 2 is a so-called scanning exposure apparatus, and projects the image of the mask pattern formed on the outer peripheral surface of the cylindrical mask M onto the surface of the substrate P while transporting the substrate P in the transport direction. Expose. Note that, in FIG. 2, an orthogonal coordinate system in which the X direction, the Y direction, and the Z direction are orthogonal to each other is the same as the orthogonal coordinate system in FIG.

  First, the mask M used in the exposure apparatus U3 will be described. The mask M is a reflective mask using, for example, a metal cylindrical body. The mask M is formed into a cylindrical body having an outer peripheral surface (circumferential surface) having a radius of curvature Rm centered on the first axis AX1 extending in the Y direction, and has a constant radial thickness. The circumferential surface of the mask M is a surface P1 on which a predetermined mask pattern is formed. The surface P1 of the mask M includes a highly reflective portion that reflects a light beam in a predetermined direction with high efficiency, and a reflection suppressing portion that does not reflect the light beam in a predetermined direction or that reflects with low efficiency. The mask pattern is formed by the high reflection portion and the reflection suppressing portion. Here, the reflection suppressing unit may reduce the light reflected in the predetermined direction. Therefore, the reflection suppressing portion may absorb the light, transmit the light, or reflect the light in a direction other than the predetermined direction (for example, irregular reflection). Here, in the mask M, the reflection suppressing portion can be made of a material that absorbs light or a material that transmits light. In the exposure apparatus U3, a mask made of a metal cylinder can be used as the mask M having the above configuration. Therefore, the exposure apparatus U3 can perform exposure using an inexpensive mask.

  The mask M may have all or a part of the panel pattern corresponding to one display device formed therein, or may have the panel pattern corresponding to a plurality of display devices formed therein. In the mask M, a plurality of panel patterns may be repeatedly formed in the circumferential direction around the first axis AX1, or a plurality of small panel patterns may be repeatedly formed in a direction parallel to the first axis AX1. May be. Further, the mask M may be formed with a panel pattern for the first display device and a panel pattern for the second display device having a size different from that of the first display device. Further, the mask M is not limited to the shape of the cylindrical body as long as it has a circumferential surface having a radius of curvature Rm centered on the first axis AX1. For example, the mask M may be an arc-shaped plate material having a circumferential surface. Further, the mask M may have a thin plate shape, and the thin plate mask M may be curved and attached to a cylindrical member so as to follow the circumferential surface.

  Next, the exposure apparatus U3 shown in FIG. 2 will be described. The exposure apparatus U3 includes a mask holding mechanism 11, a substrate supporting mechanism 12, an illumination optical system IL, and a projection optical system PL, in addition to the drive rollers R4 to R6, the edge position controller EPC3, and the alignment microscopes AM1 and AM2 described above. , Lower control device 16. The exposure device U3 guides the illumination light emitted from the light source device 13 by the illumination optical system IL and the projection optical system PL, so that the light flux of the pattern of the mask M held by the mask holding mechanism 11 is guided by the substrate supporting mechanism. It is projected on the substrate P held by 12.

  The lower-level controller 16 controls each unit of the exposure apparatus U3 and causes each unit to execute processing. The lower controller 16 may be a part or all of the upper controller 5 of the device manufacturing system 1. The lower control device 16 may be a device that is controlled by the upper control device 5 and is different from the upper control device 5. The lower control device 16 includes, for example, a computer.

  The mask holding mechanism 11 includes a mask holding drum (mask holding member) 21 that holds the mask M, and a first drive unit 22 that rotates the mask holding drum 21. The mask holding drum 21 holds the mask M so that the first axis AX1 of the mask M becomes the center of rotation. The first drive unit 22 is connected to the lower control device 16 and rotates the mask holding drum 21 about the first axis AX1.

  Although the mask holding mechanism 11 holds the cylindrical mask M by the mask holding drum 21, the mask holding mechanism 11 is not limited to this configuration. The mask holding mechanism 11 may wind and hold the thin plate-shaped mask M along the outer peripheral surface of the mask holding drum 21. The mask holding mechanism 11 may hold the mask M, which is an arc-shaped plate material, on the outer peripheral surface of the mask holding drum 21.

  The substrate support mechanism 12 includes a substrate support drum 25 that supports the substrate P on a cylindrical outer peripheral surface and is rotatable, a second drive unit 26 that rotates the substrate support drum 25, and a pair of air turn bars ATB1 and ATB2. , And a pair of guide rollers 27 and 28. The substrate support drum 25 is formed in a cylindrical shape having an outer peripheral surface (circumferential surface) having a radius of curvature Rp centered on the second axis AX2 extending in the Y direction. Here, the first axis AX1 and the second axis AX2 are parallel to each other, and a plane passing through the first axis AX1 and the second axis AX2 is a center plane CL. A part of the circumferential surface of the substrate support drum 25 serves as a support surface P2 that supports the substrate P. That is, the substrate support drum 25 supports the substrate P by winding the substrate P on the support surface P2. The second drive unit 26 is connected to the lower control device 16 and rotates the substrate support drum 25 about the second axis AX2.

  The pair of air turn bars ATB1 and ATB2 are provided on the upstream side and the downstream side in the transport direction of the substrate P, with the substrate supporting drum 25 interposed therebetween. The pair of air turn bars ATB1 and ATB2 are provided on the front surface side of the substrate P and are arranged below the support surface P2 of the substrate support drum 25 in the vertical direction (Z direction). The pair of guide rollers 27 and 28 are provided on the upstream side and the downstream side in the transport direction of the substrate P, with the pair of air turn bars ATB1 and ATB2 interposed therebetween. The pair of guide rollers 27, 28 guides the substrate P conveyed by the one guide roller 27 from the drive roller R4 to the air turn bar ATB1, and the other guide roller 28 conveyed by the air turn bar ATB2. Guide P to drive roller R5.

  Therefore, the substrate support mechanism 12 guides the substrate P conveyed from the drive roller R4 to the air turn bar ATB1 by the guide roller 27, and introduces the substrate P passing through the air turn bar ATB1 to the substrate support drum 25. The substrate support mechanism 12 rotates the substrate support drum 25 by the second drive unit 26 to support the substrate P introduced into the substrate support drum 25 on the support surface P2 of the substrate support drum 25, while the air turn bar ATB2. Transport to. The substrate support mechanism 12 guides the substrate P conveyed to the air turn bar ATB2 to the guide roller 28 by the air turn bar ATB2, and guides the substrate P passing through the guide roller 28 to the drive roller R5.

  At this time, the lower-level control device 16 connected to the first drive unit 22 and the second drive unit 26 synchronously rotates the mask holding drum 21 and the substrate support drum 25 at a predetermined rotation speed ratio, so that the mask M is rotated. The image of the mask pattern formed on the surface P1 is continuously and repeatedly projected and exposed on the surface of the substrate P wound around the supporting surface P2 of the substrate supporting drum 25 (the curved surface following the circumferential surface).

  The light source device 13 emits the illumination light flux EL1 with which the mask M is illuminated. The light source device 13 includes a light source 31 and a light guide member 32. The light source 31 is a light source that emits light having a predetermined wavelength. The light source 31 is, for example, a lamp light source such as a mercury lamp, a laser diode, a light emitting diode (LED), or the like. Illumination light emitted from the light source 31 is, for example, bright lines (g line, h line, i line) emitted from a lamp light source, far ultraviolet light (DUV light) such as KrF excimer laser light (wavelength 248 nm), ArF excimer laser light. (Wavelength 193 nm) and the like. Here, it is preferable that the light source 31 emits the illumination luminous flux EL1 including a wavelength equal to or shorter than the i-line (wavelength of 365 nm). The light source 31 emits a laser beam (wavelength of 355 nm) emitted from a YAG laser (third harmonic laser) or a YAG laser (fourth harmonic laser) as an illumination luminous flux EL1 having a wavelength of i-line or less. Laser light (wavelength of 266 nm), laser light emitted from a KrF excimer laser (wavelength of 248 nm), or the like can be used.

  The light guide member 32 guides the illumination light flux EL1 emitted from the light source 31 to the illumination optical system IL. The light guide member 32 is composed of an optical fiber, a relay module using a mirror, or the like. Further, when a plurality of illumination optical systems IL are provided, the light guide member 32 splits the illumination luminous flux EL1 from the light source 31 into a plurality of portions and guides the plurality of illumination luminous fluxes EL1 to the plurality of illumination optical systems IL. The light guide member 32 causes the illumination light flux EL1 emitted from the light source 31 to enter the polarization beam splitter PBS as light in a predetermined polarization state. Here, the polarization beam splitter PBS of the present embodiment reflects the light flux of S-polarized linearly polarized light and transmits the light flux of P-polarized linearly polarized light. Therefore, the light source device 13 emits the illumination light flux EL1 which becomes the linearly polarized (S-polarized) light flux that enters the polarization beam splitter PBS.

  The light source device 13 emits a polarized laser having the same wavelength and phase to the polarizing beam splitter PBS. For example, when the light flux emitted from the light source 31 is polarized light, the light source device 13 uses a polarization-maintaining fiber as the light guide member 32 and maintains the polarization state of the laser light output from the light source device 13. Light is guided as it is. Further, for example, the light flux output from the light source 31 may be guided by an optical fiber, and the light output from the optical fiber may be polarized by a polarizing plate. In other words, when the randomly polarized light beam is guided, the light source device 13 may polarize the randomly polarized light beam by the polarizing plate, or split it into the P polarized light beam and the S polarized light beam by using the polarization beam splitter PBS. The light transmitted through the polarization beam splitter PBS may be incident on the illumination optical system IL of one system, and the light reflected by the polarization beam splitter PBS may be used as a light flux incident on the illumination optical system IL of another system. . The light source device 13 may guide the light flux output from the light source 31 by a relay optical system using a lens or the like.

  Here, as shown in FIG. 3, the exposure apparatus U3 of the first embodiment is an exposure apparatus assuming a so-called multi-lens method. 3 is a plan view (left side of FIG. 3) of the illumination area IR on the mask M held by the mask holding drum 21 as viewed from the −Z side, and a substrate P supported by the substrate supporting drum 25. A plan view of the upper projection area PA viewed from the + Z side (right view of FIG. 3) is shown. Reference numeral Xs in FIG. 3 indicates the moving direction (rotational direction) of the mask holding drum 21 and the substrate supporting drum 25. The exposure apparatus U3 of the multi-lens type illuminates a plurality (for example, six in the first embodiment) of illumination areas IR1 to IR6 on the mask M with the illumination light fluxes EL1, respectively, and each illumination light flux EL1 is exposed to each of the illumination areas IR1 to IR6. A plurality of (for example, six in the first embodiment) projection areas PA1 to PA6 on the substrate P are projected and exposed with a plurality of projection light fluxes EL2 obtained by being reflected by.

  First, the plurality of illumination areas IR1 to IR6 illuminated by the illumination optical system IL will be described. As shown in FIG. 3, the plurality of illumination regions IR1 to IR6 are located on the mask M on the upstream side in the rotation direction with the center plane CL interposed therebetween, and the first illumination region IR1, the third illumination region IR3, and the fifth illumination region IR5. Are disposed, and the second illumination region IR2, the fourth illumination region IR4, and the sixth illumination region IR6 are disposed on the mask M on the downstream side in the rotation direction. Each of the illumination regions IR1 to IR6 is an elongated trapezoidal region having parallel short sides and long sides extending in the axial direction (Y direction) of the mask M. At this time, each of the trapezoidal illumination regions IR1 to IR6 has a short side located on the center plane CL side and a long side located outside. The first illumination region IR1, the third illumination region IR3, and the fifth illumination region IR5 are arranged at a predetermined interval in the axial direction. Further, the second illumination region IR2, the fourth illumination region IR4, and the sixth illumination region IR6 are arranged at a predetermined interval in the axial direction. At this time, the second illumination region IR2 is arranged between the first illumination region IR1 and the third illumination region IR3 in the axial direction. Similarly, the third illumination region IR3 is arranged between the second illumination region IR2 and the fourth illumination region IR4 in the axial direction. The fourth illumination region IR4 is arranged between the third illumination region IR3 and the fifth illumination region IR5 in the axial direction. The fifth illumination region IR5 is arranged between the fourth illumination region IR4 and the sixth illumination region IR6 in the axial direction. The illumination regions IR1 to IR6 are arranged such that the triangular portions of the oblique sides of adjacent trapezoidal illumination regions are overlapped (overlapped) when viewed in the circumferential direction of the mask M. Although the illumination regions IR1 to IR6 are trapezoidal regions in the first embodiment, they may be rectangular regions.

  Further, the mask M has a pattern forming area A3 in which a mask pattern is formed and a pattern non-forming area A4 in which a mask pattern is not formed. The pattern non-formation area A4 is an area that absorbs the illumination luminous flux EL1 and is difficult to be reflected, and is arranged so as to surround the pattern formation area A3 in a frame shape. The first to sixth illumination areas IR1 to IR6 are arranged so as to cover the entire width of the pattern formation area A3 in the Y direction.

  The illumination optical system IL is provided in a plurality (for example, six in the first embodiment) according to the plurality of illumination regions IR1 to IR6. The illumination luminous flux EL1 from the light source device 13 is incident on each of the plurality of illumination optical systems (divided illumination optical systems) IL1 to IL6. The respective illumination optical systems IL1 to IL6 guide the respective illumination light fluxes EL1 incident from the light source device 13 to the respective illumination regions IR1 to IR6. That is, the first illumination optical system IL1 guides the illumination light flux EL1 to the first illumination region IR1, and similarly, the second to sixth illumination optical systems IL2 to IL6 move the illumination light flux EL1 to the second to sixth illumination regions IR2. ~ Lead to IR6. The plurality of illumination optical systems IL1 to IL6 have the first illumination optical system on the side where the first, third, and fifth illumination regions IR1, IR3, and IR5 are arranged (the left side in FIG. 2) with the center plane CL interposed therebetween. IL1, a third illumination optical system IL3, and a fifth illumination optical system IL5 are arranged. The first illumination optical system IL1, the third illumination optical system IL3, and the fifth illumination optical system IL5 are arranged at a predetermined interval in the Y direction. In addition, the plurality of illumination optical systems IL1 to IL6 include the second illumination on the side (the right side in FIG. 2) on which the second, fourth, and sixth illumination regions IR2, IR4, and IR6 are arranged with the center plane CL interposed therebetween. An optical system IL2, a fourth illumination optical system IL4 and a sixth illumination optical system IL6 are arranged. The second illumination optical system IL2, the fourth illumination optical system IL4, and the sixth illumination optical system IL6 are arranged at a predetermined interval in the Y direction. At this time, the second illumination optical system IL2 is arranged between the first illumination optical system IL1 and the third illumination optical system IL3 in the axial direction. Similarly, the third illumination optical system IL3, the fourth illumination optical system IL4, and the fifth illumination optical system IL5 are arranged in the axial direction between the second illumination optical system IL2 and the fourth illumination optical system IL4, and the third illumination optical system IL4. It is arranged between the system IL3 and the fifth illumination optical system IL5, and between the fourth illumination optical system IL4 and the sixth illumination optical system IL6. Further, the first illumination optical system IL1, the third illumination optical system IL3, and the fifth illumination optical system IL5, and the second illumination optical system IL2, the fourth illumination optical system IL4, and the sixth illumination optical system IL6 are from the Y direction. It is arranged symmetrically.

  Next, a detailed configuration of each of the illumination optical systems IL1 to IL6 will be described with reference to FIG. Since each of the illumination optical systems IL1 to IL6 has the same configuration, the first illumination optical system IL1 (hereinafter simply referred to as the illumination optical system IL) will be described as an example.

  The illumination optical system IL converts the illumination light flux EL1 from the light source device 13 into a planar light source image in which a large number of point light sources are gathered in a planar manner so as to illuminate the illuminated region IR (first illuminated region IR1) with uniform illuminance. The Koehler lighting method is applied. Further, the illumination optical system IL is an epi-illumination system using a polarization beam splitter PBS. The illumination optical system IL includes an illumination optical module ILM, a polarization beam splitter PBS, and a quarter-wave plate 41 in order from the incident side of the illumination light flux EL1 from the light source device 13.

  As shown in FIG. 4, the illumination optical module ILM includes a collimator lens 51, a fly-eye lens 52, a plurality of condenser lenses 53, a cylindrical lens 54, and an illumination field stop 55 in order from the incident side of the illumination light flux EL1. , And a plurality of relay lenses 56, and are provided on the first optical axis BX1. The collimator lens 51 is provided on the emission side of the light guide member 32 of the light source device 13. The optical axis of the collimator lens 51 is arranged on the first optical axis BX1. The collimator lens 51 illuminates the entire incident side surface of the fly-eye lens 52. The fly-eye lens 52 is provided on the exit side of the collimator lens 51. The center of the exit side surface of the fly-eye lens 52 is arranged on the first optical axis BX1. The fly-eye lens 52 divides the illumination luminous flux EL1 from the collimator lens 51 into a large number of point light sources, superimposes the lights from the respective point light sources, and makes them incident on a condenser lens 53 described later.

  At this time, the surface on the exit side of the fly-eye lens 52 on which the point light source image is generated is formed by various lenses from the fly-eye lens 52 through the illumination field stop 55 to the first concave mirror 72 of the projection optical system PL described later. The first concave mirror 72 is arranged so as to be optically conjugate with the pupil surface on which the reflecting surface is located. The condenser lens 53 is provided on the exit side of the fly-eye lens 52, and its optical axis is arranged on the first optical axis BX1. The condenser lens 53 irradiates the light (illumination luminous flux EL1) from each point light source of the fly-eye lens 52 so as to be superimposed on the illumination field stop 55 via the cylindrical lens 54. In the case where the cylindrical lens 54 is not provided, the chief rays of the illumination light flux EL1 reaching each point on the illumination field stop 55 are all parallel to the first optical axis BX1. However, due to the action of the cylindrical lens 54, the principal rays of the illumination luminous flux EL1 that illuminate the illumination field stop 55 are in a telecentric state in which they are parallel to each other (parallel to the first optical axis BX1) in the Y direction in FIG. In the plane, a non-telecentric state in which the inclination with respect to the first optical axis BX1 sequentially differs depending on the image height position is obtained.

  The cylindrical lens 54 is a plano-convex cylindrical lens having a plane on the incident side and a convex cylindrical surface on the emitting side, and is provided adjacent to the incident side of the illumination field stop 55. The optical axis of the cylindrical lens 54 is arranged on the first optical axis BX1, and the generatrix of the convex cylindrical surface on the emitting side of the cylindrical lens 54 is provided so as to be parallel to the Y axis in FIG. As a result, the principal rays of the illumination light flux EL1 immediately after passing through the cylindrical lens 54 become parallel to the first optical axis BX1 in the Y direction, and at a certain point on the first optical axis BX1 (strictly, in the XZ plane). In the direction of a line extending in the Y direction orthogonal to the first optical axis BX1).

  The opening of the illumination field stop 55 is formed in a trapezoidal shape (rectangle) having the same shape as the illumination region IR, and the center of the opening of the illumination field stop 55 is arranged on the first optical axis BX1. . At this time, the illumination field stop 55 is formed by the relay lens (imaging system) 56 between the illumination field stop 55 and the cylindrical surface P1 of the mask M, the polarization beam splitter PBS, the quarter wavelength plate 41, etc. It is arranged on a plane optically conjugate with the upper illumination area IR. The relay lens 56 is provided on the exit side of the illumination field stop 55. The optical axis of the relay lens 56 is arranged on the first optical axis BX1. The relay lens 56 irradiates the illumination light flux EL1 that has passed through the opening of the illumination field stop 55 onto the cylindrical surface P1 (illumination region IR) of the mask M via the polarization beam splitter PBS and the quarter-wave plate 41. To do.

  The polarization beam splitter PBS is arranged between the illumination optical module ILM and the center plane CL. The polarization beam splitter PBS reflects an S-polarized linearly polarized light beam on the wavefront splitting surface and transmits a P-polarized linearly polarized light beam. Here, the illumination light flux EL1 incident on the polarization beam splitter PBS is a linearly polarized light of S polarization, and the reflected light (projection light flux EL2) from the mask M incident on the polarization beam splitter PBS is a quarter wavelength. It is a light flux which becomes a P-polarized linearly polarized light by the plate 41.

  As a result, the polarization beam splitter PBS reflects the illumination light flux EL1 incident on the wavefront splitting surface from the illumination optical module ILM, while transmitting the projection light flux EL2 reflected by the mask M and incident on the wavefront splitting surface. The polarization beam splitter PBS preferably reflects all of the illumination light flux EL1 incident on the wavefront splitting surface, but reflects most of the illumination light flux EL1 incident on the wavefront splitting surface and part of it on the wavefront splitting surface. It may be transmitted or absorbed. Similarly, the polarization beam splitter PBS preferably transmits all of the projection light beam EL2 incident on the wavefront splitting surface, but transmits most of the projection light beam EL2 incident on the wavefront splitting surface and reflects a part thereof. Alternatively, it may be absorbed.

  The quarter-wave plate 41 is arranged between the polarization beam splitter PBS and the mask M, and converts the illumination light flux EL1 reflected by the polarization beam splitter PBS from linearly polarized light (S polarized light) into circularly polarized light. The circularly polarized illumination light flux EL1 is applied to the mask M. The quarter-wave plate 41 converts the circularly polarized projection light beam EL2 reflected by the mask M into linearly polarized light (P-polarized light).

  Here, in the illumination optical system IL, the chief ray of the projection light flux EL2 reflected by the illumination region IR on the surface P1 of the mask M is in a telecentric state in both the Y direction and the XZ plane, The illumination luminous flux EL1 is illuminated on the illumination region IR of the mask M. The state will be described with reference to FIG.

  FIG. 5 exaggerates the behavior of the illumination light flux EL1 applied to the illumination region IR on the mask M and the projection light flux EL2 reflected by the illumination region IR in the XZ plane (the plane perpendicular to the first axis AX1). FIG. As shown in FIG. 5, the above-mentioned illumination optical system IL irradiates the illumination area IR of the mask M so that the principal ray of the projection light flux EL2 reflected by the illumination area IR of the mask M becomes telecentric (parallel system). The principal ray of the illumination luminous flux EL1 is intentionally made non-telecentric in the XZ plane and telecentric in the Y direction.

  Such a characteristic of the illumination luminous flux EL1 is given by the cylindrical lens 54 shown in FIG. Specifically, a line that goes toward the first axis AX1 through a center point Q1 in the circumferential direction of the illumination region IR on the surface P1 of the mask M and a circle that is 1/2 of the radius Rm of the surface P1 of the mask surface M. When the intersection Q2 with (Rm / 2) is set, the curvature of the convex cylindrical surface of the cylindrical lens 54 is set so that each principal ray of the illumination light flux EL1 passing through the illumination region IR is directed to the intersection Q2 on the XZ plane. . By doing so, each principal ray of the projection light flux EL2 reflected in the illumination region IR becomes parallel (telecentric) to the straight line passing through the first axis AX1, the point Q1, and the intersection Q2 in the XZ plane. Of course, since the curvature of the surface P1 of the mask M in the Y direction can be regarded as infinite, each principal ray of the projection light beam EL2 is in a telecentric state also in the Y direction.

  Next, a plurality of projection areas (exposure areas) PA1 to PA6 projected and exposed by the projection optical system PL will be described. As shown in FIG. 3, the plurality of projection areas PA1 to PA6 on the substrate P are arranged in correspondence with the plurality of illumination areas IR1 to IR6 on the mask M. That is, the plurality of projection areas PA1 to PA6 on the substrate P have the first projection area PA1, the third projection area PA3, and the fifth projection area PA5 on the substrate P on the upstream side in the transport direction with the center plane CL interposed therebetween. The second projection area PA2, the fourth projection area PA4, and the sixth projection area PA6 are arranged on the substrate P on the downstream side in the transport direction. Each of the projection areas PA1 to PA6 is an elongated trapezoidal area having a short side and a long side extending in the width direction (Y direction) of the substrate P. At this time, each of the trapezoidal projection areas PA1 to PA6 has a short side located on the center plane CL side and a long side located outside. The first projection area PA1, the third projection area PA3, and the fifth projection area PA5 are arranged at predetermined intervals in the width direction. Further, the second projection area PA2, the fourth projection area PA4, and the sixth projection area PA6 are arranged at a predetermined interval in the width direction. At this time, the second projection area PA2 is arranged between the first projection area PA1 and the third projection area PA3 in the axial direction. Similarly, the third projection area PA3 is arranged between the second projection area PA2 and the fourth projection area PA4 in the axial direction. The fourth projection area PA4 is arranged between the third projection area PA3 and the fifth projection area PA5 in the axial direction. The fifth projection area PA5 is arranged between the fourth projection area PA4 and the sixth projection area PA6 in the axial direction. Similar to the illumination areas IR1 to IR6, the projection areas PA1 to PA6 are arranged so that the triangular portions of the oblique sides of the adjacent trapezoidal projection areas PA are overlapped with each other when viewed from the transport direction of the substrate P (so as to overlap each other). ) It is arranged. At this time, the projection area PA has a shape such that the exposure amount in the overlapping area of the adjacent projection areas PA is substantially the same as the exposure amount in the non-overlapping area. The first to sixth projection areas PA1 to PA6 are arranged so as to cover the entire width in the Y direction of the exposure area A7 exposed on the substrate P.

  Here, in FIG. 2, when viewed in the XZ plane, the center points of the odd-numbered illumination areas IR1 (and IR3, IR5) on the mask M to the even-numbered illumination areas IR2 (and IR4, IR6) The perimeter distance up to is even numbered projection areas PA2 (and PA4, PA6) from the center point of odd-numbered projection areas PA1 (and PA3, PA5) on the substrate P following the support surface P2 of the substrate support drum 25. Is set to be substantially equal to the circumferential distance to the center point of. This is because the projection magnification of each of the projection optical systems PL1 to PL6 is set to 1 × (× 1).

  A plurality of (for example, six in the first embodiment) projection optical systems PL are provided in accordance with the plurality of projection areas PA1 to PA6. A plurality of projection light beams EL2 reflected from a plurality of illumination regions IR1 to IR6 are incident on the plurality of projection optical systems (divided projection optical systems) PL1 to PL6, respectively. The projection optical systems PL1 to PL6 guide the projection light fluxes EL2 reflected by the mask M to the projection areas PA1 to PA6, respectively. That is, the first projection optical system PL1 guides the projection light flux EL2 from the first illumination area IR1 to the first projection area PA1, and similarly, the second to sixth projection optical systems PL2 to PL6 are the second to sixth projection optical systems PL2 to PL6. Each projection luminous flux EL2 from the illumination areas IR2 to IR6 is guided to the second to sixth projection areas PA2 to PA6. The plurality of projection optical systems PL1 to PL6 have a first projection optical system on the side (left side in FIG. 2) on which the first, third, and fifth projection areas PA1, PA3, and PA5 are arranged with the center plane CL interposed therebetween. PL1, the third projection optical system PL3, and the fifth projection optical system PL5 are arranged. The first projection optical system PL1, the third projection optical system PL3, and the fifth projection optical system PL5 are arranged at predetermined intervals in the Y direction. In addition, the plurality of projection optical systems PL1 to PL6 have the second projection on the side (the right side in FIG. 2) on which the second, fourth, and sixth projection areas PA2, PA4, and PA6 are arranged with the center plane CL interposed therebetween. An optical system PL2, a fourth projection optical system PL4 and a sixth projection optical system PL6 are arranged. The second projection optical system PL2, the fourth projection optical system PL4, and the sixth projection optical system PL6 are arranged at a predetermined interval in the Y direction. At this time, the second projection optical system PL2 is arranged between the first projection optical system PL1 and the third projection optical system PL3 in the axial direction. Similarly, the third projection optical system PL3, the fourth projection optical system PL4, and the fifth projection optical system PL5 have a third projection optical system between the second projection optical system PL2 and the fourth projection optical system PL4 in the axial direction. It is arranged between the system PL3 and the fifth projection optical system PL5, and between the fourth projection optical system PL4 and the sixth projection optical system PL6. Further, the first projection optical system PL1, the third projection optical system PL3, and the fifth projection optical system PL5, and the second projection optical system PL2, the fourth projection optical system PL4, and the sixth projection optical system PL6 are from the Y direction. It is arranged symmetrically.

  Next, with reference to FIG. 4, a detailed configuration of each of the projection optical systems PL1 to PL6 will be described. Since the projection optical systems PL1 to PL6 have the same configuration, the first projection optical system PL1 (hereinafter simply referred to as the projection optical system PL) will be described as an example.

  The projection optical system PL projects the image of the mask pattern in the illumination area IR (first illumination area IR1) on the mask M onto the projection area PA on the substrate P. The projection optical system PL has, in order from the incident side of the projection light flux EL2 from the mask M, the above-mentioned quarter-wave plate 41, the above-mentioned polarization beam splitter PBS, and the projection optical module PLM.

  The quarter-wave plate 41 and the polarization beam splitter PBS also serve as the illumination optical system IL. In other words, the illumination optical system IL and the projection optical system PL share the quarter wavelength plate 41 and the polarization beam splitter PBS.

  The projection light beam EL2 reflected by the illumination region IR is converted from circularly polarized light to linearly polarized light (P polarized light) by the quarter-wave plate 41, and then passes through the polarization beam splitter PBS to become a telecentric imaging light beam. It is incident on the projection optical system PL (projection optical module PLM).

  The projection optical module PLM is provided corresponding to the illumination optical module ILM. That is, the projection optical module PLM of the first projection optical system PL1 uses the image of the mask pattern of the first illumination region IR1 illuminated by the illumination optical module ILM of the first illumination optical system IL1 as the first projection region on the substrate P. Project on PA1. Similarly, the projection optical module PLM of the second to sixth projection optical systems PL2 to PL6 includes the second to sixth illumination regions IR2 to IR2 illuminated by the illumination optical module ILM of the second to sixth illumination optical systems IL2 to IL6. The image of the mask pattern of IR6 is projected onto the second to sixth projection areas PA2 to PA6 on the substrate P.

  As shown in FIG. 4, the projection optical module PLM includes at least the first optical system 61 that forms an image of the mask pattern in the illumination region IR on the intermediate image plane P7 and the intermediate image formed by the first optical system 61. A second optical system 62 for re-imaging a part of the image on the projection area PA of the substrate P, and a projection field stop 63 arranged on the intermediate image plane P7 where an intermediate image is formed are provided. Further, the projection optical module PLM includes a focus correction optical member 64, an image shift optical member 65, a magnification correction optical member 66, a rotation correction mechanism 67, and a polarization adjusting mechanism (polarization adjusting means) 68.

  The first optical system 61 and the second optical system 62 are, for example, telecentric catadioptric systems obtained by modifying a Dyson system. The optical axis of the first optical system 61 (hereinafter referred to as the second optical axis BX2) is substantially orthogonal to the center plane CL. The first optical system 61 includes a first deflecting member 70, a first lens group 71, and a first concave mirror 72. The first deflecting member 70 is a triangular prism having a first reflecting surface P3 and a second reflecting surface P4. The first reflection surface P3 is a surface that reflects the projection light beam EL2 from the polarization beam splitter PBS and allows the reflected projection light beam EL2 to enter the first concave mirror 72 through the first lens group 71. The second reflection surface P4 is a surface on which the projection light beam EL2 reflected by the first concave mirror 72 enters through the first lens group 71 and reflects the incident projection light beam EL2 toward the projection field stop 63. . The first lens group 71 includes various lenses, and the optical axes of the various lenses are arranged on the second optical axis BX2. The first concave mirror 72 is arranged on the pupil plane where a large number of point light sources generated by the fly-eye lens 52 are imaged by various lenses from the fly-eye lens 52 to the first concave mirror 72 via the illumination field stop 55. There is.

  The projection light beam EL2 from the polarization beam splitter PBS is reflected by the first reflecting surface P3 of the first deflecting member 70, passes through the upper half field area of the first lens group 71, and enters the first concave mirror 72. The projection light flux EL2 that has entered the first concave mirror 72 is reflected by the first concave mirror 72, passes through the field area of the lower half of the first lens group 71, and enters the second reflecting surface P4 of the first deflecting member 70. The projection light flux EL2 that has entered the second reflection surface P4 is reflected by the second reflection surface P4, passes through the focus correction optical member 64 and the image shifting optical member 65, and enters the projection field stop 63.

  The projection field stop 63 has an opening that defines the shape of the projection area PA. That is, the shape of the projection area PA can be defined by the shape of the opening of the projection field stop 63. Therefore, when the aperture shape of the illumination field stop 55 in the illumination optical system IL shown in FIG. 4 can be made similar to the shape (trapezoid) of the projection area PA, the projection field stop 63 can be omitted. If the aperture shape of the illumination field stop 55 is a rectangle including the projection area PA, the projection field stop 63 that defines the trapezoidal projection area PA is required.

  The second optical system 62 has the same configuration as the first optical system 61, and is provided symmetrically with the first optical system 61 with the intermediate image plane P7 interposed therebetween. The optical axis of the second optical system 62 (hereinafter referred to as the third optical axis BX3) is substantially orthogonal to the center plane CL and is parallel to the second optical axis BX2. The second optical system 62 includes a second deflecting member 80, a second lens group 81, and a second concave mirror 82. The second deflecting member 80 has a third reflecting surface P5 and a fourth reflecting surface P6. The third reflecting surface P5 is a surface that reflects the projection light flux EL2 from the projection field stop 63 and allows the reflected projection light flux EL2 to pass through the second lens group 81 and enter the second concave mirror 82. The fourth reflection surface P6 is a surface on which the projection light beam EL2 reflected by the second concave mirror 82 enters through the second lens group 81 and reflects the incident projection light beam EL2 toward the projection area PA. The second lens group 81 includes various lenses, and the optical axes of the various lenses are arranged on the third optical axis BX3. The second concave mirror 82 is arranged on the pupil plane where various point light source images formed by the first concave mirror 72 are imaged by various lenses from the first concave mirror 72 through the projection field stop 63 to the second concave mirror 82. ing.

  The projection light beam EL2 from the projection field stop 63 is reflected by the third reflecting surface P5 of the second deflecting member 80, passes through the field area of the upper half of the second lens group 81, and enters the second concave mirror 82. The projection light flux EL2 that has entered the second concave mirror 82 is reflected by the second concave mirror 82, passes through the field area of the lower half of the second lens group 81, and enters the fourth reflecting surface P6 of the second deflecting member 80. The projection light beam EL2 that has entered the fourth reflection surface P6 is reflected by the fourth reflection surface P6, passes through the magnification correction optical member 66, and is projected onto the projection area PA. As a result, the image of the mask pattern in the illumination area IR is projected on the projection area PA at the same size (× 1).

  The focus correction optical member 64 is arranged between the first deflecting member 70 and the projection field stop 63. The focus correction optical member 64 adjusts the focus state of the image of the mask pattern projected on the substrate P. The focus correction optical member 64 is, for example, a structure in which two wedge-shaped prisms are reversed (opposite to the X direction in FIG. 4) and overlapped so as to form a transparent parallel flat plate as a whole. The thickness of the parallel plate is made variable by sliding the pair of prisms in the direction of the slope without changing the interval between the surfaces facing each other. Thereby, the effective optical path length of the first optical system 61 is finely adjusted, and the focus state of the image of the mask pattern formed on the intermediate image plane P7 and the projection area PA is finely adjusted.

  The image shifting optical member 65 is arranged between the first deflecting member 70 and the projection field stop 63. The image shifting optical member 65 adjusts the image of the mask pattern projected on the substrate P so that it can be finely moved within the image plane. The image shifting optical member 65 is composed of a transparent parallel flat glass plate that can be tilted in the XZ plane of FIG. 4 and a transparent parallel flat glass plate that can be tilted in the YZ plane of FIG. By adjusting the inclination amounts of the two parallel flat glass plates, the image of the mask pattern formed on the intermediate image plane P7 and the projection area PA can be slightly shifted in the X direction or the Y direction.

  The magnification correction optical member 66 is arranged between the second deflecting member 80 and the substrate P. The magnification correction optical member 66 includes, for example, three lenses, a concave lens, a convex lens, and a concave lens, which are coaxially arranged at a predetermined interval, the front and rear concave lenses are fixed, and the convex lens between them is moved in the optical axis (principal ray) direction. It is configured in. As a result, the image of the mask pattern formed in the projection area PA is isotropically enlarged or reduced by a very small amount while maintaining a telecentric image formation state. The optical axes of the three lens groups forming the magnification correction optical member 66 are tilted in the XZ plane so as to be parallel to the principal ray of the projection light beam EL2.

  The rotation correction mechanism 67 is, for example, an actuator (not shown) that slightly rotates the first deflection member 70 around an axis that is perpendicular to the second optical axis BX2 and parallel to the Z axis. By rotating the first deflecting member 70, the rotation correction mechanism 67 can slightly rotate the image of the mask pattern formed on the intermediate image plane P7 within the intermediate image plane P7.

  The polarization adjusting mechanism 68 is, for example, an actuator (not shown) that rotates the quarter-wave plate 41 around an axis orthogonal to the plate surface to adjust the polarization direction. The polarization adjusting mechanism 68 can finely adjust the illuminance of the projection light flux EL2 projected on the projection area PA by rotating the quarter-wave plate 41.

  In the projection optical system PL configured in this way, each principal ray of the projection light beam EL2 from the mask M is emitted from the surface P1 of the mask M in the illumination region IR in a telecentric state, and the quarter wavelength plate 41 is used. And enters the first optical system 61 through the polarization beam splitter PBS. The projection light beam EL2 that has entered the first optical system 61 is reflected by the first reflecting surface (flat mirror) P3 of the first deflecting member 70 of the first optical system 61, passes through the first lens group 71, and is reflected by the first concave mirror 72. Is reflected. The projection light flux EL2 reflected by the first concave mirror 72 passes through the first lens group 71 again and is reflected by the second reflecting surface (flat mirror) P4 of the first deflecting member 70 to be used for the focus correction optical member 64 and image shifting. The light passes through the optical member 65 and enters the projection field stop 63. The projection light flux EL2 that has passed through the projection field stop 63 is reflected by the third reflecting surface (flat mirror) P5 of the second deflecting member 80 of the second optical system 62, passes through the second lens group 81, and is reflected by the second concave mirror 82. To be done. The projection light flux EL2 reflected by the second concave mirror 82 passes through the second lens group 81 again, is reflected by the fourth reflecting surface (flat mirror) P6 of the second deflecting member 80, and enters the magnification correcting optical member 66. . The projection light flux EL2 emitted from the magnification correction optical member 66 is incident on the projection area PA on the substrate P, and the image of the mask pattern appearing in the illumination area IR is projected on the projection area PA at the same magnification (× 1). .

<Relationship between projected image plane of mask pattern and exposed surface of substrate>
Next, the relationship between the projected image plane of the mask pattern and the exposure plane of the substrate in the exposure apparatus U3 of the first embodiment will be described with reference to FIGS. 6A and 6B. FIG. 6A is an explanatory diagram showing the relationship between the projected image plane of the mask pattern and the exposure plane of the substrate. FIG. 6B is an explanatory diagram schematically showing changes in the focus position (defocus amount) of the pattern image projected in the projection area.

  In the exposure apparatus U3, the projection light beam EL2 is imaged by the projection optical system PL, so that the projection image plane Sm of the pattern of the mask M is formed. The projection image plane Sm is the position where the pattern of the mask M is imaged, and is the position where the best focus is achieved. Here, the mask M is arranged on the curved surface (curve on the ZX plane) having the radius of curvature Rm as described above. As a result, the projected image plane Sm also becomes a curved surface having a radius of curvature Rm. In the exposure device U3, the surface of the substrate P serves as the exposure surface Sp. Here, the exposure surface Sp is the surface of the substrate P. The substrate P is held by the cylindrical substrate support drum 25 as described above. As a result, the exposure surface Sp becomes a curved surface (curve on the ZX plane) having a radius of curvature Rp. Further, the projection image surface Sm and the exposure surface Sp have curved surface axes in a direction orthogonal to the scanning exposure direction.

  Therefore, as shown in FIG. 6A, the projection image surface Sm and the exposure surface Sp are curved surfaces in the scanning exposure direction (the circumferential direction of the outer peripheral surface of the substrate supporting drum 25). Therefore, the projection image plane Sm is curved with a surface position difference of maximum ΔFm in the direction of the principal ray of the projection light beam EL2 at the end position and the center position of the exposure width A in the scanning exposure direction of the projection area PA, and the exposure is performed. The surface Sp is curved with a maximum surface position difference of ΔFp in the direction of the principal ray of the projection light flux EL2 between the end position and the center position of the exposure width A in the scanning exposure direction of the projection area PA. Here, as shown in FIG. 6A, the exposure apparatus U3 moves the mask M so that the exposure surface Sp (the surface of the substrate P) positioned at the time of actual exposure becomes the actual exposure surface Spa with respect to the projection image surface Sm. The first axis AX1 and the second axis AX2 of the substrate supporting drum 25 are pivotally supported by the exposure apparatus main body.

  The actual exposure surface Spa intersects in the scanning exposure direction at two positions FC1 and FC2 different from the projection image surface Sm. The exposure apparatus U3 adjusts the position of each optical member of the projection optical system PL, or finely adjusts the distance between the mask M and the substrate P by using either the mask holding mechanism 11 or the substrate supporting mechanism 12. Alternatively, by adjusting the focus correction optical member 64, the position in the normal direction (focus adjustment direction) of the actual exposure surface Spa to the projection image surface Sm can be changed.

  The projection image plane Sm and the actual exposure surface Spa are set so as to intersect at two different positions FC1 and FC2 within the exposure width A of the projection area PA in the scanning exposure direction. Therefore, at each of the positions FC1 and FC2 within the exposure width A, the pattern image of the mask M is projected and exposed on the surface of the substrate P in the best focus state. Further, in the area between the position FC1 and the position FC2 within the exposure width A, the best focus plane (projection image plane Sm) of the projected pattern image is located behind the actual exposure plane Spa and is in a rear focus state, In a region outside the position between the position FC1 and the position FC2, the best focus plane (projection image plane Sm) of the projected pattern image is located in front of the actual exposure plane Spa and is in the front focus state.

  That is, when the surface of the substrate P extends from the one end portion As of the exposure width A toward the other end portion Ae along the actual exposure surface Spa, the pattern image on the substrate P is the end portion As at the start of exposure. The position is exposed with a predetermined defocus amount, then the defocus amount decreases with time, and the position FC1 is exposed with the best focus (the defocus amount is zero). After the best focus state at the position FC1, the defocus amount increases in the opposite direction and reaches the maximum defocus amount at the center position FC3 of the exposure width A. With the center position FC3 of the exposure width A as an inflection point, the defocus amount decreases thereafter, and the pattern image is exposed on the substrate P again at the position FC2 in the best focus state. When the best focus state at the position FC2 is passed, the defocus amount increases again, and the exposure of the pattern image ends at the other end Ae. Thus, the area between the positions FC1 and FC2 and the area outside the positions FC1 and FC2 have different defocus directions, that is, the defocus signs.

  As described above, each point in the pattern image projected on the substrate P while the substrate P moves at a constant peripheral speed from the end portion As to the end portion Ae of the exposure width A of the projection area PA. 6B, the exposure is started in the front focus state (position As), and the best focus state (position FC1), the rear focus state (position FC3), the best focus state (position FC2), the front focus state ( The substrate P is exposed while continuously changing in the order of the position Ae). The focus position (or defocus amount) on the vertical axis of FIG. 6B is zero, which is the best focus state in which the difference (Sm-Spa) between the position of the projection image surface Sm and the position of the actual exposure surface Spa is zero. The horizontal axis of FIG. 6B represents the linear position of the exposure width A, but it may be the position of the outer peripheral surface of the substrate supporting drum 25 in the circumferential direction.

  The defocus amount in the front focus state (positive direction) at the end portions As and Ae of the exposure width A and the defocus amount in the rear focus state (negative direction) at the center position FC3 are formed by the projection optical system PL. Performance (resolution, depth of focus), exposure width A of projection area PA, minimum dimension of mask pattern to be projected, radius of curvature Rm of surface P1 of mask M (projection image surface Sm), outer peripheral surface of substrate supporting drum 25 (substrate A suitable range is determined by the radius of curvature Rp of the exposed surface Spa on P. Although specific numerical examples will be described later, as described above, by continuously changing the focus state during the scanning exposure over the exposure width A, particularly thin lines or discrete contacts in the mask pattern are obtained. It is possible to increase the apparent depth of focus of isolated patterns such as holes (via holes).

  Further, in the present embodiment, the surface P1 of the mask M and the surface of the substrate P are formed into a cylindrical shape, so that the mask image is projected onto the substrate P side in the scanning exposure direction and the exposure of the substrate to be exposed. A cylindrical shape can be provided differently from the surface. Therefore, the exposure apparatus U3 can continuously change the focus state according to the position in the scanning exposure direction within the projection area PA only by the rotational movements of the mask M and the substrate support drum 25, and further, substantially. It is possible to suppress a change in image contrast with respect to various focuses. Further, in the present embodiment, the exposure width A is set so that the best focus is obtained at two positions in the scanning exposure direction within the projection area PA, so that the average defocus amount within the exposure width A is reduced. The exposure width A can be increased. With this, even when the illuminance of the projection light flux EL2 is reduced, or when the scanning speed of the mask M or the substrate P in the scanning exposure direction is increased, an appropriate exposure amount can be ensured, which results in high production efficiency. The substrate can be processed at. Further, since the average defocus amount can be reduced with respect to the exposure width, the quality can be maintained.

In the present embodiment, the focus position is exposed differently according to the coordinate position (perimeter position) of the exposure width A, and as a result, the pattern image projected on the substrate P in different focus states over the exposure width A. The integrated image of is the final image intensity distribution formed on the exposed surface of the substrate P. Here, the integrated image will be described, but for simplicity, first, the concept will be described with the point image intensity distribution. Generally, the point image intensity distribution has a correlation with the contrast. The point image intensity distribution I (z) at the position defocused by z in the optical axis direction (focus change direction) is given by the following equation. Where λ is the wavelength of the illumination light beam EL1, NA is the numerical aperture on the substrate side of the projection optical system PL, and I ₀ is the intensity distribution at the ideal best focus position,
ΔDz = (π / 2 / λ) × NA ² × z,
Then, the point image intensity distribution I (z) is
I (z) = [sin (ΔDz) / (ΔDz)] ² × I ₀
Becomes

  When such point image intensity distribution I (z) is used, the integrated value (or average value) of the exposure width A is obtained, and the defocus amount at the actual center position (center position FC3 in FIG. 6A) is further calculated. Is plotted on the horizontal axis, and the intensity distribution for each defocus amount can be obtained as a simulation. Based on this, the exposure apparatus U3 adjusts the focus state (positional relationship between the projection image plane Sm and the actual exposure plane Spa) to obtain the optimum intensity distribution (image contrast) of the pattern image obtained during exposure. Can be adjusted to.

Further, generally, the resolving power R and the depth of focus DOF of the projection optical system PL are expressed by the following equations.
R = k1 · λ / NA (0 <k1 ≦ 1)
DOF = k2 · λ / NA ² (0 <k2 ≦ 1)
Here, k1 and k2 are coefficients that can change depending on the exposure conditions, the photosensitive material (photoresist, etc.), or the development processing or film formation processing after exposure, but the k1 factor of the resolution R is approximately 0.4 ≦. The range is k1 ≦ 0.8, and the k2 factor of the depth of focus DOF can be expressed as approximately k2≈1.

Based on such a definition of the depth of focus DOF of the projection optical system PL, in the present embodiment, it is preferable to adjust so as to approximately satisfy the following relational expression.

Here, ΔRm and ΔRp are the following based on the radius of curvature Rm of the projection image surface Sm (the surface P1 of the mask M), the radius of curvature Rp of the surface of the substrate P (actual exposure surface Spa), and the exposure width A, respectively. It is calculated by the formula.

  As is clear from this equation, ΔRm and ΔRp represent ΔFm and ΔFp shown in FIG. 6A, respectively. Further, it is preferable that the above relational expression 1 further satisfies DOF <(ΔRm + ΔRp). In the exposure apparatus U3 of the present embodiment, the exposure width A and the radii of curvature Rm, Rp are determined so as to satisfy the above relational expression 1, but the exposure width A and the radii of curvature Rm and Rp are formed on the substrate P by satisfying the above relational expression 1. It is possible to improve productivity while maintaining the quality of various patterns for display panels (line width accuracy, position accuracy, overlay accuracy, etc.). This point will be described in detail in the second embodiment.

  Further, in the present embodiment, the change range of the defocus amount within the exposure width A, that is, the defocus amount in the positive direction at the end portions As and Ae shown in FIG. 6B, and the center position FC3 of the exposure width A When the difference from the defocus amount in the negative direction of is ΔDA, it may be set so as to satisfy the relationship of 0.5 ≦ (ΔDA / DOF) ≦ 3 from the relationship with the depth of focus DOF of the projection optical system PL. Is more preferable, and it is more preferable that 1 ≦ (ΔDA / DOF) is satisfied. By setting the exposure apparatus U3 so as to satisfy this relationship, the productivity can be improved while maintaining the quality (line width accuracy, position accuracy, overlay accuracy, etc.) of various patterns for the display panel formed on the substrate P. Can be increased. This point will also be described in detail in the second embodiment.

  In the exposure apparatus U3, as shown in FIG. 6B of the present embodiment, the difference between the projected image plane Sm of the pattern of the mask M and the actual exposure surface Spa of the substrate P in the scanning exposure direction is the exposure width of the projection area PA. The center position FC3 of A is preferably set so as to change symmetrically about the axis (left-right symmetry in FIG. 6B).

  Further, in the present embodiment, as shown in FIG. 6B, in the exposure width A of the projection area PA, a section from the end portion As to the position FC1 and a section from the position FC2 to the end portion Ae where the defocus amount is positive. And a value obtained by integrating the positive defocus amount (absolute value) and a value obtained by integrating the negative defocus amount in the section from the position FC1 where the defocus amount is negative to the position FC2 (absolute value) May be compared, and the positional relationship between the projection image plane Sm and the actual exposure surface Spa may be set so that they are substantially equal.

  The exposure apparatus U3 of the present embodiment arranges a plurality of projection optical modules PLM in at least two rows in the scanning exposure direction, and in the Y direction orthogonal to the scanning exposure direction, the ends of the projection areas PA of the adjacent projection optical modules PLM. The portions (triangle portions) are overlapped with each other, and the pattern of the mask M is continuously exposed in the Y direction for exposure. As a result, the contrast of the pattern image at the joint (overlap area) between the two projection areas PA adjacent to each other in the Y direction and the occurrence of band-shaped unevenness due to different exposure amounts are suppressed. In the present embodiment, in addition to this, in the scanning exposure direction in the projection area PA on the actual exposure surface Spa (the surface of the substrate P), the best focus position can be set at two positions (positions FC1 and FC2) so that the projection image plane Since the positional relationship between Sm and the actual exposure surface Spa is set, the change in the image contrast caused by the dynamic defocus in which the positional relationship between the projected image surface Sm and the actual exposure surface Spa slightly changes during scanning exposure is reduced. be able to. Therefore, it is possible to reduce the difference in image contrast generated in the overlap area between the adjacent projection areas PA, and it is possible to manufacture a high-quality flexible display panel in which the joint portion is inconspicuous.

  When the projection areas PA of the plurality of projection optical modules PLM are arranged in the Y direction orthogonal to the scanning exposure direction (X direction) as in the present embodiment, the substrate is spread over the width of each projection area PA in the scanning exposure direction. The integrated value obtained by integrating the illuminance on P (the intensity of the exposure light) is preferably substantially constant at any position in the Y direction orthogonal to the scanning exposure direction. In addition, even in a portion (triangular overlapping area) where the ends of two projection areas PA adjacent in the Y direction partially overlap, the integrated value in one triangular area and the integrated value in the other triangular area are The total is set to be the same as the integrated value in the non-overlapping area. This makes it possible to prevent the exposure amount from changing in the direction orthogonal to the scanning exposure direction.

  In addition, the exposure apparatus U3 uses the projection image surface Sm and the exposure surface Sp (actual exposure surface Spa) as cylindrical surfaces, so that a plurality of projection optical modules PLM are arranged in the scanning exposure direction (an odd number) as in the present embodiment. No. 2 and even-numbered columns are arranged), the relationship between the projection image plane Sm and the exposure surface Sp (actual exposure surface Spa) is the same in each projection optical module PLM. Can be adjusted together. When the projection image plane and the exposure plane are flat as in a normal multi-lens type projection exposure apparatus, for example, in the projection area of an odd-numbered projection optical module, the projection image plane is exposed to increase the depth of focus. If the surface (the surface of the flat substrate) is tilted, unacceptably large defocus occurs in the projection area of the even numbered projection optical module. On the other hand, as in the present embodiment, the projection image surface Sm and the exposure surface Sp (actual exposure surface Spa) are cylindrical surfaces, so that each projection of the two columns of the projection optical module PLM arranged in the scanning exposure direction. Focus adjustment in the area PA is performed by the Z-direction distance between the first axis AX1 of the rotation center of the cylindrical mask M and the first axis AX1 of the rotation center of the substrate support drum 25, or in each projection optical module PLM. It can be easily realized by adjusting the magnification correction optical member 66. This makes it possible to suppress a change in image contrast with respect to defocus with a simple device configuration. Since the exposure width in the scanning exposure area can be increased while suppressing the change in image contrast, the production efficiency can be improved.

[Second Embodiment]
Next, with reference to FIG. 7, the exposure apparatus U3a of the second embodiment will be described. In addition, in order to avoid duplicated description, only different parts from the first embodiment will be described, and components similar to those of the first embodiment will be described with the same reference numerals as in the first embodiment. FIG. 7 is a diagram showing the overall configuration of an exposure apparatus (substrate processing apparatus) according to the second embodiment. Although the exposure apparatus U3 of the first embodiment has a configuration in which the substrate P that passes through the projection area PA is held by the cylindrical substrate support drum 25, the exposure apparatus U3a of the second embodiment planarizes the substrate P. It is configured to be supported and held by a movable substrate support mechanism 12a.

  In the exposure apparatus U3a of the second embodiment, the substrate support mechanism 12a scans and moves the substrate stage 102 that holds the substrate P in a plane and the substrate stage 102 in the plane orthogonal to the center plane CL along the X direction. And a moving device (not shown). Therefore, the substrate P may be a flexible thin sheet (resin film such as PET or PEN, an ultrathin bendable glass sheet, a thin metal foil, etc.) or a single bend glass substrate.

  Since the support surface P2 of the substrate P in FIG. 7 is a plane (radius of curvature ∞) substantially parallel to the XY plane, it is reflected from the mask M, passes through each projection optical module PLM, and is projected onto the substrate P. The principal ray of the light flux EL2 is perpendicular to the XY plane.

  Also in the second embodiment, similarly to FIG. 2 described above, when viewed in the XZ plane, the illumination area IR2 (and IR3 (and IR3, IR5) from the center point of the illumination area IR1 (and IR3, IR5) on the cylindrical mask M is seen. The perimeter to the center point of IR4, IR6) is the center point of the projection area PA1 (and PA3, PA5) on the substrate P following the support surface P2 to the center point of the second projection area PA2 (and PA4, PA6). Is set to be substantially equal to the linear distance in the X direction.

  In the exposure apparatus U3a shown in FIG. 7 as well, the lower-order control apparatus 16 controls the moving device (the linear motor for scanning exposure, the actuator for fine movement, etc.) of the substrate support mechanism 12a, and in synchronization with the rotation of the mask holding drum 21. The substrate stage 102 is driven.

  Next, the relationship between the projected image plane of the mask pattern and the exposure plane of the substrate in the exposure apparatus U3a of the second embodiment will be described with reference to FIG. FIG. 8 is an explanatory diagram showing the relationship between the projected image plane of the mask pattern and the exposure plane of the substrate.

  The exposure apparatus U3a forms the projection image plane Sm1 of the pattern of the mask M by forming an image of the projection light beam EL2 by the projection optical system PL. The projection image surface Sm1 is a surface on which the cylindrical mask pattern surface of the mask M is imaged in the best focus state, and is a cylindrical surface. Here, since the illumination region IR on the mask M is a part of the curved surface (arc in the XZ plane) having the radius of curvature Rm1, as described above, the projection image plane Sm1 also has the curved surface (in the XZ plane, having the radius of curvature Rm1). Part of the arc). Further, the planar surface of the substrate P onto which the image of the mask pattern is projected becomes the exposure surface Sp1 (radius of curvature ∞). Therefore, as shown in FIG. 8, the projection image plane Sm1 (left side) of the odd-numbered projection areas PA and the projection image plane Sm1 (right side) of the even-numbered projection areas PA are both in the scanning exposure direction (X direction). 6A, the difference between the focus position at both ends and the focus position at the center of the exposure width A in the exposure width A in the scanning exposure direction of the projection area PA is the same as that shown in FIG. 6A. And the surface position difference (focus change width) ΔFm. Here, it is assumed that the surface of the substrate P is arranged on the actual exposure surface Spa1 during scanning exposure. Since the exposure surface Sp1 and the actual exposure surface Spa1 are flat surfaces, the change amount of the surface position in the Z direction is 0 within the exposure width A of the projection area PA in the scanning exposure direction. The actual exposure surface Spa1 is set so as to intersect at two different positions FC1 and FC2 on the projection image surface Sm1 which are separated in the scanning exposure direction. That is, the exposure apparatus U3a adjusts the magnification correction optical member 66 and the like in the projection optical system PL, or finely moves one of the mask holding mechanism 11 (first axis AX1) and the substrate stage 102 in the Z direction. By doing so, the relative positional relationship between the projection image surface Sm1 and the actual exposure surface Spa1 is set to a predetermined state.

  Each of the two positions FC1 and FC2 is a position at which the mask pattern image in the projection image plane Sm1 is exposed in the best focus state.

  As a result, in the present embodiment as well, the rotational movement of the cylindrical mask M allows the scanning exposure in which the focus state is continuously changed within the predetermined range within the exposure width A in the scanning exposure direction. It is possible to suppress a change in image contrast with respect to a temporary focus change. As described above, even if the exposure surface Sp1 (actual exposure surface Spa1) is a flat surface, the projection image surface Sm1 is formed into a cylindrical surface curved in the scanning exposure direction, so that the substrate P is not tilted on the substrate P. The effect of apparently enlarging the depth of focus of the mask pattern image to be exposed can be obtained, and the change in image contrast can be suppressed. Such actions and effects can be similarly obtained even when a pattern image from an ordinary flat mask is projected and exposed on the surface (exposure surface) of a substrate supported in a cylindrical surface shape.

で求められる。そこで、この式２をベースとして、図７の露光装置Ｕ３ａにおける投影状態や結像特性等の各種シミュレーションを行ってみると、図９〜図１７のような結果が得られる。 By the way, in the case of the present embodiment, the surface position difference (focus change width) ΔFm shown in FIG. 8 is the same as ΔRm in the above Expression 2,

Required by. Therefore, when various simulations of the projection state, the image forming characteristics, etc. in the exposure apparatus U3a of FIG. 7 are performed based on the equation 2, the results shown in FIGS.

In the simulation, the radius Rm of the surface P1 (projection image plane Sm1) of the cylindrical mask M is 250 mm (500 mm in diameter φ), the wavelength λ of the illumination light flux EL1 for exposure is the i-line (365 nm), and the projection optics is used. The system PL is an ideal projection system with the same numerical aperture NA of 0.0875 and the exposure surface Sp1 (actual exposure surface Spa1) is a plane with a radius of curvature ∞. If the k2 factor of the process-dependent depth of focus DOF is 1.0, the depth of focus DOF of such a projection optical system PL is about 48 μm in width (approximately ± 24 μm with respect to the best focus plane) from λ / NA ^2. Range). In the following simulation, the depth of focus DOF may be set to 40 μm in width (range of approximately ± 20 μm with respect to the best focus surface) for convenience.

  Now, FIG. 9 shows the defocusing characteristic Cm in the exposure width A by such a projection optical system PL, the horizontal axis represents the coordinates in the X direction with the center position of the exposure width A as the origin, and the vertical axis. The defocus amount of the projection image plane Sm1 with the best focus position as the origin (zero point) is shown. The graph of FIG. 9 is also a plot of the surface position difference ΔRm obtained by setting the exposure width A to 20 mm and changing the coordinate position of the width A from −10 mm to +10 mm in Expression 2 above. As shown in the graph of FIG. 9, since the surface P1 (projection image surface Sm1) of the mask M is curved in the scanning exposure direction into a cylindrical surface shape, the defocus characteristic Cm in the exposure width A has an arc shape. Changes to.

  FIG. 10 is a graph simulating how the point image intensity changes with the change of the width of the depth of focus DOF in the defocus characteristic Cm shown in FIG. 9, and the horizontal axis represents the substrate P. Represents the amount of blur in the focus direction (deviation in the focus direction of the surface of the substrate P relative to the defocus characteristic Cm) that may occur due to an error in the surface accuracy of the surface of the substrate or the mask pattern surface, aberration in the image plane direction of the projection optical system PL, and the like. , The vertical axis represents the value of the point image intensity. In FIG. 10, the point image intensity at the center (origin) of the exposure width A in the point image intensity distribution calculated when the depth of focus DOF is 0 × DOF under the defocus characteristic Cm in FIG. 9. Is standardized as 1.0. FIG. 11 is a graph simulating an example of the relationship between the amount of change in the defocus characteristic Cm of FIG. 9 that changes in an arc shape within the exposure width A and the intensity difference (intensity change amount). FIG. 12 shows the defocus characteristic Cm that changes in an arc shape within the exposure width A and the line and space (L / S, L & S) when the apparatus sets the best focus and when the defocus generated in the apparatus is 24 μm. ) A graph simulating an example of the relationship with the contrast change of a pattern. FIG. 13 is a graph simulating another example of the relationship between the defocus characteristic Cm which similarly changes in an arc shape within the exposure width A and the change in the contrast ratio of the L / S pattern. FIG. 14 is a graph simulating an example of the relationship between the defocus characteristic Cm that changes in an arc shape within the exposure width A, the CD value (critical dimension) of the L / S pattern, and the slice level. FIG. 15 is a graph simulating an example of the relationship between the defocus characteristic Cm that changes in an arc shape within the exposure width A and the contrast change of an isolated line (ISO pattern). FIG. 16 is a graph simulating another example of the relationship between the defocus characteristic Cm that changes in an arc shape within the exposure width A and the change in the contrast ratio of an isolated line. FIG. 17 is a graph that simulates an example of the relationship between the defocus characteristic Cm that changes in an arc shape within the exposure width A and the CD value and slice level of an isolated line.

First, under the above conditions, the point image intensity distribution I (z) with respect to the defocus amount generated when the defocus characteristic Cm that changes in an arc shape within the exposure width A is shaken in units of the depth of focus DOF is shown in FIG. Ask like. The point image intensity distribution is the equation described above,
I (z) = [sin (ΔDz) / (ΔDz)] ² × I _0,
ΔDz = (π / 2 / λ) × NA ² × z
Required at.

  Next, if the substrate is adjusted so that the average of the defocus amounts becomes the best focus, the defocus width that changes the point image intensity distribution on the arc within the exposure width A to various values, for example, 0, 1 Calculation is performed for the cases of × DOF, 2DOF, 3 × DOF, and 4 × DOF. Further, with respect to various defocus widths that change on the arc within the exposure width A, the point image intensity distribution when defocusing from that position is calculated based on the defocus amount and the slit width. In this way, the relationship between the point image intensity distribution and the defocus when the defocus width changes on an arc within each exposure width A that is uniquely determined by the calculated exposure width A is summarized. Specifically, the defocus width that changes on the arc within the exposure width in the exposure device U3a is 0, 0.5 × DOF, 1 × DOF, 1.5 × DOF, 2 × DOF, 2.5 × DOF. , 3 × DOF, 3.5 × DOF, and 4 × DOF, the relationship between the point image intensity distribution and the focus error and defocus assumed during exposure was calculated.

  Next, the point image intensity distribution when the substrate P is adjusted so that the average of the defocus amounts becomes the best focus, the defocus characteristic Cm that changes in an arc shape within the exposure width A is set to various values, for example, The calculation is performed for the cases of 0 × DOF, 1 × DOF, 2 × DOF, 3 × DOF, and 4 × DOF. Further, for various cases where the defocus characteristic Cm that changes in an arc shape within the exposure width A is various, the point image intensity distribution when defocusing from that position is calculated based on the defocus amount and the slit width thereof. . In this way, the relationship between the point image intensity distribution and the defocus at each defocus characteristic Cm that is uniquely determined by the calculated exposure width A is summarized. Specifically, the defocus characteristic Cm as shown in FIG. 9 set on the simulation as the exposure apparatus U3a is set to 0 × DOF, 0.5 × DOF, 1 × DOF, 1.5 × DOF, 2 × DOF, For each of 2.5 × DOF, 3 × DOF, 3.5 × DOF, and 4 × DOF, the point image intensity distribution and the focus error assumed during exposure (the projection image plane Sm1 to be set and the substrate P The deviation of the positional relationship from the surface to be set) was calculated. This corresponds to the graph in FIG.

  In FIG. 10, the horizontal axis represents the defocus amount [μm] and the vertical axis represents the normalized point image intensity value. Since the exposure apparatus U3a performs the rotational movement of the cylindrical mask pattern surface, that is, the projection image surface Sm1 to project the projection light beam EL2 onto the substrate P, the focus error assumed during exposure is secondary. Make a big change. Therefore, the behavior of the point image is slightly different between the plus side and the minus side of defocus. In the present embodiment, the best focus is a position where the image intensity at the position where the defocus is +40 μm and the image intensity at the position where the defocus is −40 μm are symmetrical. As shown in the graph of FIG. 10, when the swing width due to rotation increases, that is, as the defocus width increases along the defocus characteristic Cm as shown in FIG. The point image intensity of is decreased, and the change of the point image intensity during defocusing is also small.

  Next, a change in the point image intensity, that is, a difference between the maximum value and the minimum value of the point image intensity is calculated for each of the cases where the defocus characteristic Cm that changes in an arc shape within the exposure width A is changed. In A, the difference in point image intensity change at two points where the defocus characteristic Cm differs by 0.5 DOF was calculated. The calculation result is shown in FIG. The vertical axis in FIG. 11 represents the difference amount between two point image intensity changes, and the horizontal axis represents the target for which the difference amount is obtained when the defocus characteristic Cm is changed in 0.5 DOF increments. That is, on the horizontal axis of FIG. 11, for example, the leftmost point image intensity difference (about 0.02) is obtained when the defocus characteristic Cm is changed by 0 × DOF and when it is changed by 0.5 × DOF. It is the difference with. According to the simulation result of FIG. 11, the difference in point image intensity change is that the defocus characteristic Cm changes when the defocus characteristic Cm changes from 0.5 × DOF by 1 × DOF. When the state changed by 2.5 × DOF is changed to the state changed by 3 × DOF, the difference is large in general. That is, in the range of 0.5 × DOF to 3 × DOF, the effect of gradual change in the point image intensity with respect to the change in the defocus amount is high. Therefore, it can be understood that it is effective to set the defocus amount along the defocus characteristic Cm to have a swing width of 0.5 to 3 times the depth of focus DOF.

In the graph shown in FIG. 10, when a photoresist is applied to the surface of the substrate P as a photosensitive layer with a constant thickness, the value of the point image intensity formed as an image on the photoresist is used. Although it depends on the resist or the like, according to the experiment, when the k1 factor of the resolution is about 0.5, an image can be formed when the point image intensity is about 0.6 or more.
Here, when the focus error expected as an exposure apparatus is the defocus width up to the definition formula λ / NA ² of the depth of focus DOF (± 24 μm in this embodiment), it is the swing width of the defocus within the exposure area. By setting the defocus width to 2.5 × DOF, the change in the image intensity is small and the image of the mask pattern can be formed well.

  Next, various calculations were performed when the mask pattern to be projected was an L / S (line and space) pattern. Here, in the following, the target of defocus is set to the range of the definition formula of the depth of focus, that is, ± 24 μm in the present embodiment. The L / S (line and space) pattern was a pattern in which a plurality of linear patterns having a line width of 2.5 μm were arranged in a grid pattern at 2.5 μm intervals in the line width direction. Further, since the image formation state varies depending on the illumination condition, the illumination numerical aperture σ which is the illumination condition by the illumination optical system IL is set to 0.7 in this embodiment.

  First, when the defocus characteristic Cm shown in FIG. 9 is variously changed, that is, as in the above, 0 × DOF, 0.5 × DOF, 1 × DOF, 1.5 × DOF, 2 × DOF, 2 .5 × DOF, 3 × DOF, 3.5 × DOF, 4 × DOF, and the light intensity distribution of the L / S pattern image in the best focus state and DOF / 2 in the case of changing by 0.5 DOF unit. The light intensity distribution of the L / S pattern image in the defocused state, that is, the state of defocusing at +24 μm or −24 μm was calculated.

  Based on the calculation result, the change in contrast is calculated in each of the best focus state and the DOF / 2 defocus state, and the change is plotted in FIG. The horizontal axis of FIG. 12 represents the defocus width of the defocus characteristic Cm that changes in an arc shape within the exposure width A, the vertical axis represents the contrast, and the contrast change in the best focus state is 0 μm (BestF), the defocus state. Change in contrast was ± 24 μmDef. Further, based on the results shown in FIG. 12, the ratio between the contrast in the best focus state [0 μm (BestF)] and the contrast in the DOF / 2 defocus state [± 24 μmDef], that is, [0 μm (BestF)] / [± 24 μmDef ] The result of having calculated is shown in FIG. In FIG. 13, the horizontal axis represents the defocus width of the defocus characteristic Cm that changes in an arc shape within the exposure width A, and the vertical axis represents the contrast.

  Further, a CD (Critical Dimension) value [μm] in the defocus width of the defocus characteristic Cm that changes in an arc shape within each exposure width A and a slice level (image light intensity) assuming a photoresist were calculated. The CD value was calculated for a defocus of ± 24 μm, and the slice level was calculated for a best focus. The calculation result is shown in FIG. The horizontal axis of FIG. 14 represents the defocus width on the defocus characteristic Cm that changes in an arc shape within the exposure width A, the left side of the vertical axis represents the CD value, and the right side of the vertical axis represents the relative light intensity at the slice level. .

  As shown in FIG. 14, when the image to be projected is the L / S pattern, the change in the line width (the change in the CD value) is small with respect to the change in the defocus swing width in the exposure area. As shown in 12, the contrast changes greatly. However, as shown in FIG. 13, it can be seen that the ratio of the contrast in the best focus state and the contrast in the ± 24 μm defocus state approaches 1 as the swing width of the defocus increases. As described above, in the scanning exposure method in which the exposure width A is set along the circumferential direction of the cylindrical projection image surface Sm1, the defocus width due to the defocus characteristic Cm that changes in an arc shape within the exposure width A is increased. By doing so, it is possible to bring the contrast ratio close to 1 and reduce the difference between the image contrast in the best focus state and the image contrast in the defocus state. As a result, in the case of the cylindrical mask M (cylindrical projection image surface Sm1), the change of the contrast at the time of best focus and the change at the time of defocus is suppressed to be small by only the rotational movement, and the line of the pattern to be exposed. It is possible to perform scanning exposure with a large variation margin in the focus direction (radial direction of the cylindrical surface) between the projection image surface Sm1 and the surface of the substrate P while suppressing the change in width.

  Next, various calculations were performed when the mask pattern was an isolated line pattern. Here, even in the following, the target of defocus is set to the range of the definition formula of the depth of focus DOF, that is, ± 24 μm in the present embodiment. The isolated line pattern was a linear pattern having a line width of 2.5 μm. Further, since the image formation state varies depending on the illumination condition, the illumination numerical aperture σ as the illumination condition is set to 0.7.

  Similar to the case of the L / S pattern previously simulated, first, when the defocus characteristic Cm shown in FIG. 9 is variously changed, that is, as in the above, 0 × DOF, 0.5 × DOF, 1 Isolation of the best focus state when changing in units of 0.5 DOF such as x DOF, 1.5 x DOF, 2 x DOF, 2.5 x DOF, 3 x DOF, 3.5 x DOF, and 4 DOF. The light intensity distribution of the line pattern image and the light intensity distribution of the isolated line pattern image in the defocused state of DOF / 2, that is, the state of defocusing at +24 μm or −24 μm were calculated. Based on the calculation result, the change characteristic of the image contrast with respect to the change of the defocus width for every 0.5 DOF as shown in FIG. 15 is obtained.

  The horizontal axis of FIG. 15 represents the defocus width of the defocus characteristic Cm that changes in an arc shape within the exposure width A, and the vertical axis represents the contrast of the isolated line pattern image. Further, based on the results shown in FIG. 15, the ratio of the contrast in the best focus state [0 μm (BestF)] and the contrast in the DOF / 2 defocus state [± 24 μm Def], that is, [[ FIG. 16 shows the calculation result of 0 μm (BestF)] / [± 24 μmDef]. In FIG. 16, the horizontal axis represents the defocus width of the defocus characteristic Cm that changes in an arc shape within the exposure width A, and the vertical axis represents the contrast ratio.

  Further, a CD (Critical Dimension) value [μm] in the defocus width of the defocus characteristic Cm that changes in an arc shape within each exposure width A and a slice level (image light intensity) assuming a photoresist were calculated. The CD value was calculated for a defocus of ± 24 μm, and the slice level was calculated for a best focus. The calculation result is shown in FIG. The horizontal axis in FIG. 17 represents the defocus width on the defocus characteristic Cm that changes in an arc shape within the exposure width A, the left side of the vertical axis represents the CD value, and the right side represents the relative light intensity at the slice level. . As shown in FIG. 17, when the pattern is an isolated line, the change in contrast with respect to the change in the defocus swing width in the exposure area is smaller than that in the L / S pattern. On the other hand, when the pattern is an isolated line, it can be seen that the change in the line width (CD value) is large with respect to the change in the defocus amount.

  Therefore, by increasing the defocus width due to the defocus characteristic Cm that changes in an arc shape within the exposure width A to, for example, 2.5 × DOF or 3.0 × DOF, the set focus position varies. Also, it is possible to suppress the change in the line width of the pattern exposed on the substrate P. That is, even if the relative positional relationship in the focus direction between the projection image plane Sm1 and the surface of the substrate P that has been preset fluctuates due to various reasons during exposure, it is possible to suppress the change in the line width due to the focus fluctuation. The quality of display panels and electronic devices sequentially manufactured on the substrate P can be kept good. Further, the slice level at which an isolated line having a line width of 2.5 μm at the time of best focus becomes 2.5 μm becomes a larger value as the defocus width due to the defocus characteristic Cm that changes in an arc shape within the exposure width A is increased. As a result, the change in the line width with respect to the defocus becomes small.

  Further, comparing the difference in slice level due to the difference in pattern using FIG. 14 and FIG. 17, the defocus width due to the defocus characteristic Cm changing on the arc within the exposure width A is 2.25 × With DOF, the slice levels (light intensities) for both the L / S pattern and the isolated line pattern substantially match. Therefore, by setting the defocus width according to the defocus characteristic Cm in the range of 2.25 × DOF, a high quality substrate can be manufactured even in the case of a mask pattern in which an L / S pattern and an isolated line pattern are mixed. As a result, the L / S pattern and the isolated line pattern are made to coexist without considering the line width correction (OPC, line width offset) of the mask pattern, which is required when the slice levels do not match. be able to. Further, since the mask is recreated due to the line width correction (OPC, offset) and it is not necessary to manufacture a plurality of masks for adjustment, manufacturing labor and cost can be reduced. . Further, by setting an offset to the line width and changing the line width of a part of the mask pattern, it is possible to suppress the disadvantage such as conversely narrowing the depth of focus at that part.

[Third Embodiment]
Next, with reference to FIG. 18, an exposure apparatus U3b of the third embodiment will be described. In addition, in order to avoid duplicated description, only parts different from the second embodiment will be described, and constituent elements similar to the second embodiment will be described with the same reference numerals as in the second embodiment. FIG. 18 is a diagram showing the overall configuration of an exposure apparatus (substrate processing apparatus) according to the third embodiment. The exposure apparatus U3a of the second embodiment has a configuration that uses a reflective mask in which the light reflected by the mask becomes a projection light beam. However, in the exposure apparatus U3b of the third embodiment, the light transmitted through the mask becomes a projection light beam. The transparent mask is used.

  In the exposure apparatus U3b of the third embodiment, the mask holding mechanism 11a includes a mask holding drum 21a that holds the mask MA, a guide roller 93 that supports the mask holding drum 21a, and a driving roller 94 that drives the mask holding drum 21a. , And a drive unit 96.

  The mask holding drum 21a forms a mask surface on which the illumination area IR on the mask MA is arranged. In the present embodiment, the mask surface includes a surface (hereinafter referred to as a cylindrical surface) obtained by rotating a line segment (bus line) around an axis (a central axis of a cylindrical shape) parallel to the line segment. The cylindrical surface is, for example, an outer peripheral surface of a cylinder or an outer peripheral surface of a cylinder. The mask holding drum 21a is made of, for example, glass, quartz, or the like, has a cylindrical shape having a constant thickness, and its outer peripheral surface (cylindrical surface) forms a mask surface. That is, in the present embodiment, the illumination region IR on the mask MA is curved from the center line into a cylindrical surface having a constant radius of curvature Rm. A portion of the mask holding drum 21a that overlaps with the pattern of the mask MA when viewed in the radial direction of the mask holding drum 21a, for example, a central portion other than both ends of the mask holding drum 21a in the Y-axis direction is transparent to the illumination light flux EL1. It has a light property.

  The mask MA is created as a transmissive flat sheet mask in which a pattern is formed on one surface of a strip-shaped ultrathin glass plate (for example, a thickness of 100 to 500 μm) having good flatness with a light shielding layer such as chrome, The mask holding drum 21a is used by being curved along the outer peripheral surface of the mask holding drum 21a and wound (attached) on the outer peripheral surface. The mask MA has a pattern non-formation region in which no pattern is formed, and is attached to the mask holding drum 21a in the pattern non-formation region. The mask MA can be released to the mask holding drum 21a. Similar to the mask M of the first embodiment, the mask MA is a mask made of a light shielding layer such as chrome directly on the outer peripheral surface of the mask holding drum 21a made of a transparent cylindrical base material instead of being wound around the mask holding drum 21a made of a transparent cylindrical base material. You may draw and form a pattern and may integrate. In this case also, the mask holding drum 21a functions as a mask supporting member.

  The guide roller 93 and the drive roller 94 extend in the Y-axis direction parallel to the central axis of the mask holding drum 21a. The guide roller 93 and the drive roller 94 are rotatably provided around an axis parallel to the central axis. Each of the guide roller 93 and the drive roller 94 has an outer diameter at the end in the axial direction larger than the outer diameters of other portions, and the end is in contact with the mask holding drum 21a. In this way, the guide roller 93 and the drive roller 94 are provided so as not to come into contact with the mask MA held by the mask holding drum 21a. The drive roller 94 is connected to the drive unit 96. The drive roller 94 rotates the mask holding drum 21a around the central axis by transmitting the torque supplied from the driving unit 96 to the mask holding drum 21a.

  The mask holding mechanism 11a includes one guide roller 93, but the number is not limited and may be two or more. Similarly, the mask holding mechanism 11a includes one driving roller 94, but the number is not limited and may be two or more. At least one of the guide roller 93 and the drive roller 94 is disposed inside the mask holding drum 21a and may be inscribed in the mask holding drum 21a. Further, of the mask holding drum 21a, portions (both ends in the Y-axis direction) that do not overlap with the pattern of the mask MA when viewed in the radial direction of the mask holding drum 21a have translucency with respect to the illumination light flux EL1. Or may not have translucency. Further, one or both of the guide roller 93 and the drive roller 94 may have, for example, a truncated cone shape, and the central axis (rotational axis) thereof may be non-parallel to the central axis.

  The light source device 13a of the present embodiment includes a light source (not shown) and an illumination optical system ILa. The illumination optical system ILa includes a plurality (for example, six) of illumination optical systems ILa1 to ILa6 arranged in the Y-axis direction corresponding to each of the plurality of projection optical systems PL1 to PL6. As the light source, various light sources can be used similarly to the above-described various light source devices 13a. The illumination light emitted from the light source has a uniform illuminance distribution and is distributed to the plurality of illumination optical systems ILa1 to ILa6 via a light guide member such as an optical fiber.

  Each of the plurality of illumination optical systems ILa1 to ILa6 includes a plurality of optical members such as lenses. Each of the plurality of illumination optical systems ILa1 to ILa6 includes, for example, an integrator optical system, a rod lens, a fly-eye lens, etc., and illuminates the illumination area IR with an illumination light flux EL1 having a uniform illuminance distribution. In the present embodiment, the plurality of illumination optical systems ILa1 to ILa6 are arranged inside the mask holding drum 21a. Each of the plurality of illumination optical systems IL1 to IL6 illuminates each illumination area on the mask MA held on the outer peripheral surface of the mask holding drum 21a from the inside of the mask holding drum 21a through the mask holding drum 21a.

  The light source device 13a guides the light emitted from the light source by the illumination optical systems ILa1 to ILa6, and irradiates the guided illumination light flux EL1 to the mask MA from the inside of the mask holding drum 21a. The light source device 13 illuminates a part (illumination region IR) of the mask MA held by the mask holding mechanism 11a with uniform brightness by the illumination light flux EL1. The light source may be arranged inside the mask holding drum 21a or may be arranged outside the mask holding drum 21a. The light source may be a device (external device) different from the exposure device U3b.

  Even when a transmissive mask is used as the mask, the exposure apparatus U3b has a position in which the best focus state on the exposure surface is 2 as in the relationship between the projection image plane and the exposure surface, as in the exposure apparatuses U3 and U3a. By setting the relationship in some places, the same effect as the above can be obtained.

[Fourth Embodiment]
Next, with reference to FIG. 19, an exposure apparatus U3c of the fourth embodiment will be described. In addition, in order to avoid duplicated description, only different parts from the first embodiment will be described, and components similar to those of the first embodiment will be described with the same reference numerals as in the first embodiment. FIG. 19 is a diagram showing the overall configuration of an exposure apparatus (substrate processing apparatus) according to the fourth embodiment. The exposure apparatus U3 of the first embodiment has a configuration in which the cylindrical reflective mask M is held by the rotatable mask holding drum 21, but the exposure apparatus U3c of the fourth embodiment has a flat reflection surface. The mold mask MB is held by a movable mask holding mechanism 11b.

  In the exposure apparatus U3c of the fourth embodiment, the mask holding mechanism 11b scans and moves the mask stage 110 holding the planar mask MB and the mask stage 110 in the plane orthogonal to the central plane CL along the X direction. And a moving device (not shown).

  Since the plane P1 of the mask MB in FIG. 19 is a plane substantially parallel to the XY plane, the chief ray of the projection light flux EL2 reflected from the mask MB is perpendicular to the XY plane. Therefore, the chief ray of the illumination light beam EL1 from the illumination optical systems IL1 to IL6 that illuminates the illumination regions IR1 to IR6 on the mask MB is also arranged to be perpendicular to the XY plane.

  When the principal ray of the illumination light flux EL1 illuminated on the mask MB is perpendicular to the XY plane, the polarization beam splitter PBS determines that the incident angle θ1 of the principal ray of the illumination light flux EL1 incident on the ¼ wavelength plate 41 is the Brewster angle. θB, and the principal ray of the illumination light beam EL1 reflected by the quarter-wave plate 41 is arranged so as to be perpendicular to the XY plane. With the change of the arrangement of the polarization beam splitter PBS, the arrangement of the illumination optical module ILM is also changed appropriately.

  Further, when the chief ray of the projection light beam EL2 reflected from the mask MB becomes perpendicular to the XY plane, the first reflection surface P3 of the first deflection member 70 included in the first optical system 61 of the projection optical module PLM is polarized. The projection light beam EL2 from the beam splitter PBS is reflected, and the reflected projection light beam EL2 passes through the first lens group 71 and is incident on the first concave mirror 72. Specifically, the first reflecting surface P3 of the first deflecting member 70 is set at substantially 45 ° with respect to the second optical axis BX2 (XY plane).

  Also in the fourth embodiment, as in the case of FIG. 2 described above, when viewed in the XZ plane, from the center point of the illumination area IR1 (and IR3, IR5) on the mask MB to the illumination area IR2 (and IR4, IR6). ) Is the circumference from the center point of the projection area PA1 (and PA3, PA5) on the substrate P following the support surface P2 to the center point of the second projection area PA2 (and PA4, PA6). It is set to be substantially equal to the length.

  In the exposure apparatus U3c of FIG. 19 as well, the lower-order control apparatus 16 controls the moving device (the linear motor for scanning exposure, the actuator for fine movement, etc.) of the mask holding mechanism 11b, in synchronization with the rotation of the substrate supporting drum 25. The mask stage 110 is driven. The exposure apparatus U3c shown in FIG. 19 requires an operation (rewinding) of returning the mask MB to the initial position in the −X direction after performing scanning exposure by synchronously moving the mask MB in the + X direction. Therefore, when the substrate support drum 25 is continuously rotated at a constant speed to continuously feed the substrate P at a constant speed, pattern exposure is not performed on the substrate P during the rewinding operation of the mask MB, and the substrate P is conveyed in the transport direction. The panel pattern is formed in a scattered manner (spaced). However, in practice, since the speed of the substrate P (here, the peripheral speed) and the speed of the mask MB during scanning exposure are assumed to be 50 to 100 mm / s, the mask stage 110 is set at the time of rewinding the mask MB. For example, by driving at the maximum speed of 500 mm / s, it is possible to narrow the margin in the carrying direction between the panel patterns formed on the substrate P.

  Next, the relationship between the projected image plane of the mask pattern and the exposure plane of the substrate in the exposure apparatus U3c of the fourth embodiment will be described with reference to FIG. FIG. 20 is an explanatory diagram showing the relationship between the projected image surface of the mask pattern and the exposure surface of the substrate.

  In the exposure apparatus U3c, the projection optical system PL forms an image of the projection light flux EL2, so that the projection image plane Sm2 of the pattern of the mask MB is formed. The projection image plane Sm2 is the position where the pattern of the mask MB is imaged, and is the position where the best focus is achieved. Here, the mask MB is arranged in a plane as described above. As a result, the projection image plane Sm2 also becomes a plane (straight line in the ZX plane). In the exposure device U3c, the surface of the substrate P becomes the exposure surface Sp. Here, the exposure surface Sp is the surface of the substrate P. The substrate P is held by the cylindrical substrate support drum 25 as described above. As a result, the exposure surface Sp becomes a curved surface (curve on the ZX plane) having a radius of curvature Rp. Further, the exposure surface Sp has a curved surface axis in a direction orthogonal to the scanning exposure direction. Therefore, as shown in FIG. 20, the exposure surface Sp has a curved line in the scanning exposure direction. On the exposure surface Sp, the amount of change in position in the exposure width A of the projection area PA in the scanning exposure direction is Δp. The projection image plane Sm2 is a plane. Therefore, in the projection image plane Sm2, the amount of change in position in the exposure width A of the projection area PA in the scanning exposure direction becomes zero. Here, the exposure apparatus U3c sets the position of the exposure surface Sp with respect to the projection image surface Sm2 as the actual exposure surface Spa. The actual exposure surface Spa intersects in the scanning exposure direction at two positions Pa2 and Pb2 different from the projection image surface Sm2. The exposure apparatus U3c adjusts the position of each optical member of the projection optical system PL, and adjusts the distance between the mask MB and the substrate P by either the mask holding mechanism 11b or the substrate supporting mechanism 12. Thus, the position of the exposure surface with respect to the projection image surface Sm2 can be changed.

  In the exposure apparatus U3c, the projection image plane Sm2 and the actual exposure surface Spa intersect at two different positions Pa2 and Pb2, so that the focus state becomes the best focus at the position Pa2 on the actual exposure surface Spa within the exposure width A. , The focus state is the best focus at the position Pb2 on the actual exposure surface Spa.

  In the exposure apparatus U3c, even if the surface of the mask Mb is flat and the surface of the substrate P is cylindrical, the mask pattern is projected on the substrate P side in the same manner as the exposure apparatuses U3, U3a, and U3b. A cylindrical shape difference can be provided between Sm2 and the exposed surface Sp of the substrate P to be exposed. Further, in the exposure apparatus U3c, the projection image surface Sm2 and the actual exposure surface Spa intersect at two different positions Pa2 and Pb2, and the focus state of the exposure surface becomes the best focus at two different positions.

  As a result, the exposure apparatus U3c can also continuously change the focus state within the exposure width A in the scanning exposure direction by the rotational movement of the mask holding drum 21, and further, substantially change the image contrast with respect to the focus. Can be suppressed. Further, the exposure apparatus U3c can obtain various effects similar to those of the exposure apparatus U3. Thus, even when only one of the projection image surface and the exposure surface (the surface of the substrate P) is a curved surface, the same effect as when both the projection image surface and the exposure surface are curved surfaces can be obtained. .

で求められる。 Here, the exposure apparatus U3c calculates the defocus width Δ that changes in an arc within the exposure width A by the following equation, where 0 is the cylindrical radius r ₁ of the projection image plane Sm2 in the scanning exposure direction of the substrate P in the above equation. Can be found at.
Δ = r ₂ − ((r ₂ ² ) − (A / 2) ² ) ^1/2
Here, in the exposure apparatus U3c, since the radius of curvature of the projection image surface Sm2 of the mask pattern is ∞, the defocus characteristic Cm that changes in an arc shape within the exposure width A can be obtained only by the above Expression 3. . That is, the defocus characteristic Cm (= ΔRp) of the exposure apparatus U3c is

Required by.

  In the exposure apparatus of the present embodiment, of the mask holding mechanism and the substrate supporting mechanism, the one holding the curved surface is the first supporting member, and the one supporting the curved surface or the flat surface is the second supporting member.

<Exposure method>
Next, the exposure method will be described with reference to FIG. FIG. 21 is a flowchart showing the exposure method.

  In the exposure method shown in FIG. 21, first, the substrate support mechanism supports the substrate P on the support surface P2 (step S101), and the mask holding mechanism supports the mask M on the surface P1 (step S102). As a result, the mask M and the substrate P face each other. The order of step S101 and step S102 may be reversed. Further, one of the surface P1 and the support surface P2 is the first surface, and the other is the second surface. The first surface has a shape curved into a cylindrical surface with a predetermined curvature.

  Then, the focus position with respect to the exposure surface is adjusted (step S103). Specifically, within the exposure width A of the projection area PA set on the surface of the substrate P, the focus position is set at a position that includes two best focus positions in the scanning exposure direction.

  When the adjustment of the focus position is completed, the relative movement (rotation) of the substrate P and the mask M in the scanning exposure direction is started (step S104). That is, at least one of the substrate support mechanism and the mask holding mechanism starts an operation of moving at least one of the substrate P and the mask M in the scanning exposure direction.

  When the relative movement is started, the projection of the projection light beam into the projection area PA is started (step S105). That is, the light flux from the pattern of the mask arranged in the illumination area IR of the illumination light is projected onto the projection area PA in which the substrate P is arranged. As a result, in the exposure method shown in FIG. 21, a light flux having two best focus positions in the scanning exposure direction is projected onto the projection area on the exposure surface of the substrate P.

  In the exposure method, by projecting the light flux whose focus position is adjusted as described above, it is possible to project the light flux having the two best focus positions in the scanning exposure direction on the exposure area of the substrate onto the projection area. . As a result, the various effects described above can be obtained. In the present embodiment, the case where the focus position is adjusted has been described, but the position where the best focus position is included in two positions in the scanning exposure direction may be the focus position depending on the setting of the apparatus.

<Device manufacturing method>
Next, with reference to FIG. 22, a device manufacturing method will be described. FIG. 22 is a flowchart showing a device manufacturing method by the device manufacturing system.

  In the device manufacturing method shown in FIG. 22, first, the function / performance of a display panel is formed by self-luminous elements such as organic EL, and necessary circuit patterns and wiring patterns are designed by CAD or the like (step S201). Next, the mask M for the necessary layers is manufactured based on the pattern of each layer designed by CAD or the like (step S202). Further, a supply roll FR1 around which a flexible substrate P (resin film, metal foil film, plastic, etc.) serving as a base material of the display panel is wound is prepared (step S203). The roll-shaped substrate P prepared in this step S203 has its surface modified as necessary, an underlayer (for example, fine concavities and convexities by an imprint method) preformed, and a photosensitivity. A functional film or transparent film (insulating material) previously laminated may be used.

  Next, a backplane layer composed of electrodes, wirings, insulating films, TFTs (thin film semiconductors), etc., which constitute the display panel device is formed on the substrate P, and organic EL or the like is formed so as to be laminated on the backplane. A light emitting layer (display pixel portion) is formed by the self-luminous element (step S204). In step S204, the exposure process using any of the exposure apparatuses U3, U3a, U3b, and U3c described in the above embodiments is performed. The exposure process includes a conventional photolithography process of exposing a photoresist layer, but the substrate P coated with a photosensitive silane coupling material instead of the photoresist is pattern-exposed to form a pattern having hydrophilicity / repellency on the surface. It also includes a step of patterning and exposing a photosensitive catalyst layer for formation or electroless plating. In the conventional photolithography process, a photoresist development process is performed, in the electroless plating method, a wet process of forming a pattern of a metal film (wiring, electrodes, etc.), or by a conductive ink containing silver nanoparticles is used. A printing process, etc. for drawing is executed.

  Then, the substrate P is diced for each display panel device continuously manufactured on the long substrate P by the roll method, and a protective film (environment barrier layer) or a color filter is provided on the surface of each display panel device. A device or the like is assembled by laminating sheets or the like (step S205). Next, an inspection process is performed to determine whether the display panel device functions normally or satisfies desired performance and characteristics (step S206). A display panel (flexible display) can be manufactured as described above.

1 Device Manufacturing System 2 Substrate Supplying Device 4 Substrate Collecting Device 5 Upper Control Device 11 Mask Holding Mechanism 12 Substrate Supporting Mechanism 13 Light Source Device 16 Lower Controlling Device 21 Mask Holding Drum 25 Substrate Supporting Drum 31 Light Source 32 Light Guide Member 41 1/4 Wavelength Plate 51 Collimator lens 52 Fly's eye lens 53 Condenser lens 54 Cylindrical lens 55 Illumination field stop 56 Relay lens 61 First optical system 62 Second optical system 63 Projection field stop 64 Focus correction optical member 65 Image shift optical member 66 Magnification correction Optical member 67 Rotation correction mechanism 68 Polarization adjustment mechanism 70 First deflection member 71 First lens group 72 First concave mirror 80 Second deflection member 81 Second lens group 82 Second concave mirror 110 Mask stage P Substrate FR1 Supply roll FR2 times Acquisition rolls U1 to Un processing device U3 exposure device (substrate processing device)
M mask MA mask AX1 1st axis AX2 2nd axis P1 Mask surface P2 Support surface P7 Intermediate image surface EL1 Illumination luminous flux EL2 Projected luminous flux Rm Curvature radius Rp Curvature radius CL Center plane PBS Polarized beam splitter IR1 to IR6 Illumination area IL1 to IL6 Illumination Optical system ILM Illumination optical module PA1-PA6 Projection area PLM Projection optical module F

Claims (10)

A cylindrical long mask having a reflective mask pattern held along a circumferential surface curved with a first radius from a first axis is rotated around the first axis while being flexible and long. A scanning exposure apparatus that moves a sheet-shaped substrate in a scanning exposure direction along a lengthwise direction to expose the mask pattern on the surface of the substrate,
An illumination area that is set on the mask pattern to be a slender rectangular shape or a rectangle in the direction of the first axis and has a predetermined width in the circumferential direction of the circumferential surface corresponding to the scanning exposure direction. An illumination optical system that irradiates the illumination light toward the outside from the outside of the cylindrical mask,
By projecting a reflected light flux from the mask pattern appearing in the illumination area toward a projection area on the substrate side corresponding to the illumination area, an image of the mask pattern is formed according to the first radius. A projection optical system for forming an image along a projection image surface curved in a cylindrical surface shape in the scanning exposure direction so as to be convex on the substrate side,
The substrate is curved in the longitudinal direction along an outer circumferential surface that is curved in a cylindrical surface so as to be convex toward the projection optical system side at a second radius from a second axis that is arranged parallel to the first axis. A rotating drum for supporting and supporting the substrate and rotating the substrate about the second axis to move the substrate in a circumferential direction of the outer peripheral surface corresponding to the scanning exposure direction,
The projection image surface curved in a cylindrical surface so as to be convex toward the substrate side, and the surface of the substrate curved in a cylindrical surface so as to be convex toward the projection optical system side are within the projection area. The cylindrical mask , the rotating drum, and the projection optical system are set so as to intersect at two positions apart from each other in the scanning exposure direction,
Scanning exposure device. The scanning exposure apparatus according to claim 1, wherein
The defocus amount in the range between the end and the midpoint in the scanning exposure direction of the projection area of the reflected light flux projected on the substrate by the projection optical system is ΔDA, and the depth of focus of the projection optical system is DOF. Then, each of the projection optical system, the cylindrical mask, and the rotating drum is set so that 0.5 <ΔDA / DOF ≦ 3 is satisfied.
Scanning exposure device. The scanning exposure apparatus according to claim 2, wherein
The relationship between the defocus amount ΔDA and the depth of focus DOF is further set within the range of 1 ≦ ΔDA / DOF,
Scanning exposure device. The scanning exposure apparatus according to claim 2, wherein
The projection image plane curved so as to be convex toward the substrate side of the mask pattern that is projected in the best focus in the projection area by the projection optical system, and curved so as to be convex toward the projection optical system side. The difference in the distance in the focus direction from the surface of the substrate is set so as to change line-symmetrically in the scanning exposure direction about the position of the midpoint of the projection region in the scanning exposure direction as an axis.
Scanning exposure device. The scanning exposure apparatus according to any one of claims 1 to 4,
The projection optical system has a plurality of divided projection optical systems,
The divided projection optical systems are arranged in a row in a direction in which each of the first axis and the second axis extends and a direction orthogonal to the scanning exposure direction, and each of the reflection projections is reflected in a corresponding projection area. Project light flux,
Scanning exposure device. The scanning exposure apparatus according to claim 5, wherein
When the plurality of divided projection optical systems arranged in a row are an odd-numbered divided projection optical system and an even-numbered divided projection optical system in the order arranged in the direction orthogonal to the scanning exposure direction, the odd-numbered division The projection area corresponding to each of the projection optical systems and the projection area corresponding to each of the even-numbered divided projection optical systems are arranged apart from each other in the scanning exposure direction and orthogonal to the scanning exposure direction. Are arranged so that the end portions of the projection areas formed by the odd-numbered split projection optical systems and the even-numbered split projection optical systems that are adjacent to each other in the direction in which they overlap are overlapped.
Scanning exposure device. The scanning exposure apparatus according to claim 6, wherein
An integrated value obtained by integrating the illuminance of exposure light in the projection area by each of the odd-numbered division projection optical system and the even-numbered division projection optical system in the scanning exposure direction is a direction orthogonal to the scanning exposure direction. Is set to be constant for each position of
Scanning exposure device. The scanning exposure apparatus according to claim 6 or 7, wherein
Each of the odd-numbered split projection optical system and the even-numbered split projection optical system is arranged on a pupil plane, a plurality of deflecting members that deflect the optical path of the reflected light flux from the mask pattern. And a concave mirror to form a telecentric catadioptric optical system that is a modification of the Dyson system.
Scanning exposure device. The scanning exposure apparatus according to any one of claims 1 to 4,
The exposure width of the projection area in the scanning exposure direction is A, the radius of the projection image plane curved to be convex toward the substrate side is r ₁ , and the substrate is curved to be convex toward the projection optical system side. Where r _{2 is} the radius of the surface, NA is the numerical aperture of the projection optical system, and λ is the wavelength of the illumination light.
0.5 × (λ / NA ² ) <r ₁ − ((r ₁ ² ) − (A / 2) ² ) ^1/2 + r ₂ − ((r ₂ ² ) − (A / 2) ² ) ^{1 /} It is set so as to satisfy the relationship of ² ≦ 3 × λ / NA ² ,
Scanning exposure device. The scanning exposure apparatus according to claim 9, wherein
The exposure width A, the radius r ₁ , the radius r ₂ , the numerical aperture NA, and the wavelength λ are
Furthermore, (λ / NA ² ) <r ₁ − ((r ₁ ² ) − (A / 2) ² ) ^½ + r ₂ − ((r ₂ ² ) − (A / 2) ² ) ^1/2 Set to meet relationships,
Scanning exposure device.

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